A Study on the Prevention of Salmonella Infection by Using the Aggregation Characteristics of Lactic Acid Bacteria

Abstract

Salmonella is one of the major pathogenic bacteria that cause food poisoning. This study investigated whether heat-killed as well as live Lactobacillus protects host animal against Salmonella infection. Live and heat-killed Lactobacillusacidophilus was administered orally to Sprague-Dawley rats for 2 weeks before the rats were inoculated with Salmonella. Rise in body temperature was moderate in the group that was treated with heat-killed bacteria as compared to the Salmonella control group. The mean amount of feed intake and water consumption of each rat in the heat-killed bacteria group were nearly normal. The number of fecal Salmonellae was comparable between the live and the heat-killed L. acidophilus groups. This finding shows that L. acidophilus facilitates the excretion of Salmonella. Moreover, the levels of pro inflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, in the heat-killed L. acidophilus group were significantly lower when compared to the levels in the Salmonella control group. These results indicate that nonviable lactic acid bacteria also could play an important role in preventing infections by enteric pathogens such as Salmonella.

Beneficial effect of immunobiotic strains on attenuation of Salmonella induced inflammatory response in human intestinal epithelial cells

“…Another in vitro study showed that Lactobacillus pre-treatment decreased the level of IL-8 in Caco2 cells that had been stimulated with Salmonella [18]. In addition, the expression of IL-1β in L. acidophilus treated rats was significantly lower than that of Salmonella alone [32]. Oral administration of L. casei abrogated Salmonella induced IL-6 and IL-1β expression in mice [33].…”

Effects of Mixed Probiotic Spores of Bacillus Coagulans and Bacillus Subtilis on Gut Microbiota and Intestinal and Liver Damage of Rats Infected with Salmonella Typhimurium

“…They were incubated at 37 °C and 42 °C, respectively, for 24 h. After which a loop of the selective enrichment broth was cultured on Xylose Lysine Deoxycholate agar (XLD agar, Merck, Germany) and Brilliant Green agar (BG agar, Merck, Germany). The plates were incubated at 37 °C for 24 h and checked for Salmonella colonies [21].…”

“…The concentration of probiotic spores fed to the rats was determined based on our previous study [18] and the concentration of challenged bacterium was determined based on Havelaar et al (2001), Abdel Hamid et al (2013) and Kim et al (2013) [19 -21].…”

An in vitro Investigation of the Antagonistic Effects of Multiple Strains of Lactobacillales on Salmonella enterica Serovar Choleraesuis

“…In recent years, researchers have found that after thermal death, the inhibitory and immunomodulatory effects of Lactobacillales remain unchanged or become even stronger [15,16]. Heat-killed LAB has advantages over viable LAB in that it has a long shelf-life and is therefore easy to store and transport [17].…”