Fecal carriage of Metallo Beta Lactamase Producing Organisms Isolated from Indoor Patients

Incidence of MBL producing isolates has been increasing distinctly over last few years. Discovery of NDM-1 in Enterobacteriaceae has further complexed the picture. Treatment of these patients pose a serious challenge, as these pathogens are resistant to all commonly used antibiotics. Plasmidic location of the gene has facilitated their spread to the normal human flora. The emergence of these strains is therefore a major concern and the one that microbiologists cannot afford to ignore. So an observational prospective study was conducted in a tertiary care teaching hospital to detect the presence of MBL producing bacteria among the stool of indoor patients. A total of 62 isolates from 130 stool samples were studied for MBL production using imipenem and MPA discs. Any increase in zone of inhibition was considered positive. Antimicrobial sensitivity profile was determined against commonly used antimicrobials. MBL production was found in 20(32.25%) isolates. Out of 62 isolates, 12 (29.26) E coli and 8 (38.09%) Klebsiella spp were found to be positive for MBL production. Maximum sensitivity (100%) was seen with polymixin B and colistin. These isolates were highly resistant (>60%) to the rest of the antimicrobials tested. Our data reports that MBL enzyme exists among stool isolates in our institute. These MBL producing strains in the stool may contribute to both nosocomial and community transmission of these highly resistant strains. Good infection control practices and antibiotic management interventions are instrumental in containing these strains.