The Comparative Pathology ofClostridium difficile-associated Disease

Abstract

Abstract. Clostridium difficile is a confirmed pathogen in a wide variety of mammals, but the incidence of disease varies greatly in relation to host species, age, environmental density of spores, administration of antibiotics, and possibly, other factors. Lesions vary as well, in severity and distribution within individuals, and in some instances, age groups, of a given species. The cecum and colon are principally affected in most species, but foals and rabbits develop severe jejunal lesions. Explanations for variable susceptibility of species, and age groups within a species, are largely speculative. Differences in colonization rates and toxin-receptor densities have been proposed. Clostridium difficile-associated disease is most commonly diagnosed in Syrian hamsters, horses, and neonatal pigs, but it is reported sporadically in many other species. The essential virulence factors of C. difficile are large exotoxins, toxin A (TcdA) and toxin B (TcdB). Receptor-mediated endocytosis of the toxins is followed by endosomal acidification, a necessary step for conversion of the toxin to its active form in the cytosol. Cell-surface receptors have been characterized for TcdA, but remain to be identified for TcdB. Both TcdA and TcdB disrupt the actin cytoskeleton by disrupting Rho-subtype, intracellular signaling molecules. Disruption of the actin cytoskeleton is catastrophic for cellular function, but inflammation and neurogenic stimuli are also involved in the pathogenesis of the disease.

Detection of enterotoxin A and cytotoxin B, and isolation of Clostridium difficile in piglets in Minas Gerais, Brazil

“…In addition, the carrier state of C. difficile seems to vary among asymptomatic individuals by species and within the same species, depending on age and other population characteristics (KEEL & SONGER, 2006). According to ARROYO et al (2007), the high frequency of variant strains may complicate the diagnosis of diarrhea due to C. difficile since there are several commercial ELISA kits designed to detect only toxin A, which might cause false-negative results.…”

Equine Colitis X Associated with Infection by Clostridium Difficile NAP1/027

“…Differences in colonization rates and toxin-receptor densities have been proposed as explanations for variable susceptibility of species and age groups within a species. 15 Clostridium difficile causes hemorrhagic, necrotizing enterocolitis with high mortality in foals. 2 The organism and its toxins are very common in feces of diarrheic foals but uncommon in normal foals.…”

Community-acquired Clostridium difficile infection and Australian food animals

“…difficile is an enteric pathogen of companion animals (cats, dogs, horses) and food animals (cattle, sheep, goats, pigs) 13,14 . Neonates are typically colonised with C. difficile due to the lack of colonisation resistance afforded by mature intestinal microflora; hence prevalence decreases with age 15,16 .…”