Colitis caused by Clostridioides difficile infection in a domestic dog: A case report.

Clostridioides difficile has been identified as one of the primary etiologic agents of nosocomial diarrhea and pseudomembranous colitis in humans and other mammals associated following broad-spectrum antibiotics use. In Rio de Janeiro, Brazil we describe a case of C. difficile infection (CDI) in a 13-year-old male dog.

Characterization of Clostridioides difficile ribotypes in domestic dogs in Rio de Janeiro, Brazil.

Clostridioides difficile is the major etiologic agent of nosocomial bacterial diarrhoea and pseudomembranous colitis. The pathogenesis of C. difficile infection (CDI)involves two cytotoxic enzymes (TcdA, TcdB) that cause colonic epithelial damage, fluid accumulation and enteritis. CDI has been demonstrated in a variety of animal species and some reports have recently raised the importance of wild animals as a reservoir of this pathogen and possible transmission to humans and domestic animals. The aim of this study was to characterize C. difficile isolates obtained from pet dogs in Rio de Janeiro, Brazil. A total of 50 faecal samples were obtained from healthy and diarrheic dogs. Five of fifty samples (10%) grew C. difficile. Of those, three belonged to the PCR ribotype 106 (ST 42) and were toxigenic (A+B+). The other two strains belonged to the PCR ribotype 010 (ST 15) and were not toxin producers (A-B-). None of the isolates tested positive for the binary toxin genes. Considering the antimicrobial resistance patterns of all isolates using EUCAST breakpoints, all strains were sensitive to metronidazole and vancomycin. However, two strains (ribotype 106 and ribotype 010), were resistant to clindamycin (≤256 µg/mL). All strains were strong biofilm producers. Our study provides evidence that dogs can act as reservoirs for C. difficile epidemic ribotypes.

Whole-genome sequencing of Staphylococcus epidermidis bloodstream isolates from a prospective clinical trial reveals that complicated bacteraemia is caused by a limited number of closely related sequence types.

OBJECTIVES: The significance of isolating Staphylococus epidermidis from a blood culture is highly heterogeneous, ranging from contamination to an indication of a serious infection. Herein we sought to determine whether there is a relationship between S. epidermidis genotype and clinical severity of bacteraemia. METHODS: S. epidermidis bacteraemias from a prospective, multicentre trial at 15 centres in the United States and one in Spain were classified as simple (including possible contamination), uncomplicated, and complicated. Whole-genome sequencing (WGS) was performed on 161 S. epidermidis isolates, and clinical outcomes were correlated with genotypic information. RESULTS: A total of 49 S. epidermidis sequence types (STs) were identified. Although strains of all 49 STs were isolated from patients with either simple or uncomplicated infection, all strains causing complicated infections were derived from five STs: ST2, ST5, ST7, ST16, and ST32. ST2 and ST5 isolates were significantly more likely to cause uncomplicated and complicated bloodstream infections compared to simple bacteraemia (odds ratio 2.0, 95%CI 1.1-3.9, p 0.04). By multivariate regression analysis, having an ST2 or ST5 S. epidermidis bacteraemia was an independent predictor of complicated bloodstream infection (odds ratio 3.7, 95%CI 1.2-11.0, p 0.02). ST2/ST5 strains carried larger numbers of antimicrobial resistance determinants compared to non-ST2/ST5 isolates (6.34 ± 1.5 versus 4.4 ± 2.5, p < 0.001). CONCLUSION: S. epidermidis bacteraemia was caused by a genetically heterogeneous group of organisms, but only a limited number of STs-particularly multidrug-resistant ST2 and ST5 strains-caused complicated infections.