MALDI - TOF MS for the identification of obligate anaerobes and metronidazole susceptibility of anaerobic Gram negative bacilli

Abstract

MALDI-TOF MS, though has facilitated rapid and accurate anaerobe identification, the problem of rising metronidazole resistance amongst the members of Bacteroides fragilis group is cause for concern. In this one-year study period,152 anaerobic Gram negative bacilli and 60 Gram positive anaerobes were isolated from 167 samples obtained from clinically suspected anaerobic infections. Bacteroides fragilis accounted for 56 % of the total anaerobic GNB and Peptoniphilus asacchrarolyticus was the most commonly isolated Gram positive cocci. All isolates were identified by the MALDI–TOF MS except one isolate each of Clostridium and Peptostreptococcus. E-test for members of Bacteroides fragilis group, demonstrated 26.8 % metronidazole resistance.