export_ssti bacteria iii Flashcards
Clostridium features
Gram-positive
Spore forming
Anaerobic
Four major species of Clostridium
C. perfringens (gangrene, diarrhea)
C. difficile (diarrhea, colitis)
C. tetani (tetanus)
C. botulinum (botulism)
C. perfringens features
Produces hydrogen and CO2 gas
C. perfringens alpha-toxin
Phospholipase that hydrolyzes lecithin and sphingomyelin
Suppurative myositis
Inflammation of muscle
Myonecrosis
Destruction of muscle
Gas gangrene most notably with P. perfringens
Gas gangrene disease progression
Begins as cellulitis, progresses to suppurative myositis, then myonecrosis, then dissemination
Diagnose and treat C. perfringens
Gram-positive rods WITHOUT leukocytes
Treatment must be immediate, as fatality is high
Surgical debridement, clindamycin
C. tetani features
Strict anaerobe
“Drumstick” appearance
C. tetani entry
Small, local infection provides source for tetinospasmin to travel to CNS
Tetanospasmin
Heat liable neurotoxin
Inactivates inhibitory neurotransmitters, causing spastic paralysis
Rapidly degraded in GI, unlike botulinum
Three major presentation of C. tetani infection
Generalized
Localized
Neonatal
Generalized tetanus
Lock jaw
Back spasms
Autonomic involvement is most severe
Localized tetanus
Confined to muscles at site of inoculation
Neonatal tetanus
Infected umbilical stump
Risus sardonicus
Sustained contraction of fascial muscles
Caused by tetanospasmin
Opisthotonic posturing
Spinal muscles affected by tetanospasmin
Treat C. tetani
Debridement of primary wound
Human tetanus Ig