Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern.
Swiss Institute of Equine Medicine (ISME), Vetsuisse Faculty, University of Bern, and Agroscope, Switzerland.
Schweiz Arch Tierheilkd. 2022 Jul;164(7):499-512. doi: 10.17236/sat00360.
A total of 100 nasal swabs were collected from healthy horses in Switzerland between January 2020 and August 2020. The samples were taken from horses at 40 different stables in 12 different cantons and screened for both methicillin-resistant (MRSA) and methicillin-susceptible S. aureus (MSSA) using selective agar plates. S. aureus were tested for antibiotic susceptibility by measurement of the minimal inhibitory concentration (MIC) and for virulence factors, antibiotic resistance genes and phylogenetic characteristics using whole genome sequence analysis. Ten horses were found to be positive (10 %, CI: 95 %, 0,0552 - 0,1744) for S. aureus, and four of them harboured MRSA (4 %, CI: 95 %, CI: 1,5 % - 9 %). The MRSA were detected in horses from three different stables in the same region of one canton and MSSA were detected in horses from five different cantons. All the MRSA isolates were genetically related (ST398-t011-IVa), while the MSSA were diverse (ST1-t127/t398/t1508, ST816-t1294, ST133-t1403, ST30-t012). MRSA showed resistance to penicillin (blaZ), cefoxitin (mecA), trimethoprim (dfrK), gentamicin, kanamycin (aac(6')-Ie - aph(2'')-Ia), and tetracycline (tet(M)). MSSA were resistant to either none or one of the antibiotics tested like penicillin (blaZ) and erythromycin (erm(T)). Virulence genes were more abundant in MSSA than in MRSA. This study provides first insight into the prevalence and type of S. aureus in healthy Swiss horses and reveals a source of strains, which may cause infections in both horses and humans.
2020 年 1 月至 8 月期间，在瑞士从 100 匹健康马身上采集了总共 100 个鼻腔拭子。这些样本取自 12 个不同州的 40 个不同马厩的 40 匹马，使用选择性琼脂平板筛查耐甲氧西林金黄色葡萄球菌（MRSA）和甲氧西林敏感金黄色葡萄球菌（MSSA）。金黄色葡萄球菌通过最小抑菌浓度（MIC）测定检测抗生素敏感性，并通过全基因组序列分析检测毒力因子、抗生素耐药基因和系统发育特征。发现 10 匹马（10%，95%置信区间：0.0552-0.1744）对金黄色葡萄球菌呈阳性，其中 4 匹马（4%，95%置信区间：1.5%-9%）携带耐甲氧西林金黄色葡萄球菌。在同一州的三个不同马厩的马中检测到耐甲氧西林金黄色葡萄球菌，在五个不同州的马中检测到甲氧西林敏感金黄色葡萄球菌。所有耐甲氧西林金黄色葡萄球菌分离株均具有遗传相关性（ST398-t011-IVa），而甲氧西林敏感金黄色葡萄球菌具有多样性（ST1-t127/t398/t1508、ST816-t1294、ST133-t1403、ST30-t012）。耐甲氧西林金黄色葡萄球菌对青霉素（blaZ）、头孢西丁（mecA）、甲氧苄啶（dfrK）、庆大霉素、卡那霉素（aac(6')-Ie - aph(2'')-Ia）和四环素（tet(M)）具有耐药性。甲氧西林敏感金黄色葡萄球菌对测试的抗生素中没有一种或一种具有耐药性，如青霉素（blaZ）和红霉素（erm(T)）。毒力基因在甲氧西林敏感金黄色葡萄球菌中比在耐甲氧西林金黄色葡萄球菌中更为丰富。本研究首次提供了瑞士健康马中金黄色葡萄球菌流行率和类型的信息，并揭示了一种可能导致马和人感染的菌株来源。
