Clostridium (Clostridioides) difficile is the main cause of nosocomial diarrhoea. Ribotype 018 (RT018) has been recognized as the predominant strain responsible for C. difficile infection (CDI) in Italy, whereas in most other European countries only sporadic RT018 cases occur.

Between August and October 2015, a suspected C. difficile outbreak at two associated hospitals in Southern Germany was investigated by comprehensive molecular typing. Surprisingly, RT018 was detected in 9/82 CDI patients, which has never been described before in a German outbreak. Phenotypic analysis revealed fluoroquinolone and macrolide resistance. Genetic subtyping using multiple-locus variable-number tandem-repeat analysis (MLVA) and whole genome sequencing (WGS) was performed and outbreak isolates were directly compared to sporadic German RT018 isolates and to epidemic ones from Milan, Northern Italy. Molecular typing confirmed a hospital outbreak with closely related RT018 isolates. Both, MLVA and WGS revealed high similarity of outbreak strains with epidemic isolates from Italy, but low similarity to other German isolates. Comparison between both typing strategies showed that ribotyping in combination with MLVA was appropriate to identify related isolates and clonal complexes, whereas WGS provided a better discrimination with more detailed information about the phylogenetic relationship of isolates. This is the first hospital outbreak in Germany presumably caused by cross-national transmission of an Italian epidemic RT018 strain.

艰难梭菌（Clostridioides）是引起医院腹泻的主要原因。在意大利，核型018（RT018）被认为是引起艰难梭菌感染（CDI）的主要菌株，而在其他大多数欧洲国家中，仅出现零星的RT018病例。

在2015年8月至2015年10月之间，疑似艰难梭菌通过全面的分子分型对德国南部两家相关医院的暴发进行了调查。出乎意料的是，在9/82名CDI患者中检测到RT018，这在德国暴发中从未有过描述。表型分析显示氟喹诺酮和大环内酯类耐药。使用多基因座可变数串联重复分析（MLVA）和全基因组测序（WGS）进行了基因分型，并将暴发分离株与零星的德国RT018分离株以及意大利北部米兰的流行株进行了直接比较。分子分型证实了与密切相关的RT018分离株的医院暴发。MLVA和WGS均显示暴发菌株与来自意大利的流行病分离株高度相似，但与其他德国分离株相似。两种分型策略之间的比较表明，结合MLVA进行核糖分型适合鉴定相关的分离株和克隆复合体，而WGS可以提供​​更好的区分能力，并提供有关分离株的系统发生关系的更详细的信息。这是德国第一起医院暴发，可能是由意大利流行的RT018毒株的跨国传播引起的。