Finsterwalder S K, Loncaric I, Cabal A, Szostak M P, Barf L M, Marz M, Allerberger F, Burgener I A, Tichy A, Feßler A T, Schwarz S, Monecke S, Ehricht R, Ruppitsch W, Spergser J, Künzel F
Institute of Microbiology, University of Veterinary Medicine Vienna, Vienna, Austria.
Clinical Unit of Internal Medicine Small Animals, University of Veterinary Medicine Vienna, Vienna, Austria.
Zoonoses Public Health. 2022 Sep;69(6):673-681. doi: 10.1111/zph.12956. Epub 2022 May 12.
While previous research on zoonotic transmission of community-acquired Clostridioides difficile infection (CA-CDI) focused on food-producing animals, the present study aimed to investigate whether dogs are carriers of resistant and/or virulent C. difficile strains. Rectal swabs were collected from 323 dogs and 38 C. difficile isolates (11.8%) were obtained. Isolates were characterized by antimicrobial susceptibility testing, whole-genome sequencing (WGS) and a DNA hybridization assay. Multilocus sequence typing (MLST), core genome MLST (cgMLST) and screening for virulence and antimicrobial resistance genes were performed based on WGS. Minimum inhibitory concentrations for erythromycin, clindamycin, tetracycline, vancomycin and metronidazole were determined by E-test. Out of 38 C. difficile isolates, 28 (73.7%) carried genes for toxins. The majority of isolates belonged to MLST sequence types (STs) of clade I and one to clade V. Several isolates belonged to STs previously associated with human CA-CDI. However, cgMLST showed low genetic relatedness between the isolates of this study and C. difficile strains isolated from humans in Austria for which genome sequences were publicly available. Four isolates (10.5%) displayed resistance to three of the tested antimicrobial agents. Isolates exhibited resistance to erythromycin, clindamycin, tetracycline and metronidazole. These phenotypic resistances were supported by the presence of the resistance genes erm(B), cfr(C) and tet(M). All isolates were susceptible to vancomycin. Our results indicate that dogs may carry virulent and antimicrobial-resistant C. difficile strains.
虽然先前关于社区获得性艰难梭菌感染（CA-CDI）人畜共患传播的研究主要集中在食用动物上，但本研究旨在调查狗是否为耐药和/或毒力艰难梭菌菌株的携带者。从323只狗身上采集直肠拭子，获得了38株艰难梭菌分离株（11.8%）。通过抗菌药物敏感性试验、全基因组测序（WGS）和DNA杂交试验对分离株进行鉴定。基于WGS进行多位点序列分型（MLST）、核心基因组MLST（cgMLST）以及毒力和抗菌耐药基因筛查。采用E-test法测定红霉素、克林霉素、四环素、万古霉素和甲硝唑的最低抑菌浓度。在38株艰难梭菌分离株中，28株（73.7%）携带毒素基因。大多数分离株属于进化枝I的MLST序列类型（STs），1株属于进化枝V。有几株分离株属于先前与人类CA-CDI相关的STs。然而，cgMLST显示本研究的分离株与奥地利公开基因组序列的从人类分离的艰难梭菌菌株之间的遗传相关性较低。4株分离株（10.5%）对三种测试抗菌药物耐药。分离株对红霉素、克林霉素、四环素和甲硝唑耐药。这些表型耐药性由耐药基因erm(B)、cfr(C)和tet(M)的存在所证实。所有分离株对万古霉素敏感。我们的结果表明，狗可能携带毒力和抗菌耐药的艰难梭菌菌株。
