Journal of Water and Health (Aug 2021)

Lentic and effluent water of Delhi-NCR: a reservoir of multidrug-resistant bacteria harbouring blaCTX-M, blaTEM and blaSHV type ESBL genes

  • Asghar Ali,
  • Insha Sultan,
  • Aftab Hossain Mondal,
  • Mohammad Tahir Siddiqui,
  • Firdoos Ahmad Gogry,
  • Qazi Mohd. Rizwanul Haq

DOI
https://doi.org/10.2166/wh.2021.085
Journal volume & issue
Vol. 19, no. 4
pp. 592 – 603

Abstract

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Antimicrobial resistance is not restricted to clinics but also spreading fast in the aquatic environment. This study focused on the prevalence and diversity of extended-spectrum β-lactamase (ESBL) genes among bacteria from lentic and effluent water in Delhi-NCR, India. Phenotypic screening of 436 morphologically distinct bacterial isolates collected from diverse sites revealed that 106 (∼24%) isolates were ESBL positive. Antibiotic profiling showed that 42, 60, 78 and 59% ESBL producing isolates collected from Ghazipur slaughterhouse, Lodhi garden pond, Hauz Khas lake and Jasola wastewater treatment plant, respectively, were multidrug-resistant (MDR). The multiple antibiotic resistance (MAR) index varied from 0.20 to 0.32 among selected locations. The prevalence of ESBL gene variants blaSHV, blaTEM and blaCTX-M were found to be 17.64, 35.29 and 64%, respectively. Furthermore, the analysis of obtained gene sequences showed three variants of blaCTX-M (15, 152 and 205) and two variants of blaTEM (TEM-1 and TEM-116) among ESBL producers. The co-existence of 2–3 gene variants was recorded among 48% ESBL positive isolates. New reports from this study include the blaCTX-M gene in Acinetobacter lwoffii, Enterobacter ludwigii, Exiguobacterium mexicanum and Aeromonas caviae. Furthermore, the identification of blaTEM and blaSHV in an environmental isolate of A. caviae is a new report from India. HIGHLIGHTS Occurrence of ESBL genes from Exiguobacterium mexicanum was first reported.; blaCTX-M gene from environmental isolate of Aeromonas caviae is the first report.; Co-resistance of β-lactam and non-β-lactam classes of antibiotics was observed among a high proportion of ESBL positive bacterial isolates.; This study emphasizes the need for more comprehensive genetic research of diverse microorganisms from environmental settings.;

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