Pathogenic Bacteriology Flashcards
What are some factors that increase susceptibility to infections?
- age (i.e. elderly/children)
- defects in immune response
- pre-existing medicial conditions (i.e. diabetes)
- immunosupression
- malnutrition
- transplantation (immunosupression)
- preosthetics
What’s an example of different organisms causing similar / the same syndromes?
- Streptococcus pneumoniae*,
- Haemophilus influenzae type B*,
- Neisseria meningitidis*
- causing bacterial meningitis
Process for pathogenic bacterial infection
RE A ER DE
- Reservoir
- Entry into host
- Adherence, colonisation & invasion of host cell tissues
- Evade host defense mechanisms
- Replication & completion of pathogen life cycle
- Damage to the host
- Exit host (return to reservoir or enter new host)
Why are virulence factors important to pathogens?
CIDE
- Colonisation & Invasion of host tissue
- Damage host tissue
- Evasion of host immune response
What can toxins do?
RID
- trigger (immune) response
- aid in invasiveness
- damage cells
What are some Gram-positive cocci?
- Streptococcus spp.
: Streptococcus pneumoniae
: Streptococcus mutans
: Streptococcus
- Staphylococcus spp.
: Staphylococcus
- Lactococci*
- Viridans*
- Enterococci*
What are some Gram-positive rods?
- Bacteroides
- Bacillus
- Corneybacteria
- Clostridium
- Lactobacilli
- Listeria
What are some Gram-negative cocci?
- Neisseria gonorrhoea
- Neisseria meningitidis
What are Gram-negative rods?
- Enterobacteriaceae
: Klebsiella
: Shigella
: Salmonella
: Escherichia coli
- Vibrio cholerae
- Campylobacter
- Helicobacter
- Pseudomonas
- Bacteroides
- Haemophilus
- Yersinia
Transient (temporary) colonisation areas of Streptococcus pyogenes?
- Upper Respiratory Tract
- Skin
Transudate vs Exudate
Transudate: occurs due to increased hydrostatic pressure or low plasma oncotic pressure (low protein content)
Exudate: occurs due to inflammation and increased capillary permeability (high protein content)
Exotoxins & Endotoxins are mostly produced by which bacteria?
Exotoxins: Gram-positive
Endotoxins: Gram-negative
Which part of the LPS structure is responsible for its endotoxin activity?
- Lipid A
Additional common virulence factors for evading host immunity:
- Capsule
- IgA protease
- Actin-based motility
Additional common virulence factors for evading host immunity: Capsule
and examples
- prevent macrophages from effectively contacting the bacterium
e. g. Streptococcus pneumoniae, Neisseria meningitidis, & Haemophilus influenzae
