blaIMP and blaVIM mediated carbapenem resistance in Pseudomonas and Acinetobacter species in India

  • M Shanthi Amudhan Sri Ramachandra Medical College and Research Institute, Porur, Chennai, India
  • Uma Sekar Sri Ramachandra Medical College and Research Institute, Porur, Chennai, India
  • Arunagiri Kamalanathan Central Leprosy Teaching and Research Institute, Chengalpattu, Tamil Nadu, India
  • Sekar Balaraman Central Leprosy Teaching and Research Institute, Chengalpattu, Tamil Nadu, India
Keywords: carbapenems, metallo-beta-lactamases, polymerase chain reaction

Abstract

Introduction: The emergence and rapid spread of blaIMP and blaVIM metallo-beta-lactamase (MBL) producing Gram-negative bacteria causing nosocomial infections are of concern worldwide due to limited treatment options.

Methodology: A total of 179 nonreplicate, consecutive, carbapenem resistant Pseudomonas aeruginosa (61), Acinetobacter baumannii (116), Acinetobacter lwoffii (1) and Pseudomonas stutzeri (1) isolated from patients hospitalized for 48 hours or more were included in the study. The minimum inhibitory concentrations (MIC) to imipenem and meropenem were determined and interpreted according to Clinical Laboratory Standards Institute guidelines. The Modified Hodge Test (MHT) and inhibitor potentiated disk diffusion tests with ethylenediaminetetraacetic acid (EDTA) were used for screening of carbapenamases and MBL production respectively. Polymerase chain reaction (PCR) was performed for the detection of MBL (blaVIM and blaIMP) genes. Gene sequencing was performed for representative isolates.

Results: MHT was positive in 94.4% (n = 169). MBL screening with EDTA was positive in 80.4% (n = 144). MBL genes bla VIM and bla IMP were detected in 92 (51.4%) isolates. Bla VIM alone was detected in 89 isolates while two isolates had bla IMP alone. One isolate had both bla VIM and bla IMP. Among the P. aeruginosa, 36 carried the MBL gene. In A. baumannii, 54 carried the MBL gene. Bla VIM was found in P. stutzeri and A. lwoffii isolates.

Conclusion: Carbapenem resistance in P. aeruginosa and A. baumannii is chiefly mediated by MBL production. The common MBL gene is the blaVIM.

Author Biographies

M Shanthi Amudhan, Sri Ramachandra Medical College and Research Institute, Porur, Chennai, India
Assistant Professor in Microbiology
Uma Sekar, Sri Ramachandra Medical College and Research Institute, Porur, Chennai, India

Professor and Head

Department of Microbiology

Arunagiri Kamalanathan, Central Leprosy Teaching and Research Institute, Chengalpattu, Tamil Nadu, India

Technical Assistant, Department of Molecular Biology

Sekar Balaraman, Central Leprosy Teaching and Research Institute, Chengalpattu, Tamil Nadu, India

Director, Pasteur Institute of India

Coonoor, Nilgiris, Tamil Nadu

Formerly – Consultant Microbiologist

Central Leprosy Teaching and Research Institute

,Chengalpattu,Tamil nadu,India

 

Published
2012-11-26
How to Cite
1.
Amudhan MS, Sekar U, Kamalanathan A, Balaraman S (2012) blaIMP and blaVIM mediated carbapenem resistance in Pseudomonas and Acinetobacter species in India. J Infect Dev Ctries 6:757-762. doi: 10.3855/jidc.2268
Section
Original Articles