Households provide a habitat for bacteria originating from humans, animals, foods, contaminated clothes, or other sources. Thus, bacteria carrying antibiotic resistance genes (ARGs) may be introduced via household members, animals, or the water supply from external habitats into private households and vice versa. Since data on antibiotic resistance (ABR) in the domestic environment are limited, this study aimed to determine the abundance of β-lactamase, mobile colistin resistance, and class 1 integron genes and the correlation of their presence and to characterize phenotypically resistant strains in 54 private households in Germany. Additionally, the persistence of antibiotic-resistant bacteria during automated dishwashing compared to that during laundering was assessed. Shower drains, washing machines, and dishwashers were sampled and analyzed using quantitative real-time PCR. Resistant strains were isolated, followed by identification and antibiotic susceptibility testing using a Vitek 2 system. The results showed a significantly higher relative ARG abundance of 0.2367 ARG copies/16S rRNA gene copies in shower drains than in dishwashers (0.1329 ARG copies/16S rRNA gene copies) and washing machines (0.0006 ARG copies/16S rRNA gene copies). bla_CMY-2, bla_ACT/MIR, and bla_OXA-48 were the most prevalent ARG, and intI1 occurred in 96.3% of the households, while no mcr genes were detected. Several β-lactamase genes co-occurred, and the resistance of bacterial isolates correlated positively with genotypic resistance, with carbapenemase genes dominating across isolates. Antibiotic-resistant bacteria were significantly reduced during automated dishwashing as well as laundering tests and did not differ from susceptible strains. Overall, the domestic environment may represent a potential reservoir of β-lactamase genes and β-lactam-resistant bacteria, with shower drains being the dominant source of ABR.

中文翻译：

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家用电阻组-家庭环境中β-内酰胺酶，1类整合子和抗生素抗性细菌的频率及其在自动洗碗/洗涤过程中的减少量。

家庭为来自人类，动物，食物，被污染的衣服或其他来源的细菌提供了栖息地。因此，携带抗生素抗性基因（ARG）的细菌可通过家庭成员，动物或从外部栖息地的供水引入私人家庭，反之亦然。由于在家庭环境中有关抗生素抗药性（ABR）的数据有限，因此本研究旨在确定β-内酰胺酶，流动粘菌素抗性和1类整合子基因的丰度及其存在的相关性，并鉴定54种表型抗性菌株德国的私人家庭。另外，评估了自动洗碗过程中与洗碗过程中的抗药性细菌的持久性。淋浴排水管，洗衣机，并使用定量实时PCR对洗碗机进行采样和分析。分离抗性菌株，然后使用Vitek 2系统进行鉴定和抗生素敏感性测试。结果表明，淋浴排水管中的相对ARG丰度为0.2367 ARG拷贝/ 16S rRNA基因拷贝，明显高于洗碗机（0.1329 ARG拷贝/ 16S rRNA基因拷贝）和洗衣机（0.0006 ARG拷贝/ 16S rRNA基因拷贝）。bla _CMY-2，bla _{ACT / MIR}和bla _OXA-48是最常见的ARG，intI1发生在96.3％的家庭中，而未检测到mcr基因。几种β-内酰胺酶基因共存，细菌分离株的抗性与基因型抗性正相关，其中碳青霉烯酶基因在分离株中占主导。在自动洗碗和洗涤测试过程中，抗生素抗性细菌显着减少，并且与易感菌株没有区别。总体而言，家庭环境可能代表着β-内酰胺酶基因和抗β-内酰胺的细菌的潜在库，淋浴排水管是ABR的主要来源。