RESUMEN
Background: This study aimed to characterize potential probiotic strains for use in dogs to prevent infectious enteropathies. Lactic acid bacteria (LAB) isolated from canine milk and colostrum were characterized according to their functional properties, including their resistance to gastrointestinal conditions, inhibitory effect against pathogens, and intestinal adhesion. Methods: The immunomodulatory effects of the strains were also analyzed in in vitro and in vivo studies. Among the strains evaluated, two LAB strains (TUCO-16 and TUCO-17) showed remarkable resistance to pH 3.0, bile salts, and pancreatin, as well as inhibitory effects against pathogenic Escherichia coli, Salmonella sp., and Clostridium perfringens. Results: The TUCO-16 and TUCO-17 strains induced a significant increase in the expression of TNF-α, IL-8, and TLR2 in canine macrophages. The oral administration of TUCO-16 and TUCO-17 strains to mice significantly augmented their resistance to pathogenic E. coli or Salmonella intestinal infections. Both canine strains reduced intestinal damage and pathogen counts in the liver and spleen and avoided their dissemination into the bloodstream. These protective effects were related to the ability of TUCO-16 and TUCO-17 strains to differentially modulate the production of IFN-γ, IFN-ß, TNF-α, IL-6, KC, MCP-1, and IL-10 in the intestinal mucosa. Conclusion: Both strains, TUCO-16 and TUCO-17, are potential probiotic candidates for improving intestinal health in dogs, particularly for their ability to inhibit the growth of Gram-negative pathogens common in gastrointestinal infections and modulate the animal's immune response. Further studies are required to effectively demonstrate the beneficial effects of TUCO-16 and TUCO-17 strains in dogs.
RESUMEN
This report describes the draft genome sequence of Lactobacillus brevis TUCO-5E, a probiotic strain isolated from porcine maternal milk. The reads were generated by a whole-genome sequencing (WGS) strategy on an Illumina MiSeq sequencer and were assembled into contigs with a total estimated size of 2,461,089 bp. A total of 2,455 open reading frames (ORFs) were predicted, including 2,301 protein-coding sequences. The draft genome sequence of L. brevis TUCO-5E will be useful for further studies of specific genetic features and for understanding the mechanisms of its probiotic properties in the porcine host.
RESUMEN
Probiotics are usually isolated from the gastrointestinal tract of humans and animals. The search of probiotics in human milk is a recent field of research, as the existence of the human milk microbiome was discovered only about a decade ago. To our knowledge, no reports regarding the potential probiotic effect of bacteria from swine milk have been published. In this work, we isolated several lactic acid bacteria from swine milk and evaluated them for them potential as probiotics. Among the isolated strains, Lactobacillus curvatus TUCO-5E showed antagonistic effects against swine-associated gastrointestinal pathogens. TUCO-5E was able to reduce the growth of enterotoxigenic and enterohemorrhagic Escherichia coli strains as well as pathogenic salmonella. In vitro exclusion and displacement assays in intestinal epithelial cells showed a remarkable antagonistic effect for L. curvatus TUCO-5E against Salmonella sp. strain TUCO-I7 and Salmonella enterica ATCC 13096. Moreover, by using a mouse model of Salmonella infection, we were able to demonstrate that preventative administration of L. curvatus TUCO-5E for 5 consecutive days was capable of decreasing the number of Salmonella enterica serovar Typhimurium in the liver and spleen of treated mice, compared with the controls, and prevented dissemination of the pathogen to the blood stream. Therefore, we have demonstrated here that swine milk is an interesting source of beneficial bacteria. In addition, the results of this work suggest that L. curvatus TUCO-5E is a good candidate to study in vivo the protective effect of probiotics against intestinal infection and damage induced by Salmonella infection in the porcine host.
