bacteriocins nature, function and structure
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8/18/2019 Bacteriocins Nature, Function and Structure
1/13
~ ) Pergamon
PII: S0968-4328 96)00028-5
Micron
Vol, 27, No. 6, pp. 467 479. 1996
I 1997 Published by Elsevier Science Lid
All rights reserved. Printed in Great Britain
0968 4328/96 S32.00+0,00
Bacterioc ins: N atur e F un ct ion and Structure
MOHAMED A. DAW* and FREDRICK R. FALKINER+
*D epa r tm en t q f M ed ic a l M icrob io logy , Facu l O' oJ M ed ic ine , A ( fa teh Un i t 'e r s i t v ~[ Med ic a l Sc iences , P .O. Bo .v ,~;2668, Tr ipo l i.
L ib ) 'a
+ D e p a r t me n t o f C l in i c a / Mi c r o b i o l o g y , Du b l h l U n i v e r si t y , Du b li n, R e p u b l i c q f h e h m d
b s t r a c t Bacteriocins are extracellular substances produced by different types of bacteria, including both Gram positive and
Gr am negat ive species. They can be produc ed sp onta neou sly or induced by certain chemicals such as mitomy cin C. They arc
biologically one of the importa nt substances, and have been found to be useful in membrane studies and also in typing pathogenic
microorga nisms causing serious nosocomial infections. Bacteriocins are a heterogeneous group o f particles with different
morphological and biochemical entities. They range from a simple protein to a high molecular weight complex: the active moiety
of each molecule in all cases seems to be protein in nature. The genetic determinant s of most of the bacteriocins are located on the
plasmids, ap art from few which are chrom osom al[ y encoded. The se bactericidal particles are species specific. They exert their lethal
activity through adsorbtion to specific receptors located on the external surface of sensitive bacteria, followed by metabolic,
biological and morphological changes resulting in the killing of such bacteria. This review summarises the classification,
biochemical nature, mor pholog y and mode of action o f bacleriocins as well as their genetic determinants and the microbiological
relevance of these bactericidal agents, i , 1997 Publishe d by Elsevier Science Ltd
Key words: Bacteriocins. bacte rophag e, bacterium-l ike inhibit ory substances, relaxed forms, contracte d forms, pyocins, cloacins.
bacterium typing.
CONTENTS
1. In tr oduc ti on ........................................................................................................................................................................................................... 467
A. Bac kgr ound ..................................................................................................................................................................................................... 467
B. Classi ficati on of bacter iocins ......................................................................................................................................................................... 468
C. Biochemi cal na tu re of bac terioci ns ............................................................................................................................................................... 468
D. Bac teriocinogeny and lysogeny .................................................................................................................................................................... 469
II. Ultrastructural study of bac terioci ns ................................................................................................................................................................ 470
A. General structure ...........................................................................................................................................................................................70
B. Morpho lo gy of active fo rms ....................................................................................................................................................................... 471
C. Mod e of action ................................................................................................................................................................................................ 472
D. Morpho log ica l changes associat ed with bacteriocin activity .................................................................................................................... 472
I11. Molecular bio logy of bacteri oci ns ...................................................................................................................................................................... 475
A. Genetic
determinants
of bac terioci ns ........................................................................................................................................................... 475
B. Mic robiol ogical relevance of bac terio cins ................................................................................................................................................... 476
IV. Con cl usions .......................................................................................................................................................................................................... 476
Acknowledgements .............................................................................................................................................................................................. 477
References .............................................................................................................................................................................................................. 477
I. INTRODUCTION
A . B a c k g r o u n d
Bacteriocins are bactericidal, antibiotic-like sub-
stances, apparently protein in nature, which are pro-
duced by many bacteria and have a killing action on
strains of the same or closely related species. The narrow
specificity of their action and their protein nature distin-
guish them from other classical) antibiotics Reeves,
1965; Daw, 1989: Grat ia and Grenier, 1992; Laukova
and Marekova, 1993). The first discovery was reported
by Gratia in 1925 of a highly specific antib iotic principe
V) produced by a strain of
E s c h e r i c h i a c o l i
and active
against other strains of the same species. This activity
was found to be produced by various species of Entero-
bacteriaceae and for which the generic name colicine)
was proposed. With the discovery that the production of
apparently similar agents is not limited to Enterobacteri-
aceae, Jacob
et al .
1952) proposed that the general
name bacteriocine) should be used for highly specific
antibacterial proteins, produced by certain strains of
bacteria and active mainly against strains of the same
species. This defini tion still holds, although colicin e)
and bacteriocin e) are now spelt with out the final e.
Since the discovery of the bacteriocins, most of the
studies established in this field have been descriptive
Fredericq, 1957, 1963), and the basic methods of detec-
tions, assay and the bacteriocin typing of bacterial
strains have been established. Genetic studies of coli-
cinogeny and its transfer from one cell to another were
also pionered by Fredericq and his collaborators. Fur-
ther studies on the molecular biology of the bacteriocins
followed, with emphases on biosynthesis, liberation and
the mode of action of these agents Davies and Reeves,
1975a,b; Geli and Lazdunski, 1992a,b; Lakey e t a l .
1993). These led to interesting use of the bacteriocins as
a biochemical tools in cellular physiology Libertin
e t a l . 1992; Farkas-Himsley e t a l . 1992; Becker e t a l .
1993). Bacteriocins have since gained new attention,
467
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468 M.A. Daw and F. R. Falkiner
particularly in the epidemiology of nosocomial infec-
tions; they have been found to be very useful in typing
organisms particularly those which are difficult to type
by the usual methods (Pitt, 1980; Daw et al . , 1992;
Siragusa, 1992; Unlman et a l . , 1992; Lebek et a l . , 1993).
Our knowledge on bacteriocins leans heavily on re-
sults obtained by electron microscope studies describing
the morphology and the killing process of the bacteri-
ocin particles. Due to the vast expansion of research in
this area, we will devote most of this review to the
classification, biochemical nature and mode of action of
bacteriocins as well as the molecular biology and the
microbiological relevance of these bactericidal agents.
B. C lass i f ica t ion o f bac ter ioc ins
The classification, and thus the nomenclature of
bacteriocins, has changed rapidly since early this cen-
tury. The main classification was done on colicins; they
are usually classified by the scheme devised by Fredericq
(1957), according to the specificity of their adsorption
and are further classified into subgroups according to
the specificity of their immunity. For example, colicin
El, E2 and E3 differ from each other in their immunity
pattern, but are classified as E group, because all of
them apparently adsorb to the same receptor. Similarly,
colicin Ia and Ib apparently share a common receptor
and belong to group I, but can be distinguished from
each other by their immunity specificity. Many bacterio-
cins have been studied in detail and they necessarily have
to be subdivided according to their spectrum of resist-
ance (Reeves, 1965). As a result o f this, a code of
nomenclature was established. The number of producer
strain is followed by original letter, for instance colicin
CA23 D is a type D colicin produced by
E. coli
strain
CA 23 (Fredericq, 1963; Ohno
et al . ,
1977).
Reeves (1965) listed sixteen classes of bacteriocins
named on the basis of the species that produce them.
Due, perhaps, to the high degree of specificity of bac-
teriocins, the name is the almost always based on the
specific rather than generic name of the host organism.
Therefore colicins are bacteriocins of E. coli, pyocin of
Pseudomonas aeruginosa (formerly p y o c y n ia , cloacin of
Enterobac ter c loacae ,
pestisin of
Yers in ia pes t i s ,
monocin
of Lis te r ia monocy togenes , cerecin of Bacillus cereus, and
staphylococcin of Staphy lococcus . These vernacular
names used for bacteriocins are based, not on the spec-
trum activity, but the producing organism. The fact that
they are produced by specific species of bacteria means
that their host association is immediately apparent.
Bradely (1967) designed a taxonomic criterion for the
classification of the bacteriocins, based on the natural
division of these agents. The bacteriocins were divided
into two distinct groups designated as low and high
molecular weight forms. The first is a small molecule
which is usually thermostable, cannot be sedimented
in the ultracentrifugation and cannot be resolved by
the electron microscope. The second group is a larger
molecule, easily sedimented, thermolabile, trypsin resist-
ant and can be resolved by the electron microscope. This
classification allows us to include within it bactericidal
particles such as those produced by the Bac i l lus species,
since they are unable to multiply within sensitive cells.
The only morphological difference between them and
the bacteriocin of high molecular weight is that they are
closer to phage particles (Bradley, 1966). The term
bacteriocin usually refers to the colicin-type of protein,
generally restricted to the strains of Enterobacteriaceae.
Most of the bacteriocins produced by Gram positive
bacteria do not fit into the classical definition of bac-
teriocins in that they are (1) more broadly active against
Gram positive species, (2) their action is mediated by
specific receptors and (3) their release is enhanced by
lysins. Furthermore, the absence of the outer membrane
in Gram positive bacteria and the difference in the level
of immunity of the producing strain to its own bacterio-
cins, indicates that those bacteriocins of Gram positive
bacteria should be grouped differently (Tagg
et al . ,
1976;
Strasser de-Saad and Hanea de-Nadra, 1993; Havarstein
et al . ,
1994). Tagg (1992) suggested that the term bac-
teriocin should be redefined either to take into account
the non-colicin-like characteristics of many of the more
recently described particles, or the original definition
should be retained and those particles which are broadly
similar to the colicins should be referred to as bacteriocin-
like inhibitory substances (BLIS). The prevalence of BLIS
production among Gram positive bacteria was found to
be high. A survey conducted in the 1970s concluded that
all the tested strains representing most of the Gram posi-
tive bacteria could be found to produce BLIS (Tagg
et al. ,
1976; Tagg, 1992) and the incidence may closely approach
100 .
Electron microscopic studies have been particularly
useful for the identification and classification of bac-
teriocins. Negative contrast methods, which have been
described for the purpose of studying viral structure,
were equally employed for bacteriocins (Bradely, 1966;
Govan , 1974a,b; Daw, 1989) . Uranyl acetate and
potassium phosphotungstate have usually been used as
negative stains. These were mixed with equal volumes
of bacteriocin preparations and allowed to dry onto
electron microscope specimen grids covered with carbon
film, then studied using electron microscopy. These
ultrastructure studies revealed that only the large
bacteriocin particles were visible by electron microscopy.
The mode of action and the killing process of these
bacteriocins were also studied by the negative staining
(Daw, 1989; Daw and Falkiner, 1993).
C. Biochemical na ture o f bac ter ioc ins
Bacteriocins have been erroneously considered as the
only proteins secreted by bacteria. Indeed, those intially
described were isolated and identified from the extra-
cellular state of the producing species. Nowadays, other
extracellular products have also been found. Freely
secreted bacteriocins constitute a peculiar group of
exported proteins in that their export relies on the
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Bacteriocins 469
e x p r e s s i o n o f o n l y o n e g e n e c o d i n g f o r a b a c t e r i o c i n
r e l e a se p r o t e i n ( B R P ) ; a l so c a l l e d t h e l y s is o r k i ll p r o t e i n .
