Compound(s) secreted by Lactobacillus casei strain Shirota YIT9029 irreversibly and reversibly impair the swimming motility of Helicobacter pylori and Salmonella enterica serovar Typhimurium, respectively

Abstract

We conducted experiments in order to examine whether the probiotic Lactobacillus casei strain Shirota YIT9029 (LcS) in vitro and in vivo antagonism of Helicobacter pylori and Salmonella, involves inhibition of the swimming motility of these pathogens. We report the irreversible inhibition of the swimming motility of H. pylori strain 1101 and reversible inhibition of Salmonella enterica serovar Typhimurium (S. Typhimurium) strain SL1344 by compound(s) secreted by LcS. In H. pylori 1101, irreversible inhibition results in the helical cells being progressively replaced by cells with 'c'-shaped and coccoid morphologies, accompanied by a loss of FlaA and FlaB flagellin expression. In S. Typhimurium SL1344, transient inhibition develops after membrane depolarization and without modification of expression of FliC flagellin. The inhibitory activity of strain LcS against both S. Typhimurium and H. pylori swimming motilities is linked with a small sized, heat-sensitive, and partially trypsin-sensitive, secreted compound(s), and needed the cooperation of the secreted membrane permeabilizing lactic acid metabolite. The inhibition of S. Typhimurium SL1344 swimming motility leads to delayed cell entry into human enterocyte-like Caco-2/TC7 cells and a strong decrease of cell entry into human mucus-secreting HT29-MTX cells.

Morphology of Helicobacter pylori as a result of peptidoglycan and cytoskeleton rearrangements

“…The transformation of H. pylori from culturable spiral forms into non-culturable coccoids occurs during exposition to adverse conditions, including: nutrient starvation [ 19 , 20 ], prolonged in vitro incubation [ 21 , 22 ], presence of low or high temperature [ 21 , 23 , 24 ], incubation at alkaline pH [ 25 ], drastic change of culture environment from a nutrient-rich medium to pure water [ 26 , 27 ], incubation in the deficiency/absence of CO 2 [ 28 , 29 ], or exposure to antimicrobial compounds, e.g. antibiotics [ 30 , 31 ], proton pump inhibitors (PPIs) [ 22 , 32 ], and compounds secreted by bacteria of the genus Lactobacillus [ 33 , 34 ] and Streptococcus [ 35 ] ( Figure 1 ). Although coccoid forms are often observed during laboratory work with H. pylori , the presence of these forms has been reported in many in vivo cases [ 36 – 38 ].…”

Anti-Infective Activities of Lactobacillus Strains in the Human Intestinal Microbiota: from Probiotics to Gastrointestinal Anti-Infectious Biotherapeutic Agents

“…Impairment of S. Typhimurium swimming motility has been observed after treatment with CFCSs of L. acidophilus LB and L. casei Shirota as a result of membrane depolarization that affects the functionality of the flagellar motor but not flagellum expression (147,148). The inhibition of the swimming motility results from the secretion of a small compound(s) (dialysis cutoff, 1,000 Da), which in the case of the L. acidophilus LB compound(s) was heat and trypsin resistant whereas in that of the L. casei Shirota compound(s) was heat and trypsin sensitive (147,148).…”

Inhibitory Effect of Probiotic Bacteria Isolated from Camel Milk on Clinical Strains of Drug-Resistant Helicobacter pylori

“…In a study on the antagonistic effect of L. casei on H. pylori and salmonella, it was revealed that L. casei inhibited the expression of H. pylori flagellin genes A and B, which ultimately prevented from bacterial movement and resulted in morphology change to coccoid form (22). In the present study, most lactobacilli isolated from the milk of dromedary were related to L. plantarum, L. fermentum and L. casei.…”