Bacteria Symposium Flashcards
Pathogen
Organism that causes or is capable of causing disease
Commensal
Organism which colonises the host but causes no disease in normal circumstances
Opportunist Pathogen
Microbe that only causes disease if host defences are compromised
Virulence / Pathogenicity
The degree to which a given organism is pathogenic
Asymptomatic carriage
When a pathogen is carried harmlessly at a tissue site where it causes no disease
What colour do gram positive bacteria stain?
Purple
What colour do gram negative bacteria stain?
Red
A typical bacteria cell wall has…
Cell wall
1 or 2 cell membranes
Covalently closed chromosome (circular, double stranded)
Capsule
Some bacteria have flagella, pili/fimbriae
How many membranes does a gram positive bacteria have?
1
A gram positive bacteria has a capsule, peptidoglycan, lipoteichoic acid and c_____ m______
cytoplasmic membrane
Gram negative bacteria
Have lipoproteins and lipopolysaccharide (endotoxin)
Gram +ve vs gram -ve bacteria
What are the 2 main toxins made by bacteria?
Endotoxin and exotoxin
Endotoxin - component of the outer m_____ of bacteria and give an example
membrane
lipopolysacchardie in gram negative bacteria
Extoxin - secreted proteins of g__ p_____ and g___ n_____ bacteria
gram positive, gram negative