Storage procedures and time influence the detectability of Clostridium difficile toxin A but not toxin B in porcine fecal specimens

Abstract

Storage procedures are known to affect the detectability of Clostridium difficile toxins in equine and human feces. We assessed the impact of different storage conditions on the detectability of C. difficile toxins in swine feces. Specimens were inoculated with toxins, 112 ng/g of toxin A (TcdA) and 16 ng/g of toxin B (TcdB) and subjected to the following 3 storage treatments: 4°C, −30°C, repetitive freezing at −30°C and thawing. Toxin determination was assessed at 1, 2, 7, 14, and 21 d with ELISA. A decrease in concentrations of TcdA with time was observed for samples stored at 4°C and repetitive freezing–thawing ( p ≤0.05). On day 14, storage at 4°C resulted in decreased TcdA concentration as opposed to storage at −30°C and repetitive freezing–thawing ( p ≤0.05). On day 21, storage at 4°C resulted in decreased TcdA detectability compared with storage at −30°C ( p ≤0.05). The TcdB concentration was unaffected. These results on toxin detectability in swine feces should be carefully considered in in vitro studies on toxigenic C. difficile. Our results also offer valuable information for microbiologists and veterinarians monitoring the presence of virulent C. difficile in pigs.

Influence of high‐ and low‐fermentable dietary fibres in sows' diet on the colostrum potential against Clostridioides difficile toxin‐induced effects in IPEC‐J2 cells

“…Clostridioides difficile toxins are considered the primary agents causing intestinal epithelial damage being a main factor in the aetiology of C. difficile ‐infection (CDI) in neonatal piglets (Nusrat et al, 2001; Grześkowiak et al, 2018, 2020a). Specifically, toxin A (TcdA) and toxin B (TcdB) are important determinants in the veterinary diagnostic investigations of CDI (Knight et al, 2014; Grześkowiak et al, 2020b). The prevalence of toxin‐positive piglets on farms and in experimental units can vary vastly and non‐diarrhoeic besides diarrhoeic piglets often test positive for either TcdA or TcdB (Alvarez‐Perez et al, 2009; Grześkowiak et al, 2016; Songer & Uzal, 2005).…”