Session 1- Introduction to microbes, what is an infection? Flashcards
what is an infection
invasion of a host’s tissues by microorganisms and disease caused by
- microbial multiplication
- toxins
- host response
microbiata
micro-organisms carried on skin and mucosal surfaces
normally harmless or beneficial
transfer to other sites can be harmful
how do people get infections
contact
- physical contact required sometimes
- airborne
- vector
inhalation
- droplets
- aerosols
Ingestion
-faecal-oral transmission
Vertical transmission
-mother to child before or after birth
dissemination
int bloodstream
virulence factors
exotoxins
- cytolytic
- AB toxins
- superantigens
endotoxins
host cellular damage
direct
consequent to hot immune response
how do we know if a patient has an infection
history
examination
investigations
taking a history
symptoms
- focal, systemic
- severity
- duration
supportive investigative techniques
full blood count CRP blood chemistry imaging histopathology
bacteriology
specimen types
-swabs, fluids tissues
microscopy culture antibiotic susceptibility antigen detection nucleic acid detection
virology
antigen detection
antobody detection
detecting viral nucleic acid DNA or RNA
aerobes
can survive in the presence of oxygen
-obligate aerobes- require oxygen for survival
anaerobes
can survive in the absence of oxygen-free environment for survival
virulence factors for mechanics of bacterial pathogenesis
host entry adherence to host cells invasiveness iron sequestration fimbrae
gram positive
thick multi-layered peptidoglycan cell walls that are exterior to the cytoplasmic membrane
stain purple
