PREVALENCE OF METALLO β LACTAMASES IN NON-FERMENTING GRAM NEGATIVE BACILLI FROM CLINICAL ISOLATES.

Abstract

Background and Objectives:Non fermenting gram negative bacilli (NFGNB)producing Metallo β lactamases (MBL) are an increasing cause of concern in the hospitals as they produce a therapeutic dilemma for the treating physician. The present study was undertaken to know the prevalence of MBL producing non fermenting gram negative bacilli from clinical isolates and their antibiotic resistance pattern. Methods: A total of 389 non fermenting gram negative bacilli were recovered from various clinical specimens. All the samples were processed for routine bacterial culture and antimicrobial susceptibility test as per standard protocol.  They were further subjected to Metallo β-lactamase detection by Imipenem+ EDTA combined disc test. Results: By Imipenem-EDTA combined disk test 49 (12.59%) isolates were found to be Metallo β-lactamase positive.AmongPseudomonas aeruginosa 29 (10.58%) were Metallo β-lactamase producing while among Acinetobacter species 20 (17.39%) Metallo β-lactamase producing. Majority of Metallo β-lactamase producers were resistant to Gentamicin (87.75%), Levofloxacin (83.67%) and Gatifloxacin (71.42%) respectively. All isolates were sensitive to Polymyxin B. Conclusion: The prevalence of Metallo β-lactamase was 12.59% among NFGNB. Significantly higher resistance rate was observed by these isolates to almost all the drugs routinely used

Key words: NFGNB., Metallo β-lactamase., Imipenem-EDTA combined disk test.,