YCP student anticipates research on pathogenic bacteria

By Isabella Zafra

Photo from medicinenet.com

A junior biology student plans to student a bacteria that contaminates water environments — Helicobacter pylori.

Access to clean drinking water around the world is a major problem. Contamination by toxins, industrial and human waste and other issues cause major health issues, especially in third-world countries. Another threat lurking in the water is the presence of harmful and pathogenic bacteria. Helicobacter pylori is known to live inside of the human stomach and small intestine where it can cause major health complications such as ulcers and in some cases stomach cancer. In a review article published in Helicobacter, researcher Anthony Axon from the University of Leeds in the U.K. reported that over a million deaths occur worldwide every year caused by peptic ulcer disease and gastric carcinoma combined.

Given its role as a public health concern, it’s important to continue researching and exploring how this bacterium is able to live in the acidic stomach and also to understand where it resides outside of the human host. It is not entirely known how it is passed to individuals, although some scientists believe a likely possibility is ingestion — an individual eats or drinks something contaminated with the bacteria and as it passes through the digestive system where it attaches and burrows itself inside the stomach’s lining, taking up residence.

Considering ingestion a likely form of acquiring the bacteria, it is necessary to understand what physical locations are home to this bacteria from which it could then be passed into food, drink, or other sources. The contamination of groundwater, lakes, and rivers, especially in developing countries in Africa and Asia, has been studied. Researchers Victor Dinda, the Masinde Muliro University of Science and Technology, and Andrew Kimang’a, the Jomo Kentaya University of Agriculture and Technology, found traces of H. pylori genetic material in a lake that is used as a drinking water source in Kenya in a study found in African Health Sciences in 2016.

Scientists have also found that the bacteria is able to form biofilms when it is under environmental stress. Biofilms are clusters of bacterial cells that are protected by compounds produced by these same bacteria which act as a tough, mucous covering, allowing the bacteria to survive in unfavorable conditions. These biofilms are made by other types of bacteria and are difficult to remove. They are formed in environments which are wet most of the time, ranging from teeth to water pipes.

Underdeveloped nations are more at risk of having these bacterial infections due to crowded homes, poor understanding of public hygiene and inadequate waste disposal. Considering these factors, we need to wonder if the way these nations treat their drinking water is at the same level of efficiency as other nations such as the United States and European nations, which have lower rates of H. pylori infection. Another area for consideration is whether the materials that are being used in these third-world nations are somehow related to higher numbers of bacteria being found within these water systems. Are they using certain materials in drinking water pipes that harbor bacteria more easily than others? There is a need for the development of laboratory models to simulate environmental conditions for the investigation of how these organisms behave.

The objective of the senior thesis research to be performed by Isabella Zafra, a junior biology major, is to address the first of these questions by designing a model to study H. pylori in biofilms using another bacterium more easily obtained in the lab, P. aeruginosa. A better understanding of the substances H. pylori can form biofilms on in static as well as fluid models will be used to understand the ideal materials to be used in drinking water systems. The materials to be explored are stainless steel, copper, and two plastics (PVC and polyethylene). The different materials will be compared for their ability to grow a P. aeruginosa biofilm using crystal violet staining which will measure the relative thickness of any biofilm that forms on the surface of these materials. Biofilm growth for different concentrations of bacteria after different time intervals will also be compared.

The implications of this research will be to lay the groundwork for future studies involving pathogenic bacteria, such as H. pylori, and the biofilm they create in water systems.

Zafra hopes that in the future scientists will pass their discoveries to industries and governmental programs to improve the quality of water around the world. “Public health initiatives will need to be carefully planned with science as the guide in order to improve quality of life worldwide,” said Zafra.