Search of antimicrobial lactic acid bacteria from Salmonella-negative dogs

Abstract

Background Salmonellosis is one of the most important food-borne zoonotic disease affecting both animals and humans. The objective of the present study was to identify gastrointestinal (GI) lactic acid bacteria (LAB) of canine-origin from Salmonella-negative dogs’ faeces able to inhibit monophasic Salmonella Typhimurium previously isolated from dogs’ faeces, in order to be used as a potential probiotic in pet nutrition. Results Accordingly, 37 LAB were isolated from Salmonella-negative dogs’ faeces and tested against monophasic S. Typhimurium using the spot on lawn method out of which 7 strains showed an inhibition halo higher than 2.5 cm. These 7 strains were also tested with the co-culture method and one showed the greatest inhibition value (p < 0.05). Subsequently, the isolate was identified through 16S rRNA sequencing and sequence homology and designated as Ligilactobacillus salivarius (L. salivarius). LAB from Salmonella-positive dogs were also identified and none was the selected strain. Finally, to identify the mechanism of inhibition of L. salivarius, the supernatant was analyzed, and a dose response effect was observed. Conclusions It is concluded that the canine-origin L. salivarius, could possess some in vitro functional attributes of a candidate probiotic and could prevent monophasic S. Typhimurium colonization or inhibit its activity if the infection occurs.

Antibacterial potential of commercial and wild lactic acid bacteria strains isolated from ovine and caprine raw milk against Mycoplasma agalactiae

“…They were processed for genomic DNA extraction and identified based on PCR amplification and sequencing of 16S rRNA gene using bacterial universal primers (27F 5′-AGAGTTTGATCC TGGCTCAG and 1492R 5′-GGTT ACCTTGTTA CGACTT). The PCR was performed following the methodology previously described ( 21 ). The PCR products were purified, and sequenced and analyzed for sequence homology by BLAST.…”

Ligilactobacillus murinus Strains Isolated from Mice Intestinal Tract: Molecular Characterization and Antagonistic Activity against Food-Borne Pathogens

“…Molecular identification allowed the detection of a high proportion of L. murinus and one L. animalis. Specifically, L. murinus strains have been isolated from different niches, such as rodent gastrointestinal tract [39], dog feces [40], fermented dough [41], and marine sediments [19], while L. animalis has been found in the gastrointestinal tract of several animal species [42]. Furthermore, the identity matrix and the phylogenetic analysis determined the similarity between the sequences using the V2 variable region of the 16S rRNA gene from the 16 L. murinus strains and confirmed its close relationship with L. animalis, which has been described by several authors, identifying these two species at the same phylogenetic level with similarity percentages of up to 99% between 16S rRNA gene regions [41,43].…”

The impact of protein source and grain inclusion on digestibility, fecal metabolites, and fecal microbiome in adult canines

“…A specific strain of Lactobacillus acidophilus, when incorporated into dry dog food, demonstrated probiotic functions in adult dogs ( Baillon et al, 2004 ). One study by Jimenez-Trigos et al (2022) evaluated the potential of Ligilactobacillus salivarius being a probiotic in dogs and found functional probiotic attributes in an in vitro analysis. The increase in Megamonas was also depicted in previous research with dogs fed pulse-containing diets compared with grain-inclusive diets ( Sandri et al, 2019 ; Reilly et al, 2021b ).…”