Conceição Teresa, de Lencastre Hermínia, Aires-de-Sousa Marta
1 Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal .
2 Laboratory of Microbiology and Infectious Diseases, The Rockefeller University , New York, New York.
Microb Drug Resist. 2017 Oct;23(7):845-851. doi: 10.1089/mdr.2017.0074. Epub 2017 Jun 26.
The nosocomial prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Portugal is close to 50% and remains one of the highest in Europe. MRSA reservoirs in the animal setting in Portugal have been very poorly investigated, namely among animal husbandry. A total of 52 samples (nasal, inguinal region, and milk) were obtained from bovine animals and analyzed for the presence of S. aureus. The isolates were characterized by pulsed-field gel electrophoresis (PFGE), spa typing, SCCmec typing, and multilocus sequence typing and tested for antimicrobial susceptibility, presence of mecA and mecC genes, and virulence determinants. Overall, 54% of the screened animals were colonized with S. aureus in at least one body site. Notably, S. aureus nasal carriage followed an increasing trend with animal age (p = 0.0006). None of the isolates harbored the mecA or mecC genes. Resistance to penicillin, rifampicin, and tetracycline was observed in 24%, 18%, and 6% of the isolates, respectively. The isolates were distributed into three clonal lineages: PFGE type A, spa type t1166, ST1247-CC133 (43%), PFGE B-t267-ST352-CC97 (30%), and PFGE C-t091-ST7-CC7 (27%). CC133 was associated to older animals (p = 0.0025), whereas CC97 was isolated from calves (p = 0.0016). Virulence determinants commonly found in mastitis were widely detected in carriage isolates: lukDE and hlgv (100%), hlb (76%), and lukM (35%). Although healthy bovines do not represent a MRSA reservoir in Portugal, they are mainly colonized with S. aureus pathogenic lineages associated to mastitis in cattle (CC97 and CC133).
葡萄牙耐甲氧西林金黄色葡萄球菌（MRSA）的医院感染率接近50%，仍是欧洲最高之一。葡萄牙动物环境中的MRSA宿主研究非常少，尤其是在畜牧业中。从牛身上总共采集了52份样本（鼻腔、腹股沟区域和牛奶），并分析其中金黄色葡萄球菌的存在情况。分离株通过脉冲场凝胶电泳（PFGE）、spa分型、SCCmec分型和多位点序列分型进行鉴定，并检测其抗菌药敏性、mecA和mecC基因的存在情况以及毒力决定因素。总体而言，54%的被筛查动物至少在一个身体部位被金黄色葡萄球菌定植。值得注意的是，金黄色葡萄球菌的鼻腔携带率随动物年龄呈上升趋势（p = 0.0006）。分离株均未携带mecA或mecC基因。分别有24%、18%和6%的分离株对青霉素、利福平及四环素耐药。分离株分为三个克隆谱系：PFGE A型、spa t1166型、ST1247-CC133（43%），PFGE B-t267-ST352-CC97（30%），以及PFGE C-t091-ST7-CC7（27%）。CC133与年龄较大的动物相关（p = 0.0025），而CC97是从犊牛中分离得到的（p = 0.0016）。在乳腺炎中常见的毒力决定因素在携带分离株中广泛检测到：lukDE和hlgv（100%）、hlb（76%）和lukM（35%）。尽管在葡萄牙健康牛不是MRSA的宿主，但它们主要被与牛乳腺炎相关的金黄色葡萄球菌致病谱系（CC97和CC133）定植。