I n c o m p a r i s o n , e x p o r t o f o t h e r s e c r e t e d p r o t e i n s r el ie s
o n t h e a c t i v i ty o f a t l e a s t t h r e e p r o t e i n s ( W a n d e r s m a n
a n d D e l e p e l i a r e , 1 9 9 0 ; H a v a r s t e i n e t a l . 1 9 9 4 ) . H o w -
e v e r , t h e y a r e e x p o r t e d l a t e a f t e r s y n t h e s i s a n d a c c u m u -
l a t e i n t h e c y t o p l a s m i n a s o l u b l e f o r m b e f o r e t h e y a r e
r e l e a s e d . T h e c o l i c i n l y s i s p r o t e i n s h a v e b e e n t h e m o s t
e x t e n s i v e ly s t u d i e d a n d , t o g e t h e r w i t h t h e B R P e n c o d e d
b y t h e C o l D F 1 3 p l a s m i d , t h e y s h a r e m a n y p r o p e r t i e s
i n c l u d i n g t h e i r g e n e t i c o r g a n i s a t i o n , t r a n s c r i p t i o n , s y n -
t h e s i s , a s s e m b l y a n d f u n c t i o n ( H o w a r d s e t a l . 1989;
C a v a r d a n d O u d e g a , 1 9 9 2 ) .
T h e p r o t e i n n a t u r e o f b a c t er i o c in s w a s d e t e r m i n e d
e a r ly b y t h e d e g r a d a t i o n o f c r u d e p r e p a r a t io n s b y p r o -
t e o ly t ic e n z y m e s a n d t h e ir a p p r o x i m a t e m o l e c u l a r
w e i g h t w a s d e t e r m i n e d b y t h e d i f f u s i b i li t y o f t h e l y sa t e s
t h r o u g h a g a r o r s e m i p e rm e a b l e m e m b r a n e s . S u c h
m e t h o d s w e r e f o u n d t o b e u s e f u l i n t h e i n i t i a l c h a r -
a c t e r i s a t io n o f b a c t e r i o c i n s ( L o y o l a - R o d r i g u e z
e t a l .
1 9 9 2 ) . D u e t o m o r e a d v a n c e d p u r i f i c a t i o n , s e v e r a l b a c -
t e r i o c i n s h a v e b e e n d e s c r i b e d a n d t h e i r c h e m i c a l
a n d p h y s i c a l p r o p e r t i e s a r e k n o w n ( S t i l e s e t a l . 1994;
H a s t i n g s e t a l . 1995).
D i f f e r e n t s tu d i e s h a v e s h o w n t h a t t h e b a c t e r i o c i n s a r e
p r o t e i n m o l e c u l e s w i th t r a c e s o f c a r b o h y d r a t e s ( l e ss t h a n
1 ) a n d p h o s p h o r u s ( le s s t h a n 0 . 1 ) ( K i n g s b u r y , 1 96 6;
R e e v e s , 1 9 7 2; D a w a n d F a l k i n e r , 1 9 93 ). T h e n o t a b l e
d i f fe r e n c e s b e t w e e n t h e m w e r e f o u n d t o b e a s s o c i a t ed
w i t h a m i n o a c i d c o m p o s i t i o n . D i f f e r e n t s e q u e n c e s o r
c r os s c o m p o s i t i o n o f a m i n o a c i ds w e r e fo u n d a m o n g t h e
b a c t e r i o c i n m o l e c u l e s v a r y i n g f r o m o n e b a c t e r i o c i n t o
a n o t h e r , e v e n a m o n g t h e s a m e g r o u p o f b a ct e r io c i n
( K o n i s k y a n d R i c h a r d s , 1 97 0; H o w a r d e t a L 1989:
N i e t o - L a z a n o
e t a l .
1 9 92 ; K o e b i n k a n d B r a u n , 1 9 93 ).
I n d e e d c o l i c i n E i s n o w d i v i d e d i n t o t h r e e su b c l a s se s
u s i n g S D S g e l e l e c t r o p h o r e s i s : c o l i c i n E l , E 2 a n d
E 3 . T h e m a i n d i f f e r e n c e s b e t w e e n t h e se su b c l a s se s i s
a s s o c i a t e d w i t h a m i n o a c i d t e r m i n a l s e q u e n c e .
T h e e a r l y d e t a i l e d w o r k o n t h e b i o c h e m i c a l n a t u r e o f
b a c t e r i o c i n s w a s d o n e o n c o l i c in s a n d h a s b e e n d i s c u ss e d
b y s e v e r a l i n v e s t i g a t o r s ( I v a n o v i c s , 1 9 6 2 ; K o n i sk y , 1 9 7 3 ;
L a k e y e t a l . 1 9 9 2 : B r a u n e t a l . 1 9 9 4 ) . T w o d i f f e r e n t
p u r i f i e d c o l i c i n s w e r e o b t a i n e d ; o n e i s a l i p o p o l y sa c -
c h a r i d e p r o t e i n c o m p l e x a s s o c i a t e d w i t h t h e O s o m a t i c
a n t i g e n o f t h e p r o d u c i n g E . c o l i s u c h a s c o l i ci n K - K 2 3 5 ,
a n d f o l l o w i n g i t s d i s a s so c i a t i o n t h e a c t i v i t y w a s a s so c i -
a t e d w i t h t h e c a r b o x y a l m o i e t y ( C H O ) ( V i e j o e t a l .
1 9 9 1 ; M i r a n d a
e t a L
1 9 93 ). T h e o t h e r g r o u p o f c o li c i n s
w a s f o u n d t o b e a p r o t e i n c o n t a i n i n g l i t t l e o r n o c a r b o -
h y d r a t e , s u c h a s c o l i c i n E 2 - P 9 , w h i c h w a s f o u n d t o b e a
p r o t e in w i t h a m o l e c u l a r m a s s o f a b o u t 6 0 k D a . O t h e r
r e l a t e d c o l i c i n s , E 2 - C A 4 2 a n d c o l i c i n A , w e r e a l so
p u r i f ie d a n d s h o w n t o b e a p r o t e i n w i t h l o w c a r b o -
h y d r a t e c o n t e n t ( a b o u t 1 0 ) . T h e s e t w o w e r e d i f f e re n t
f r o m t h e c o l i c i n K - K 2 3 5 ( G o o r m a g h t i g h
e t a l .
1991;
G o n z a l e z - M a n a s e t a l . 1992).
T h e b i o c h e m i ca l n a t u r e o f o t h e r b a c t e r io c i n g r o u p s
h a v e a ls o b e e n d e t e r m i n ed : t y p e - R P y o c i n s p r o d u c e d b y
P . a e r u g i n o s a w e r e p u r i f i e d b y K a g e y a m a a n d E g a m i
Fig. 1. Transmission electron micrograph of a bacteriocin
part ic les obtained from Enterobac te r c loacae negativelly
stained w ith sod ium silicotungstate 2 '7,, w/v. The bacteriocins at
field (A) are seen as bu llet-like particles possessing a base plate.
A flagellum (F) is al so see n across the field. Scale marker
indicates 0.1 nm.
( 1 9 6 2) a n d s h o w n t o b e p r o t e i n p a r t ic l e s t Ye e o f c a r b o -
h y d r a t e a n d n u c l ei c a c id . T h e s y n t h e s i s o f t h is p y o c i n i s
i n d u c i b l e a n d a c c o m p a n i e d b y c e l l l y s i s . A n o t h e r g r o u p
o f p y o c i n s , a l so c a l l e d S p y o c i n s , w a s p u r i f i e d f r o m
m i t o m y c i n C - i n d u c e d l y s a t e o f P . a e r u g i n o s a . T h e s e
w e r e d i s t i n g u i s h e d f r o m t h e R t y p e p y o c i n s b y t h e i r
d i f f u s i o n r a t e t h r o u g h a g a r , t h e i r s e n s i t i v i t y t o p r o t e a se
d i g e s t i o n a n d b y t h e f a c t t h a t t h e y a r e n o t n e u t r a l i s e d
w i t h a n t i s e r u m a g a i n s t a n y t y p e R p y o c i n s ( S a n o
e t a l .
1 9 9 3 ) . C l o a c i n C 5 , o n t h e o t h e r h a n d , i s a m a c r o m o l -
e c u l e s i m i l a r t o R p y o c i n ( D a w , 1 9 8 9 ) . A l l b a c t e r i o c i n s
a p p e a r t o r e p r e s e n t a h e t e r o g e n e o u s g r o u p o f s u b s ta n c e s
r a n g i n g f r o m a s m a l l p r o t e i n t o a h i g h m o l e c u l a r w e i g h t
p a r t ic l e w i th c o m p l e x s t r u c t u r e a n d c o m p o s i t i o n , b u t t h e
p a r t r e sp o n s i b l e f o r k i l li n g a c t i v i ty s e e m s t o b e p r o t e i n i n
e v e r y c a se .
D . B a c t e r i o c i n o g e n y a n d ly s o g e n y
T h e a n a l o g y b e t w e e n b a c t e r i o c i n p r o d u c t i o n a n d
b a c t e r i o p h a g e l i b e r a t i o n w a s n o t e d f o l l o w i n g th e d i s c o v -
e r y o f b a c t e r io c i n s , l n t i a l s t u d ie s c o n d u c t e d b y G r a t i a
( 1 9 2 5 ) e s t a b l ish e d t h e d i f f e r e n c e s b e t w e e n c o l i c i n s a n d
b a c t e r i o p h a g e s , n o t a b l y t h e a b s e n c e o f b a c t e r i o p h a g e -
l i k e m u l t i p l i c a t i o n o f c o l i c in s . L a t e r i n v e s t i g a t i o n r e -
e s t a b l i s h e d c e r t a i n c o n n e c t i o n s , p a r t i c u l a r l y b e t w e e n
t h o s e b a c t e r i o p h a g e s a n d c o l i c i n s t h a t a t t a c h t o t h e
sa m e r e c e p t o r s ( A l a t o s s a v a , 1 9 94 ). U l t r a s t r u c t u r a l
s t u d i e s s h o w e d a c e r t a i n a n a l o g y b e t w e e n t h e s e t w o
b a c t e r i c i d a l a g e n t s ( D a w , 1 9 89 ; D a w a n d F a l k i n e r ,
1 9 9 3 ) . B a c t e r i o c i n s w e r e c o n s i d e r e d t o b e i n c o m p l e t e
p h a g e s . T h i s w a s e v i d e n t i n su c h s t u d i e s , a s sh o w n i n
F i g s 1 a n d 2 . A r e l a x e d f o r m o f a b a c t e r i o c i n i so l a t e d
f r o m E . c l o a c a e i s sh o w n ( F i g . 1 ) a n d a b a c t e r i o p h a g e
i so l a t e d f r o m t h e s a m e s t r a i n ( F i g . 2 ) . T h e p h a g e i s
c o m p o s e d o f p o l y h e d r a l h e a d a n d t ai l w i t h c o n t r a c t i l e
sh e a t h a n d c o r e , a s w e l l a s t a i l f i b r e s ( D a w . 1 9 8 8 ) . B y
c o m p a r i s i o m t h e s e t w o f i g u r e s s h o w a c o n s i d e r a b l e
r e se m b l a n c e o f p h a g e t a i ls t o t h e b a c t e r i o c i n p a r t i c l e s .
