Kecerova Zuzana, Cizek Alois, Nyc Otakar, Krutova Marcela
Equine Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic.
Institute of Infectious Diseases and Microbiology, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic; Central European Institute of Technology, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic.
Anaerobe. 2019 Apr;56:17-21. doi: 10.1016/j.anaerobe.2019.01.005. Epub 2019 Jan 7.
Clostridium difficile has been recovered from the faeces of several animal species as well as horses. Between April 2015 and October 2016, 213 samples of faeces from non-hospitalized (n = 138) and hospitalized horses (n = 75) were investigated and eighteen C. difficile isolates were cultured using an enrichment method. Sixteen C. difficile positive samples were identified from hospitalised horses (p < 0.01). Molecular typing revealed seven ribotypes and sequence types (RT033/ST11 n = 8, 44.4%; RT081/ST9 n = 4, 22.2%; RT009/ST3 n = 2, 11.1%; RT003/ST12 n = 1, 5.6%; RT010/ST15 n = 1, 5.6%; RT012/ST54 n = 1, 5.6%; RT039/ST26 n = 1, 5.6%). Seven identified STs clustered to two clades (1 and 5). All C. difficile isolates were susceptible to amoxicillin, metronidazole, moxifloxacin, and vancomycin. One isolate (RT039) exhibited a high level of resistance to erythromycin and clindamycin (256 mg/L) and carried the ermB, adenine methylase gene. Five isolates were resistant to clindamycin at lower minimal inhibitory concentrations (MICs = 8-16 mg/L) and were susceptible to erythromycin and also ermB negative. All isolates were resistant to enrofloxacin (MICs ranged between 4 and 32 mg/L). Eight isolates were resistant to tetracycline (MICs 12-32 mg/L). Of them, four isolates carried the tetM gene and four isolates the tetW gene. In addition, the tetracycline resistance determinants identified were: tetA (P) (n = 4); tetB (P); and tetL (n = 1 each). The presence of tetW or tetM, together with other tet-class mechanisms, lead to an increase in the MICs to tetracycline. C. difficile isolates derived from Czech horses are identical to the ribotypes identified in humans and carry acquired antimicrobial resistance genes whose dissemination from veterinary healthcare sector to humans should be monitored by the "One health" approach.
艰难梭菌已从包括马在内的多种动物粪便中分离出来。在2015年4月至2016年10月期间，对213份来自非住院马（n = 138）和住院马（n = 75）的粪便样本进行了调查，并采用富集培养法培养出18株艰难梭菌分离株。从住院马中鉴定出16份艰难梭菌阳性样本（p < 0.01）。分子分型显示有7种核糖体分型和序列分型（RT033/ST11，n = 8，占44.4%；RT081/ST9，n = 4，占22.2%；RT009/ST3，n = 2，占11.1%；RT003/ST12，n = 1，占5.6%；RT010/ST15，n = 1，占5.6%；RT012/ST54，n = 1，占5.6%；RT039/ST26，n = 1，占5.6%）。鉴定出的7种序列型聚为两个进化枝（1和5）。所有艰难梭菌分离株对阿莫西林、甲硝唑、莫西沙星和万古霉素敏感。1株分离株（RT039）对红霉素和克林霉素表现出高水平耐药（256 mg/L），并携带ermB腺嘌呤甲基化酶基因。5株分离株对克林霉素耐药，最低抑菌浓度较低（MICs = 8 - 16 mg/L），对红霉素敏感且ermB阴性。所有分离株对恩诺沙星耐药（MICs范围为4至32 mg/L）。8株分离株对四环素耐药（MICs为12 - 32 mg/L）。其中，4株携带tetM基因，4株携带tetW基因。此外，鉴定出的四环素耐药决定簇为：tetA(P)（n = 4）；tetB(P)；tetL（各n = 1）。tetW或tetM的存在，以及其他四环素类耐药机制，导致对四环素的MICs升高。源自捷克马的艰难梭菌分离株与在人类中鉴定出的核糖体分型相同，并携带获得性抗菌药物耐药基因，应通过“同一健康”方法监测其从兽医医疗领域向人类的传播。
