clostridium difficile (CD) epidemiology

• part of normal flora (4%)

• spore forming

• overgrowth, produces toxins, resistant antibiotics:

  • clindamycin

  • ampicillin/amoxicillin

  • cephalosporins

CD:  pathogenesis

• toxin A: enterotoxin--potent chemo attractant of neutrophils

• toxin B:  cytotoxin--effects on the colonic mucosa damages the cellular lining of bowel wall

CDAD (CD associated diarrhea)

metronidazole

Clostridium Perfingens VIRULENCE (non pyogenic)

• phospholipase C
• protease

clostridium perfringens treatment

• drainage & debridement

  • metronidazole

  • clindamycin

  • imipenem-cilastatin

  • piperacillin-tazobactam

  • cefoxitin, cefotetan

clostridium tetani

• anaerobic

• spore forming

• gram +

  • umbilical stump infection

  • injection drug use

Tetanus: pathogenesis

• transported by axons

• prevents release of inhibitory neurotransmitters, glycine or GABA; loss of motor inhibition--spasms

• spastic paralysis

tetanus: treatment

• supportive care: airway, benzodiazepines (gaba agonist), nutrition

• metronidazole

• tetanus doesn't render pt immune, so immunize (booster)

clostridium botulinum

• obligate anaerobic

• spore-forming

• g +

• resembles tetaospasmin

• binds to specific receptor @ cholinergic neuromuscular jxns

• blocks ACh release & muscle contraction

• flaccid paralysis

botulism treatment

• hospitalize immediately, monitor respiration, ventilate

• anti-toxin

• not aminoglycosides!!

  • PEN G

  • Metronidazole

bacteroides fragilis

• pleomorphic

• gram -

• anaerobic bacilli

• normal component of intestine, oral, vaginal flora

• most significant in polymicrobial abscesses

• only anaerobe to have capsule

bacteroides fragilis: sites of infection

• intra-abdomen: peritoneal abscess

• lung: aspiration pnemonia; empyema

• genital urinary

• skin/soft tissue: post-surgical, necrotizing fasciitis; decubitus & diabetic ulcers

bacteroides fragilis treatment

• metronidazole
• imipenem
• piperacillin/tazobactam
• 3rd ceph or FQ

MDR-TB

• resistant to 1st line anti-TB drugs

  • isoniazid & rifampin

• Use FQ

• 1 of 3 2nd line injectable TB drug

  • amikacin, capreomycin, kanamycin

XDR-TB

• resistant to 2 1st line anti-TB drugs

  • isoniazid

  • rifampin

  • FQ & other injectables...

• treatment failure serious morbidity & mortality