Guérin François, Fines-Guyon Marguerite, Meignen Pierrick, Delente Géraldine, Fondrinier Caroline, Bourdon Nancy, Cattoir Vincent, Léon Albertine
Université de Caen Normandie, EA 4655 (équipe "Antibio-résistance"), F-14032, Caen, France.
CHU de Caen, Service de Microbiologie & CNR de la Résistance aux Antibiotiques (laboratoire associé "entérocoques et résistances particulières des bactéries à Gram positif"), Av. Côte de Nacre, 14033, Caen, Cedex 9, France.
BMC Microbiol. 2017 May 3;17(1):104. doi: 10.1186/s12866-016-0924-z.
The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolated in horse infections is not well documented, especially in France. The aim of the study was to evaluate the prevalence of MRSA isolates in horse infections from 2007 to 2013 in France and to characterize phenotypically and genotypically this collection.
Out of 1393 S. aureus horse isolates, 85 (6.1%) were confirmed to be MRSA. Interestingly, the prevalence of MRSA significantly increased from 2007-2009 to 2010-2013 (0.7 vs. 9.5%, P <0.0001). Resistance to methicillin was due to the presence of the mecA gene in 84 strains (98.8%) while one strain (1.2%) possessed the mecC gene. The vast majority of the strains (83/85, 97.6%) was resistant to at least three different classes of antibiotics. Multi-locus sequence typing (MLST) showed that MRSA strains belonged mainly since not all belong to two sequence types (STs): ST398 (53/85, 62.4%) and ST8 (28/85, 32.9%). It is worth to note that all ST398 MRSA isolates were detected in the period 2010-2013. Other molecular typing methods were also used, such SCC analysis, spa typing and rep-PCR (Diversilab, bioMérieux). All these four techniques were in good agreement, with spa typing and rep-PCR being more discriminative than MLST and SCC typing.
This study is the first epidemiological study in France with extensive characterization of MRSA isolates associated with horse infections in stud farms. It shows that there is a significant increase of MRSA prevalence between 2007 and 2013, which mainly results from the spread of ST398 clones. It also highlights the importance of horses as a potential reservoir of important antimicrobial resistance genes.
在马匹感染中分离出的耐甲氧西林金黄色葡萄球菌（MRSA）的流行病学情况尚无充分记录，尤其是在法国。本研究的目的是评估2007年至2013年法国马匹感染中MRSA分离株的流行情况，并对该菌株进行表型和基因型特征分析。
在1393株金黄色葡萄球菌马匹分离株中，85株（6.1%）被确认为MRSA。有趣的是，MRSA的流行率从2007 - 2009年到2010 - 2013年显著增加（0.7%对9.5%，P <0.0001）。84株（98.8%）菌株对甲氧西林的耐药性是由于存在mecA基因，而1株（1.2%）拥有mecC基因。绝大多数菌株（83/85，97.6%）对至少三类不同抗生素耐药。多位点序列分型（MLST）显示，MRSA菌株主要属于（并非全部属于）两种序列类型（STs）：ST398（53/85，62.4%）和ST8（28/85，32.9%）。值得注意的是，所有ST398 MRSA分离株均在2010 - 2013年期间检测到。还使用了其他分子分型方法，如SCC分析、spa分型和rep-PCR（生物梅里埃公司的Diversilab）。这四种技术的结果高度一致，其中spa分型和rep-PCR比MLST和SCC分型更具鉴别力。
本研究是法国首次对种马场中与马匹感染相关的MRSA分离株进行广泛特征分析的流行病学研究。研究表明，2007年至2013年间MRSA流行率显著增加，这主要是由于ST398克隆的传播。它还突出了马匹作为重要抗菌耐药基因潜在储存库的重要性。