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4 7 0 M . A . D a w a n d F . R . F a l k i n e r
F i g . 2 . A m i c r o g r a p h o f b a c t e r i o p h a g e i s o l a te d f r o m t h e s a m e
s t r a i n o f Enterobacter cloacae f o r m e d f ro m h e a d H ) , p h a g e
ta i l T) a nd t a i l f ib re s TF) . The pha g e t a il Y) r e se m ble s the
ba c te r ioc in pa r t i c le s A) . Sc a le m a rke r ind ic a te s 0 .1 nm .
P h a g e P S 3
o
160 70 150
I n t a c t S h r u n k I n t a c t
P y o c i n R 4
180
7 0
S h r u n k
F ig . 3 . M o r p h o l o g i c a l c o m p a r i s o n o f p h a g e P S 3 a n d R - t y p e
p y o c i n o f Pseudomonas aeruginosa. The pha ge t a i l i s s l igh t ly
l a r g e r t h a n t h e b a c t e r i o c i n p a r t i c l e . D i m e n s i o n s a r e s h o w n
in A .
The bacteriocin seems to be headless phage. This empha-
sised the striking structural resemblance between bacte-
riocin and bacteriophage tail. Indeed, one of the earliest
technical problems was to make the distinction between
these two structures. This was further complicated if
these two anti-bacterial agents were produced by the
same bacterial strain. Both agents are adsorbed by
specific receptors of the cell wall and kill the sensitive
bacteria. In some cases receptors are common for certain
bacteriocins and phages, such as colicin K and phage T6
or colicin E and phage BF23 Ito e t a l . 1970). Both
bacteriocinogenic bacteria and lysogenic bacteria are
immune to the agents they produce. Bacteriocinogeny
and lysogeny are both potential characters and the
production of bacteriocin and bacteriophage is often
enhanced by some treatments, e.g. UV irridiation.
Each phenomenon, however, is a lethal process for the
bacterium. Studies on pyocins found that some had
structures very similar to phage tails, and they were
categorised as R type pyocins Ito and Kageyama, 1970;
Govan, 1974a,b). Morphologically, the tail of the phage
PS3 is similar but not identical to R type pyocins; the
phage tail is slightly bigger. The dimension of the phage
is schematically illustrated in Fig. 3. The tail of the
phage closely resembles R type, except that the size of
the tail is a little longer than that of the pyocins. The
fact that antiserum against R pyocins can neutralize
the phage activity to a considerable extent, suggests
that there are some common or very similar antigenic
component s) in their structure.
The similarity between prophage induction and of
bacteriocin synthesis suggests that a similar mechanism
is responsible for both events. Many treatments which
inhibit DNA synthesis bring about prophage induction
and also induce the synthesis of bacteriocins Hardy and
Meynell, 1972a,b; Issacson and Konisky, 1974: Hardy,
1975; Boemare e t a l . 1992). Unlike prophage induction,
induction of bacteriocin synthesis is not necessarily
accompanied by enhanced replication of the Col factor.
In P r o t e u s m i r a b i l i s the increase in ColE1-K30 after
mitomycin C treatment parallels the increase in bacterio-
cin titer, but in E . c o l i the extensive replication is not a
necessary condition for increased titers of colicins after
induction Durkacz and Sherratt, 1973; Schiess and
Goebel, 1974).
The initial studies Ito and Kageyama, 1970) estab-
lished the important differences between bacteriocins
and bacteriophages as the latter is self reproducible in
the sensitive bacteria, while the former is not. Some
studies Daw, 1989) indicated that bacteriophages, on
dilution, would show a decreasing number of discrete
phage plaques; a bacteriocin on the other hand would
show a diffuse thinning of growth becoming less marked
with increasing dilution of the supernatant. When a
culture with a high percentage of lacuna-forming cells
LFC) is diluted and maintained at a constant density,
the number of LFC remains constant for several gener-
ations. Cells releasing bacteriocin exist for several hours,
but they do not divide to produce LFC, while spon-
taneous induction of prophages varies similarly in batch
cultures. Although bacteriocins and bacteriophages lend
themselves to obvious comparisons, there is no indi-
cation for the existence of any direct relationship
between the two antibacterial agents, such as a colicin
being the product of incomplete phage development. In
particular, no case has as yet been found of antigenic
similarities between bacteriocins and bacteriophages.
Even when the same bacterial strain is lysogenic and
bacteriocinogenic, no connection between bacteriocin
and bacteriophage can be demonstrated. Neither has
any instance of conversion from the lysogenic to the
bacteriocinogenic state been observed. One must, there-
fore, conclude that in spite of many remarkable simi-
larities between lysogeny and bacteriocinogeny, there is
no compelling reason to believe that they are in any way
connected.
II. ULTRASTRUCTURAL STUDY OF
B C T E R I O C I N S
A . G e n e r a l s t r u c t u re
Little work has been done on the physical structure
of bacteriocins. Early electron microscope studies of
clocins ML, E, V and K did not produce any definitive
results concerning their morphology Konisky, 1982).
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Ba c te r ioc ins 471
C o l i c i n E 3
N - t e r m i n u s C - t e r m i n u s
3 5 k D a 1 5 k D a
T r a n s l o c a t i o n c a p a c i t y R N a s e a c t i v i t y
i n t o t h e c e l l b i n d i n g o f I P
F ig . 4 . Co l ic in E 3 o f
Esherichi~l coli
u n d e r p r o t e a s e d i g e s t i o n
y i e l d s t w o f r a g m e n t s : 5 3 k D a a m i n o t e r m i n a l f r a g m e n t a n d a
1 5 k D a c a r b o x y t e r m i n a l f r a g m e n t .
F u r t h e r s t u d ie s s u g g e s t e d t h a t b a c t e r i o c i n s c a n f it
i n t o t w o g r o u p s : t h o s e t h a t c a n n o t b e r e s o l v e d b y t h e
e l e c t r o n m i c r o s c o p e s u c h a s E , V , K a n d p y o c i n S a n d
o t h e r s t h a t h a v e a d e f i n i t e s t r u c t u r e , su c h a s c l o a c i n C 5
a n d R p y o c i n . C o l i c i n E 3 r e p r e s e n t s a n e x a m p l e o f t h e
f i rs t g r o u p . P r o t e o l y t i c d i g e s t i o n o f c o l ic i n E 3 w i t h
t r y p s i n u n d e r m i l d c o n d i t i o n s y i e l d s t w o f r a g m e n t s , a
3 5 k D a a m i n o - t e r m i n a l f ra g m e n t a n d a 1 5 k D a c a r b o x y -
t e r m i n a l f r a g m e n t i n c o m p l e x w i th t h e i m m u n i t y p r o t e i n
a s s h o w n i n F i g . 4 , w h i c h s u g g e s t e d a d o m a i n s t r u c t u r e
f o r c o li c in E 3 ( O h n o et al . 1 9 7 7 ; S o h a m a n d D j e b l i ,
1992; Ya j ima et al . 1992).
M o s t o f th e s t u di es c o n c e r n i n g t h e m o r p h o l o g y
o f b a c t e r io c i n s w e r e p e r f o r m e d o n p a r t ic l e s o b t a i n e d
f r o m p y o c i n o g e n i c st ra i n s o f P. aeruginosa. E l e c t r o n
m i c r o s c o p y o f p y o c i n p r e p a r a t i o n r e v e a l e d t h e p r e s e n c e
o f n u m e r o u s s t r u c t u r e s r e s e m b l i n g t h e p h a g e t a il c o m -
p o n e n t s a s s h o w n i n F i g . 5 . C o n t r a c t e d p a r t i c l e s ( F i g .
5 a ) c o n s i s t o f a c o r e p a r t ia l l y s u r r o u n d e d b y a s h e a t h . I n
m o s t p a r t i c l e s t h e c o r e a p p e a r s e m p t y , b u t o c c a s i o n a l l y
c o r e s c a n b e s e e n t o c o n t a i n m a t e r ia l . U n c o n t r a c t e d
p a r t i c l e s ( F i g . 5 b ) r e se m b l e d b u l l e t s a n d a b a se - p l a t e
w a s v i s i b l e a t b r o a d e r e n d . H o o k - l i k e p i n s e x t e n d f r o m
t h e l o w e r e n d s o f c o n t r a c t e d s h e a t h s a n d o c c a s i o n a l l y
se v e r a l f i b r e s w e r e s e e n a t t a c h e d t o t h e b a se p l a t e .
I s o l a t e d c o n t r a c t e d s h e a t h s w e r e o b s e r v e d a n d l o n g
s h e a t h - li k e s t r u c t u r e s w e r e s e e n c o m p o s e d o f n u m e r o u s
c o n t r a c t e d s h e a t h s . H o l l o w r i n g le t s a n d m i n u t e c o g -
w h e e l s a r e a ls o o b s e r v e d . T h e m a j o r i t y o f p a r t ic l e s ,
r e g a r d le s s o t t h e p y o c i n o g e n i c s tr a i n u s e d , m e a s u r e d
a p p r o x i m a t e l y 1 00 x 1 5 n m i n t h e u n c o n t r a c t e d s t a te ;
c o n t r a c t e d p a r t ic l e s c o n s i s t o f a h o l l o w t a il p i ec e , a p -
p r o x i m a t e l y 1 0 0 x 7 n m , p a r t i a l l y e n c l o se d i n a sh e a t h
m e a s u r i n g a b o u t 4 5 x 17 n m ( G o v a n , 1 9 7 4a ). T h e m o r -
p h o l o g y o f th e s e b a c t e r i o c i n s c a n b e c h a n g e d b y f r e e z i n g
a n d t h a w i n g w h i c h m a y r e n d e r t h e s e p a r t i c l e s i n a c t i v e .
H o w e v e r , w h e n p u r i f i e d p y o c i n p r e p a r a t i o n s i n T r i s -
H C I b u f f e r ar e s u b m i t t e d t o a f a s t f r ee z e i n a n a c e t o n e -
d r y i c e b a t h , t h e p a r t i c l e s f o r m r o se t t e c l u s t e r s .
A s c h e m a t i c d i a g r a m o f t h e v a r i o u s m o r p h o l o g i c a l
f o r m s a n d s t r u c t u r e s s e e n i n e l e c t r o n m i c r o g r a p h s o f
p y o c i n s i s p r e se n t e d i n F i g . 6 : t h e se c o n s i s t o f a c o n -
t r a c t e d p a r t i c l e , a l o c k - w a sh e r r i n g l e t ( F i g . 6 a ) a n d t w o
f o r m s o f r e l a x e d p a r t i c l e s d i f f e r i n g i n s i z e a n d s t r i a t i o n
( F i g . 6 b a n d c ) . T h e s e t w o f o r m s a r e f r e q u e n t l y s e e n
t o g e t h e r i n t h e s a m e p r e p a r a t i o n ( H i g e r d et al . 1969;
G o v a n , 1 9 7 4 a: D a w , 1 9 89 ). I n g e n e r a l t h e y a r e a ll
m o r p h o l o g i c a l l y i d e n t ic a l e x c e p t f o r m i n o r d i f f er e n c e s i n
d i m e n s i o n s ; t h e c h i e f fe a t u r e b e i n g t h a t t h e y r e s e m b l e
h e a d l e s s p h a g e s .
