Cholecystitis--etiology and treatment--microbiological aspects.

Acute cholecystitis is initially a chemical inflammation, but regularly complicated by bacterial invasion from the gut. Escherichia coli, Klebsiella and Streptococcus faecalis dominate among aerobic bacteria, whereas Bacteroides fragilis and clostridia are commonly encountered anaerobes. Mixed infections are prevalent. Bactibilia occurs in at least 60% of the early stage of acute cholecystitis and is particularly prevalent in the elderly. Also, bactibilia is very common in recurrent cholecystitis. A close connection is found between the presence of bactibilia and infectious complications. Although antimicrobial treatment does not sterilize the bile of an obstructed gall bladder, most authors favour such treatment in cases of febrile cholecystitis, particularly in the elderly, in order to prevent septic complications. Various regimens of preoperative antimicrobial prophylaxis have significantly reduced the infectious complications, in spite of persistent bactibilia. Prophylactic courses should not exceed one or two days, one single preoperative dose is probably adequate. The choice of antimicrobial drugs for prophylaxis varies with local experience and patterns of bacterial resistance. A combination of broad spectred betalactam antibiotics and nitroimidazole would generally seem to provide an appropriate and atoxic coverage.