HYDERABAD: An ongoing scientific investigation has raised fresh concerns over the spread of antibiotic-resistant bacteria in Hyderabad’s drainage network, particularly in areas surrounding major hospitals. Researchers from the Centre for Cellular and Molecular Biology and the Tata Institute for Genetics and Society have found that sewage flowing from hospital zones into municipal drains and eventually into the Musi River carries a significantly higher diversity of drug-resistant organisms.
The study examined sewage samples from 17 locations across the city, including 10 open drains, selected stretches of the Musi and drainage channels within a two-kilometre radius of major multispecialty hospitals. Preliminary findings show that sites near hospitals consistently recorded a higher abundance and diversity of antibiotic resistance genes compared to locations farther away.
Laboratory analysis revealed bacteria that no longer respond to commonly prescribed antibiotics such as azithromycin and tetracycline. In total, nearly 89 different pathogens were identified in the sewage, many at various stages of evolving resistance. Several of these organisms are known to cause urinary tract infections, pneumonia and gastrointestinal illnesses. Public health experts warn that continued circulation of such pathogens in open environments could make routine infections harder to treat.
Senior experts explain that hospitals are natural hotspots for antibiotic use, particularly powerful “last-resort” drugs administered to critically ill patients. While solid biomedical waste is generally treated before disposal, liquid waste—including water from laundries, disinfected floors and patient wards — may contain residual antibiotics that enter municipal drains. “These are often sub-lethal concentrations,” said environmental microbiologist J Keshvani. “They create conditions where surviving bacteria adapt and share resistance genes.”
Researchers caution that Hyderabad’s wastewater system, which combines effluents from hospitals, households, pharmaceutical residues and industries, may be acting as a reservoir for antimicrobial resistance.
Untreated hospital wastewater is also emerging as a broader environmental concern. The study found that chemical cleaners and antibiotic traces are altering the natural microbial balance of water bodies, reducing oxygen levels and weakening the self-purifying capacity of rivers and streams. “These compounds accumulate in sediments and seep into groundwater, gradually affecting aquatic ecosystems,” Keshvani said.
Drains near healthcare facilities showed a higher concentration of resistant microbes and chemical contaminants, indicating ecological stress. These polluted channels ultimately merge with larger water bodies, spreading contamination. Environmental activist Subba Rao said the findings highlight gaps in monitoring and enforcement. “Hospitals are vital institutions, but their waste must not come at the cost of rivers and biodiversity. Effluent treatment systems need strict oversight,” he said.
Nearly 578 million DNA reads were sequenced from 17 sites, with 2.48 million matching resistance entries in the Comprehensive Antibiotic Resistance Database. The analysis showed macrolide resistance accounting for 40.1% of detected drug-class reads, followed by aminoglycoside resistance at 24.4% and tetracycline resistance at 11.3%. Overall, 85.4% of resistance signatures were concentrated in just five drug classes.
“If this trend continues, infections that we currently treat with simple antibiotics could become much harder to manage,” Keshvani warned. Experts have called for stronger hospital wastewater pre-treatment systems, stricter discharge standards, improved sewage treatment infrastructure and antibiotic stewardship programmes. As Hyderabad continues to grow, they stress that integrating environmental surveillance into public health planning will be crucial to prevent the city’s drains from becoming long-term reservoirs of antimicrobial resistance.