F i g . 5. E l e c t r o n m i c r o g r a p h s o f t w o d i f f e r e n t f o r m s o f p y o c i n
o b t a i n e d f r o m s t r a i n s o f
Pseudomonas aeruginosa
C o n t r a c t e d
p y o c i n p a r t i c l e s c o n s i s t e d o f c o r e p a r t i al l y s u r r o u n d e d b y a
s h e a t h a ) a n d t h e u n c o n t r a c t e d r e l a x e d ) p y o c i n f o r m r e s e m b l e
b u l l e t s w i t h a p l a t e a t t h e b r o a d e r e n d b ) . N e g a t i v e l y st a i n e d .
Sc a le m a r ke r s ind ic a te I011 nm .
F i g . 6. A s c h e m a t i c d i a g r a m s h o w i n g b a c t e r io c i n m o r p h o l o g y .
T h e c o n t r a c t e d b a c t e r i o c i n p y o c i n ) p a r t i c l e a ) r e s e m b l e s a
l o c k - w a s h e r r i n g l et a n d t w o r e l a x e d p y o c i n p a r t i c l e s b . c) s h o w
d i f f e r e n t a p p e a r a n c e s .
B . M o r p h o l o g y o / a c ti ve j b r m s
P r e v i o u s l y , i t w a s n o t k n o w n w h e t h e r b a c t e r i c i d a l
a c t i v i t y o f t h e b a c t e r i o c i n s w a s a s so c i a t e d w i t h a d i s c r e t e
m o r p h o l o g y o r n o t , o r w h e t h e r t h e a c ti v i ty w a s c o n -
f i n e d t o t h e r e l a x e d o r c o n t r a c t e d f o r m s ( B r a d l e y a n d
R o b e r t s o n , 1 9 68 ). F u r t h e r s t u d ie s f o u n d a d i re c t c o r r e -
l a t io n b e t w e e n t h e p e r c e n t a g e o f r e la x e d p a r t i c le s a n d
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4 7 2 M . A . D a w a n d F . R . F a l k i n e r
t he reduc t ion in ac t iv i ty dur ing convers ion to the con-
t rac t ed s t a t e (Higerd
e t a l .
1 9 6 9 ; G o v a n , 1 97 4b ; D a w ,
1989) . I t was conc luded tha t , once con t rac t ion occurs ,
there appears to be l i t t l e o r no increase in ac t iv i ty upon
subsequen t re l axa t ion .
I n a n a t t e mp t t o u n d e r s t a n d t h e b i o l o g i c a l n a t u r e o f
c o n t r a c t e d f o r ms o f b a c t e r io c i n , H i g e r d
et al .
(1969)
adde d a so lu t ion o f pyoc ins to pur i f ied ce ll wal l p repa r -
a t ions o f sens it ive s t ra ins o f
P . a e r u g i n o s a .
A d s o r p t i o n
to the ce l l wal l o f the sens i tive s t ra ins occu r red a t t he
f l a tt e n e d e n d o f t h e b a c t e r i o c in w i t h i n o n e m i n u t e a f t e r
adso rp t ion o f the re l axed par t i c l es to the cel l wal l s and a
c o n t r a c t i o n o f th e o u t e r s h e a t h w a s o b s e r v e d . E a r l y
s tud ies on
P r o t e u s v u l g a r i s
b y C o e t z ee
et al .
(1968) also
s h o w e d t h a t a h i g h t i t e r o f b a c t e r io c i n p r e p a r a t i o n s
t rea t ed wi th
H 2 0 2
a n d e t h a n o l a n d t h e n a d s o r b e d w i t h a
s u s p e n s i o n o f s u s c e p t i b l e s t r a i n s , h a d ma n y c o n t r a c t e d
ta i l - l i ke s t ruc tu res in the superna tan t f lu id and very few
a r o u n d t h e s u s c e p t i b le o r g a n is m. T h i s s u g g e s te d t h a t t h e
r e la x e d f o r m o f t h e p a r ti c l e ma y b e t h e n a t i v e s t a te o f
the bac te r ioc in , s ince ac t iv i ty and ce l l wal l adsorp t ion
w e r e d e mo n s t r a b l e o n l y w i t h p a r t i c l e s i n t h e r e l a x e d
state.
C . M o d e o f a ct io n
M o s t o f t h e i n f o r ma t i o n r e g a r d i n g t h e mo d e o f a c t i o n
o f b a c t e r i o c i n s h a s b e e n b a s e d o n s t u di e s o f s e v e ra l
b a c t e r i o c i n s p e r f o r me d b y N o mu r a a n d h i s c o l l e a g u e s
(Nomura , 1967) . Bac ter ioc ins exer t t he i r b io log ica l
ac t ion th rough adsorp t ion to the i r spec i f i c recep to rs ,
loca ted a t t he ex te rna l su r face o f sens i tive cel ls , and a re
then t ra ns loca ted to the i r spec if i c t a rge t s w i th in these
cel ls (Parker
e t a l .
1989) . Kine t i c da ta ind ica te tha t
bac te r ioc ins behave as par t i cu la t e l e tha l agen t s , k i l l i ng
sens i t ive ce l l s i n what amount s to a s ing le h i t p rocess .
Th i s to the so ca l l ed qu an ta l k i ll i ng ra ther than
m ola r coo pera t ive k i ll i ng ac t ion o f c l as s ica l an t i -
b i o t i c s ( Ma y r - H a r t i n g
e t a l .
1972).
T h e m o d e o f a c t io n o f b a ct e ri o c in s m a y v a r y f r o m o n e
t y p e t o a n o t h e r ( B r a u n
e t a l .
1 9 9 4 ; Mo n t v i l l e a n d
Br u n o , 1 9 9 5 ) . E a r l y e x p e r i me n t s d e mo n s t r a t e d t h a t c o -
l icin E3 led to specif ic inhibi t ion of prote in syn thesis
(Schwar tz and Hel insk i , 1971) . Co l i c in E2 l eads to
s p ec i fi c i n h i bi t io n o f D N A s y n t h e si s a n d i n d u c e s D N A
d e g r a d a t i o n . O t h e r s t u d i e s i mp l i c a t e d t h e c y t o p l a s mi c
me m b r a n e a s p r i ma r y t a r g e t o f c o l ic i n A , E l , K , I a , a n d
Ib . These bac te r ioc ins and o ther re l a t ed co l i c ins c rea te
d i s r u p t i o n o f a c ti v e t r a n s p o r t a n d p r o d u c e l e a k a g e o f
i o n s b y f o r mi n g v o l t a g e - d e p e n d e n t c h a n n e l s i n p h o s -
p h o l i p i d b i l a y e r me mb r a n e s , t h e r e b y d e s t r o y i n g t h e
ce l l ' s po ten t i a l (Sche in
et al .
1978). This resul ted in the
inh ib i t ion o f p ro te in a nd nuc le i c ac id b iosyn thes i s and
u n c o u p l e d e l e c t r o n t r a n s p o r t f r o m a c t i v e t r a n s p o r t o f
t h i o me t h y l - f l - D - g a l a c t o s i d e a n d p o t a s s i u m ( L u s k a n d
Nel son , 1972) . T rea ted ce l l s l eaked po tas s ium and mag-
nes ium ions . The los s o f such ions has been imp l i ca t ed as
the p r ima ry cause o f ce ll dea th (Ko ni sky , 1982) . Neve r -
the less , each o f these co li c ins has i ts own imm uni ty
P e r i p l a s m
I m m u n i t y p r o t e i n P o r e - f o r m i n g d o m a i n
N L2 C
C y t o p l a s m
Fig . 7 . The h ydrop hi l i c a -he l i c e s of c o l i c in A o f Esherichia col l
A p o r e f o r m i n g d o m a i n a - h e li c e s 8 a n d 9 ) a re r e s p o n s i b le f o r
r e c o g n i t i o n o f t h e i m m u n i t y p r o t e i n .
p r o t e i n s ( W e a v e r
e t a l .
1981a ,b ; Van der Goo t
e t a l .
1991) . I t i s mo re l ike ly tha t imm uni ty p ro te ins inac t iva te
the i r co r respo nd ing co l i c ins by d i rec t in t e rac t ion . Di f fe r -
e n t s tu d i e s ( Ma n k o v i c h
e t a l .
1 9 8 4 ; Sh o h a m a n d D j e b li ,
1992) , us ing a cons t ruc t ion o f hybr id p ro te ins b e twee n
co l i c ins Ia , Ib , A and E1 have shown tha t t he C- t e rmina l
pore- fo rming domain was respons ib le fo r the reCog-
n i t ion o f immu ni ty p ro te in by pore fo rm ing co l ic ins .
M o s t i n v e s ti g a to r s ( T o k u d a a n d K o n i s k y , 1 9 7 8; W e a v e r
e t a l .
1981b ; Gel i and L azdunsk i , 1992a) conc luded tha t
imm uni ty p ro te ins o f pore fo rm ing co l ic ins in t e rac t
w i t h t h e p o r e - f o r mi n g d o m a i n s o f t h e ir c o r r e s p o n d i n g
co l i c ins a t t he level o f the inner me m bran e and thus the i r
a c t i o n s h o u l d p r e v e n t t h e f o r ma t i o n o f th e p o r e .
A p p a r e n t l y t h e i n se r ti o n o f p o r e f o r mi n g b a c t e r io c i n s
i s t r i g g e r e d b y s p o n t a n e o u s p e n e t r a t i o n i n t h e b i o l a y e r
o f a h y d r o p h o b i c h e l ic a l h a ir p i n n o r ma l l y b u r i e d i n
t h e w a t e r - s o l u b l e p r o t e i n s . T h e ma j o r d e t e r mi n a n t f o r
immuni ty spec i f i c i ty o f such co l i c in i s l oca ted be tween
a-he l ices 8 and 9 , as shown in F ig . 7 . Gel i and Lazdu nsk i
(1992b) , repor t ed tha t co l i c in A recogn i ses i t s immuni ty
p r o t e i n t h r o u g h i t s h y d r o p h o b i c H 2 , H 3 a n d H 4
a-he l i ces , i n add i t ion to the per ip l asmic loop . On the
o t h e r h a n d , t h e ma c r o mo l e c u l a r b a c t e r i o c i n s s u c h a s R
pyocin and c loac in C5 adsorb to sens i t ive ce l l s and exer t
the i r b io log ica l ac t iv i ty . Kazi ro and Tanaka (1965a) and
K a z i r o a n d T a n a k a ( 1 9 6 5 b ) r e p o r t e d t h a t t h e a d d i t i o n
o f R p y o c in , p r o d u c e d b y
P . a e r u g i n o s a
t o g r o w i n g
cu l tu re o f the sens i tive s tra in , caused a rap id and c om -
p le t e cessa t ion and inh ib i t ion o f the syn thes i s o f RNA,
DNA and p ro te in in the sens i t ive ce l l s . Th i s was found
due to inac t iva t ion o f the r ibosom es . The k i l l ing ac t ion
of these bac te r ioc ins i s t herefo re remin i scen t o f the
ac t ion o f v i ru l en t phages on the hos t ce ll s (Coetzee
e t a l .
