MOLECULAR STUDIES REVEAL HIGH GENETIC DIVERSITY IN A BACTERIA ASSOCIATED WITH CHILDHOOD DIARRHEA IN MOZAMBIQUE

Delfino Vubil, First Author

Diarrhea remains one of the leading causes of child mortality in low- and middle-income countries, highlighting the need to deepen knowledge about the infectious agents involved and to strengthen prevention and treatment strategies. In this context, researchers from the Manhiça Health Research Centre (CISM) identified a high genetic diversity in virulence genes of enteropathogenic Escherichia coli (EPEC), a bacterium frequently associated with diarrhea in children under five years of age in Mozambique.

The results of the analysis, recently published in the scientific journal BMC Infectious Diseases, reveal allelic variations of the eae virulence gene, which is essential for the adhesion of EPEC strains to the intestinal mucosa—an important step in the infection process. The identification of these genetic variations constitutes a valuable tool for characterizing EPEC strains, with relevant applications in diagnosis, understanding pathogenesis, immunology, and molecular epidemiology.

The main objective of the study was to identify allelic variants of the eae gene and explore their possible association with clinical characteristics, using a collection of EPEC isolates from children under five years of age, with or without diarrhea, in Manhiça District in southern Mozambique. These data are part of the Global Enteric Multicenter Study (GEMS).

According to the first author of the article and CISM researcher in the Bacterial, Viral and Neglected Tropical Diseases Area, Delfino Vubil, “the results show that typical EPEC was the most frequent, representing about 72% of the cases analyzed. In addition, 18 different types of the eae gene were identified, with the most common being the eae-λ, eae-β1 and eae-ξR/β2B variants.” He further noted that although no clear associations were found between the studied alleles and clinical severity, some variants were more common in certain clinical profiles, suggesting a possible role in disease manifestation. “Other factors, beyond the gene analyzed, may play an important role in disease development,” he emphasized.

“This is the first study conducted in Mozambique to characterize the molecular diversity of this important virulence gene in EPEC strains. The findings reinforce the need for further research, including more comprehensive genomic analyses, to better understand the determinants of severity in childhood diarrhea associated with this pathogen,” he added.

The GEMS (Global Enteric Multicenter Study) was a case-control study on diarrhea coordinated by the Center for Vaccine Development at the University of Maryland, School of Medicine. It was implemented in seven countries in Asia and Africa—namely The Gambia, Kenya, Mali, Mozambique, Bangladesh, India, and Pakistan, encompassing approximately 22,568 children under five years of age.

Reference

• Vubil D, Chidimatembue A, Garrine M, Nhampossa T, Bassat Q, Acácio S, Messa A Jr, Mandomando I. Allelic variations of intimin virulence gene (eae) in typical and atypical enteropathogenic Escherichia coli isolated from children with and without diarrhea in a rural area of southern Mozambique. BMC Infect Dis. 2026 Mar 25. doi: 10.1186/s12879-026-13146-4. Epub ahead of print. PMID: 41877076.