In Vitro Antimicrobial Activity and Downregulation of Virulence Gene Expression on Helicobacter pylori by Reuterin

Abstract

Helicobacter pylori is an infectious agent commonly associated with gastrointestinal diseases. The use of probiotics to treat this infection has been documented, however, their potential antimicrobial metabolites have not yet been investigated. In the present study, the effect of reuterin produced by Lactobacillus reuteri on H. pylori growth and virulence gene expression was evaluated. It was observed that reuterin caused significant (P < 0.05) H. pylori growth inhibition at concentrations from 0.08 to 20.48 mM, with minimal inhibitory concentrations (MICs) of 20.48 mM for H. pylori ATCC700824 and 10.24 mM for H. pylori ATCC43504. In a reuterin bacterial killing assay, it was observed that half of the MIC value for H. pylori (ATCC700824) significantly (P < 0.01) reduced colony numbers from 5.65 ± 0.35 to 3.78 ± 0.35 Log CFU/mL after 12 h of treatment and then increased them to 5.25 ± 0.23 Log CFU/mL at 24 h; at its MIC value (20.48 mM), reuterin abrogated (P < 0.01) H. pylori (ATCC700824) growth after 20 h of culture. In addition, reuterin significantly (P < 0.01) reduced H. pylori (ATCC 43504) colony numbers from 5.65 ± 0.35 to 4.1 ± 0.12 Log10 CFU/mL from 12 to 24 h of treatment and abrogated its growth at its MIC value (10.24 mM), after 20 h of treatment. Reuterin did not alter normal human gastric Hs738.St/Int cell viability at the concentrations tested for H. pylori strains. Furthermore, 10 μM reuterin was shown to significantly (P < 0.01) reduce mRNA relative expression levels of H. pylori virulence genes vacA and flaA at 3 h post-treatment, whose effect was higher at 6 h post-treatment, as measured by RT-qPCR. The observed direct antimicrobial effect and the downregulation of expression of virulence genes on H. pylori by reuterin may contribute to the understanding of the mechanisms of action of probiotics against H. pylori.

Antimicrobial and Anti-Biofilm Effect of an Electrolyzed Superoxidized Solution at Neutral-pH againstHelicobacter pylori

“…Activation of H. pylori was performed in 5 mL of trypticase soy broth (TSB; Becton Dickinson, Franklin Lakes, NJ), supplemented with 5% (v/v) heat inactivated fetal bovine serum (FBS; Gibco, Gaithersburg, MD). A er, 50 μL of bacterial suspension was plated on trypticase soy agar (TSA; Becton Dickinson), supplemented with 5% (v/v) de brinated sheep blood (DSB), as reported by Urrutia-Baca et al [32]. Broth and agar cultures were placed into a sealed jar with CampyGen sachet (Oxoid Ltd, Basingstoke, UK) to maintain microaerobic conditions and incubated at 37°C for seven days.…”

Helicobacter pylori treatment in the post-antibiotics era—searching for new drug targets

“…Probiotic supplementation is an emerging field in H. pylori treatment (Chey et al 2017). In vitro studies report inhibitory effects of probiotics on the expression level of genes encoding virulence factors, including ureB, vacA, flaA, and sabA (Lesbros-Pantoflickova et al 2007;de Klerk et al 2016;Urrutia-Baca et al 2018). Some probiotics, such as Lactococcus lactis, Lactobacillus reuteri, and Lactobacillus bulgaricus produce peptide and nonpeptide antipathogen substances that can inhibit the growth, as well as the adhesion process, of H. pylori (Kim et al 2003;Boyanova et al 2017;Urrutia-Baca et al 2018).…”

Using Probiotics as Supplementation for Helicobacter pylori Antibiotic Therapy

“…Boyanova et al found that the bacteriocin secreted by seven L. bulgaricus strains not only inhibited the growth of antibiotic-sensitive H. pylori strains, but also the antibiotic-resistant strains [72]. In addition to these peptide-like bacteriocins, a nonpeptide antipathogen substance synthesized by L. reuteri, called reuterin, can inhibit H. pylori growth and downregulate the expression of the virulence genes vacA and flaA [73].…”