ROLE OF THE REFERENCE LABORATORY IN SUSCEPTIBILITY TESTING OF ANAEROBES AND A SURVEY OF ISOLATES REFERRED FROM LABORATORIES IN ENGLAND AND WALES DURING 1993-1994

Methods for susceptibility testing of anaerobes and their patterns of susceptibility remain debatable. The responsibilities of the Public He alth Laboratory Service Anaerobe Reference Unit include identification of referred isolates; development of methods; monitoring of the occur rence of anaerobic infections; performance of taxonomic studies; maint enance of a reference collection; and monitoring of the antibiotic sus ceptibility of clinical isolates. Selection of antibiotics for anaerob ic infections is often based upon the findings of batch tests on refer red isolates in specialized centers. If the information gathered is to be a reliable guide, there should be a structured rolling survey of c linical isolates from a wide range of hospital laboratories. Strains o f Bacteroides, Prevotella, Clostridium, and Propionibacterium species and peptostreptococci referred to the Anaerobe Reference Unit during 1 993-1994 were tested with the Etest to determine the minimum inhibitor y concentrations of metronidazole, penicillin, amoxicillin/clavulanate , cefoxitin, imipenem, erythromycin, clindamycin, and tetracycline. Me tronidazole susceptibility (generally) and penicillin resistance among Bacteroides species were consistent findings, and most isolates were susceptible to imipenem, but other results varied between and within s pecies.