Intro to microbiology Flashcards
Pathogen classification and genome size
- virus
- prokaryote
- eukaryote
virus
- DNA/RNA/ss/ds/enveloped/ non enveloped
prokaryotes
bacteria, actinomyocyte, myobacteria
eukaryotes
protozoa, helminths, fungi
smallest to biggest pathogen
the biggest is a parasite, middle is a bacteria and the virus is the smallest
short incubation period
- cholera (2hrs-5d)
- influenza (1-3d)
intermediate incubation period
- chicken pox (11-20d)
- malaria (10-15d)
long incubation period
- hepatitis b (6wks - 6 mths)
- TB (1-12mths)
direct transmission - 5
- direct contact
- direct spread of droplets
- transplacental/perinatal
- direct exposure to agent in the environment
- bite
indirect transmission
- mechanical vector and vehicle
- biological vector and intermediate host
- airbone
Human transmitted infections
STI - chylamydia and HIV
Airbone - chicken pox and TB
Vertical - CLS
Droplet- strpt pneu, N meningitis
Formites/ direct hand contact - MDR organims in hopitals
what is faeco-oral transmision and what are the 5 F’s
- faeces contaminate food, eater or hands and then get ingested.
- floods, fluids, fingers, flies, fields
what is vertical transmission
infection passed from mother to baby
exogenous encounters
- insects - mosquitoes/tick
- animals - rabies, toxoplasmosis and brucellosis
what is meant by exogenous encounters
different routes in which external pathogens can cause infections/diseases
endogenous encounters - 5
- ecoli = diarrhea
- candida in hiv = thrush and oesophagitis
- cmv with immune suppression = colitis and pneumonia
- antibiotics can cause pc and mc
difference between gram positive and negative - 4
- lipotechicoic acid in gram + and LPS in gram - cell wall
- positive has thicker peptidoglycan
- positive lacks an outermembrane outside of the peptidoglycan layer
- negative has a larger periplasmic space, allowing it break down antibiotics (resistance)
6 bacterial structure
- capsule - phospholipid layer that resists phagocytosis
- cell wall - peptido sugar backbone with peptide side chains cross linked by transp - rigidity and resists osmotic pressure
- cell membrane - gram negative, lps, proins, transport
- flagellum - motility
- pili - adherence to cell surface - sex pilus formed by conjugation
- spore= keratin like coat that resists dehydration, heat and chemicals
cell walls of bacteria
ALL bacteria have cell walls excluding mycoplasma spp, which are OFTEN extracellular but we do have some intracellularly
obligate intracellular bacteria
chlymadia
facultative intracellular bacteria
N gonorrhoeae, M tuberculosis
facultative anaerobe = CHBM
- campylobacter
- helicobacter
- bacteriodes
- microaerophillic
avoids phagocytosis
- s. pneumonae
- h. influenza
cylindirc
spherical
spiral
- bacilli
- coccus
- spirochete
positive stain
retains the crytsal violet dye and stains blue
gram negative cocci
Nesseria family and moraxella catarhallis
fluoroscence stain
auramine for TB and FTA for syphilis
gram negative bacili
SSSKEEPP YV
gram positive bacili
BLLAAINCC
gram positive cocci- cluster
Staph spec
gram positive cocci- chains
Strep and enterococi
