Performance of commercial PCR assays to detect toxigenic Clostridioides difficile in the feces of puppies

• Published in: Veterinary medicine and science 2021-09, Vol.7 (5), p.1536-1541
• Main Authors: Anis, Eman, Barnart, Denise, Barnard, Amanda, Kelly, Donna J., Redding, Laurel E.
• Format: Article
• Language: English
• Subjects: Animals; Bacterial Toxins - analysis; Bacterial Toxins - genetics; Clostridioides; Clostridioides difficile; Clostridioides difficile - genetics; Dogs; Epidemiology; Feces; Feces - chemistry; Genes; Laboratories; Morbidity; Multiplex Polymerase Chain Reaction - veterinary; Original; Pathogens; PCR; Pets; Sensitivity and Specificity; validity; Veterinary medicine
• ISSN: 2053-1095; 2053-1095
• DOI: 10.1002/vms3.567

Clostridioides difficile is an important enteric pathogen that causes significant morbidity and mortality in humans. With community‐acquired infections on the rise, it is important to identify reservoirs of the pathogen. Companion animals can be asymptomatic carriers of C. difficile and may therefore represent a reservoir, but epidemiological studies of C. difficile within the pet‐owner unit are needed, along with validated methods to detect C. difficile in both people and animals. The goal of this study was to assess the performance of commercial qPCR assays and a multiplex PCR for C. difficile compared to toxigenic culture. These assays were tested on up to 103 fecal samples from puppies, a population in which the prevalence of C. difficile is the highest. The sensitivities, specificities, positive predictive values and negative predictive values were respectively 84.2%, 87.7%, 61.5%, and 95.9% for the Cepheid GeneXpert; 66.7%, 66.7%, 29.6%, and 90.9% for the DiaSorin Simplexa; and 94.4%, 85.0%, 65.4%, and 98.1%, for the multiplex qPCR. The agreement was highest between the GeneXpert and the multiplex PCR (90.1% agreement, with a kappa statistic of 0.77). For diagnostic purposes, the positive predictive values of the assays were low. However, the high sensitivities of the assays could render them useful for epidemiologic purposes. Companion animals might be a reservoir of Clostridioides difficile. Diagnostic assays that are validated in both people and pets are needed to conduct epidemiological investigations within the pet‐owner unit. We found that at least one commercial PCR assay to detect C. difficile in people is also highly sensitive in dogs and could therefore be used for epidemiological purposes within the pet‐owner unit.