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CC BY-NC-ND 4.0 · J Lab Physicians 2014; 6(01): 001-006
DOI: 10.4103/0974-2727.129082
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Detection of AmpC β Lactamases in Gram-negative Bacteria

Gunjan Gupta
Department of Laboratory Medicine, Jai Prakash Narain Apex Trauma Centre, All India Institute of Medical Sciences, New Delhi, India
,
Vibhor Tak
Department of Laboratory Medicine, Jai Prakash Narain Apex Trauma Centre, All India Institute of Medical Sciences, New Delhi, India
,
Purva Mathur
Department of Laboratory Medicine, Jai Prakash Narain Apex Trauma Centre, All India Institute of Medical Sciences, New Delhi, India
› Author Affiliations Source of Support: We acknowledge the financial support of ICMR for the performance of this study.
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ABSTRACT

AmpC β-lactamases are clinically important cephalosporinases encoded on the chromosomes of many Enterobacteriaceae and a few other organisms, where they mediate resistance to cephalothin, cefazolin, cefoxitin, most penicillins, and β-lactamase inhibitor/β-lactam combinations. The increase in antibiotic resistance among Gram-negative bacteria is a notable example of how bacteria can procure, maintain and express new genetic information that can confer resistance to one or several antibiotics. Detection of organisms producing these enzymes can be difficult, because their presence does not always produce a resistant phenotype on conventional disc diffusion or automated susceptibility testing methods. These enzymes are often associated with potentially fatal laboratory reports of false susceptibility to β-lactams phenotypically. With the world-wide increase in the occurrence, types and rate of dissemination of these enzymes, their early detection is critical. AmpC β-lactamases show tremendous variation in geographic distribution. Thus, their accurate detection and characterization are important from epidemiological, clinical, laboratory, and infection control point of view. This document describes the methods for detection for AmpC β-lactamases, which can be adopted by routine diagnostic laboratories.

Key words:

AmpC β-lactamases - disk approximation test - gram-negative bacteria - three-dimensional extract test


Publication History

Article published online:
19 April 2020

© 2014.

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