Anaerobic infections of soft tissue Flashcards
how are anaerobic infections initiated?
following deep tissue trauma- accidents, cancer, surgery, immunosuppression and IV drug abouse
which anaerobic infections have vaccines available?
tetanus
what are the morphologies of clostridia, bacteriodes, prevotella and actinomyces?
all are rods
clostridia and actinomyces are gram positive and bacteriodes and prevoella are gram negative
which anaerobic pathogens are environmental?
C. tetani and C. botulinum
which anaerobic pathogens are also normal flora?
c. difficile, bacteriodes, prevotella and actinomyces
which anaerobic pathogen can be either normal flora or environmental?
C. perfringens
what is the mechanism of pathogenesis of C tetani and C botulinum? how do they differ?
both produce neurotoxins with synaptobrevin II protease activity. They are different because of the nerves they effect
what part of the nervous system is affected by tetanus? what is the toxin involved? what is the result?
tetanospasmin affects the inhibitory portion of the central nervous system. results in spasms
what part of the nervous system does botulism affect? what is the result?
botulinum toxin is active in the stimulatory portion of the peripheral nervous system. It causes flaccid paralysis
what is the treatment for botulism and tetanus?
antitoxin to bind and inactivate the neurotoxin
how is botulism introduced into the body, primarily?
by eating improperly canned foods
what pathogen causes gas gangrene? what is the method of pathogenesis?
c perfringens
produces tissue degrading enzymes
why must gas gangrene be resolved quickly?
because lethal exotoxemia may ensue
how are C perfringens, bacteroides and prevotella identified?
by anaerobic culture and gas cromatography of their metabolic products
which are the tissue degrading anaerobes and how are they treated?
c perfringens, bacteroides and prevotella
treat with antibiotics and surgical removal
what disease does c perfringens produce, other than gangrene?
causes food poisoning by producing enterotoxin
what disease is caused by c difficile? when is it usually transmitted?
pseudomembranous colitis
occurs after antibiotic use and it is often nosocomial
how should C difficile be treated?
change the antibiotic and intervene surgically if necessary.
what symptoms are caused by actinomyces?
produdces nodules containing pus with sulfur granules near the mouth or in the colon
how should actinomyces be treated?
with penicillin. surgical care is usually necessary as well.
