Detection 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

Abstract

<jats:p> <jats:bold>Background.</jats:bold> Organisms possessing the <jats:italic>bla</jats:italic> <jats:sub>NDM-1</jats:sub> 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.</jats:p> <jats:p> <jats:bold>Methods.</jats:bold> One hundred and thirty-eight organisms belonging to <jats:italic> <jats:named-content content-type="genus"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.3092" xlink:type="simple">Escherichia</jats:ext-link> </jats:named-content> </jats:italic>, <jats:italic> <jats:named-content content-type="genus"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.3202" xlink:type="simple">Klebsiella</jats:ext-link> </jats:named-content> </jats:italic>, <jats:italic> <jats:named-content content-type="genus"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.2552" xlink:type="simple">Pseudomonas</jats:ext-link> </jats:named-content> </jats:italic> and <jats:italic> <jats:named-content content-type="genus"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.2765" xlink:type="simple">Acinetobacter</jats:ext-link> </jats:named-content> </jats:italic> spp. 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 <jats:italic>bla</jats:italic> <jats:sub>NDM-1</jats:sub> genes.</jats:p> <jats:p> <jats:bold>Results.</jats:bold> Of the 138 organisms, 86 (62.3 %) were imipenem-resistant (<jats:italic>P</jats:italic>&lt;0.05). One hundred and twenty-four (89.9 %) organisms had one or both of the genes. Overall, the <jats:italic>bla</jats:italic> <jats:sub>NDM-1</jats:sub> gene (genotypic resistance) was present in 71 % (98/138) of organisms. 53.6 % (74/138) organisms were double gene-positive (<jats:italic>bla</jats:italic> <jats:sub>NDM-1</jats:sub> + Int-1), of which 40 were producing the metallo-beta-lactamase enzyme, making up almost 28.9 % (40/138) of the collected organisms.</jats:p> <jats:p> <jats:bold>Conclusion.</jats:bold> 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.</jats:p>

Escalating antimicrobial resistance among Enterobacteriaceae: focus on carbapenemases

“…Acquisition of MDR genes occurs most commonly in hospitals and chronic care facilities, but community-acquired sources including wild and domestic animals, food products, and environmental contamination may drive resistance 5,10,50,93,94 . Spread of MDR genes has also been linked to community and hospital effluent treatment systems 95,96 . Movement of humans, wild or domestic animals, livestock and food products is a key factor in spreading MDR in the environment 93,94,[97][98][99] .…”

Detection and Characterization of Carbapenemase-Producing Escherichia coli and Klebsiella pneumoniae from Hospital Effluents of Ouagadougou, Burkina Faso

“…The presence of carbapenemaseproducing bacteria in the CHU-B raw and treated wastewater highlights the inefficiency of the treatment, which normally should reduce the load of antibiotic-resistant pathogenic bacteria. This situation is worrisome with Enterobacterales, especially E. coli and K. pneumoniae, which are now emerging as difficult-to-treat bacteria [24]. Multidrug resistance of carbapenemase-producing E. coli and K. pneumoniae was confirmed, and even pan resistance of the latter to almost all antibiotics tested.…”