Characterization and specificity of probiotics to prevent salmonella infection in mice

Abstract

Background: Probiotic strains of bacteria can prevent Salmonella from causing disease by preventing the pathogen from colonizing the intestines. Two strains of probiotics, Lactobacillus acidophilius and Pediococcus spp, that were obtained from poultry fecal samples have been shown to be efficacious in poultry. The objective of this study was to determine if these strains of probiotics could prevent salmonellosis in a mouse model.Methods: First, both strains of probiotics were evaluated for in vitro efficacy to inhibit the growth of and interfere with virulence gene regulation in Salmonella enterica. For in vivo efficacy, mice was used which models Typhoid illness. Mice were divided into 2 groups: Control and treatment, Lactobacillus and Pediococcus (LP; 108 Log CFU). Two experiments were conducted. In the first experiment, the mice were treated with LP in water for the first two days of the experiment and challenged with Salmonella at day three. In the second experiment, the LP treatment was given in the water for 10 days and challenge was performed on day 11. In both experiments, at day 20 post-challenge, all mice were sacrificed, intestinal tracts and organs removed and cultured for Salmonella. Results: The probiotic strains inhibited the growth of Salmonella and down-regulation of virulence genes was noted, but dependent on the strain of Salmonella being evaluated. For the in vivo experiment, the probiotics did not afford the mice protection from infection and increasing the length of time the probiotics were administered did not improve the efficacy of the probiotics.Conclusions: It appears that these strains of probiotic bacteria are effective against Salmonella in vitro. However, these isolates did not afford protection from Salmonella infection to mice which may be due to host specifity as these isolates were obtained from poultry.Keywords: Salmonella, Probiotic, Lactobacillus, Pediococcus, Mice

The Influence of Feed-Supplementation with Probiotic Strain Lactobacillus reuteri CCM 8617 and Alginite on Intestinal Microenvironment of SPF Mice Infected with Salmonella Typhimurium CCM 7205

“…Furthermore, Salmonella persists for as long as 30 days post-inoculation, infecting organs but absent from the gastrointestinal tract [ 32 ]. In the study by Andino et al [ 25 ], the results of 2-day administration of probiotics before infection with salmonella support these statements. However, it appears that in experiment 2, in which probiotics were administered for longer time (10 days) prior to infection, salmonella was capable of colonising the intestinal tract as the culturing recovered salmonella from faecal and intestinal samples [ 25 ].…”

“…In the study by Andino et al [ 25 ], the results of 2-day administration of probiotics before infection with salmonella support these statements. However, it appears that in experiment 2, in which probiotics were administered for longer time (10 days) prior to infection, salmonella was capable of colonising the intestinal tract as the culturing recovered salmonella from faecal and intestinal samples [ 25 ]. The reason for this difference is unclear because the mice were given the same challenge dosage of salmonella in both experiments.…”

“…Frizzo et al [ 24 ] observed inhibitory effects of a combination of probiotics ( Lactobacillus casei DSPV 318T, Lactobacillus salivarius DSPV 315T and Pediococcus acidilactici DSPV 006T) in the study on mice of Swiss line using Salmonella serotype Dublin DSPV 595T as a pathogen. In another study, Andino et al [ 25 ] investigated two strains of probiotics obtained from poultry faecal samples ( Lactobacillus acidophilius and Pediococcus spp.) with respect to their potential to prevent salmonellosis in a mouse model.…”

“…casei DSPV 318T, Lact. salivarius DSPV 315T and Pediococcus acidilactici DSPV 006T) and in the study by Andino et al [ 25 ] the final concentration of probiotic bacteria was 10 9 CFU, and these bacteria were provided daily in drinking water. There were differences also in the duration of administration of probiotics before infection with pathogen from the genus Salmonella .…”

“…There were differences also in the duration of administration of probiotics before infection with pathogen from the genus Salmonella . Frizzo et al [ 24 ] and Steinberg et al [ 26 ] used 10-day continuous administration prior to infection, Andino et al [ 25 ] decided on 2-day and 10-day administration in 2 experiments and we administered the lactobacilli strain continuously for 7 days before infection.…”