Department of Environmental Health and Engineering, Whiting School of Engineering, Johns Hopkins University, 3400 North Charles Street, 313 Ames Hall, Baltimore, Maryland 21218, United States.
The Johns Hopkins Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, United States.
Environ Sci Technol. 2020 Dec 15;54(24):15946-15957. doi: 10.1021/acs.est.0c03803. Epub 2020 Dec 1.
The use of nontherapeutic broad-spectrum antimicrobial agents triclosan (TCS) and benzalkonium chloride (BC) can contribute to bacterial resistance to clinically relevant antibiotics. Antimicrobial-resistant bacteria within wastewater may reflect the resistance burden within the human microbiome, as antibiotics and pathogens in wastewater can track with clinically relevant parameters during perturbations to the community. In this study, we monitored culturable and resistant wastewater bacteria and cross-resistance to clinically relevant antibiotics to gauge the impact of each antimicrobial and identify factors influencing cross-resistance profiles. Bacteria resistant to TCS and BC were isolated from wastewater influent over 21 months, and cross-resistance, taxonomy, and monthly changes were characterized under both antimicrobial selection regimes. Cross-resistance profiles from each antimicrobial differed within and between taxa. BC-isolated bacteria had a significantly higher prevalence of resistance to "last-resort antibiotic" colistin, while isolates resistant to TCS exhibited higher rates of multidrug resistance. Prevalence of culturable TCS-resistant bacteria decreased over time following Food and Drug Administration (FDA) TCS bans. Cross-resistance patterns varied according to sampling date, including among the most clinically important antibiotics. Correlations between strain-specific resistance profiles were largely influenced by taxonomy, with some variations associated with sampling date. The results reveal that time, taxonomy, and selection by TCS and BC impact features of cross-resistance patterns among diverse wastewater microorganisms, which could reflect the variety of factors influencing resistance patterns relevant to a community microbiome.
非治疗性广谱抗菌剂三氯生（TCS）和苯扎氯铵（BC）的使用可能导致细菌对临床相关抗生素产生耐药性。废水中的抗菌药物耐药细菌可能反映了人类微生物组中的耐药负担，因为废水中的抗生素和病原体可以在社区受到干扰时与临床相关参数相吻合。在这项研究中，我们监测了可培养的和耐药的废水细菌以及对临床相关抗生素的交叉耐药性，以评估每种抗菌药物的影响并确定影响交叉耐药谱的因素。在 21 个月的时间里，从废水进水口分离出了对 TCS 和 BC 具有耐药性的细菌，并在两种抗菌药物选择条件下对其交叉耐药性、分类学和每月变化进行了表征。每种抗菌药物的交叉耐药谱在分类学内和分类学之间都有所不同。BC 分离出的细菌对“最后一线抗生素”多粘菌素的耐药率明显更高，而对 TCS 耐药的分离株则表现出更高的多药耐药率。在美国食品和药物管理局（FDA）禁止 TCS 后，可培养的 TCS 耐药细菌的流行率随时间的推移而降低。交叉耐药模式根据采样日期而有所不同，包括最具临床重要性的抗生素。菌株特异性耐药谱之间的相关性主要受分类学的影响，其中一些变化与采样日期有关。研究结果表明，时间、分类学以及 TCS 和 BC 的选择会影响不同废水微生物之间交叉耐药模式的特征，这可能反映了影响与社区微生物组相关的耐药模式的各种因素。
