Arsenic-contaminated water causes antibiotic resistance in children

A new study by icddr,b scientists and partners published in PLOS Pathogens has found a higher prevalence of antibiotic-resistant ‘Escherichia coli’(E. coli)  in both water and child stool in areas with high arsenic concentration in water in rural Bangladesh.

E. coli is a bacteria that is commonly found in the lower intestine of warm-blooded organisms and often causes diarrhea.

The resistance is higher in areas where arsenic contamination in drinking water is more evident compared to regions with less arsenic contamination.

Antibiotic resistance is one of the leading causes of death and hospitalisation worldwide.

Researchers collected water and stool samples from mothers and children of 100 families (50 in each such upazilas) in two upazilas - Hajiganj and Matlab of Chandpur District. Families in Hajiganj upazila use drinking water from shallow tube wells, which is found to have a high concentration of arsenic. In contrast, families in Matlab collect their drinking water from arsenic-free deep tube wells.

The prevalence of antibiotic-resistant E. coli was significantly higher in water in Hajiganj (48%) compared to water in Matlab (22 per cent) and among children in Hajiganj (94 per cent) compared to children in Matlab (76 per cent), but not among mothers.  Moreover, a higher proportion of E. coli from Hajiganj were resistant to multiple antibiotics, including penicillin, cephalosporin, and chloramphenicol.

The researchers feared that a positive association between arsenic exposure and antibiotic resistance among children in arsenic-affected areas in Bangladesh is an important public health concern. That warrants redoubling efforts to reduce arsenic exposure.

The study’s lead researcher, Mohammad Aminul Islam, adjunct scientist at icddr,b and assistant professor at the Washington State University, USA said, “Heavy metals such as arsenic are more stable than antibiotics in the environment. They continue to exert selective pressure on bacteria over a more extended period driving the evolution and expansion of antimicrobial resistance in the community.”

“It is likely that antibiotic-resistant organisms may colonise humans and animals exposed to heavy metals even without being exposed to antibiotics. The extent to which this phenomenon drives the observed higher rates of antimicrobial resistance, as opposed to other confounders, would benefit from further study; nevertheless, it is critical to contain this environmental driver of antimicrobial resistance along with responsible antimicrobial usage in medicine and agriculture” - added Islam.

“Our current research findings indicate that it is the right time to investigate further about the influence of other heavy metals like lead, mercury, iron which has a high burden in various environments of the country,” mentioned Mohammed Badrul Amin, Associate Scientist at icddr,b.

Prabhat Talukdar, a postdoctoral researcher in Dr Islam’s lab who shared co-first authorship with Mohammed Badrul Amin on the publication, said, “We found that arsenic-resistant E. coli are more likely to be resistant to a particular group of antibiotics, especially the third-generation cephalosporins, which are commonly used for the treatment of bacterial infections. Our current study is investigating the mechanisms of co-resistance to arsenic and antibiotics among these isolates.”