Developing Gut Microbiota Exerts Colonisation Resistance to Clostridium (syn. Clostridioides) difficile in Piglets

Abstract

<i>Clostridium</i> (syn. <i>Clostridioides</i>) <i>difficile</i> is considered a pioneer colonizer and may cause gut infection in neonatal piglets. The aim of this study was to explore the microbiota-<i>C. difficile</i> associations in pigs. We used the DNA from the faeces of four sows collected during the periparturient period and from two to three of their piglets (collected weekly until nine weeks of age) for the determination of bacterial community composition (sequencing) and <i>C. difficile</i> concentration (qPCR). Furthermore, <i>C. difficile</i>-negative faeces were enriched in a growth medium, followed by qPCR to verify the presence of this bacterium. <i>Clostridium</i>-sensu-stricto-1 and <i>Lactobacillus</i> spp. predominated the gut microbiota of the sows and their offspring. <i>C. difficile</i> was detected at least once in the faeces of all sows during the entire sampling period, albeit at low concentrations. Suckling piglets harboured <i>C. difficile</i> in high concentrations (up to log₁₀ 9.29 copy number/g faeces), which gradually decreased as the piglets aged. Enrichment revealed the presence of <i>C. difficile</i> in previously <i>C. difficile</i>-negative sow and offspring faeces. In suckling piglets, the <i>C. difficile</i> level was negatively correlated with carbohydrate-fermenting bacteria, and it was positively associated with potential pathogens. Shannon and richness diversity indices were negatively associated with the <i>C. difficile</i> counts in suckling piglets. This study showed that gut microbiota seems to set conditions for colonisation resistance against <i>C. difficile</i> in the offspring. However, this conclusion requires further research to include host-specific factors.