Bacteria Flashcards
Virulence
Degree of pathogenicity indicated by fatality rates or ability of organism to invade the tissues of host
Pathogenicity
ability of pathogen to produce infectious disease
infective dose
amt of pathogenic orgs it takes to cause infection
lethal dose
amt of org it takes to cause death
antigenic switching
altering of organisms surface antigens through genetic rearrangement to elude detection
Transmissibility
how bacteria is transferred ex: droplets phys contact, airborne, fecal-oral
adherence to host cells
requires receptor and ligand- ex pilli and fimbriae
Invasion of host
invasins- damage to host cells, assist in growth or transmission
exotoxins
extracellular, protien, denatured by boiling, antigenic, highly potent, gram positive or negative
endotoxin
component of cell- released at death of cell, lipopolysaccaride, not denatured by boiling, low potency, Gram negative only
Evade immune sx
cover with host fibrin and Igs to avoid detection
Bacterial subtyping
Treatment based on type, detect and track food bourne illnesses, abc targeted to subtype
Importance of Normal Flora
harmless and often beneficial- outcompete pathogens, synthesize vitamins, secrete microbial antagonists
Skin- Flora
Staph & Proionbacterium acnes most common
Very diverse- removed by washing
Mouth/ Upper Resp Flora
Staph, Corynebacterium. Sinuses & lower resp tract normally sterile
