Department of Environmental Microbiology, School of Earth and Environmental Sciences, Babasaheb Bhimrao Ambedkar University (A Central University), Lucknow, 226025, Uttar Pradesh, India.
State Level Water Analysis Laboratory, UP Jal Nigam (Urban) 6, Rana Pratap Marg, Lucknow, 226001, India.
Chemosphere. 2024 Aug;362:142829. doi: 10.1016/j.chemosphere.2024.142829. Epub 2024 Jul 9.
Municipal wastewater treatment plants (MWWTPs) are a global source of antibiotic resistance genes (ARGs), collecting wastewater from a variety of sources, including hospital wastewater, domestic wastewater, runoff from agricultural and livestock farms, etc. These sources are contaminated with organic and inorganic pollutants, ARGs and antibiotic-resistant bacteria (ARB). Such pollutants aided eutrophication and encouraged bacterial growth. During bacterial growth horizontal gene transfer (HGT) and vertical gene transfer (VGT) of ARGs and extended-spectrum β-lactamase (ESBL) encoding genes may facilitate, resulting in the spread of antibiotic resistance exponentially. The current study investigated the prevalence of multidrug resistance (MDR) and ESBL encoding genes in various treatment units of MWWTP and their spread in the environment. A total of three sampling sites (BUT, BRO, and BFB) were chosen, and 33 morphologically distinct bacterial colonies were isolated. 14 of the 33 isolates tested positive for antibiotic resistance and were further tested for the coexistence of MDR and ESBL production. The selected 14 isolates showed the highest resistance to trimethoprim (85.71%), followed by ciprofloxacin, azithromycin, and ampicillin (71.42%), tetracycline (57.14%), and vancomycin, gentamicin, and colistin sulphate (50%). A total of 9 isolates (64.28%) were phenotypically positive for ESBL production (BUT2, BUT3, BUT5, BRO1, BRO2, BRO3, BRO4, BRO5 and BFB1). The molecular detection of ESBL encoding genes, i.e. bla, bla, and bla was carried out. The most prevalent gene was bla (69.23%), followed by bla (46.15%), and bla (23.07%). In this study, 9 isolates (64.28%) out of 14 showed the coexistence of MDR and ESBL encoding genes, namely BUT3, BUT4, BUT5, BUT6, BUT7, BRO1, BRO2, BRO4, and BFB1. The coexistence of ESBL encoding genes and resistance to other antibiotic classes exacerbates human health and the environment.
城市污水处理厂（MWWTP）是抗生素耐药基因（ARGs）的全球性来源，从各种来源收集废水，包括医院废水、生活污水、农业和畜牧场的径流等。这些来源受到有机和无机污染物、ARGs 和抗生素耐药菌（ARB）的污染。这些污染物助长了富营养化并促进了细菌的生长。在细菌生长过程中，水平基因转移（HGT）和垂直基因转移（VGT）以及扩展谱β-内酰胺酶（ESBL）编码基因的转移可能会促进抗生素耐药性的指数级传播。本研究调查了 MWWTP 中各种处理单元中多重耐药（MDR）和 ESBL 编码基因的流行情况及其在环境中的传播情况。选择了三个采样点（BUT、BRO 和 BFB），并从 33 个形态不同的细菌菌落中分离出 33 株。对 33 株分离株中的 14 株进行了抗生素耐药性检测，并进一步检测了 MDR 和 ESBL 产生的共存情况。所选的 14 株分离株对甲氧苄啶的耐药性最高（85.71%），其次是环丙沙星、阿奇霉素和氨苄西林（71.42%）、四环素（57.14%）和万古霉素、庆大霉素和硫酸粘菌素（50%）。共有 9 株（64.28%）分离株表现出 ESBL 产生的表型阳性（BUT2、BUT3、BUT5、BRO1、BRO2、BRO3、BRO4、BRO5 和 BFB1）。对 ESBL 编码基因，即 blaTEM、blaCTX-M 和 blaSHV 进行了分子检测。最常见的基因是 blaCTX-M（69.23%），其次是 blaTEM（46.15%）和 blaSHV（23.07%）。在这项研究中，14 株分离株中有 9 株（64.28%）同时存在 MDR 和 ESBL 编码基因，即 BUT3、BUT4、BUT5、BUT6、BUT7、BRO1、BRO2、BRO4 和 BFB1。ESBL 编码基因的共存以及对其他抗生素类别的耐药性加剧了人类健康和环境的风险。
