Microbiology

Introduction.

Morphology and structure of microorganisms

Protozoa

Amoeba Paramecium

Fungi (mycota)

Aspergillus

Viruses

Adenovirus Bacteriophage

Medical, Pharmaceutical and Biotechnological Applications

A variety of fermented foods produced by microbes

Medical, Pharmaceutical and Biotechnological Applications

Antibiotics, vaccines

Medical, Pharmaceutical and Biotechnological Applications

Human insulin. Made by

recombinant DNA technology

Microbes Cause Food Spoilage and Decomposition

• Penicillium mold growth on orange • Soft rot on peaches caused by the fungus Monilia

Aspergillus mold on shower curtain.

Mold growth in the home, work environment can lead to respiratory infections and allergies

Antony van Leeuwenhoek Leeuwenhoek was a tailor in Delft, Holland. As a draper, he used magnifying glasses to examine fabrics. He made simple microscopes with which he magnified objects too small to be seen with the naked eye.

Leeuwenhoek`s investigations included observations of tiny organisms he called animalcules (little animals), blood, and other human tissues (including his own tooth scrapings), insects, other. Leeuwenhoek transmitted his findings in a series of letters, from 1674 to 1723, to the Royal Society in London, though which his observations were dissemenated.

The first microorganisms were observed at 1676 by Antony van Leeuwenhoek

Antony van Leeuwenhoek is known as the father of bacteriology and protozoology.

A brass replica of a Leeuwenhoek`s microscope

Leeuwenhoek constructed more than 250 small, powerful microscopes that could magnify up to 300 times.

Lens

Specimen holder

Focus screw

Handle

Using of Leeuwenhoek`s microscope

If you can get the lighting just right, it works

Examples of bacteria drawn by Leeuwenhoek

Leeuwenhoek`s letters, which he transmitted to the Royal Society, contained detailed drawings, some of which clearly show microorganisms.

“I discovered living creatures in rain water which had stood but a few days in a new earthen pot. This invited me to view this water with great attention, especially those little animals appearing to me ten thousand times less than those which may be perceived in the water with the naked eye”.

This is probably the first observation of bacteria.

General properties of microorganisms

Microscopic sizeComparative simplicity of organization High rate of reproductionHigh biochemical activityCapacity for rapid adaptability Widely distribution in worldPossibility of pathogenic properties

MICROBIOLOGY

is the science, which studies

representative of microbe world, their interaction with environment, using of microorganisms for human profit.

Branches of microbiology

Science Area of study Microbial morphology Studies the detailed structure of microorganisms

Microbial physiology Microbial function (metabolism) at the cellular and molecular levels

Microbial ecology Interrelationships between microbes and the environ-ment; the role of microorganisms in the nutrient cycles of soil, water, and other natural communities

Veterinary microbiology

The pathogenic microorganisms causing infectious diseases in animals.

Agricultural microbiology

The role of microorganisms in agriculture. It deals with maintenance of soil fertility, the role of microorganisms in causing plant disease

Oceanic microbiology The microflora of the seas, rivers and others

MEDICAL MICROBIOLOGY

is the branch of science, which studies characteristics of pathogenic representative of microbe world, their interaction with human organism, mechanism of infectious disease development, methods its diagnostics, treatment and prophylaxis.

Branches of medical microbiologyScience Area of study Bacteriology The bacteria – the smallest, simplest single-celled procariotic

organisms

Virology Viruses – minute, noncellular particles that are obligate intracellular genetic parasite living only in cells of host

Rickettsiology Rickettsiae – the celled procariotic organisms which are obligate intracellular parasite

Mycology The fungi, a grope of organisms that includes microscopic forms molds and yeasts

Protozoology The protozoa – animal-like and mostly single-celled organisms

Sanitary microbiology

Microflora of ground, water, air, environment object, food stuffs and other objects for the hygienic characteristic and their estimation as probable sources of pathogenic microorganisms transfer.

Immunology Study immune response of human to microorganisms. An understanding of the causative agents of diseases and the body’s defenses against infectious agents has led to preventive and treatment methods that have reduced morbidity and mortality arising from many infectious diseases

Original methods of microbiological investigation

Microscopy Staining Cultivation Obtaining of pure cultureImmunology methodsModelling using animals Virology methodsBiotechnology and gene-ingenering methods

Morphology and structure of microorganisms

The size of microorganisms

Bacterial shapes and arrangements

Micrococci

Single cocci not joint with each other cell

Arrangements of cocci resulting from different planes of cell division

a. Division in one plane produce diplococci and streptococci

b. Division in two planes produces tetrads and packets

c. Division in several planes produces irregular clusters

Diplococci

These are cocci with couple arrangement

Tetracocci

are cocci, duplicating alternately in 2 mutually perpendicular planes with tetrad formation

Streptococci

Spherical bacteria that form chains, they duplicate in 1 plane and in 1 direction without the subsequent branching of affiliated individuals.

Staphylococci

Cocci , which duplicating in various planes with formation clusters resembling bunches of grapes.

