Principles of Bacteriology Flashcards
What is present in the wall of a gram + bacteria that is not present in a gram negative bacteria?
thick peptidoglycan layer
teichoic acid in wall
T/F: Spores are metabolically active.
false
How does bacterial infection cause fever?
endotoxin activates macrophages to release IL-1 and TNF, causing fever
Name 5 common zoonotic bacteria.
Borrelia burgdorferi, Brucella, Francisella tularensis, Yersinia pestis, Pasteirella multocida
Enterobaceriaceae: describe O, K, and H antigens
O - somatic, polysaccharide of endotoxin
K - capsular, related to virulence
H - flagellar, found in motile species
What kind of bacteria form spores and when?
certain gram + rods when nutrients are limited
Where is beta-lactamase in bacteria? What does it do?
periplasm of gram - bacteria
enzyme hydrolyzes beta-lactam antibiotics, conferring resistance
What molecule is specific to gram - bacterial cell membranes?
LPS
What are exotoxins and endotoxins, chemically speaking?
exotoxins tend to be polypeptides, while endotoxins are usually lipopolysaccharides
How could bacterial infection cause hypotension?
endotoxin induces macrophages to release nitric oxide -> vasodilation, hypotension
can also activate alternate complement pathway C3a, causing hypotension
Which organisms have exotoxin that acts by ADP ribosylation?
Corynebacterium diphtheriae, Escherichia coli, Vibrio cholerae, and Bordetalla pertussis
What helps organisms adhere to indwelling catheters?
glycocalyx (composed of polysaccharide)
Name the dominant normal flora on the teeth.
strep. mutans
Being in a newborn nursery is a risk factor for which two pathogens?
CMV and RSV
Name the dominant normal flora in the oropharynx.
strep. viridans
Name the dominant normal flora in the vagina.
Lactobacillus, E. coli, group B strep.
What disinfecting procedure kills spores?
autoclaving
Which pathogen is most associated with total parenteral nutrition?
Candida albicans
Where do bacteria keep their exotoxin or endotoxin genes?
exotoxin genes on plasmids or bacteriophages
endotoxin genes on bacterial chromosomes