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Legionella may be the headline

Pseudomonas is the real issue

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Let’s start with some facts……………...

A Study conducted in Seoul, South Korea found:

⚫ Pseudomonas was the most common bacterial infection in hospitals

⚫ 78.7% of cases were acquired in the hospital

⚫ The 30 day mortality rate was 39%

Cheol-In Kang et al 2003

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Most Common infections:

⚫ Respiratory tract

⚫ Urinary tract

⚫ Skin

⚫ Eyes

⚫ Ears

⚫ Bloodstream

Less Common infections:

(But still prevalent)

⚫ Bone

⚫ Joints

⚫ Brain & Central Nervous System

⚫ Gastrointestinal tract

⚫ Heart valves

Let’s start with some facts……………...

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⚫ Pseudomonas is responsible for a wide range of health conditions

⚫ Pseudomonas is becoming increasingly drug resistant.

⚫ Pseudomonas is MDRO – Is one of the ESKAPE group of organisms

ESKAPE is an acronym made from the first letters of their scientific names and also areference to their ability to escape the effects of commonly used antibiotics.

The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiellapneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species)are the leading cause of nosocomial infections throughout the world.

Let’s start with some facts……………...

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Let’s start with some facts……………...

Another issue to consider:

VBNC

Viable But Non-Culturable

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Let’s start with some facts……………...

VBNCViable But Non-Culturable bacteria refers to bacteria that are in

a state of very low metabolic activity and do not divide, but are

alive and have the ability to become culturable once

resuscitated.

Oliver JD (February 2005). "The viable but nonculturable state in bacteria". The Journal of Microbiology. 43 (special issue (No. S)): 93–100. PMID 15765062.

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Let’s start with some facts……………...

VBNC

What does this all mean?

The organisms do NOT show up in a standard plate

count, even though they are still alive!

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Let’s start with some facts……………...

VBNC

On resuscitation from the VBNC state, the cells regain

culturability and the renewed ability to cause infection.

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Let’s start with some facts……………...

VBNCThis phenomena occurs when the organism is stressed.

It is likely that the VBNC state is a survival strategy

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Let’s start with some facts……………...

VBNCQuite a number of micro-organisms are understood to

enter into the VBNC state if conditions are met, including:

» Pseudomonas

» Legionella

» Yersinia

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Let’s start with some facts……………...

Aeromonas salmonicida

Agrobacterium tumefaciens

Burkholderia cepacia

Burkholderia pseudomallei

Brettanomyces bruxellensis

Campylobacter coli

Campylobacter jejuni

Campylobacter lari

Cytophaga allerginae

Escherichia coli (including EHEC)

Enterobacter aerogenes

Enterobacter cloacae

Enterococcus faecalis

Enterococcus hirae

Enterococcus faecium

Erwinia amylovora

EscFrancisella tularensis

Helicobacter pylori

Klebsiella aerogenes

Klebsiella pneumoniae

Klebsiella planticola

Legionella pneumophila

Listeria monocytogenes

Micrococcus luteus

Mycobacterium tuberculosis

Mycobacterium smegmatis

Pasteurella piscicida

Pseudomonas aeruginosa

Pseudomonas syringae

Ralstonia solanacearum

Rhizobium leguminosarum

Rhizobium meliloti

Salmonella enterica

Salmonella Typhi

Salmonella Typhimurium

Serratia marcescens

Shigella dysenteriae

Shigella flexneri

Shigella sonnei

Streptococcus faecalis

Vibrio anguillarum

Vibrio campbellii

Vibrio cholerae

Vibrio harveyi

Vibrio mimicus

Vibrio parahaemolyticus

Vibrio shiloi

Vibrio vulnificus (types 1 and 2)

Xanthomonas campestris

Xanthomonas axonopodis pv. citri

Yersinia pestis

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Pseudomonas

=

Biofilm

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What does Biofilm look like?

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What does Biofilm look like?

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Biofilm – continued...

Pseudomonas (and other bacteria) exist in two different forms.

➔ Planktonic – Free floating

➔ Sessile – Attached to a solid surface

Their DNA changes depending on what state they are in!

Lab tests found planktonic Pseudomonas can attach to electro-polished

stainless steel in

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Biofilm – continued...

As part of / during this attachment process the organisms secrete a sticky

conglomeration of extracellular polysaccharides, proteins, lipids and DNA

This material is what we refer to as BIOFILM

The reason for producing this is threefold:

1.To anchor themselves to the surface

2.Provide catchment area for nutrients

3.Protect themselves (and others) from environmental attack

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Five Stages of biofilm development

Stage 1

Initial

attachment

Stage 2

Irreversible

attachment

Stage 3

Maturation

Stage 4

Advanced

maturation

Stage 5

Dispersion

cycle repeats

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Biofilm bacteria display a resistance to biocides that may be

considered stunning. (LeChevallier, 1988.)

[It was] demonstrated that biofilm associated bacteria may be

150-3000 times more resistant to free chlorine and 2-100

times more resistant to monochloramine than free-floating

bacteria.

Bacterial resistance to Disinfection

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Roger Anderson & his colleagues at the Atlanta-based Centres

for Disease Control:

➢ Incubated plastic pipes with two strains of Pseudomonas for 8

weeks

➢ Emptied pipes and refilled with heavy duty biocides for one

week

➢ Refilled pipes with sterile water

Result: both strains survived in the treated pipes &

re-established colonies

Bacterial resistance to Disinfection

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It is virtually impossible for micro-organisms to develop a

general resistance to compounds such as chlorine. However,

bacteria in a biofilm can resist biocides because they are

shielded in slime.

Mittelman M W, (1986)

Bacterial resistance to Disinfection

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Bacterial resistance to Disinfection

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Control measures

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Systemic DisinfectionEffective across the whole of

the Water Distribution System

Focal DisinfectionActive in only a portion of the

Water Distribution System

Temporary DisinfectionBiocide has a limited period of efficacy

Residual DisinfectionBiocide is continuously active

over a long period of time

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Let’s start with some facts……………...

Another issue to consider:

VBNC

Viable But Non-Culturable

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Control measuresThermal flushing and continuous low level chlorination induce

the VBNC state in some organisms.*

Several studies have also suggested that these forms of control

also cause the weaker bugs to die off and allow the resistant

strains of organisms to proliferate once conditions allow.

*Oliver JD (2005)

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Control measuresPoint 1:

UV light is an accepted method of decomposing chlorine in

water.

Whilst chlorine is NOT a good form of control, employing UV

any where within a WDS will remove the last line of defence you

have against micro-organisms.

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Control measuresPoint 2:

TMV’s are designed to mitigate the risk of scalds and burns from

hot water.

They are NOT a method of disinfection

Downstream of the TMV is by definition, a Warm Water System.

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Control measuresThe take home message:

Only Systemic (system wide) forms of

disinfection that give a measurable residual at

EVERY outlet connected to the Water

Distribution System can be employed in health

and aged care facilities.

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Thank you for

your attention

Questions?