Sarcines

cocci, duplicating in 3 mutually perpendicular planes and forming cubic packages from 8, 16, 32, 64 or more cells.

Rod-shaped bacteria

Spiral-shaped bacteria

Spirochetes

Pleomorphic shape

Mycoplasma pneumoniae

Structure of procariotic and eucariotic cells

Bacterial structure

Comparison of prokaryotic and eukaryotic cells

FEATURES OF CELLS PROKARYOTIC EUKARYOTIC

Cytoplasmic membrane Yes Yes

Nucleus containing a nuclear membrane surrounding DNA

No Yes

DNA associated with Polyamines Histone proteins

Chromosome number 1 More then 1

Ribosomes 70S 80S

Cell wall containing of peptidoglican Yes No

Membrane-bound organelles (mitochondria, lysosomes)

No Yes

Endoplasmic reticulum No Yes

Golgi apparatus No Yes

Mitotic division No Yes

Essential structures of bacteria

Cell wall with peptidoglycan

Gives rigid support, protect against osmotic pressure

Cytoplasmic membrane

Site of oxidative and transport enzymes

Cytoplasm Motionless colloid system bounding all structures

Ribosome Protein synthesis

Nucleoid Contain genetic material

Mesosome Participates in cell division and secretion

Periplasm Contain many hydrolytic enzymes

Ribosomes

Bacteria ribosomes are the site of protein synthesis, but they differ from eudaryotic cells ribosomes in size and chemical composition.

Bacteria ribosomes are 70S in size, with 50S and 30S subunits

Function of cytoplasmic membrane (plasma membrane)

Enclosing bacteria cytoplasm from cell wall and internal periplasmatic space

Active transport of molecules into the cell Energy generation by oxidative

phosphorylation Synthesis of precursors of the cell wall Secretion of enzymes and toxins

Function of the bacteria cell wall

Define a shape of a bacteria Protect bacteria from environment factors Contain endotoxin in gram-negative

bacteria Consist porin proteins, which play a role in

regulating the passage of small molecules into the cell.

Its polysaccharides and proteins are antigens that are useful in laboratory identification.

Define a Gram staining.

Gram-positive bacterial cell wall

Gram-negative bacterial cell wall

Gram-stained bacterial mix

Purple Staphylococci are gram positive

Red rods are gram negative

Scanning electron micrograph of Mycoplasma pneumoniae

Cells like these that naturally lack a cell wall exhibit

extreme pleomorphism

Nonessential structures of bacteria

Capsule Protects against phagocytosis

Pilus or fimbria Common pilus - attachment to cell surfaces sex pilus – attachment of two bacteria during conjugation

Flagellum Motility

Spore Provides resistance to unfavourable conditions

Granule Storage sites of food

Plasmid Contains a variety of genes for antibiotic resistance, toxins

Bacterial flagella

Flagella are organelles of movement

Flagella consist protein those are antigens, and this properties may be used for identification of bacteria species.

Arrangements of flagella on surface of bacterial cell

Colorized electron micrograph of Vibrios’s monotrichous (polar) flagellum

Colorized electron micrograph of Salmonella’s peretrichous flagella

Structure of bacterial flagellum

Colorized electron micrograph of E.coli pili

Sex-pili (F-pili) Take part in conjugation process.They join bacteria together prior

to the transfer of DNA from on cell (donor) to the other (recipient)

Common-pili It is a factor of virulence. Its proteins (adhesins) attach

bacteria to cells in the urinary of intestinal tracts of the host as the first step in infection.

Flagellum and pili of E.coli

Bacteria’s spores Spore conditions resistance of the bacterium to heat,

dehydration, freezing, and toxic chemicals This resistance is mediated by thick, keratinlike coat and

dipicolinic acid Vegetative cells develop endospores in unfavourable

conditions Only gram-positive bacteria can form endospore, they called

bacilli The sporogenesis is not bacterial reproduction Spores are located at characteristic positions inside the cell

of different kinds of bacteria, their location can be helpful in identifying the particular species

Clostridium botulinum

These are bacillus that forms subterminal endospores

Clostridium difficile

These bacilli form terminally located endospores

Bacillus anthracis

The endospores are located centrally.

Spore structure

Formation of a bacterial spore

Spores. Acid-fast stain

For visualization of spores may be used special methods of stain, for instance, acid-fast stain

Gram stained bacilli

The capsule or slime layer

mediates adherence of bacteria to human tissue

determines virulence of many bacteria protecting bacterial cells from engulfment by phagocytes

protect cells from perennial effects of desiccation

determines antigen properties of bacterium and can be used for serologic identification

Capsule

For observing of capsule special staining may be used.

Capsules are most easily seen by negative staining, outlined as a light area against a darkened background

Inclusion (granules)

Composition:

glycogen polyphosphate

(volutin granules) protein granules fat drops

Function:

reserve carbon, phosphate and energy source

Volutin granules in cells of Corynebacterium diphtheria

Granules can be seen with special stains

Volutin granules are characterized by metachromasia. Upon staining with special method color of granules is differ from sytoplasm

color