Clostridioides difficile in Pigs and Dairy Cattle in Northern Italy: Prevalence, Characterization and Comparison between Animal and Human Strains

Abstract

It has been observed that novel strains of Clostridioides difficile can rapidly emerge and move between animal and human hosts. The aim of this study was to investigate the prevalence of C. difficile in pigs and dairy cattle in northern Italy and to characterize and compare C. difficile animal strains with those from patients from the same geographical area. The C. difficile strains were isolated from animals from farms and slaughterhouses (cross-sectional studies) and from neonatal animals with enteric disorders in routine diagnostic investigations (passive surveillance). Samples positive for C. difficile were found in 87% of the pig farms and in 40% of the cattle farms involved in the cross-sectional studies, with a 20% prevalence among suckling piglets and 6.7% prevalence in neonatal calves, with no significant difference between animals with and without diarrheal symptoms. The prevalence of C. difficile in older animal categories was significantly lower. This result suggests that young age is an important risk factor for C. difficile colonization. In cross-sectional studies at slaughterhouses, in both the heavy pigs and dairy cows examined, only 2% of the intestinal content samples were positive for C. difficile and no contamination was found on the surface of the carcasses. Considering passive surveillance, the prevalence rates of positive samples were 29% in piglets and 1.4% in calves. Overall, 267 strains of animal origin and 97 from humans were collected. In total, 39 ribotypes (RTs) were identified, with RT 078 and RT 018 being predominant among animals and humans, respectively. Several RTs overlapped between animals and patients. In particular, RT 569 was identified as an emergent type in our country. Resistance to erythromycin and moxifloxacin was widely diffused among C. difficile strains, regardless of origin. This study supports C. difficile as a pathogen of one-health importance and highlights the need for a collaborative approach between physicians and veterinarians to control and prevent infections that are able to cross species and geographical barriers.

Clostridioides difficile from Fecally Contaminated Environmental Sources: Resistance and Genetic Relatedness from a Molecular Epidemiological Perspective

“…RT126 was predominately detected in the feces of calves. RT126 has already been described in cattle [21,44] and pigs [44,48]. Furthermore, RT126 has been observed as one of the predominant RTs in a veal calf farm in Belgium [49].…”

“…The impact of environmental sources for CDI development is still poorly understood. The presence of toxigenic or non-toxigenic C. difficile has been documented in different environmental sources outside healthcare institutions, such as animal feces, manure, soil, food, and municipal WWTPs [17,21,22,24,44], which could be served as potential sources of CA-CDI.…”

“…Of note, RT078, which is commonly associated with CA-CDI, was isolated from 19%, 8%, 35%, and 60% of primary sludge, digested sludge, biosolids, and river sediments, respectively [25], suggesting that RT078 strains might have resistance mechanisms that could enhance its survival during sewage sludge treatment. Furthermore, the RT078 is frequently reported in farm animals, such as cattle [21,44,52,53], poultry [54], and pigs [26,44,55]. Its epidemiologic importance concerning humans might be illustrated in that RT078 was among the five most frequently encountered RTs in Europe [56].…”

Design and Development of Molecular Beacon-Based Real-Time PCR Assays to Identify Clostridioides difficile Types of Main Evolutionary Clades

“…These RTs, such as RT 027, RT 014/020, RT 078, and more recently, RT 023, are associated to a higher occurrence and severity of infection in humans [4,6,7,[12][13][14], but they have also been identified as a cause of infection in animals and are isolated in food and environments [4][5][6][7]9,13,15]. Different domestic and wild animal species can be colonized and infected by C. difficile, including food-producing animals [4,[16][17][18]. In general, although the pathological lesions observed in animals with CDI are similar to those described in humans [9], clinical manifestations can vary among the different animal species [4,16].…”

“…Among food-producing animals, CDI prevalence has been reported globally in both swine (mean value 43%, range 0-100%) and cattle (mean value 14%, range 0.5-56.4%) [19]. In particular, CDI prevalence and mortality is very high in neonatal piglets with rates that can reach up to 100% and 50%, respectively [4,16,[18][19][20][21]. For these reasons, CDI not only has a significant impact on the health of the animals but, in the case of food-production animals, also a relevant economic burden for industries [19].…”