Isolation and screening of Lactobacillus species from dogs for probiotic action

The present study aimed at the detection of suitable Lactobacillus species from dogs for usage as probiotic. A total of 67 rectal swabs from healthy pups were analyzed and 49 (73.1%) Lactobacillus isolates were identified based on morphological, biochemical characteristics and confirmed by genus specific PCR targeting 16S rRNA gene. A total of 20 isolates that showed strong aggregation, high cell surface hydrophobicity, acid and bile tolerance were screened for in-vitro antibacterial activity by agar well diffusion assay, where prominent inhibitory zones were observed against majority of the test pathogens. Reduction in antibacterial activity was noticed after neutralization, proteinase K and heat treatment of supernatants. Partial 16S rRNA nucleotide sequence analysis of seven Lactobacillus isolates that showed prominent in-vitro antibacterial activity revealed maximum sequence homology with Lactobacillus fermentum (for six isolates) and Lactobacillus agilis (for one isolate). The in-vitro antibacterial activity results highlighted the need for in-vivo studies in India to establish probiotic potential of canine faecal Lactobacillus species in the near future.