Department of Biotechnology and Genetic Engineering, Faculty of Science and Arts, Jordan University of Science and Technology, Irbid, Jordan.
J Appl Microbiol. 2022 Jun;132(6):4486-4500. doi: 10.1111/jam.15526. Epub 2022 Mar 21.
Methicillin-resistant Staphylococcus (MRSA) is a public and occupational health concern, both in community and healthcare settings. In recent years, community-acquired MRSA (CA-MRSA) has emerged as a major causative agent of infections in individuals with no health care exposure or any of the classical risk factors associated with infections. Environmental surfaces frequently touched by hands play a role in the transmission of CA-MRSA, where inanimate objects are considered potential reservoirs and the source of MRSA infections. The purpose of this study was to examine the prevalence of MRSA on environmental surfaces inside a university campus.
A total of 1078 high-touch surface samples were collected from door handles, light switches, desks, keyboards and restroom surfaces. MRSA isolates were identified and confirmed by PCR, utilizing the Staph. aureus nuc and mecA genes. Antibiotic resistance profiles were determined using disc diffusion and minimum inhibitory concertation methods. In addition, the ability to form biofilms was investigated by the 96-well plate microdilution technique. PCR assays were performed to detect enterotoxin and antibiotic-resistant genes. The genetic diversity of MRSA was determined through multi-locus sequence typing (MLST), spa and agr typing methods. The overall contamination of Staph. aureus and MRSA was 14.6% (157/1078) and 2.8% (30/1078), respectively. The highest rate of MRSA contamination was detected in restroom sinks and door handles. All MRSA isolates were MDR, with the highest resistance observed was against trimethoprim-sulfamethoxazole. Most MRSA isolates (29/30, 97%) carried at least one gene encoding for staphylococcal enterotoxins (SE), with 10 different SE genotypes were observed. A total of 16 different spa types were detected among the 30 MRSA isolates. Multi-locus sequence typing revealed that 21 MRSA isolates belonged to eight known sequence types (ST), while nine isolates were novel strains. The most detected ST and spa types were ST22 and t223, respectively. Agr types I and III were represented in 28 out of the 30 isolates. The majority of the isolates carried SCCmec type IV, but only one isolate was positive for PVL.
Our findings signify the potential of the high-touch surfaces in harbouring and transmitting MRSA to campus staff and students. Thus, the implementation of effective prevention measures outside the healthcare setting is needed to reduce the risk of acquiring CA-MRSA infections.
MRSA infections impose a profound economic burden due to illness and productivity loss. The results of this study not only help us to better understand the environmental reservoirs of this pathogen, but also provide information about its transmission pathways and healthcare settings entry routs.
耐甲氧西林金黄色葡萄球菌（MRSA）是一个公共和职业健康问题，无论是在社区还是医疗机构中。近年来，社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）已成为无医疗接触或任何与感染相关的经典危险因素的个体感染的主要病原体。经常被手触摸的环境表面在 CA-MRSA 的传播中起着作用，无生命的物体被认为是潜在的储层和 MRSA 感染的来源。本研究旨在检测大学校园内环境表面上的 MRSA 流行情况。
共采集门把手、电灯开关、书桌、键盘和浴室表面的 1078 个高接触表面样本。利用金黄色葡萄球菌 nuc 和 mecA 基因，通过 PCR 鉴定和确认 MRSA 分离株。使用圆盘扩散和最小抑菌浓度法确定抗生素耐药谱。此外，通过 96 孔板微量稀释技术研究了生物膜形成能力。通过 PCR 检测检测肠毒素和抗生素耐药基因。通过多位点序列分型（MLST）、spa 和 agr 分型方法确定 MRSA 的遗传多样性。金黄色葡萄球菌和 MRSA 的总污染率分别为 14.6%（157/1078）和 2.8%（30/1078）。在浴室水槽和门把手处检测到最高的 MRSA 污染率。所有 MRSA 分离株均为 MDR，对甲氧苄啶-磺胺甲恶唑的耐药性最高。大多数 MRSA 分离株（29/30，97%）携带至少一个编码葡萄球菌肠毒素（SE）的基因，观察到 10 种不同的 SE 基因型。在 30 株 MRSA 分离株中检测到总共 16 种不同的 spa 型。多位点序列分型显示，21 株 MRSA 分离株属于 8 种已知序列型（ST），而 9 株分离株为新型菌株。检测到的最常见 ST 和 spa 型分别为 ST22 和 t223。30 株分离株中有 28 株携带 agr 型 I 和 III。大多数分离株携带 SCCmec 型 IV，但只有一株分离株为 PVL 阳性。
我们的研究结果表明，高接触表面具有携带和传播 MRSA 给校园工作人员和学生的潜力。因此，需要在医疗机构外实施有效的预防措施，以降低获得 CA-MRSA 感染的风险。
MRSA 感染会因疾病和生产力损失而造成巨大的经济负担。本研究的结果不仅帮助我们更好地了解这种病原体的环境储库，还提供了有关其传播途径和医疗机构进入途径的信息。
