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conditions.<br />
conditions.<br />
The structural features of pathogenic bacteria are important in the production of disease and also very useful for the identification and diagnosis of infection in veterinary medicine.<br />
The structural features of pathogenic bacteria are important in the production of disease and also very useful for the identification and diagnosis of infection in veterinary medicine.<br />
==Structure of Bacterial Cell==
==Capsule==
===Capsule===
The outermost part of a bacterial cell is the capsule, often described as the glycocalyx. Most capsules are composed of polysaccharides, although in some species the capsule is made of polypeptides. Capsules can be visualised
The outermost part of a bacterial cell is the capsule, often described as the glycocalyx. Most capsules are composed of polysaccharides, although in some species the capsule is made of polypeptides. Capsules can be visualised
The main function of bacterial capsules is to provide protection from adverse environmental conditions, prolonging the period of survival in such conditions. The capsule also facilitates adherence to surfaces and interferes with host cells involved in phagocytosis.<br />
The main function of bacterial capsules is to provide protection from adverse environmental conditions, prolonging the period of survival in such conditions. The capsule also facilitates adherence to surfaces and interferes with host cells involved in phagocytosis.<br />
==Cell Wall==
===Cell Wall===
[[Image:478px-Bacteria cell wall svg- franciscosp2.png|thumb|right|100px|'''Structure of cell wall''' Franciscop2 2008, WikiMedia Commons]]
[[Image:478px-Bacteria cell wall svg- franciscosp2.png|thumb|right|100px|'''Structure of cell wall''' Franciscop2 2008, WikiMedia Commons]]
an outer membrane, a periplasmic space and an inner membrane. For further information on the structure of both types of cell wall please see [[Bacterial_Structure|''Bacterial structure'']]<br />
an outer membrane, a periplasmic space and an inner membrane. For further information on the structure of both types of cell wall please see [[Bacterial_Structure|''Bacterial structure'']]<br />
Antibiotic treatments such as penicillin interefere with the ability of the bacterial cell to produce peptidoglycan and therefore cannot produce their cell wall making them more vulnerable to the environment.<br />
Antibiotic treatments such as penicillin interefere with the ability of the bacterial cell to produce peptidoglycan and therefore cannot produce their cell wall making them more vulnerable to the environment.<br />
==Cytoplasmic Membrane==
===Cytoplasmic Membrane===
Bacterial cytoplasmic membranes are flexible structures composed of phospholipids and proteins and are similar to the lipid bi-layer membranes found in eukaryotic cells. Only a limited number of small molecules such as water, carbon dioxide and lipid-soluable compounds can enter bacterial cells by passive diffusion. Nutrients and waste metabolites are transferred via active transport using ATP (adenosine triphosphate).<br />
Bacterial cytoplasmic membranes are flexible structures composed of phospholipids and proteins and are similar to the lipid bi-layer membranes found in eukaryotic cells. Only a limited number of small molecules such as water, carbon dioxide and lipid-soluable compounds can enter bacterial cells by passive diffusion. Nutrients and waste metabolites are transferred via active transport using ATP (adenosine triphosphate).<br />
The cytoplasmic membrane is also the site of electron transport for bacterial respiration and also contains enzymes and carrier
The cytoplasmic membrane is also the site of electron transport for bacterial respiration and also contains enzymes and carrier
molecules that function in the biosynthesis of DNA, cell wall polymers and membrane lipids.<br />
molecules that function in the biosynthesis of DNA, cell wall polymers and membrane lipids.<br />
==Cytoplasm==
===Cytoplasm===
The cytoplasm is enclosed by the cytoplasmic membrane and is an aqueous fluid containing nuclear material, ribosomes, nutrients and the enzymes involved in most cellular functions. Storage granules can often be seen in the cytoplasm under certain environmental conditions. Storage granules mainly contain starch and glycogen.<br />
The cytoplasm is enclosed by the cytoplasmic membrane and is an aqueous fluid containing nuclear material, ribosomes, nutrients and the enzymes involved in most cellular functions. Storage granules can often be seen in the cytoplasm under certain environmental conditions. Storage granules mainly contain starch and glycogen.<br />
==Nuclear Material==
===Nuclear Material===
The bacterial genome is composed if a single haploid circular chromosome containing double-stranded DNA (dsDNA). Bacterial genomes
The bacterial genome is composed if a single haploid circular chromosome containing double-stranded DNA (dsDNA). Bacterial genomes
can be transferred between bacteria during binary fission or through a process called conjugation. Plasmid DNA codes for characteristics including antibiotic resistance and endotoxin production.<br />
can be transferred between bacteria during binary fission or through a process called conjugation. Plasmid DNA codes for characteristics including antibiotic resistance and endotoxin production.<br />
==Flagella & Pili/Fimbrae==
===Flagella & Pili/Fimbrae===
Motile bacteria have flagella allowing them to move into suitable micro-environments in response to physical or chemical stimuli. It is mainly gram negative bacteria that possess flagella and they are rarely present in cocci species. Flagella are normally several times longer than the bacterial cell and are composed of the protein flagellin. Flagella are usually anchored
Motile bacteria have flagella allowing them to move into suitable micro-environments in response to physical or chemical stimuli. It is mainly gram negative bacteria that possess flagella and they are rarely present in cocci species. Flagella are normally several times longer than the bacterial cell and are composed of the protein flagellin. Flagella are usually anchored
Pili are straight, hair-like appendages composed of pilin and also anchored to the cell wall. Pili are most common on gram negative
Pili are straight, hair-like appendages composed of pilin and also anchored to the cell wall. Pili are most common on gram negative
bacteria. In pathogenic bacteria pili function as adhesions for receptors on mammalian cells. <br />
bacteria. In pathogenic bacteria pili function as adhesions for receptors on mammalian cells. <br />
==Endospores==
===Endospores===
Endospores are dormant bodies that are highly resistant to the environment. The only genera of pathogenic bacteria that are able to
Endospores are dormant bodies that are highly resistant to the environment. The only genera of pathogenic bacteria that are able to