Porcine and bovine Clostridium difficile ribotype 078 isolates demonstrate similar growth and toxigenic properties

Porcine Colostrum Protects the IPEC-J2 Cells and Piglet Colon Epithelium against Clostridioides (syn. Clostridium) difficile Toxin-Induced Effects

Clostridioides difficile toxins are one of the main causative agents for the clinical symptoms observed during C. difficile infection in piglets. Porcine milk has been shown to strengthen the epithelial barrier function in the piglet’s intestine and may have the potential to neutralise clostridial toxins. We hypothesised that porcine colostrum exerts protective effects against those toxins in the IPEC-J2 cells and in the colon epithelium of healthy piglets. The IPEC-J2 cells were treated with either the toxins or porcine colostrum or their combination. Analyses included measurement of trans-epithelial electrical resistance (TEER), cell viability using propidium iodide by flow cytometry, gene expression of tight junction (TJ) proteins and immune markers, immunofluorescence (IF) histology of the cytoskeleton and a TJ protein assessment. Colon tissue explants from one- and two-week-old suckling piglets and from five-week-old weaned piglets were treated with C. difficile toxins in Ussing chamber assays to assess the permeability to macromolecules (FITC-dextran, HRP), followed by analysis of gene expression of TJ proteins and immune markers. Toxins decreased viability and integrity of IPEC-J2 cells in a time-dependent manner. Porcine colostrum exerted a protective effect against toxins as indicated by TEER and IF in IPEC-J2 cells. Toxins tended to increase paracellular permeability to macromolecules in colon tissues of two-week-old piglets and downregulated gene expression of occludin in colon tissues of five-week-old piglets (p = 0.05). Porcine milk including colostrum, besides other maternal factors, may be one of the important determinants of early immune programming towards protection from C. difficile infections in the offspring.

Distinct patterns of microbial metabolic fingerprints in sows and their offspring: a pilot study

Microbial metabolism and growth in the intestinal tract depend on the composition of substrates present in the digesta and their ability to be metabolised by the microorganisms. The aim of this pilot study was to characterise potential hindgut microbial activity during perinatal period in sows and their offspring. Rectal samples from three sows (1-3 weeks before and after birth) and three of their piglets (1-5 weeks after birth), were subjected to assays using BIOLOG GEN III microplates to produce metabolic fingerprints for each animal. The number of metabolised substrates of the sow hindgut microbiota was stable during the pregnancy and lactation periods, as assessed by the richness index. In piglets, the richness was stable during the suckling period and at beginning of weaning, however, it decreased when the piglets were 5 weeks old (P ≤ 0.05). Analysis of associations between the sows and the piglets and the microbial metabolic potential showed that microbial metabolism was strongly associated with the catabolism of carbohydrates especially in sows. Only 5-week-old weaned piglets clustered together with the sows regarding the microbial catabolism of substrates, but not suckling piglets. The association analyses clustered all the piglets in two groups distinctive for litter. The analysis of metabolic fingerprints via microbial growth with different substrates can be useful to positively influence microbial community function such as selectively enhancing desirable active microbial populations to benefit health of the gut and the animal.

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

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.