Alleviating effects ofLactobacillusstrains on pathogenicVibrio parahaemolyticus-induced intestinal fluid accumulation in the mouse model

Abstract

The aim of this study was to evaluate the probiotic effects of Lactobacillus strains against Vibrio parahaemolyticus causing gastroenteritis. Six-week-old ICR mice were pretreated with four Lactobacillus strains at three dosages, and then challenged with V. parahaemolyticus TGqx01 (serotype O3:K6). The results showed that V. parahaemolyticus TGqx01 caused severe intestinal fluid accumulation (FA) and villi damage in control mice which were pretreated with phosphate-buffered saline. In contrast, significant alleviation of FA was seen in mice pretreated by with a high dose of Lactobacillus strains (P < 0.05, n = 6) but not in mice that received low-dose pretreatments. Among middle-dose treatments, two highly adhesive strains, Lactobacillus rhamnosus H15 and Lactobacillus brevis Y29-4, significantly decreased intestinal FA and villi damage in treated mice (P < 0.05). Two low-adhesive strains, Lactobacillus acidophilus Y14-3 and Lactobacillus fermentum F16-6, had no significant alleviating effects. At the same dosing levels, no significant differences in FA were observed in mice pretreated with strains with similar adhesive abilities but different antagonistic activities. Our findings suggest that Lactobacillus strains can alleviate V. parahaemolyticus-induced intestinal FA in mice, and the doses required for in vivo efficacy depend more on adhesive ability than on the antibacterial activity of strains.

Bioluminescence Imaging to Track Bacteroides fragilis Inhibition of Vibrio parahaemolyticus Infection in Mice

“…Most research about the antagonistic effects of other bacterial species on V. parahaemolyticus has focused on applications for aquaculture (Wu et al, 2014; Liu et al, 2015), and most of the strains used cannot be considered probiotics. Studies on the use of probiotics for treating intestinal infection caused by V. parahaemolyticus are rare, and only strains of Lactobacillus have been shown to inhibit V. parahaemolyticus both in vitro and in vivo in mice (Yang et al, 2013). In the current study, we identified a novel commensal B. fragilis strain (Deng et al, 2016) that could reduce cellular damage caused by V. parahaemolyticus and short the colonization period of V. parahaemolyticus in the intestines of mice.…”

“…Although, mice are not natural hosts of V. parahaemolyticus , mouse models are still common used for examining the pathogenesis of V. parahaemolyticus in vivo (Hiyoshi et al, 2010; Yang et al, 2013; Whitaker et al, 2014). In addition to the mouse model, it has been reported that infant rabbits infected with V. parahaemolyticus develop severe diarrhea and enteritis that mimic the main clinical and pathologic manifestations of the disease in humans, so the infant rabbit model is also a good choice for the research of V. parahaemolyticus (Ritchie et al, 2012; Zhou et al, 2013, 2014).…”

“…In traditional gavage infection assays of V. parahaemolyticus in animals, infection is confirmed and monitored by fecal pathogen count, observation of symptoms in experimental animals, and pathological examination of intestinal injury. While previous studies have found that Lactobacillus can prevent V. parahaemolyticus infection in mice (Yang et al, 2013), technical limitations of traditional methods mean that experiments cannot truly determine the number of bacteria in the intestine or identify the site of colonization. However, bioluminescence imaging allows noninvasive monitoring of bacteria in animals.…”

Lactic acid bacteria inhibit the growth of Vibrio parahaemolyticus and the invasion of Caco-2 cells

“…by HT-29 intestinal cells via its antimicrobial activity by producing bacteriocins, lactic acid, and exopolysaccharides. Yang et al 13 also demonstrated that LAB can delay the intestinal fluid accumulation and villus damage caused by V. parahaemolyticus in mice. The authors further reported that strains with stronger adsorption ability are more protective than those with stronger antibacterial ability, indicating that the adsorption capacity is more important 14 .…”

The expression of heterologous MAM-7 in Lactobacillus rhamnosus reduces its intrinsic capacity to inhibit colonization of pathogen Vibrio parahaemolyticus in vitro

“…For example, L. plantarum AS1 show antibacterial activity against several enteropathogens and inhibit V. parahaemolyticus adhesion to the human intestinal cell line HT-29 [ 11 ]. Additionally, mice treated with L. rhamnosus and L. brevis showed a significant reduction in intestinal fluid accumulation and villi damage when animals were challenged with the pathogen [ 12 ].…”