Rehberg L, Frontzek A, Melhus Å, Bockmühl D P
Rhine-Waal University of Applied Sciences, Kleve, Germany.
Medical Care Center Dr. Stein + Colleagues, Mönchengladbach, Germany.
J Appl Microbiol. 2017 Dec;123(6):1396-1406. doi: 10.1111/jam.13574. Epub 2017 Oct 13.
To investigate the prevalence of β-lactamase genes in domestic washing machines and dishwashers, and the decontamination efficacy of laundering.
For the first investigation, swab samples from washing machines (n = 29) and dishwashers (n = 24) were analysed by real-time quantitative PCR to detect genes encoding β-lactamases. To test the impact of laundering on resistant bacteria, cotton test swatches were artificially contaminated with susceptible and resistant strains of Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus within a second investigation. They were washed in a domestic washing machine with or without activated oxygen bleach (AOB)-containing detergent at 20-50°C. β-Lactamase genes (most commonly of the AmpC- and OXA-type) were detected in 79% of the washing machines and in 96% of the dishwashers and Pseudomonadaceae dominated the microbiota. The level of bacterial reduction after laundering was ≥80% for all Ps. aeruginosa and Kl. pneumoniae strains, while it was only 37-61% for the methicillin-resistant Staph. aureus outbreak strain. In general, the reduction was tendentially higher for susceptible bacteria than for the resistant outbreak strains, especially for Staph. aureus.
β-Lactamase genes seem to be frequently present in domestic appliances and may pose a potential risk for cross-contamination and horizontal transfer of genes encoding resistance against clinically important β-lactams. In general, higher temperatures and the use of AOB can improve the reduction of antibiotic-resistant bacteria, including Staph. aureus which appears to be less susceptible to the decontamination effect of laundering.
Data on the presence of antibiotic-resistant bacteria in the domestic environment are limited. This study suggests that β-lactamase genes in washing machines and dishwashers are frequent, and that antibiotic-resistant strains are generally more resistant to the used washing conditions.
调查家用洗衣机和洗碗机中β-内酰胺酶基因的流行情况以及洗涤的去污效果。
在首次调查中，通过实时定量PCR对洗衣机（n = 29）和洗碗机（n = 24）的拭子样本进行分析，以检测编码β-内酰胺酶的基因。为了测试洗涤对耐药菌的影响，在第二次调查中，用铜绿假单胞菌、肺炎克雷伯菌和金黄色葡萄球菌的敏感菌株和耐药菌株对棉质测试拭子进行人工污染。将它们在20-50°C下用含或不含活性氧漂白剂（AOB）的洗涤剂在家庭洗衣机中洗涤。在79%的洗衣机和96%的洗碗机中检测到β-内酰胺酶基因（最常见的是AmpC型和OXA型），假单胞菌科在微生物群中占主导地位。对于所有铜绿假单胞菌和肺炎克雷伯菌菌株，洗涤后的细菌减少水平≥80%，而对于耐甲氧西林金黄色葡萄球菌暴发菌株，这一比例仅为37-61%。一般来说，敏感菌的减少趋势高于耐药暴发菌株，尤其是金黄色葡萄球菌。
β-内酰胺酶基因似乎在家用电器中频繁存在，可能对临床上重要的β-内酰胺类耐药基因的交叉污染和水平转移构成潜在风险。一般来说，较高的温度和使用AOB可以提高对抗生素耐药菌的减少效果，包括对洗涤去污效果似乎不太敏感的金黄色葡萄球菌。
关于家庭环境中抗生素耐药菌存在情况的数据有限。本研究表明，洗衣机和洗碗机中的β-内酰胺酶基因很常见，而且抗生素耐药菌株通常对所用的洗涤条件更具抗性。
