Servicio de Microbiología, Hospital Universitario Son Espases and Instituto Universitario de Investigaciones en Ciencias de la Salud (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain.
Int J Med Microbiol. 2013 Apr;303(3):128-33. doi: 10.1016/j.ijmm.2013.02.016. Epub 2013 Mar 22.
Epidemiological surveillance of Clostridium difficile infection has gained importance in recent years as a result of the rapid spread of epidemic strains, including hypervirulent strains and strains with reduced susceptibility to antimicrobials. The molecular epidemiology and antimicrobial susceptibility of C. difficile in the reference hospital of the Balearic Islands (Spain) is reported in this study. One hundred isolates of toxigenic C. difficile from different patients were selected using rapid dual EIA screening test. All isolates were characterized through toxin profile, PCR ribotyping and, in addition, multi-locus sequence typing (MLST) was performed on fifty selected strains. MICs to metronidazole, vancomycin, erythromycin and moxifloxacin were also determined. A total of 43 different ribotypes were distinguished, with higher prevalence of ribotype 014 (34%). Twenty one per cent of the isolates expressed binary toxin and it is noteworthy that 62% of these were identified as the hypervirulent ribotype 078, the second most prevalent ribotype found in our hospital (13%). A total of 20 different sequence types (STs) were found, including a new described allele and ST. MLST data showed a clear concordance between some ribotypes and STs, mainly represented by ribotype 014/ST-2, ribotype 078/ST-11 and ribotype 001/ST-3. Phylogenetic analysis also revealed that most of the isolates were genetically related, forming a large clonal complex. Finally, ribotypes 078 (ST-11) and 001 (ST-3) were associated with higher resistance to erythromycin and to erythromycin and moxifloxacin, respectively. All these data suggest that the combination of ribotyping and MLST is a good tool for the surveillance of the changing epidemiology of C. difficile. A wide dissemination of clones has been observed in our setting, ribotype 014 (ST-2) being the most prevalent followed by the hypervirulent ribotype 078 (ST-11) and ribotype 001 (ST-3), their spread in our setting probably influenced by their higher resistance.
近年来，由于流行菌株（包括高毒力菌株和对抗微生物药物敏感性降低的菌株）的快速传播，艰难梭菌感染的流行病学监测变得越来越重要。本研究报告了巴利阿里群岛（西班牙）参考医院的艰难梭菌的分子流行病学和药敏情况。使用快速双重 EIA 筛选试验从不同患者中选择了 100 株产毒艰难梭菌分离株。所有分离株均通过毒素谱、PCR 核糖体分型进行鉴定，此外，还对 50 株选定的菌株进行了多位点序列分型（MLST）。还测定了甲硝唑、万古霉素、红霉素和莫西沙星的 MIC。共区分出 43 种不同的核糖体型，其中 014 核糖体型的流行率较高（34%）。21%的分离株表达二元毒素，值得注意的是，其中 62%被鉴定为高毒力核糖体型 078，这是我们医院发现的第二大流行核糖体型（13%）。共发现 20 种不同的序列类型（ST），包括一个新描述的等位基因和 ST。MLST 数据显示，某些核糖体型和 ST 之间存在明显的一致性，主要代表为核糖体型 014/ST-2、核糖体型 078/ST-11 和核糖体型 001/ST-3。系统发育分析还表明，大多数分离株在遗传上是相关的，形成了一个大的克隆复合体。最后，核糖体型 078（ST-11）和 001（ST-3）分别与红霉素和红霉素加莫西沙星的耐药性增加有关。所有这些数据表明，核糖体分型和 MLST 的结合是监测艰难梭菌不断变化的流行病学的良好工具。在我们的环境中观察到了克隆的广泛传播，014 核糖体型（ST-2）是最流行的，其次是高毒力的 078 核糖体型（ST-11）和 001 核糖体型（ST-3），它们在我们环境中的传播可能是由于它们的耐药性更高所致。
