Leão Célia, Clemente Lurdes, Cara d'Anjo Maria, Albuquerque Teresa, Amaro Ana
Laboratory of Bacteriology and Mycology, National Institute of Agrarian and Veterinary Research (INIAV, IP), 2780-157 Oeiras, Portugal.
MED-Mediterranean Institute for Agriculture, Environment and Development, 7006-554 Évora, Portugal.
Antibiotics (Basel). 2022 Oct 19;11(10):1439. doi: 10.3390/antibiotics11101439.
Livestock-associated methicillin-resistant (LA-MRSA) ST398 is mainly found in Europe and North America, colonizing the nasal cavity of pigs. This study characterized the MRSA isolates recovered from pig nasal swabs ( = 171) by evaluating the antimicrobial susceptibility profile by broth microdilution and characterizing the genetic lineages by -typing. Three linezolid-resistant isolates were subjected to Whole-Genome Sequencing (WGS). All strains harbored the gene and were resistant to tetracycline and susceptible to vancomycin. A high frequency of multidrug resistance (97.6%) was evidenced, with 55 different multidrug resistance profiles identified. The MRSA strains were found to belong to 17 -types, three being novel. The linezolid-resistant strains appeared to belong to the ST398 type, -type t011, and SCC_type_Vc and to harbor the , A, Z, A, M, and K genes. The gene was predicted to be carried in the plasmid, flanked by Sau9 and the transposon TnpR. MRSA from Portuguese fattening pigs present a high diversity of genetic lineages. The presence of -positive LA-MRSA may represent a risk of transmission to humans, mainly to those in contact with livestock.
与家畜相关的耐甲氧西林金黄色葡萄球菌（LA-MRSA）ST398主要在欧洲和北美被发现，定殖于猪的鼻腔。本研究通过肉汤微量稀释法评估抗菌药物敏感性谱以及通过spa分型对从猪鼻拭子中分离出的耐甲氧西林金黄色葡萄球菌（n = 171）进行特征分析。对三株耐利奈唑胺的分离株进行全基因组测序（WGS）。所有菌株均携带mecA基因，对四环素耐药，对万古霉素敏感。证实了多药耐药的高频率（97.6%），鉴定出55种不同的多药耐药谱。耐甲氧西林金黄色葡萄球菌菌株被发现属于17种spa型，其中三种是新的。耐利奈唑胺菌株似乎属于ST398型、spa型t011和SCCmec型Vc，并且携带cfr、A、Z、A、M和K基因。cfr基因预计携带在质粒中，两侧是Sau96和转座子TnpR。来自葡萄牙育肥猪的耐甲氧西林金黄色葡萄球菌呈现出高度多样的遗传谱系。携带spa的LA-MRSA的存在可能代表着向人类传播的风险，主要是对那些与家畜接触的人。