1968) . The e l ec t ron microscop ic s tud ies on the
mo r p h o l o g i c a l c h a n g e s o f th e s e n s it iv e b a c t e r ia ma y l e a d
t o f u r t h e r u n d e r s t a n d i n g t o t h e mo d e o f a c t io n o f t h e s e
bac te r ioc ins .
D . M o r p h o l o g i c a l c h a n g e s a s s o c i a t e d w i t h b a c te r i o c in
a c t i v i t y
The k il li ng o f suscep t ib l e bac te r i a by a b ac te r ioc in i s a
k ine t i c p rocess . The ac t ion o f those bac te r ioc ins which
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B a c t e r i o c i n s 4 7 3
a r e s h o w n t o h a v e a d e f i n i te s t r u c t u r e h a s b e e n s t u d i e d
i n a p r e l i m i n a r y m a n n e r u s i n g t h e e l e c t r o n m i c r o s c o p e .
T h e m o d e o f b a c t e r i o c i n a c t i o n i s a s s o c i a te d w i t h d i ff e r-
e n t m o r p h o l o g i c a l c h a n g e s o f b o th , t h e s h a p e o f t h e
b a c t e r i o c i n s a n d t h e m o r p h o l o g y o f th e s u s c e p t ib l e
b a c t e r i a . T h e r e h a v e b e e n r e l a ti v e l y f e w r e p o r t s o n t h e
n a t u r e o f th e m o r p h o l o g i c a l c h a n g e s p r o d u c e d i n su s -
c e p t i b le c e ll s o n t r e a t m e n t w i t h b a c t e r i o c i n s , p a r t i c u l a r l y
G r a m p o s i t i v e b a c t e r i a , d u e t o t h e f a c t t h a t m o s t o f
t h e s e b a c t e r i o c i n s a r e n o t r e s o l v a b l e b y e l e c t r o n m i c r o -
s c o p e ( V l a e m y n c k et al . 1 9 9 5 ) . E x t e n s i v e s t r u c t u r a l
c h a n g e s o c c u r r e d i n g r o u p A S t r e p t o c o c c u s s t r a i n a f t e r
e x p o s u r e t o s t a p h y l o c o c c o c i n C 55 ( C l a w s o n a n d D a j a n i ,
1970; E l l i son et al . 1 9 7 1 ) . T h e se c h a n g e s i n c l u d e t h e
c o n d e n s a t i o n o f n u c l e a r m a t e r i a l , l o ss o f r ib o s o m e s ,
m o d i f i c a t i o n o f m e s o s o m e s a n d d i s s o l u t i o n o f ce ll c o n -
t e n t s . S i m i l a r c h a n g e s w e r e a l so o b se r v e d i n s e n s i t i v e
s t r a i n o f S t r e p t o c o c c u s p y o g e n e s ( T a g g et al . 1973)
t r e a t e d w i t h s t r e p t o c i n A . T h e s e c h a n g e s r a n g e d f r o m
t h e n o r m a l a p p e a r a n c e o f t h e S t r e p t o c o c c i t o t h o s e w i th
a c o n d e n s a t i o n o f n u c l e a r m a t e r i a l w i t h a n i n c r e a s e in
t h e p e r i n u c l e a r s p a c e .
O n t h e o t h e r h a n d , m o r p h o l o g i c a l s t u di e s c o n c e r n i n g
t h e b a c t e r i o c i n s o f G r a m n e g a t i v e b a ci ll i w e re d o n e
u s i n g p y o c i n p a r t i c le s a n d m o r e r e c e n t l y w i t h c l o a ci n C 5
o f E n t e r o b a c t e r c l o a c a e ( G o v a n , 1 9 7 4 a , b ; D a w , 1 9 8 9 :
D a w a n d F a l k i n e r , 1 9 9 3) . T h e s e g r o u p s c o n d u c t e d
d e t a i l e d s t u d i e s o n a d s o r p t i o n a n d i n h i b i t o r y a c t i o n o f
p y o c i n 2 1 o n s e n s i t i v e c e l l s o f P. aeruginosa a n d c l o a c i n
C 5 o f E. c loacae u s i n g e l e c t r o n m i c r o s c o p y . T h e u n c o n -
t r a c t e d p a r t i c l e s ( t h e a c t iv e f o r m s o f b a c t e r i o c i n s , F i g s 1
a n d 5 b ) a t t a c h e d r a p i d l y b y t h e b r o a d e r o r b a s e p l a t e
e n d t o s e n s i t i v e b a c t e r i a a n d n o i m m e d i a t e a d s o r p t i o n
o f t h e b a c t e r i o c i n u s u a l l y o c c u r s a s s h o w n i n F i g . 8
( G o v a n . 1 9 7 4 a) ; w i t h a P . aeruginosa i n d i c a t o r s t r a i n
a f t e r o n e m i n u t e c o n t a c t w i t h i n d u c e d p y o c i n 2 1 . T h e
b a c t e r i a l s u r f a c e i s h e a v i l y s u r r o u n d e d b y p y o c i n
p a r t ic l e s a n d n o c o n t r a c t i o n o f a d s o r b e d p a r t ic l e s is
s h o w n . C o n s e q u e n t l y , a f t e r a d s o r p t i o n , c o n t r a c t i o n o c -
c u r s a n d t h e b a c t e r i o c i n s s t a r t t o e x e r t t h e i r a c t i o n s a s
sh o w n i n F ig . 9 ( D a w a n d F a l k i n e r , 1 99 3 ); E. c loacae
s t r a in s e n s it iv e t o c l o a c i n C 5 a f t e r f o u r m i n u t e s c o n t a c t .
T h e c o n t r a c t e d b a c t e r i o c i n s c a n b e s e e n a d s o r b e d t o t h e
b a c t e r i a l su r f a c e a n d i n t h e v i c i n i t y o f t h e b a c t e r i a l c e ll .
F i g u r e 1 0 ( G o v a n , 1 9 7 4 a) a ls o s h o w s t h e s a m e f o r a
P. aeruginosa s t r a in a f t e r f iv e m i n u t e s c o n t a c t w i t h
se n s i t i v e p y o c i n s . T h e b a c t e r i a l c e l l i s a l so su r r o u n d e d
b y c o n t r a c t e d b a c t e r i o c i n s .
A f t e r t h e a d d i t i o n o f b a c t e r i o c i n s t o s e n s i ti v e b a c te r i a
f o r a l o n g e r p e r i o d , a v a r i e t y o f c h a n g e s h a v e b e e n
o b s e r v e d . T h e e n t i r e s u r f a c e o f t h e s e n s it iv e b a c t e r i u m
a p p e a r s c o v e r e d w i t h r o d l i k e p a r t i c l e s , w i t h a n i m m i -
n e n t d i s r u p t i o n o f t h e b a c t e r i a l c e ll a s sh o w n i n F i g s 11
a n d 1 2 ( D a w a n d F a l k i n e r , 1 9 93 ; D a w , 1 9 89 ; G o v a n ,
1 9 7 4 a ) . T h e b a c t e r i a l c e l l s , a t t h i s s t a g e , w e r e d e a d a n d ,
i n d e e d , a l t e r t w o h o u r s i n c u b a t i o n w i t h t h e b a c t e r i o c i n
p r e p e r a t i o n s , m o r e t h a n 9 0 7 ,, o f t h e b a c t e r i a w e r e s e e n
t o b e c o m p l e t e l y d i s r u p t e d . T h i s , h o w e v e r , r e s u l t e d i n
t h e k i l l in g o f s e n s i t iv e b a c t e r i a w i t h o u t l y s is . O n t h e
o t h e r h a n d . w h e n b a c t e r i o c i n s w e r e m i x e d w i t h r e s i s ta n t
Fig. 8 . Pseudomonas aerughu~sa s t r a i n a f t e r o n e r a i n c o n t a c l a t
3 7 ° C w i t h p y o c i n p a r t i c l e s . T h e b a c t e r i a l s u r f a c e i s s u r r o u n d e d
b y m a n y u n c o n t r a c t e d b a c t e r i o c i n p a r ti c l es . N e g a t i v e l y s t a i n e d
w i t h p o t a s s i u m p h o s p h o t u n g s t a t e 2 , ~ , w / v . S c al e m a r k e r
i n d i c a t es 2 0 0 n m
ii L
Fig. 9 .
nterobacter cloacae
a f t e r 4 r a i n c o n t a c t w i t h c l o a c i n a t
3 1 ° C . F e w u n c o n t r a c t e d p a r t i c l e s (U ) a r e v i s ib l e c l o s e t o t h e
b a c t e ri a l s u r F ac e a n d m a n y c o n t r a c t e d ( C ) p a r t ic l e s c a n b e s e e n
a d s o r b e d t o t h e b a c t e r i a l s u r f a c e a n d i n t h e v i c i n i ty o f t h e
b a c t e r i u m . S c a l e m a r k e r i n d i c a t e s 1 0 (I n m .
s t r ai n s , n o n e o f t h e a b o v e - m e n t i o n e d k i l l in g p r o -
c e s s e s o c c u r r e d . T h e e l e c t r o n m i c r o g r a p h s s h o w n o
a t t a c h m e n t o f b a c t e r io c i n p a r t i c le s t o t h e s u r f a c e o f
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474 M .A . Daw and F. R. Falkiner
Fig. 10.
Pseudomonas aeruginosa
after 5 min contact at 37°C
with pyocin. The bacterial cell is surrounded by contracted
particles which can be se en adsorbed to the bacterial surfaces
and in the v icinity of the bacterium. S cale marker indicates
200 nm.
t h e r e s is t a n t b a c t e r i a , a n d m o s t o f t h e p a r ti c le s r e m a i n e d
u n c o n t r a c t e d a n d s o m e d is t a n c e f r o m t h e b a c t e r i a l
c e l l, a s s h o w n i n F i g . 1 2 ; E cloacae s t a i n r e s i s t a n t t o
c l o a c i n C 5 a f t e r 3 0 m i n c o n t a c t . T h e b a c t e r i o c i n
p a r t i c l e s d i d n o t a t t a c h t o t h e s u r f a c e o f t h e r e s i s ta n t
b a c t e ri a a n d m o s t o f t h e m r e m a i n e d u n c o n t r a c t e d ( D a w ,
1989) .
