Multiplex-PCR to detect pAmpC β-lactamases among Enterobacteriaceae at a tertiary care laboratory in Mumbai, India

Post Date: 
2018-12-13
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Publication: 
Microbiology
Summary: 

Drug-resistance due to AmpC β-lactamases represents a growing problem worldwide. In this study, a previously collected sample of 108 cefoxitin-resistant clinical isolates was assessed for AmpC β-lactamase production through routine phenotypic testing and double-disc cefoxitin/cloxcallin (DD-CC), cefoxitin/phenylboronic acid (CDT-PBA) and AmpC disc tests. The same isolates were characterized by a novel multiplex polymerase chain reaction molecular assay to detect the presence of blaACT, blaDHA, blaCIT, blaFOX, blaMIR and blaMOX. By phenotypic analysis, 56%, 55% and 48 % were detected as being AmpC β-lactamase producers by the CDT-PBA, DD-CC and AmpC disc tests, respectively. By molecular analysis, 57  % were determined to be AmpC β-lactamase producers, including 34 % blaFOX, 8 % blaCIT and 1.6 % blaDHAas mono-AmpC producers. The production of multiple AmpC molecular types was common, including 30 % with both blaCIT+FOX and 1.6 % each of blaCIT+DHA, blaACT+MIR, blaACT+FOX, blaACT+DHA and blaMIR+FOX. Molecular characterization of AmpC would help detect the prevalence of AmpC β-lactamase producers, facilitate proper patient management and implement infection control practices.

Citation: 
Kazi M, Ajbani K, Tornheim JA, Sheetty A, Rodrigues C. Multiplex-PCR to detect pAmpC β-lactamases among Enterobacteriaceae at a tertiary care laboratory in Mumbai, India. Microbiology. 2018 Dec 13. doi: 10.1099/mic.0.000748. [Epub ahead of print]
Collaborators: 

Department of Microbiology, P. D. Hinduja Hospital and Medical Research Centre, Veer Sarvarkar Marg, Mahim, Mumbai, India