A novel approach to determine how carcinogenic bacteria find their targets

February 10, 2021

The gram-negative bacteria Helicobacter pylori (H. pylori) colonize the stomachs of the majority of the world's population. Although most people may never experience major complications due to the pathogen, H. pylori infections increase the risk of certain types of gastric cancer, as well as other illnesses such as peptic ulcers and gastritis.

Currently, H. pylori infections are treatable with a cocktail of antibiotics, but the rapid emergence of antibiotic resistance in H. pylori is a significant concern. To counter these threats, Pushkar Lele, assistant professor in the Artie McFerrin Department of Chemical Engineering at Texas A&M University, investigated how H. pylori locate their ideal environment within a host's stomach.

Motile bacteria such as H. pylori swim by rotating string-like appendages called flagella. They navigate by sensing chemical signals in their environment, a process known as chemotaxis. An intracellular signaling pathway - the chemotaxis network - aids navigation by controlling the direction of rotation of the flagella. Current understanding of how the chemotaxis network operates is based on studies of Escherichia coli (E. coli), which is a model system for bacterial chemotaxis and motility. The chemotaxis network in E. coli modulates the probability of clockwise rotation in otherwise counterclockwise-rotating flagella to help the cell migrate toward favorable chemical environments. How the chemotaxis network modulates flagellar functions in H. pylori is not known.

Popular techniques that use probes to study chemotactic function in bacteria do not work well in H. pylori. This creates significant challenges in understanding flagellar functions in this species. To overcome these challenges, Lele's group pioneered a novel probe-free approach to study flagellar functions in H. pylori.

Their approach exploited the fact that cells swam around in clockwise circles near glass surfaces when their flagella rotated counterclockwise, and counterclockwise circles when their flagella rotated clockwise. In a paper published in eLife, Lele and his research team used this approach to report the probability of the clockwise rotation in H. pylori for the first time. Jyot Antani, a doctoral student in Lele's group, performed the experiments that further showed that H. pylori's chemotaxis network modulates flagellar functions similar to that in E. coli.

Lele said the similarity in the form of flagellar control in the two bacterial species is intriguing given that they differ in many key aspects. Whereas H. coli prefer the stomach, E. coli are found in the lower gastrointestinal tract. The physical characteristics of H. pylori are such that they run forward and reverse, unlike E. coli, which run forward and then tumble. As a result, the modulation of the probabilities of clockwise flagellar rotation, which suits E. coli very well, is predicted to cause errors in chemotaxis in H. pylori.

Lele predicts that future work with their new approach will reveal how H. pylori reach their targets despite the errors and how dietary interventions can be developed to inhibit chemotaxis.
-end-
This research was supported by a High Impact High Risk Awards grant from the Cancer Prevention and Research Institute of Texas.

Texas A&M University

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.