Open AccessDetection of New Delhi metallo-beta-lactamase enzyme gene bla NDM-1 associated with the Int-1 gene in Gram-negative bacteria collected from the effluent treatment plant of a tuberculosis care hospital in Delhi, India
Author(s) -
Aruna Aggarwal,
Manpreet Bhalla,
Khan Hena Fatima
Publication year - 2020
Publication title -
access microbiology
Language(s) - English
Resource type - Journals
ISSN - 2516-8290
DOI - 10.1099/acmi.0.000125
Subject(s) - integron , imipenem , microbiology and biotechnology , biology , klebsiella pneumoniae , acinetobacter , multiple drug resistance , antibiotic resistance , carbapenem , acinetobacter baumannii , drug resistance , antibiotics , pseudomonas aeruginosa , gene , bacteria , escherichia coli , genetics
Background Organisms possessing the bla NDM-1 gene (responsible for carbapenem resistance) with a class-1 integron can acquire many other antibiotic resistance genes from the community sewage pool and become multidrug-resistant superbugs. In this regard, hospital sewage, which contains a large quantity of residual antibiotics, metals and disinfectants, is being recognized as a significant cause of antimicrobial resistance (AMR) origination and spread across the major centres of the world and is thus routinely investigated as a marker for tracing the origin of drug resistance. Therefore, in this study, an attempt has been made to identify and characterize the carbapenem-resistant microbes associated with integron genes amongst the organisms isolated from the effluent treatment plant (ETP) installed in a tertiary respiratory care hospital in Delhi, India. Methods One hundred and thirty-eight organisms belonging toEscherichia ,Klebsiella ,PseudomonasandAcinetobacterspp. were collected from the incoming and outgoing sewage lines of the ETP. Carbapenem sensitivity and characterization was performed by the imipenem and imipenem-EDTA disc diffusion method. Later DNA extraction and PCR steps were performed for the Int-1 and bla NDM-1 genes. Results Of the 138 organisms, 86 (62.3 %) were imipenem-resistant ( P <0.05). One hundred and twenty-four (89.9 %) organisms had one or both of the genes. Overall, the bla NDM-1 gene (genotypic resistance) was present in 71 % (98/138) of organisms. 53.6 % (74/138) organisms were double gene-positive ( bla NDM-1 + Int-1), of which 40 were producing the metallo-beta-lactamase enzyme, making up almost 28.9 % (40/138) of the collected organisms. Conclusion The current study strengthens the hypothesis that Carbapenem resistant organisms are in a high-circulation burden through the human gut and hospital ETPs are providing an environment for resistance origination and amplification.