At a Glance
- Researchers in Nairobi found that contaminated stored drinking water is a major pathway for spreading E. coli between people in the same household, especially in urban informal settlements with poor sanitation.
- Using the PIC-seq technique, scientists traced bacterial strains and discovered that water shared more E. coli strains with humans than animals, especially when stored in plastic containers.
- Many E. coli strains in stored water carried antibiotic resistance genes, raising concerns about treating bacterial infections in low-resource environments.
- Households with chlorinated water had significantly less contamination, suggesting that chlorination effectively reduces bacterial transmission and antibiotic resistance.
- The study emphasizes the urgent need for improved water treatment in informal settlements to reduce the spread of harmful, drug-resistant bacteria and protect public health.
A recent study conducted by researchers from UC Berkeley has revealed new insights into the spread of harmful bacteria, specifically E. coli, in households within urban informal settlements in Nairobi, Kenya. The researchers focused on understanding how bacteria spread between humans, animals, and the environment, particularly through drinking water. They found that stored drinking water, often contaminated, played a significant role in transmitting E. coli between people in the same household. This discovery is important because unsafe drinking water is a major factor contributing to gastrointestinal diseases, especially in areas with poor sanitation.
The research team used an advanced technique called Pooled Isolated Colonies-seq (PIC-seq) to track bacterial strains more efficiently. This method allowed the scientists to analyze multiple strains from each sample, providing a more detailed picture of how bacteria are shared between people, animals, and the environment. The study showed that while animals did share some E. coli strains with humans, the strongest link for bacterial transmission was between humans and their contaminated drinking water, with high levels of strain-sharing occurring in households that stored water in plastic containers.
The study, published in Nature Microbiology, also found that E. coli in stored water often carried antibiotic resistance genes, making it harder to treat bacterial infections. These resistance genes can spread to other bacteria, potentially causing more serious health problems. However, households with access to chlorinated water saw less contamination in their stored drinking water. This suggests that chlorination could effectively reduce the spread of harmful and drug-resistant bacteria within these communities.
In conclusion, this research highlights the importance of safe drinking water in preventing the spread of bacterial infections, including antibiotic-resistant strains. The findings suggest that improving water treatment methods, like chlorination, could help protect vulnerable populations, especially children, in low-resource areas. Public health strategies can be improved by focusing on environmental factors like water quality to reduce the risk of infectious diseases in communities worldwide.
References
- Kim, D. D., Swarthout, J. M., Worby, C. J., Chieng, B., Mboya, J., Earl, A. M., Njenga, S. M., & Pickering, A. J. (2025). Contaminated drinking water facilitates Escherichia coli strain-sharing within households in urban informal settlements. Nature Microbiology, 10(5), 1198–1209. https://doi.org/10.1038/s41564-025-01986-w
- Ellery, M. & University of California- Berkeley. (2025, May 6). Household drinking water identified as key pathway for bacterial transmission. Phys.Org; University of California- Berkeley. https://phys.org/news/2025-05-household-key-pathway-bacterial-transmission.html
