Microbiology Flashcards
virus
- not living
- no cellular structures
- protein capsule around DNA or RNA
- can mutate
- antibiotics are ineffective
- size = billionths of a metre
bacteria
- prokaryote
- mostly uni-cellular
- different shapes
- have a cell wall
protozoa
- eukaryote
- unicellular
- usually motile
- size from 1 to 150 microns
fungi
- eukaryote
- uni or multi-cellular
- has a cell wall
- produce spores
- size about 2-10 microns
helminths
- eukaryote
- multi-cellular
- large
- don’t proliferate in host
bacteria oxygen - obligate aerobes
can only grow in the presence of oxygen
bacteria oxygen - obligate anaerobes
can not grow in the presence of oxygen
bacteria gram stain
structural difference in cell wall
- gram +ve, thick layer of peptidoglycan
- gram -ve, reinforced with 2nd membrane
microbiota - skin
reduces pH
- change environment conditions
- not ideal for other species
microbiota - oral and vagina
completes and inhibits pathogens and yeasts
microbiota - intestine
- excrete antibacterial chemicals
- synthesise and secrete vitamins
- stimulate local immunity
microbiota - possible harmful effects
- competition for nutrients
- bacterial synergism
- endogenous disease
- opportunistic infection
mode of transmission - contact
contact between people, either direct or indirect
mode of transmission - vehicle
transmission of pathogens via vehicles such as air, water, food
mode of transmission - vector
transfer of pathogens via an animal
