Biofilm of Helicobacter pylori: Life Cycle, Features, and Treatment Options

Abstract

Helicobacter pylori is a gastric pathogen that infects nearly half of the global population and is recognized as a group 1 carcinogen by the Word Health Organization. The global rise in antibiotic resistance has increased clinical challenges in treating H. pylori infections. Biofilm growth has been proposed to contribute to H. pylori's chronic colonization of the host stomach, treatment failures, and the eventual development of gastric diseases. Several components of H. pylori have been identified to promote biofilm growth, and several of these may also facilitate antibiotic tolerance, including the extracellular matrix, outer membrane proteins, shifted morphology, modulated metabolism, efflux pumps, and virulence factors. Recent developments in therapeutic approaches targeting H. pylori biofilm have shown that synthetic compounds, such as small molecule drugs and plant-derived compounds, are effective at eradicating H. pylori biofilms. These combined topics highlight the necessity for biofilm-based research in H. pylori, to improve current H. pylori-targeted therapeutic approaches and alleviate relative public health burden. In this review we discuss recent discoveries that have decoded the life cycle of H. pylori biofilms and current biofilm-targeted treatment strategies.

Keywords: Helicobacter pylori; abiotic/biotic adhesion; anti-biofilm strategies; antibiotic resistance; biofilms; clinical treatment strategies; dispersion; extra polymeric substance; planktonic.

Scheme 1

Helicobacter pylori Biofilm Lifecycle. H. pylori adheres to both abiotic and biotic surfaces, where it forms microcolonies that susbquently assemble into mature biofilms characterized by the presence of extracellular polymeric susbtances (EPSs). Dispersion allows bacteria to colonizes new niches.

Figure 1

SEM images of mature H. pylori biofilms grown on abiotic surfaces. (A) Mature H. pylori biofilms contain a mixed population of mostly cocoid-shaped cells with a minority of spiral-shaped cells, (B) higher resolution image showing spiral-shaped cells (white arrow) and coccoid cells aggregating via the flagella (red arrow).