There is an increasing concern about the role of animals as reservoirs of Clostridioides difficile. In this study, we investigated prevalence, antimicrobial resistance and zoonotic potential of C. difficile in dogs. Two-hundred and twenty-five dog faecal deposits were collected from trashcans in nine public gardens. C. difficile was isolated using selective plating and enrichment culture, identified by MALDI-TOF, tested for susceptibility to seven antibiotics by E-test, and sequenced on an Illumina NextSeq platform. Genome sequences were analysed to determine multilocus sequence types and resistance and toxin gene profiles. Zoonotic potential was assessed by measuring genetic variations of core genome (cg)MLST types between canine isolates and 216 temporally and spatially related human clinical isolates from a national database. C. difficile was isolated from 11 samples (4.9%). Seven isolates were toxigenic (tcdA+, tcdB+, cdtA/B-) and belonged to the sequence types ST2, ST6, ST10 and ST42. The four non-toxigenic isolates were assigned to ST15, ST26 and one novel ST. ST2, corresponding to PCR ribotype RT014/020, was the dominating lineage (n = 4) and, together with ST26 and ST42 isolates, showed close resemblance to human isolates, i.e. 2-5 allelic differences among the 1999 genes analysed by cgMLST. Three non-toxigenic isolates displayed resistance to clindamycin, erythromycin and tetracycline mediated by erm(B) and tet(M). Resistance to metronidazole, moxifloxacine, rifampicin or vancomycin was not detected. In conclusion, a small proportion of faecal deposits contained toxigenic C. difficile such as ST2 (RT014/020), which is a major cause of community-acquired infections. Our finding suggests that pathogenic strains can be exchanged between dogs and humans.

人们越来越关注动物作为艰难梭菌宿主的作用。在这项研究中，我们调查了犬中艰难梭菌的流行率、抗菌素耐药性和人畜共患病的可能性。从九个公共花园的垃圾桶中收集了 225 份狗粪便沉积物。艰难梭菌使用选择性铺板和富集培养分离，由 MALDI-TOF 鉴定，通过 E-test 测试对七种抗生素的敏感性，并在 Illumina NextSeq 平台上测序。分析基因组序列以确定多位点序列类型以及抗性和毒素基因谱。通过测量犬分离株和来自国家数据库的 216 种时间和空间相关的人类临床分离株之间核心基因组 (cg) MLST 类型的遗传变异来评估人畜共患病潜力。从 11 个样品中分离出艰难梭菌(4.9%)。7 个分离株具有毒性（tcdA +、tcdB +、cdtA/B-) 并且属于序列类型 ST2、ST6、ST10 和 ST42。四种无毒株被分配到 ST15、ST26 和一种新型 ST。ST2 对应于 PCR 核糖型 RT014/020，是主要谱系 (n = 4)，并且与 ST26 和 ST42 分离株显示出与人类分离株的密切相似性，即 cgMLST 分析的 1999 基因之间有 2-5 个等位基因差异。三个非产毒分离株显示出对克林霉素、红霉素和四环素的抗性，由erm(B)和tet(M)介导。未检测到对甲硝唑、莫西沙星、利福平或万古霉素的耐药性。总之，一小部分粪便沉积物中含有产毒艰难梭菌例如 ST2 (RT014/020)，这是社区获得性感染的主要原因。我们的发现表明致病菌株可以在狗和人之间交换。