D e s p i te t h e a m b i g u i t y o f th e e l e c tr o n m i c r o s c o p e
e v i d e n c e c o n c e r n i n g t h e c h a n g e s a s s o c i a t e d w i th b a c -
t e r i o c i n p a r t i c l e s d u r i n g t h e k i l l i n g p r o c e s s , i t s e e m s t h e y
a ls o g o th r o u g h m o r p h o l o g i c a l a n d c o n f o r m a t i o n a l
c h a n g e s d u r i n g t h e i r a c t i v i t y . O n l y r e l a x e d f o r m s a d s o r b
t o t h e s u s c ep t i b le s t r a in . W h e n t r ig g e r e d , a c o n t r a c t e d
t a i M i k e s t r u c t u r e c a n n o t b i n d . D i f f e r e n t a g e n t s c a n
e f f ec t t h i s a c t i v i ty . G o v a n ( 1 9 7 4 a ) f o u n d t h a t t h e a c t i v i t y
o f t h e p y o c i n w a s d e s t r o y e d a f t e r t r e a t m e n t w i t h 0 . 0 2
S D S a n d t h a t t h e p y o c i n s l o s t t h e ir o u t e r c o n t r a c t i l e
s h e a t h a n d d i d n o t a d s o r b o n t h e s e n s i t i v e b a c t e r i a l c e l l s .
T h i s a c t i v i t y w a s n o t a f f e c t e d w h e n S D S w a s u s e d a t a
c o n c e n t r a t i o n l e ss t h a n 0 . 0 1 .
D i f f e r e n t s t u d ie s ( K r i m m a n d A n d e r s o n , 1 9 67 ;
M o o d y , 1 9 6 7 a ,b ; B r a u n , 1 9 94 ), s u g g e s t e d th a t t h e
m e c h a n i s m o f c o n t r a c t io n o f th e t ai l s h ea t h o f T 4
b a c t e r i o p h a g e i n v o lv e s a c o n f o r m a t i o n a l c h a n g e i n t h e
p r o t e i n s u b u n i t , in d i c a t i n g c o n f o r m a t i o n a l c h a n g e s in
t h e d o m a i n r e q u i r e d f o r th e i n f e c ti v i ty p r o c e s s o f t h e
b a c t e r i o p h a g e . B a c t e r i o c i n s re s e m b l e c o n t r a c t i le b a c -
t e r i o p h a g e s i n m a n y r e s p ec t s , t h o u g h t h e y d o n o t
(a)
Fig. 11. Enterobacter cloacae sensitive to cloacin C5 (a) and
Pseudomonas aeruginosa
sensitive to pyocin (b) after 30 min
contact at 37 0C w ith the bacteriocin particles. In both con-
ditions, the bacterial surfa ce appears con voluted and c overed
with many bacteriocin part icles contracted (C) and uncon-
tracted (U). E mpty sheaths (E) were also seen in the vicini ty of
the sensitive bacterium. Scale markers indicate 200 nm.
Fig. 12. Enterobacter cloacae strain resistant to bacteriocin C5.
The bacteriocin part icles ha ve not at tached to the bacterial
surface and most o f the bacteriocins have rem ained uncon-
tracted. Scale marker indicates 200 nm.
r e p l i c a t e in s e n s i ti v e h o s t b a c t e r i a . I n m o r p h o l o g i c a l
t e r m s , t h e i r l a c k o f a n y s t r u c t u r e r e s e m b l i n g a b a c t e r i o -
p h a g e h e a d i n d i c a t e s a c o n c o m i t a n t l a c k o f t h e m a i n
r e s e r v o i r f o r n u c l e i c a c i d .
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B a c t e r i o c i n s 4 7 5
P c o l >
c e a l
P i m m > E 9
i m m l y s
D N A - 0 -
P r o t e i n s
C o l i c i n
c o m p l e x
( l l l l l ' l l l [ l l l [ l i l l i ' l l l )
C o l i c i n E 9 I m m u n i t y L y s i s
p r o t e i n p r o t e i n
F i g . 1 3 . G e n e t i c o r g a n i s a t i o n o f c o l i c i n E9 o p e r o n o f
E s h e r i c h i a
coli P c o l is a n S O S - i n d u c i b l e p r o m o t e r ceal C o l i c i n E 9
s t r u ct u r a l g e n e P i m m i m m u n i t y g en e p r o m o t e r . E 9 i m m :
i m m u n i t y p r o t e i n g e n e l v s ; l y s i s g e n e i n v o l v e d i n s e c r e t i o n o f
t h e c o l i c i n c o m p l e x .
I I I M O L E C U L A R B I O L O G Y O F B A C T E R I O C I N S
A . G e n e t i c d e t e r m i n a n t s o J b a c t e r i o c i n s
The production of bacteriocins seems to be a heredi-
tary feature associated with cytoplasmic genes (i.e
bacteriocinogenic factors). The genetic determinants of
colicins (colicinogenic factors) have been the most com-
monly studied (Reeves, 1972; Nieto-Lozano e t a l . , 1992;
Schved e t a l . , 1993; Braun et al . 1994). Most of the
genetic determinants of the bacteriocins are plasmid-
borne with few exceptions, including pneumocin and
pyocins, which are found to be chromosomally located
(Kageyama, 1975: Quirantes
e t a l . ,
1994). Bacteriocino-
genic genes may determine, not only the chemical com-
position of the bacteriocin, but also the regulation of its
biosynthesis, its release from the cell and the host cell
immunity to its own bacteriocin. Plasmid-encoded bac-
teriocins could be easily transferred from bacteriocino-
genic bacteria to compatible recipient strains either by
conjugation or transduction. The transfer of such a
plasmid emparts to the recipeint strains all the features
encoded. Transfer of bacteriocinogenic activity has
been demons trat ed with many colicins. E colicins are
plasmid-encoded proteins produced by E . c o i l , which kill
the sensitive cells by binding to the btuB-encoded cell
surface receptor (Di Masi e t a l . , 1973). The E colicin
plasmid also codes for the production of a specific
immunity protein which, upon synthesis, binds to the C
terminal domain of its cognate. James e t a l . (1992)
studied the genetic determinant of the interaction be-
tween colicin E9 and its immunity proteins. ColE9-J
plasmid encodes the colicin structural and immunity
genes in an operon (Chak and James, 1986). The pro-
moter of
E 9 i m m
genes is located within the colicin E9
structural gene. Transcription from such a promoter
allows constitutive expression of the immunity protein
and provides immunity to colicin E9. Transcription
from the inducible promotor results in the expression of
the genes of the operon, as shown in Fig. 13 and leads to
the synthesis and secretion of the colicin/immunity
protein complex.
Plasmid elimination curing can be accelerated by
exposing the host strains to certain agents such as the
intercalating dye acridine orange and ethidium bromide
or by growing the bacteriocinogenic cells at an elevated
temperature (Tolmasky
e t a l . ,
1993). Such agents could
eliminate the plasmids encoded for the bacterJocins.
Bacteriocinogenic factors from
S t a p h y h , c o c c o u s a u r e u s ,
and
C o l i s t r i d i u m p e r f e r i n g e s
have been cured by such
methods (Gagl iano and Hinsdill, 1970; Ionesco and
Bouanchaud, 1973). Dajani and Taube (1974) noted that
the curing of bacteriocin production in staphylococci
resulted in alteration the resistance of producer cells to
the action of the staphylococcin. Where staphylococcin
producer strains were unable to adsorb the bacteriocin
and were naturally resistant to its killing effect, cured
strains adsorbed the staphylococcin and were rapidly
killed by it. This makes the bacteriocinogenic strains
whose bacteriocins were plasmid-encoded readily lose
their bacteriocinogenic activity, in comparison to those
strains possessing chromosomal borne bacteriocins.
Pyocins on the other hand have peculiar features since
their genetic determinants are all located at definte sites
on the chromosome. This is in sharp contrast to the case
for many other bacteriocins such as colicins, which are
of plasmid origin. Thus, the loci of pyocins types R and
F are between alteration of t r p C D and tlT~E (Kageyama,
1975; Shinomiya e t a l . , 1983), the locus for pyocin AP41
is between @ s ' - 9 0 1 5 and a r g F and the locus for pyocin S
is close to fl a Y (Sano and Kageyama, 1984: Sano
e t a l . ,
1990) on the chromosome of the producer strains. Sano
et al .
(1990) studied the pyocin genes in detail and cloned
them on appropriate plasmids. The genes governing
pyocins AP41, S1 and $2 were found to each encode two
proteins, large and small, transcribed in the same direc-
tion; AP41, 83.6 and 10 kDa; SI, 64.6 and 10 kDa and
$2, 74 and 10 kDa. Striking homology in the amino acid
sequences found among these pyocins and colicins,
particularly the C-terminal amino acids, the central
region of the pyocins and the peptides stretching
between the N-terminal and the central parts of colicins
E2 and E3 and cloacin DF 13. Comparison of the genetic
components of these bacteriocins is depicted in Fig. 14.
The S-type pyocin has been purified and cloned from E.
c o l i cells using DEAE-cellulose and chromotography
(Ohkawa e t a l . , 1973; Sano and Kageyama, 1981). The
purified preparation is a complex composed of two
proteins, a larger component which showed essentially
the same level of killing activity as did the complex
molecule and a smaller component which made the cells
immune to pyocins. When indicator strains were trans-
formed with a cloned DNA for the smaller component,
they became insensitive to the respective pyocin (Sano
e t a l . ,
1990). In conclusion, bacteriocins differ not only
in the range of target bacteria but also in the location of
their genes, chromosomal or plasmid borne. However,
the similarity found among these agents in amino acid
sequence and in function may give clues concerning their
etiology.
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4 7 6 M . A . D a w a n d F . R . F a l k i n er
P y o c i n
A P 4 1
S I
$ 2
C o l i c i n E 2
C - T e r m i n a l s T - T e r m i n a l s
0 400 800
I I I I I I I I I A m i n o a c i d s
I I I I I I V
R 6 4 0
I ' , . I . ' , I I I I I l I I I I I l I I I l I V A v 7 6
> , \ R 487
1
i ' ,l , , ; ', i il l ' il " I i l V / / / A 6 1 7
7 7 7
i l t
~ / / / / R 5 58
I [{ l
] 1 ' , I , I , 1 i l l i l i 1 1 1 : l I I ] i I V / / / A 6 8 9
~ - [ / ~ R 4 5 2
R 4 5 4
E 3 ~ / / A I I l l l l l l l l l k . + ~ \ ~ 5 5 l
: : : : : R 46 4
I i l ] l ] l l l l l l l l l l l [ I t k \ \ q 5 6 1
T r a n s l o c a t i o n R e c e p t o r
n u c l e a s e
F i g . 1 4 . A m i n o a c i d s e q u e n c e h o m o l o g y i n t h e k i ll er c o m p o -
n e n t s o f p y o c i n s A P 4 1 , S l a n d $ 2 o f Pseudomonas aeruginosa
c o l i c i n s E 2 a n d E 3 o f
Escherichia coil
a n d c l o a ci n D F 1 3 o f
Enterobacter cloacae. D o m a i n s s h o w i ng h o m o l o g y h a v e th e
s a m e s h a d i n g . L e n g t h s a re p r o p o r t i o n a l t o t h e n u m b e r o f
a m i n o a c i d s o f e a c h m o l e c u l e . A n A r g r e s i d u e n e a r t h e s t a rt
p o i n t o f e a c h n u c l e a s e d o m a i n i s f ix e d a s a r e f er e n c e p o i n t
( R 6 4 0 i n A P 4 1 ) . T h e N - t e r m i n a l M e t i s la c k i n g i n t h e p u ri f ie d
p y o c i n s .
