Unveiling the culturable bacterial diversity, pathogens and impact of seasonality on microflora of raw goat milk: A phylogenetic outlook

Abstract

Goat milk can be beneficial in cardiac diseases, mouth ulcers, dengue fever, etc. but ingestion of raw goat milk may have severe side effects as it may comprise pathogenic bacteria. Raw goat milk samples (n-55) were collected from diverse villages of the Udaipur district, Rajasthan, India and analyzed for bacterial diversity and pathogens using biochemical, molecular, and bioinformatic methods. Goat milk samples displayed an incidence of 36.36% for bacterial pathogens and the most prevalent bacteria reported were Listeria spp. and Staphylococcus spp. Bacillus cereus and Staphylococcus xylosus showed high resistance to tested antibiotics followed by Listeria. The dominant phylum found in the raw goat milk was Firmicutes (67.47%) and the dominant genus was Bacillus (28.32%). Listeria sp. was found dominant during the winter season while Staphylococcus spp. was dominant during summer. Three novel species were identified viz. S. xylosus (GM61), Streptomyces sp. C7 (GM2) and Pantoea agglomerans (GM31) can be further explored for their potential applications as bacteriocin producers' which can be used as food preservatives. New antibiotics or any antimicrobial produced by these three novel species can be used for the treatment of diseases. Pseudomonas yangonensis and Streptomyces sp. have not been previously reported in goat milk at the global level while S. xylosus at the National level.