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CC BY-NC-ND 4.0 · J Lab Physicians 2017; 9(02): 081-083
DOI: 10.4103/0974-2727.199624
Original Article

Comparison of four phenotypic methods for detection of metallo-β-lactamase-producing Gram-negative bacteria in rural teaching hospital

Chinjal A. Panchal
Department of Microbiology, GMERS Medical College, Gotri, Gujarat, India
,
Sweta Sunil Oza
Department of Microbiology, CU Shah Medical College and Hospital, Surendranagar, Gujarat, India
,
Sanjay J. Mehta
Department of Microbiology, CU Shah Medical College and Hospital, Surendranagar, Gujarat, India
› Author Affiliations Financial support and sponsorship Nil.
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Abstract

CONTEXT: Metallo-β-lactamase (MBL)-producing bacteria lead to resistance to carbapenem an antibiotic that used as the last resort for treatment of multidrug-resistant bacteria, extended spectrum beta-lactamases, and AmpC β-lactamase-producing Gram-negative bacteria (GNB). The emergence of MBL-producing GNB is challenge to microbiology laboratories because there are no standardized guidelines available to detect them. The aim of this study was to compare four phenotypic methods to detect MBL production in GNB and to determine antibiotic sensitivity of MBL-producing isolates.

MATERIALS AND METHODS: A total of 107 clinical isolates of GNB were tested for MBL production. Imipenem (IPM)-resistant GNB were taken as positive for MBL screening. MBL detection was done using ethylene diamine tetra acetic acid (EDTA) as MBL inhibitor. Four phenotypic methods were evaluated: (1) Combined disk synergy test (CDST) with 0.5M EDTA (CDST-0.5 M EDTA), (2) CDST with 0.1 M EDTA (CDST-0.1 M EDTA), (3) double-disk synergy test (DDST) with 0.5M EDTA (DDST-0.5 M EDTA), and (4) DDST with 0.1 M EDTA (DDST-0.1 M EDTA).

RESULTS: Out of 107 GNB, 30 were resistant to IPM considered as screening positive. Out of 30, 21 (70%) isolates were MBL positive by CDST-0.1 M EDTA, 19 (63.33%) by CDST-0.5M EDTA, 17 (56.67%) by DDST-0.1 M EDTA, and 16 (53.33%) by DDST-0.5M EDTA. All MBL-producing Gram-negative Bacilli were resistant to ampicillin/sulbactam. Polymyxin B was found to be the most sensitive drug.

CONCLUSION: CDST-0.1 M EDTA is the most sensitive method MBL detection. The detection of MBL-producing GNB is very important to control spread of the resistance.

Keywords

Carbapenem - combined disk test - double-disk test - ethylene diamine tetra acetic acid - Gram-negative bacteria - imipenem - metallo-β-lactamase


Publication History

Received: 10 February 2016

Accepted: 05 July 2016

Article published online:
19 February 2020

© 2017.

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  • References

  • 1 Hemalatha V, Sekar U, Kamat V. Detection of metallo betalactamase producing Pseudomonas aeruginosa in hospitalized patients. Indian J Med Res 2005;122:148-52.
  • 2 Ranjan S, Banashankari GS, Sreenivasa Babu PR. Evaluation of phenotypic tests and screening markers for detection of metallo-β-lactamases in clinical isolates of Pseudomonas aeruginosa: A prospective study. Med J DY Patil Univ 2015;8:599-605.
  • 3 Pandya N, Prajapati S, Mehta S, Kikani K, Joshi P. Evaluation of various methods for detection of metallo-β-lactamase (MBL) production in Gram-negative Bacilli. Int J Biol Med Res 2011;2:775-7.
  • 4 Lucena A, Dalla Costa LM, Nogueira Kda S, Matos AP, Gales AC, Raboni SM. Comparison of phenotypic tests for the detection of metallo-beta-lactamases in clinical isolates of Pseudomonas aeruginosa. Enferm Infecc Microbiol Clin 2014;32:625-30.
  • 5 Noyal MJ, Menezes GA, Harish BN, Sujatha S, Parija SC. Simple screening tests for detection of carbapenemases in clinical isolates of nonfermentative Gram-negative bacteria. Indian J Med Res 2009;129:707-12.
  • 6 Clinical and Laboratory Standards Institute. Performance Standard for Antimicrobial Susceptibility Testing; 22nd Informational Supplement M100-S22. Vol. 32 No 3. Wayne, PA, USA: Clinical and Laboratory Standards Institute; 2012.
  • 7 Yong D, Lee K, Yum JH, Shin HB, Rossolini GM, Chong Y. Imipenem-EDTA disk method for differentiation of metallo-β-lactamase-producing clinical isolates of Pseudomonas spp. and Acinetobacter spp. J Clin Microbiol 2002;40:3798-801.
  • 8 Franklin C, Liolios L, Peleg AY. Phenotypic detection of carbapenem-susceptible metallo-β-lactamase-producing gram-negative Bacilli in the clinical laboratory. J Clin Microbiol 2006;44:3139-44.
  • 9 Walsh TR, Toleman MA, Poirel L, Nordmann P. Metallo-β-lactamases: The quiet before the storm? Clin Microbiol Rev 2005;18:306-25.
  • 10 Hirakata Y, Yamaguchi T, Nakano M, Izumikawa K, Mine M, Aoki S, et al. Clinical and bacteriological characteristics of IMP-type metallo-beta-lactamase-producing Pseudomonas aeruginosa. Clin Infect Dis 2003;37:26-32.
  • 11 Laupland KB, Parkins MD, Church DL, Gregson DB, Louie TJ, Conly JM, et al. Population-based epidemiological study of infections caused by carbapenem-resistant Pseudomonas aeruginosa in the Calgary Health Region: Importance of metallo-beta-lactamase (MBL)-producing strains. J Infect Dis 2005;192:1606-12.
  • 12 Peleg AY, Franklin C, Bell JM, Spelman DW. Dissemination of the metallo-beta-lactamase gene blaIMP-4 among gram-negative pathogens in a clinical setting in Australia. Clin Infect Dis 2005;41:1549-56.
  • 13 Behera B, Mathur P, Das A, Kapil A, Sharma V. An evaluation of four different phenotypic techniques for detection of metallo-β-lactamase producing Pseudomonas aeruginosa. Indian J Med Microbiol 2008;26:233-7.