A cross-sectional study to understand the correlation among Salmonella enterica infection and Lactobacillus reuteri concentration in fecal samples of post weaning piglets and their association in causation of diarrhea

Interaction among host gut microbiome and disease-causing organisms play an important role in the establishment of infection. Considering it, the relationship between the concentration of Lactobacillus reuteri and the level of Salmonella infection was assessed in the feces of post weaning piglets, in reference to diarrheic (sick) and healthy piglets. Eighty fecal samples from piglets (40-50 days of age) of eight different pig farms were examined. Piglets were classified as sick (diarrhea) and healthy (norm) by Indikal indicator paper method. Fecal samples were processed for the extraction of genomic DNA of Lactobacilli and Salmonella and subjected to real-time PCR to detect concentration of microorganisms in the sample. The results indicated that Salmonella infection did not directly affect the development of post weaning diarrheal syndrome in piglets. Positive correlation between the presence of reuteri and the PCR prevalence of salmonellosis in piglets was puzzling, since this contradicts a lot of literature data. The relationship between opportunistic intestinal microbiota and Lactobacilli of normal microflora is more complex under conditions of long-term coevolution. The probiotics based on L. reuteri may be more effective, provided that there was no long-term adaptation of Salmonella to Lactobacilli of this species.