Researchers show bacteriophages can affect melioidosis disease acquisition

An international research team including Leicester researchers has developed a mathematical model for monitoring and controlling the spread of melioidosis in Southeast Asia.

The findings are presented in Scientific Reports, a prestigious journal from the publishers of Nature.

Melioidosis is a serious infectious disease manifesting itself as multiple abscesses of various organs due to severe sepsis. In 40 percent of the cases, the disease leads to death. Patients with diabetes are at a higher risk of being infected. Melioidosis, which is also known as Whitmore’s disease, is caused by the bacterium Burkholderia pseudomallei, which is particularly active in soil and water. This pathogen is widespread in Southeast Asia, Australia, West and East Africa.

“Melioidosis is a severe and dangerous disease, but much of the research into it focuses on the bacterium that causes. Meanwhile, the phages abundantly found in the habitat of the pathogen are not getting enough attention. We wondered whether we could predict the variation in the number of pathogenic bacteria and the impact of phages on it depending on season and environmental conditions,” explains the study co-author Dr Andrew Morozov from our Department of Mathematics.

To achieve this goal, the researchers developed several mathematical models predicting the seasonal and daily dynamics of the size of B. pseudomallei populations. They focused on the bacterial populations on rice fields in two Thailand provinces — Nakhon Phanom and Sa Kaeo — and how the pathogen is affected by temperature-dependent phages, viruses selectively killing bacteria. The variation was explored in terms of the change in temperatures and ultraviolet radiation levels.

The findings on B. pseudomallei-phage interactions reveal opportunities for disease control. For example, the work on rice fields can be rescheduled depending on season. Also, once the risky periods are identified, preventive measures can be introduced, such as the use of protective gear. Finally, field owners can use agrochemicals that do not harm the phages limiting the population of pathogenic bacteria.