Evaluation of the Minitek system for direct identification of anaerobic rods from positive blood cultures.

The direct inoculation of the Minitek anaerobe identification system (BBL Microbiology Systems, Cockeysville, Md.) from positive blood cultures was compared with subculture and Minitek results obtained using the manufacturer's recommended procedures. A total of 40 clinical anaerobic blood cultures were processed for rapid identification utilizing bacterial pellets obtained by centrifugation. Of these cultures, 30 yielded pure isolates of anaerobic rods that were used for comparison. In 87% of the pure cultures, identification from the direct inoculum method was identical to the routine procedure using Minitek biochemicals. When the additional test for lecithinase and lipase production was included, the identification agreement was 97%. Direct identification of anaerobic rods from blood cultures utilizing the Minitek system is reliable, easy to perform, and can provide a complete identification in 24 h from the time a blood culture showed growth.