Amarasiri Mohan, Takezawa Tsubasa, Malla Bikash, Furukawa Takashi, Sherchand Jeevan B, Haramoto Eiji, Sei Kazunari
Laboratory of Environmental Hygiene, School of Allied Health Sciences, Kitasato University, Sagamihara, Japan.
Interdisciplinary Center for River Basin Environment, University of Yamanashi, Kofu, Japan.
Front Microbiol. 2022 Aug 22;13:894014. doi: 10.3389/fmicb.2022.894014. eCollection 2022.
Antibiotic-resistant bacteria-associated infections are responsible for more than 1.2 million annual deaths worldwide. In low- and middle-income countries (LMICs), the consumption of antibiotics for human and veterinary uses is not regulated effectively. Overused and misused antibiotics can end up in aquatic environments, which may act as a conduit for antibiotic resistance dissemination. However, data on the prevalence of antibiotic resistance determinants in aquatic environments are still limited for LMICs. In this study, we evaluated the prevalence and concentration of antibiotic resistance genes (ARGs) in different drinking and environmental water sources collected from the Kathmandu Valley, Nepal, using droplet digital polymerase chain reaction to understand the current situation of ARG contamination. River water and shallow dug well water sources were the most contaminated with ARGs. Almost all samples contained (94%), and and (A) were detected in 83 and 60% of the samples, respectively. Maximum ARG concentration varied between 4.2 log copies/100 ml for and 9.3 log copies/100 ml for . Significant positive correlations were found between ARGs ( > 0.5, < 0.01), except for , and . As and were detected in almost all samples, the presence of these genes in a given sample may need to be considered as background antibiotic resistance in LMICs. Therefore, monitoring of ARGs, such as β-lactam ARGs, quinolone resistance genes, and vancomycin resistance genes, may provide a better picture of the antibiotic resistance determinants in aquatic environments of LMICs.
全球范围内，与抗生素耐药菌相关的感染每年导致超过120万人死亡。在低收入和中等收入国家（LMICs），用于人类和兽医的抗生素消费未得到有效监管。过度使用和滥用的抗生素最终可能进入水生环境，这可能成为抗生素耐药性传播的一个渠道。然而，关于低收入和中等收入国家水生环境中抗生素耐药性决定因素流行情况的数据仍然有限。在本研究中，我们使用数字液滴聚合酶链反应评估了从尼泊尔加德满都谷地采集的不同饮用水和环境水源中抗生素耐药基因（ARGs）的流行情况和浓度，以了解ARGs污染的现状。河水和浅井水水源受ARGs污染最严重。几乎所有样本都含有（94%），并且分别在83%和60%的样本中检测到和（A）。最大ARGs浓度在的4.2 log拷贝/100毫升至的9.3 log拷贝/100毫升之间变化。除了、和外，在ARGs之间发现了显著的正相关（>0.5，<0.01）。由于几乎在所有样本中都检测到了和，在低收入和中等收入国家的特定样本中这些基因的存在可能需要被视为背景抗生素耐药性。因此，监测β-内酰胺类ARGs、喹诺酮耐药基因和万古霉素耐药基因等ARGs，可能会更好地了解低收入和中等收入国家水生环境中的抗生素耐药性决定因素。
