Detection of Different β-Lactamases and their Co-existence by Using Various Discs Combination Methods in Clinical Isolates of Enterobacteriaceae and Pseudomonas spp.

Vinita Rawat; Monil Singhai; Pankaj Kumar Verma

doi:10.4103/0974-2727.115918

Journal of Laboratory Physicians, Table of Contents

CC BY-NC-ND 4.0 · J Lab Physicians 2013; 5(01): 21-25
DOI: 10.4103/0974-2727.115918

Original Article

Detection of Different β-Lactamases and their Co-existence by Using Various Discs Combination Methods in Clinical Isolates of Enterobacteriaceae and Pseudomonas spp.

Vinita Rawat

Departments of Microbiology, Government Medical College, Haldwani, Nainital, Uttarakhand, India

,

Monil Singhai

Departments of Microbiology, Government Medical College, Haldwani, Nainital, Uttarakhand, India

,

Pankaj Kumar Verma

Departments of Microbiology, and Surgery, Government Medical College, Haldwani, Nainital, Uttarakhand, India

› Author Affiliations

Abstract

PDF Download

ABSTRACT

Background: Resistance to broad spectrum beta-lactams mediated by extended spectrum β-lactamase (ESBL), AmpC, and metallobetalactamase (MBLs) enzymes are an increasing problem worldwide. The study was aimed to detect occurrence rate and to evaluate different substrates and inhibitors by disc combination method for detecting varying degree of β-lactamase enzymes and their co-production.

Materials and Methods: A disc panel containing imipenem (IMP), IMP/EDTA, ceftazidime (CA), ceftazidime-tazobactum (CAT), CAT/cloxacillin (CLOX), ceftazidime-clavulanic acid (CAC), CAC/CLOX, cefoxitin (CN), and CN/CLOX in a single plate was used to detect presence of ESBLs, AmpC, and MBLs and/or their co-existence in 184 consecutive, nonrepetitive, clinical isolates of Enterobacteriace (n = 96) and Pseudomonas spp. (n = 88) from pus samples of hospitalized patients, resistant to 3^rd generation cephalosporins.

Results: Out of a total of 96 clinical isolates of Enterobacteriaceae, 18.7, 20.8, and 27% were pure ESBL, AmpC, and MBL producers, respectively. ESBL and AmpC were co-produced by 25% isolates. Among 88 Pseudomonas spp. 38.6, 13, and 6% were pure MBL, ESBL, and AmpC producers, respectively. ESBL/AmpC and MBL/AmpC co-production was seen in 20% and 18% isolates, respectively. Among ESBL and AmpC co-producers, CA/CAC/CLOX disc combination (DC) missed 7 of the 24 ESBL producers in Enterobacteriace and 4 of the 18 ESBL in Pseudomonas spp., which were detected by CA/CAT/CLOX DC. No mechanism was detected among 8.3% Enterobacteriaceae and 2.3% Pseudomonas isolates.

Conclusion: Diagnostic problems posed by co-existence of different classes of β-lactamases in a single isolate could be solved by disc combination method by using simple panel of discs containing CA, CAT, CAT/CLOX, IMP, and IMP/EDTA.

Key words:

AmpC - co-production - extended spectrum β-lactamase - metallobetalactamase

PDF (774 kb)

References

REFERENCES
1 Upadhyay S, Sen MR, Bhattacharjee A. Presence of different beta-lactamase classes among clinical isolates of Pseudomonas aeruginosa expressing AmpC beta-lactamase enzyme. J Infect Dev Ctries 2010;4:239-42.
2 Clinical and Laboratory Standard Institute Performance standards for antimicrobial disk susceptibility tests; approved standard. 10^th ed. CLSI document M100-S18, Wayne; 2011.
3 Polsfuss S, Bloemberg GV, Giger J, Meyer V, Böttger EC, Hombach M. Practical approach for reliable detection of AmpC beta-lactamase-producing Enterobacteriaceae. J Clin Microbiol 2011;49:2798-803.
4 Pasteran F, Mendez T, Rapoport M, Guerriero L, Corso A. Controlling false-positive results obtained with Hodge and Masuda assay for detection of class a carbapenamase in species of Enterobacteriaceae by incorporating boronic acid. J Clin Microbiol 2010;48:1323-32.
5 Bhattacharjee A, Sen MR, Prakash P, Anupurba S. Role of beta-lactamase inhibitors in enterobacterial isolates producing extended-spectrum beta-lactamases. J Antimicob Chemother 2008;61:309-14.
6 Colle JG, Miles RS, Watt B. Test for the identification of bacteria. In: Collee JG, Faser AG, Marmion BP, Simmons A, editors. Mackie and McCartney. Practical Medical Microbiology. 14^th ed. London: Churchill Livingstone; 1996. p. 131-45.
7 Yong D, Lee K, Yum JH, Shin HB, Rossolini GM, Chong Y. Imipenem-EDTA disk method for differentiation of metallo-beta-lactamases-producing clinical isolates of Pseudomonas spp and Acinetobacter spp. J Clin Microbiol 2002;40:3798-801.
8 Rawat V, Singhai M, Kumar A, Jha P, Goyal R. Bacteriological and resistance profile in isolates from diabetic patients. N Am J Med Sci 2012:4;563-8.
9 Shoorashetty RM, Nagarathnamma T, Prathibha J. Comparison of the boronic acid disk potentiation test and cefepime-clavulanic acid method for the detection of ESBL among AmpC-producing Enterobacteriaceae. Indian J Med Micobiol 2011;29:297-301.
10 Yan JJ, Ko WC, Wu HM, Tsai SH, Chuang CL, Wu JJ. Complexity of Klebsiella pneumoniae isolates resistant to both cephamycins and extended-spectrum cephalosporins at a teaching hospital of Taiwan. J Clin Microbiol 2004;42:5537-40.
11 Bethel CR, Hujer AM, Helfand MS, Bonomo RA. Exploring the effectiveness of tazobactam against ceftazidime resistant Escherichia coli: Insights from the comparison between susceptibility testing and beta-lactamase inhibition. FEMS Microbiol Lett 2004;234:99-103.
12 Thomson KS. Extended-spectrum-beta-lactamase, AmpC, and Carbapenamase issues. J Clin Microbiol 2010;48:1019-25.
13 Rai S, Manchanda V, Singh NP, Kaur IR. Zinc-dependent carbapenemase in clinical isolates of family Enterobacteriaceae. Indian J Med Micobiol 2011;29:275-9.
14 Rawat V. Study of metallo-β-lactamase production in nosocomial nil fermenter gram negative bacterial isolates from clinical samples in a tertiary care hospital. Int J App Basic Med Res 2011;1:129-30.