School of Civil and Environmental Engineering and ‡School of Biology, Georgia Institute of Technology , Atlanta Georgia 30332-0512, United States.
Environ Sci Technol. 2013 Sep 3;47(17):9730-8. doi: 10.1021/es401507k. Epub 2013 Aug 19.
The effect of benzalkonium chlorides (BACs), a widely used class of quaternary ammonium disinfectants, on microbial community structure and antimicrobial resistance was investigated using three aerobic microbial communities: BACs-unexposed (DP, fed a mixture of dextrin/peptone), BACs-exposed (DPB, fed a mixture of dextrin/peptone and BACs), and BACs-enriched (B, fed only BACs). Long-term exposure to BACs reduced community diversity and resulted in the enrichment of BAC-resistant species, predominantly Pseudomonas species. Exposure of the two microbial communities to BACs significantly decreased their susceptibility to BACs as well as three clinically relevant antibiotics (penicillin G, tetracycline, ciprofloxacin). Increased resistance to BACs and penicillin G of the two BACs-exposed communities is predominantly attributed to degradation or transformation of these compounds, whereas resistance to tetracycline and ciprofloxacin is largely due to the activity of efflux pumps. Quantification of several key multidrug resistance genes showed a much higher number of copies of these genes in the DPB and B microbial communities compared to the DP community. Collectively, our findings indicate that exposure of a microbial community to BACs results in increased antibiotic resistance, which has important implications for both human and environmental health.
未暴露于苯扎氯铵（BAC）的群落（DP，以糊精/蛋白胨混合物为食）、暴露于 BAC 的群落（DPB，以糊精/蛋白胨和 BAC 的混合物为食）和富含 BAC 的群落（B，仅以 BAC 为食），研究了广泛使用的季铵盐消毒剂类 BAC 对微生物群落结构和抗微生物药物耐药性的影响。长期暴露于 BAC 会降低群落多样性，并导致 BAC 抗性物种的富集，主要是假单胞菌属物种。这两个微生物群落暴露于 BAC 会显著降低它们对 BAC 以及三种临床相关抗生素（青霉素 G、四环素和环丙沙星）的敏感性。这两个暴露于 BAC 的群落对 BAC 和青霉素 G 的耐药性主要归因于这些化合物的降解或转化，而对四环素和环丙沙星的耐药性则主要归因于外排泵的活性。对几种关键的多药耐药基因进行定量分析表明，与 DP 群落相比，DPB 和 B 微生物群落中这些基因的拷贝数要高得多。总的来说，我们的研究结果表明，微生物群落暴露于 BAC 会导致抗生素耐药性增加，这对人类和环境健康都有重要影响。
