MICROBIOLOGY OF PYOGENIC LIVER-ABSCESS

Sixteen patients with pyogenic liver abscesses were studied over 10 yr to discover the causative organisms of the condition. Pus was subjected to Gram-negative smear or gas-liquid chromatography to detect volatile fatty acid characteristics of anaerobes and then cultured. All isolates were identified by conventional methods and tested for sensitivity to appropriate antimicrobial agents. Bacteria were grown from the liver abscesses in all 16 patients. Streptococcus milleri (Lancefield group F) was the most common organism isolated from the pyogenic liver abscesses; it was found in 13 patients. If S. milleri is isolated, care should be taken not to mistake it for an anaerobe; finding the organism in the blood should alert the clinician to the possible presence of a liver abscess.