Survey of anaerobic susceptibility patterns: a French multicentre study.

In 1996, the in vitro antibiotic susceptibility of 463 anaerobes was measured in five hospitals using the reference agar dilution method. None of the 209 B. fragilis group strains showed resistance to imipenem or ticarcillin-clavulanic acid. High resistance rates (29%) were observed for cefotetan and clindamycin. beta-Lactamase production was detected respectively in 64% of the Prevotella and 7% of the Fusobacterium strains. Because the same standardized methods were used for many years, the authors were able to evaluate the evolution of antibiotic resistance. Clindamycin resistance had increased within the B. fragilis group (from 14% in 1992 to 29% in 1996) and also among strains of clostridia (32%), P. acnes (18%) and Peptostreptococcus (28%). In the B. fragilis group multidrug resistance was unlikely to occur.