major groups of disease-causing bacteria Flashcards
first way to differentiate gram + rods
spore forming vs non spore forming
how to differentiate spore forming gram + rods
aerobic vs anaerobic
two types of gram + non spore forming rods
corynebacterium spp
listeria monocytogenes
one type of anaerobic gram + spore forming rod
clostridium spp
Clostridium spp
gram + anaerobic rods, spore forming normal human intestinal microbiota soil, water, sewage strict anaerobes 4 medically relevant species: C botulinum C difficile C perfringens C tetani
Clostridium types associated with GI infection
C botulinum
C difficile
C perfringens
Clostrium types associated with traumatic and puncture wounds
C perfringens
C tetani
C botulinum
gram + rod, anaerobe, spore forming
flaccid paralysis due to ingestion of botulism toxin (food poisoning)
C difficile
gram + rod, anaerobe, spore forming
normal GI microbiota
causes antibiotic associated diarrhea and can progress to toxic mega colon
C perfringens
gram + rod, anaerobic, spore forming
found in GI tract of humans, in nature
causes food poisoning, traumatic injury associated cellulitis, myonecrosis with gas grangrene
C tetani
gram + rod, anaerobic, spore forming
found in GI tract of humans, in nature
causes tetanus: spores introduced into puncture wound –> toxin production –> spastic paralysis
Bacillus spp
gram + rod, aerobic, spore forming
2 medically relevant:
Bacillus cereus (food poisoning)
Bacillus anthracis (anthrax)
Bacillus cereus
gram + rod, aerobic, spore forming
single or in pairs
causes diarrhea or emetic food poisoning associated with re-heated rice
Bacillus anthracis
gram + rod, aerobic, spore forming chains, boxcar causes 3 kinds of anthrax: cutaneous anthrax (spore in cut) pulmonary anthrax (inhalation of spores via working with pelts or bioterrorism) GI anthrax (ingestion of spores)
how to distinguish between B cereus and B anthracis
motility gelatin hydrolysis hemolysis
one type of gram + aerobic spore forming species
bacillus spp
includes B cereus and B anthracis
Corynebacterium diptheriae
gram + rods, non spore forming
highly pleomorphic (club shaped, Chinese characters)
causes diphtheria, pharyngitis:
malaise and sore throat –> stupor, coma, death
Listeria monocytogenes
gram + rods, facultative anaerobe, non spore forming INTRACELLULAR PATHOGEN raw veggies and ready to eat meats at risk: pregnant women, age extremes can be transmitter in utero WIDE TEMP GROWTH RANGE resistant to salt conc, wide pH range