Biofilm Formation as a Complex Result of Virulence and Adaptive Responses of Helicobacter pylori

Abstract

Helicobacter pylori is a bacterium that is capable of colonizing a host for many years, often for a lifetime. The survival in the gastric environment is enabled by the production of numerous virulence factors conditioning adhesion to the mucosa surface, acquisition of nutrients, and neutralization of the immune system activity. It is increasingly recognized, however, that the adaptive mechanisms of H. pylori in the stomach may also be linked to the ability of this pathogen to form biofilms. Initially, biofilms produced by H. pylori were strongly associated by scientists with water distribution systems and considered as a survival mechanism outside the host and a source of fecal-oral infections. In the course of the last 20 years, however, this trend has changed and now the most attention is focused on the biomedical aspect of this structure and its potential contribution to the therapeutic difficulties of H. pylori. Taking into account this fact, the aim of the current review is to discuss the phenomenon of H. pylori biofilm formation and present this mechanism as a resultant of the virulence and adaptive responses of H. pylori, including morphological transformation, membrane vesicles secretion, matrix production, efflux pump activity, and intermicrobial communication. These mechanisms will be considered in the context of transcriptomic and proteomic changes in H. pylori biofilms and their modulating effect on the development of this complex structure.

Effects of Lactobacillus salivarius LN12 in Combination with Amoxicillin and Clarithromycin on Helicobacter pylori Biofilm In Vitro

“…The downregulation effect of the combined use was greater than that of the single use. Many interactions have occurred during the formation of microbial biofilms, and it is difficult to clearly assess the usefulness or unavailability of H. pylori genes during the formation of this complex structure [ 13 ].…”

“…Biofilms play a vital role in resisting external threats, and H. pylori has the ability to form biofilms in vivo and in vitro [ 11 , 12 ]. The matrix of H. pylori biofilms contains mannan and LPS-related structures, extracellular DNA (eDNA), protein, and outer membrane vesicles (OMV) [ 13 ]. Studies have shown that H. pylori biofilms increase clarithromycin, amoxicillin, and metronidazole resistance in vitro, and the expression of proton pump genes related to antibiotics is increased 10–1000 times compared with the planktonic state [ 11 , 14 ].…”

Synthesis and Evaluation of Thymol-Based Synthetic Derivatives as Dual-Action Inhibitors against Different Strains of H. pylori and AGS Cell Line

“…Among the first cluster of alkyloxy derivatives (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14), the MIC results demonstrated no or weak efficacy against all the strains as well as their parent compound, despite the presence of branched alkyl chains, unsaturations or specific functional groups (ketone, carboxylic acid, ethyl ester). Only three derivatives (3,9,12) with linear and increasing alkyl chains (Et, n-Pr, n-Bu) presented improved MIC values with respect to thymol against some clinical isolates (MIC/MBC = 16 µg/mL).…”

“…The survival of the microorganism as well as the recalcitrance of the infection are due to H. pylori aptitude to adapt itself to the host and to develop resistance towards the antimicrobials commonly used in therapy [5]. The resistance rate to the clinically approved drugs is increasing worldwide and most of the therapeutic failures are ascribed to adaptive mechanisms linked to the biofilm formation [6], which limit the efficacy of the current therapy. The triple therapy based on the administration on proto-pump inhibitor and two antibiotics has been considered the standard therapy for many years, however, the increasing rate of triple-therapy failure was registered in many countries as well as the spreading of H. pylori antibiotic resistance.…”

MicroRNA Modulation of Host Immune Response and Inflammation Triggered by Helicobacter pylori

“…H. pylori presents a lipopolysaccharide (LPS), virulence factors, and even the capacity of forming a biofilm, which helps in neutralizing immune response. Biofilm formation has been attributed to morphological changes (cell wall rearrangement), membrane vesicles secretion, and inter-microbial communication, which constitute virulence and adaptive responses of the pathogen [6,7]. Eradication of the infection is therefore essential for Int.…”