PREVALENCE OF METALLO BETA LACTAMASE (MBL) PRODUCING PSEUDOMONAS SPECIES AMONG CLINICAL SAMPLES FROM S.V.R.R.G.G.HOSPITAL, A TERTIARY REFERRAL HOSPITAL OF S.V. MEDICAL COLLEGE, TIRUPATI.

Dr. Ediga .V. Lavanya, Dr. Gandikota Rajaram*, Dr. Tippireddy Palli Gururaju,
Dr.  Boddu Maha Lakshmi4, Dr. Sharabu Yamini, Dr. CH. Srinivasarao.

ABSTRACT

Hospital-acquired infections are a major challenge to patient safety. Carbapenems are one of the best for the treatment of critically ill patients. Patients treated with routine antibiotics for Metallo-beta-lactamases (MBL) producing Pseudomonas aeruginosa strains resulted several nosocomial outbreaks in tertiary referral hospitals and poor patient outcome. Early detection of metallo-beta lactamase (MBL) producing Pseudomonas aeruginosa among critically ill hospitalized patients is crucial for optimal treatment and to prevent the spread of resistance. The present study was done over a period of one year from January 2011 to December 2011, in the Department of Microbiology, S.V. Medical College, Tirupati. 200 non repetitive Pseudomonas species were isolated from clinical specimens based on standard tests. Antimicrobial sensitivity was performed by Kirby-Bauer disk diffusion method and evaluated for multidrug resistance and screened for MBL production by combined disk diffusion test (CDDT) using imipenem (IMP), and imipenem (IMP) with EDTA. Among 200 Pseudomonas isolates 22 (11 %) were identified to be MBL producers and 75 (37.5 %) were multi drug resistant (MDR). All the MBL positive strains were belonging to this MDR group constituting 29.33%. All MBL strains were resistant to ceftazidime and imipenem and 95.45% of strains of MBL were resistant to carbenicillin. Early detection of MBL-production among Pseudomonas isolates may help to initiate appropriate antimicrobial therapy and to prevent the development and dissemination of these multi drug resistant strains.

Keywords: Pseudomonas aeruginosa, Metallo-beta-lactamase (MBL) Imipenem-EDTA combined disc diffusion test (CDDT).