C l o a c i n D F I 3
B. Microbiological relevance of bacteriocins
Bacteriocins have found a widespread significance in
medical microbiology, particularly in epidemiological
studies. Bacteriocin typing can be done in two ways: 1)
by determining the bacteriocin production pattern of a
strain against a set of standard indicators and 2) by
determining the bacteriocin susceptibility pattern of the
strain against a set of bacteriocins which are applied
to it. Each method has been used in epidemiology to
determine whether the isolates from different sources are
the same. If the isolates are from the same strain, their
bacteriocin production or susceptibility patterns will be
identical. The bacteriocin typing technique has been
widely used to answer the epidemiological questions in
the nosocomial infections. Although the bacteriocin
fingerprinting was found to be applicable for both Gram
positive and Gram negative bacteria, the scheme has
been most successfully used in the studies of Gram
negative bacilli.
Bacteriocin activity has been used as a marker for
typing epidemic strains of gram positive bacteria such as
S. aureus Streptococc us faeca lis
and
Colistridium per-
Jkingens. Hale and Hinsdill, 1973; Jack and Tagg, 1992;
Stiles, 1994). These studies, however, were never found
to have a wide range of application in microbiology.
More promising, is the application of bacteriocin typing
of mycobacteria, particularly atypical strains Takeya
and Tokiwa, 1972, 1974). Rapidly growing mycobac-
teria such as the Mycobacter iumfortui tum che lone i com-
plex cause serious infections in immunocompromised
patients and those with acquired immune deficiency
syndrome AIDS). My c obac te r ium species, isolated from
patients with prosthetic heart valves and hip joints, can
be classified to specific bacteriocin profiles. The myco-
bacteriocin activity can be combined and correlated with
other typing methods for further classification and
differentiation of such mycobacteria.
The role of Gram negative bacilli in a wide variety of
diseases is well known, particularly in the nosocomial
infection Du Pont and Spink, 1969; Daw and Falkiner,
1994). Hence, not only the recognition of the causative
agent is critical, but also determinat ion as to whether all
strains of a particular pathogenic organism isolated from
an outbreak o f disease originate from a common source.
Bacteriocin typing has been used to trace such organisms
and most of the definitive investigations of bacteriocin
typing have been used on Gram negative infections.
Early data on the epidemiological relevance of bacterio-
cin typing was reported on typing of E. coil and related
pathogens such as
Proteus
species and
Shigella sonnei.
A significant resurrection of interest in the bacteriocin
typing started in the early seventies. This was due the
fact that bacteriocin typing is, 1) reliable in tracing the
source of the infecting organisms, 2).discr imantory
and reproducible, 3) does not need a sophisticated
instruments and 4) can be easly used by a small labora-
tories with no need to rely on reference laboratories. The
most significant bacteriocin typing of Gram negative
bacilli concerns those groups of opportunistic bacteria
such as
Pseudomonas Klebsiella Enterobacter
and
Serratia which often cause serious infections in hospital-
ised patients Daw, 1989). The microbiological rele-
vance of bacteriocin is evident. As an epidemiological
tool, the system was found to be applicable and com-
parable to the classical typing methods. Further to
its practicability, bacteriocin typing almost always pro-
vides answers to pertinent epidemiological questions,
which make it one of the favourite typing methods,
particularly with those laboratories possessing only basic
equipment.
IV. CONCLUSIONS
Bacteriocins are protein-like antibiotics. They differ
from traditional antibiotics because of their composition
and narrow spectrum of activity, in which they kill
bacteria of the same or closely related species. The
producing strain usually shows immunity to the bac-
teriocin they produce. The classification and thus
the nomenclature of bacteriocins has gone through a
major changes since the discovery of these bactericidal
particles. Further to their classification according to the
producing bacterial strains, they have also been classi-
fied according to their electron microscopical appear-
ance. Both ultrastructure and biochemical data seem
to suggest that bacteriocin particles are heterogeneous
molecules, varying from a small unidentified structure to
a large one resolvable by electron microscopy.
The macromolecular bacteriocins exert their action by
adsorbtion to specific receptors located on the external
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B a c t e r i o c i n s 4 7 7
s u r f a c e o f t h e se n s i t i v e s t r ai n f o l l o w e d b y m a j o r b i o l o g i -
c a l a n d m o r p h o l o g i c a l c h a n g e s o f b o t h t h e b a c t er i a l c el l
and the bac ter ioc in par t i c l e . This re s ul t s in the k i l l ing
o f t h e s e n s i t i v e s t r a i n w i t h o u t p r o d u c t i o n o f f u r t h e r
b a c t e r i o c i n p a r t ic l e s o n e o f t h e m a i n f e a t u r e s w h i c h
m a k e s t h e m c l e a r l y d i f f e r e n t t o b a c t e r i o p h a g e s .
T h e m o s t i n t e n s i v e l y s t u d i e d g r o u p s o f b a c t e r i o c i n a r e
t h e c o l i c i n s w h i c h a r e p r o d u c e d b y E . co l i a n d c l o s e l y
re la ted enterobac ter ia .
T h e y a r e a r e t y p i c a l l y p l a s m i d - e n c o d e d p r o t e i n s . T h e
o t h e r m a j o r g r o u p i s t h e p y o c i n o f P. aerug in osa w h i c h
i s c o n t r o l l e d b y t h e p r e s e n c e o f s p e c if i c g e n e t ic d e t e r m i -
n a n t s e n c o d e d o n t h e c h r o m o s o m e o f t h e p r o d u ci n g
bacter ia .
I n a d d i t i o n t o t h e i n t e n s i v e s t u d i e s o n t h e s e b a c t e r i o -
c in s a n d t h ei r c o n t r i b u t i o n t o m o d e r n b i o l o g y t h e y h a v e
g a i n e d n e w a t t e n t i o n i n m e d i c i n e p a r t i c u la r l y in t h e
e p i d e m i o l o g y o f n o s o c o m i a l i n fe c t io n s . D u e t o t h e
s i m p l e p r o d u c t i o n o f t h e b a c t e r i o c i n s i t m a k e s t h e m a
f a v o u r i t e t y p i n g a s s a y f o r p a t h o g e n i c o r g a n i s m s . T h i s
a l l o w s c o n t r o l o f t h e c r o s s - i n f e c t i o n s w h i c h o c c u r i n
t h e h o s p i t a l s t h a t m a y r e s u l t i n s e r i o u s c o n s e q u e n c e s
p a r t i c u l a r l y a m o n g i m m u n o c o m r o m i s e d p a t i e n t s .
A c k n o w l e d g e m e n t s - - T h e a u t h o r s w o u l d l ik e to t h a n k D r s M o h a m e d J .
M a b r u k , K . S . G e n g h i s h , M . I . M a h m o u d , N a g e t S a i e d , M u s t a f a
H a j a j i , M . F a r o u k i , S . T l o b a a n d A . R a h o m a , d e p a r t m e n t s o f M e d i c a l
M i c r o b i o l o g y a n d P a r a s i t o l o g y , F a c u l t y o f M e d i c i n e , T r i p o l i , L i b y a
f o r t h e i r h e l p f u l c o m m e n t s a n d s u g g e s ti o n s .
R E F E R E N C E S
A l a t o s s v a , T . , 1 9 9 4 . A n a l o g i e s b e t w e e n s u p e r i n f e c t io n e x c l u s io n a n d
b a c t e r i o c i n i m m u n i t y . Tr e nds M ic r ob io l . , 2, 215 216.
Becker , R . J . , Cooper , A. J . and S tar zyka , M. J , , 1993 . Ev idence fo r
a s s o c i a t i o n o f b a c t e r i o c i n o g e n i c a c t i v it y w i t h m e m b r a n e v e si cl es
o f The r mu s r ube ns. M ic r ob ios . , 73, 123-133.
Boemare , N. E . , Boyer -Gig l io , M. H. , Thaler , J . O. , Akhur s t , R . J . and
Brehel in , M. , 1992. Lys ogey and ba c te r ioc inoge ny in X e n o r h a b d u s
ne matoph i lus a n d o t h e r X e n o r h a b d u s spp. Appl. Env iron. M icro-
biol., 58 , 3032-3037 .
Brad ley , D. E . , 1 966 . The s t ruc ture o f pyocin par t i c l es r e leas ed f rom
P s e udomonas ae r ug inos a b y m i t o m y c i n C . Int . Congr . Elec t .
Microsc . , 6 , 115 116.
Bradley , D. E . and Rober t s on , D. , 1968 . The s t ruc ture and in f ec t ive
p r o c e s s o f a c o n t r a c t i l e P s e udomonas ae r ug inos a b a c t e r i o p h a g e .
J. Gen. Virol.. 3, 247 254.
B r a d l e y , D . , 1 9 6 7 . U l t r a s t r u c t u r e o f b a c t e r i o p h a g e a n d b a c t e r i o c i n s .
Bacteriol. Rev.. 3 1 , 2 3 0 - 3 1 4 .
Braun , V., P i ls i, H. an d Gro s s , P . , 199 4 . Col i c ins , s truc ture , m ode o f
a c t i o n , t r a n s f e r t h r o u g h m e m b r a n e s a n d e v o l u t i o n . A r c h . M ic r o-
biol., 161, 199-206.
C a v a r d , D . a n d O u d e g a , B . , 1 9 9 2 . G e n e r a l i n t r o d u c t i o n t o t h e
s ecre t ion of bac te r ioc ins . I n : B ac te r ioc ins , M ic r oc ins and Lan t i -
hiotics , J ames , R . , Lazduns k i , C . and Pa t tus , F . ( eds ) . NATO ASI
s er i es Vol 65 , pp . 297-305 .
C h a k , K . F . a n d J a m e s , R . , 1 9 8 6 . C h a r a c t e r i s a t i o n o f th e C o l E 9 - J
p l a s m i d a n d a n a l y s i s o f i t s g e n e t i c o r g a n i s a t i o n . J. Gen.
Micr ibiol . , 132, 61 71.
C law s on , C . C . and D ajan i , A. S . , 1970 . E fec t o f bac te r i c ida l s ubs tanc e
f r o m
S taphy loc oc c us aur e us
o n g r o u p A s t r e p to c o c c i I I . S t ru c t u r a l
a l t e r a t ions . In le c t . Immun . . 1 , 4 9 1 - 4 9 8 .
Coetzee , H . L . , Coetzee , J. N. an d Sm i t , J . A. , 1968 . Bac ter ioph age t a i l
l i ke par t i c l es as s oc ia t ed wi th in t r a s pec ies k i l l i ng o f P r o te us
vulgaris. J. Gen. Virol., 2 , 29-36 .
Davies , J . K. a nd Reeves , P . , 1975 . Ge net i c o f r es i s t ance to co l i c ins in
Escherchia coli K - 1 2 : c r o s s - re s i s ta n c e a m o n g c o l i c in s o f g r o u p B .
J . Bac ter iol . . 123, 96 101.
Davies , J . K. a nd Reeves , P . , 1975 . Ge net i c o f r es i s t ance to co l i c ins in
E s c he r c h ia c o l i
K-12: c ros s - r es i s t ance among co l i c ins o f g roup B .
J . Bac ter iol . , 123, 102-117.
D a j a n i , A . S . , T a u b e , Z . , 1 9 7 4 . P l a s m i d - m e d i c a t e d p r o d c t i o n o f
s t a p h y l o c o c c i n i n b a c t e r i o p h a g e t y p e 7 1 Staphy lococcus aureus .
A n t im ic r ob . A ge n ts Che mothe r . , 5 , 594-598 .
Daw, M. A. , 1989 . PhD thes i s , Dubl in Univer s i ty , T r in i ty Col l ege
D u b l i n , I r e l a n d .
D a w , M . A . a n d F a l k i n e r , F . R . , 1 9 9 3 . T h e u l t r a s t r u c t u r e o f c lo a c i n
C 5 o f E nte r obac te r c loacae . P r oc e e d ings o f the R oy a l M ic r os c op i -
c a l Soc ie ty . 28 , (Supplement 1 ) , 24 .
D a w , M . A . a n d F a l k i n e r , F . R . , 1 9 9 4 . P r e v e n t i o n o f g r a m n e g a t i v e
i n f e c t i o n s i n n e u r o p e n i c c a n c e r p a t i e n t s . Saud. Med. J . , 15,
196 203.
Daw, M. A. , Corcorn , G. D. , Fa lk iner , F . R . and Keane , C . T . , 1992 .
A p p l i c a t i o n a n d a s s e s s m e n t o f c l o a c i n t y p i n g o f E nte r ohac te r
cloacae. J. Hosp. lnJect., 20, 141 151.
Di Mas i , R . D. , Whi t e , J . , Scha i tman , C . A. and Bradbeer , C . , 1973 .
T r a n s p o r t o f v i t a m i n B 1 2 i n Esherichia coli; c o m m o n r e c e p t o r
s i te s fo r v i t a m i n B I 2 a n d E c o l i c in s o n t h e o u t e r m e m b r a n e o f t h e
cel l envelop. J . Bac ter iol . . 115, 506--573.
D u P o n t , H . L . a n d S p i n k , W . W . , 1 9 6 9 . I n f e c t i o n s d u e t o G r a m -
n e g a t i v e o r g a n i s m s : a n a n a l y s i s o f o f 8 6 0 p a t i e n t s w i t h b a c t e r i -
am ia a t t he un iver s i ty o f Minn es o ta Med ica l Center , 1958-1966 .
M e dic ine , 48 ,
307-316 .
D u r k a c z , B . W . a n d S h e r r a t t , D . J . , 1 9 7 3 . S e g r e g a t i o n K i n e t i c s o f
c o l i c in o g e n i c f a c t o r C o l E l f r o m a b a c t e r i a l p o p u l a t i o n
t e m p e r a t u r e - s e n s i t i v e f o r D N A p o l y m e r a s e 1 . Mol. Gen. Genet.,
121, 71 75.
E l l i s on , J . S . , Mat t e rn , C . F . T . and Danie l , W. A. , 1971 . S t ruc tura l
c h a n g e s i n Cols t r id ium bo tu l inum t y p e E a f t e r t r e a t m e n t w i t h
bo t i c in $51 . J . Bac ter iol . , 1 0 8 , 5 2 6 5 3 4 .
Farkas -Hims ley , H. , Zhang , Y. S . , Yuan , M. and Mus clow, C . E . ,
1992 . Par t i a l ly pur i f i ed bac te r ioc in k i l l s mal ignan t ce l l s by apop-
t o s is ; p r o g r a m m e d c el l d e a t h . Cell Mol. Biol . No isy h, grand, 38,
643 65 t.
F reder i cq , P . , 1957 . Col i c ins . A nn . R e v . M ic r ob io l . , I1, 7 22.
Freder i cq , P . , 1963 . On the na ture o f co l i c inogenic f ac to r s: a r ev iew.
J. Theor. Biol., 4, 159 161.
G a g l i a n o , V . F . a n d H i n d s i ll , R . D . , 1 9 7 0 . C h a r a c t e r i s a t i o n o f
S taphy loc oc c us aur e us
bac ter ioc in .
J . Bac ter iol . ,
104, 117 125.
G e l i , V . a n d L a z d u n s k i , C . , 1 9 92 a . I m m u n i t y p r o t e i n t o p o r e f o r m i n g
col icins . In The B ac te r ioc in , M ic r oc ins and Lan t ib io t i c s b y J a m e s
R , L a z d u n s k i C a n d P a t t u s F . p p 1 71 1 7 9 . S p r i n g e r - V e r l a g ,
Ber l in . NATO ASI Ser i es .
G e l i , V . a n d L a z d u n s k i , C . , 1 9 9 2 . A n a - h e li c a l h y d r o p h o i c h a i r p i n a s
a s p ec if ic d e t e r m i n a n t i n p r o t e i n - p r o t e i n i n t e r a c t i o n o c c u r i n g i n
Escherichia coli c o l i c in A a n d B i m m u n i t y s y s t em s . J . Bac ter iol . ,
147, 6432-6437.
G r a t i a . A . , 1 9 2 5 . s u r u n r e m a r q u a b l e e x a m p l e d ' a n t a g o n i s m e e n t r e
deux s ouches de co l ibac i l l e . C R. Soc. Biol., 93, 1040 1041.
Gra t i a , J . P . and Gren ier , L . , 1992 . Di f f e r en t i a l ac t iv i ty o f bac te r io c ins
a n d c e f o t a x i m e a g a i n i s t Se r r a t ia mar c e s c e ns c l in i ca l i s o l a t e
S M G 4 0 a n d i t s p i g m e n t e d v a r i a n t . Int. J . Microbiol. Virol.
Parasitol . ln/ec t . Dis . , 276 , 340-346 .
G o n z a l e z - M a n a s , J . M . , L a k e y , J . H . a n d P a t t u s , F , , 1 9 9 2 . B r o m i n a t e d
p h o s p h p l i p i d s a s f o r m o n i t o r i n g t h e m e m b e r a n e i n s e r t i o n o f
co l i c in A. B ioc he mis t r y , 31 , 7294-7300 .
G o o r m a g h t i g h , E . , V i g n e r o n , L . , K n i b i e h l e r , M . , L a z d u n s k i , C . a n d
R u y s s c h a e t , J . M . , 1 9 9 1 . S e c o n d a r y s t r u c t u r e o f t h e m e m b r a n e -
b o u n d f o r m o f th e p o r e f o r m i n g d o m a i n o f c o l i c in A . Eur. J.
B ioc he m. , 202, 1299 1305.
G o v a n , J . R . W . , 1 9 7 4 . S t u d i e s o n t h e p y o c i n s o f P s e u d o m o n a s
ae r ughws a: m o r p h o l o g y a n d m o d e o f a c t io n o f c o n t r a c ti l e
pyocins . J . Gen. Micr ibiol . . 80, 1 15.
G o v a n , J . R . W . , 1 9 7 4 . S t u d i e s o n t h e p y o c i n s o f P s e u d o m o n a s
aeruginosa: p r o d u c t i o n o f c o n t r a c t i l e s a n d f l e x u o u s p y o c i n s o f
Pseu dom onas aeruginosa. J . Gen. Micr ib ioL. 80, 15 30.
Hale , E . M. and H ins d i l l , R . D. , 19 73 . Cha rac te r i za t io n of a bac te r io -
c i n f r o m S taphy loc oc c us aur e us s train 462. A n t i m i c r o b A g e n t s
Che mothe r . , 4 , 634-640 .
H a r d y , K . G . , 1 9 7 5 . C o l i c i n o g e n y a n d r e l a t e d p h e n o m e n a . Bacter iol .
Rev . , 39, 464--515.
H a r d y , K . G . a n d M e y n e l l , G . G . , 1 9 7 2 . C o l i c in f a c t o r s a n d
m i t o m y c i n - C . J . Gen. MicrobioZ, 73, 547 549.
H a r d y , K . G . a n d M e y n e l l, G . G . , 19 7 2 . I n d u c t i o n o f c o l i c i n f a c t o r
E 2 - P 9 b y m i t o m y c i n C. J . Bac ter iol . , 112, 1007 1009.
Has t ing s , J . W. , S ti les , M. E . and V on H oly , A. , 1995 . Bac ter ioc ins o f
l e u c o n o s t o c s i s o l a t e d f r o m m e a t . Int . J . Fo ,d Microh ioL. 24,
75 82.
-
8/18/2019 Bacteriocins Nature, Function and Structure
12/13
4 7 8 M . A . D a w a n d F . R . F a l k i n e r
Havar s t e in , L . S . , Holo , H. and Nes , I . F . , 1994 . The l eader pep t ide o f
c o l i ci n V s h a r e s c o n s e n u s s e q u e n c e w i t h l e a d e r p e p t i d e s t h a t a r e
c o m m o n a m o n g p e p t i d e b a c te r i o ci n p ro d u c e d b y G r a m p o s it i ve
bac ter i a . M i c r o b i o l o g y , 140, 2383 2389.
Higerd , T . B . , Baech ler , C . A. and Berk , R . S . , 1969 . Morpholog ica l
s t u d i e s o n r e l a x e d a n d c o n t r a c t e d f o r m s o f p u r i f i e d p y o c i n
par t i c l es . J . B a c t e r i o l . , 98 , 1378-1389 .
H o w a r d s , P . , C a v a r d , D . a n d L a z d u n s k i , C . , 1 9 8 9 . A m i n o a c i d
s e q u e n c e a n d l e n g h t r e q u i r e m e n t s f o r a s s e m b l y a n d f u n c t i o n o f
the co l i c in A lys i s p ro te in . J . Bac t er io l . , 1 7 1 , 4 1 0 - 4 1 8 .
I t o , S . a n d K a g e y a m a , M . , 1 9 70 . R e l a t i o n s h i p b e t w e e n p y o c i n s a n d a
b a c t e r i o p h a g e i n p s e u d o m o n a s a e r u g i n o s a . J . G e n . A p p . M i c r o -
b io l . , 16 , 231-240 .
I t o , K . , K a g e y a m a , M . a n d E g a m i , F . , 1 9 70 . I s o l a t i o n a n d c h a r a c t e r i s-
a t i o n o f p y o c i n s f r o m s e v e ra l s t r a in s o f P s e u d o m o n a s a e r u g i n o s a .
J . G e n , A p p l . M i c r o b i o l . , 16, 205 214.
I s s acs on , R . E . and Koni s ky , J . , 1974 . s tud ies on the r egu la t ion of the
c o l i c i n I b s y n t h s i s : r e p l i c a t i o n o f t h e C o l I b - P 9 p l a s m i d d u r i n g
c o l i c in i n d u c t i o n . A n t i m i c r o b . A g e n t s C h e m o t h e r . , 6 , 848-852 .
I o n e s c o , H . a n d B o u a n c h a u d , D . H . , 1 9 73 . P r o d u c t i o n d e b a c t e r i o c i n e
l iee a l a p r es ence d un p la s mid chez C o l i s t r i d i u m p e r f e r i n g s t y p e A .
C . R . A c a d . S e i . ( D ) P a r i s , 276 ,
top related