HYDERABAD: A collaborative study by scientists from CSIR-Centre for Cellular and Molecular Biology and LV Prasad Eye Institute has uncovered alarming levels of antimicrobial resistance (AMR) in bacteria causing eye infections, raising concerns over treatment practices and wider public health risks. Published in Communications Biology, the study is among the most comprehensive genomic analyses of ocular pathogens in India and was led by Karthik Bharadwaj, Divya Tej Sowpati and Joveeta Joseph. CCMB researchers led genomic and bioinformatics analysis, while LVPEI contributed clinical expertise, patient samples and microbiological characterisation.
“To understand and solve a problem like AMR, it is essential for clinicians and scientists to come together. This is not a problem to be solved with model organisms but with real patient samples,” said Vinay K Nandicoori.
The team analysed 291 patient samples collected over a year and isolated bacteria tested against known antibiotics. More than 45% of isolates were multidrug-resistant, including Gram-positive and Gram-negative pathogens. The study identified vancomycin-resistant Staphylococcus aureus and extensively drug-resistant Klebsiella pneumoniae strains in eye infections. “These findings are worrying because such bacteria can spread AMR genes to other bacteria and can also infect other parts of the body,” Dr Bharadwaj told TNIE.
Using whole genome sequencing, researchers identified new AMR-associated mechanisms and mutations, while also noting resistance without known genes and vice versa, pointing to possible new pathways. The study also establishes baseline genomic data for such pathogens, previously unavailable.
Researchers said eye infections occur when bacteria enter through minor injuries, foreign particles, environmental exposure or contact. Since symptoms such as redness, irritation, discharge or pain cannot identify the exact bacteria involved, laboratory diagnosis remains essential.
The study found resistance to fluoroquinolones, a commonly used class of antibiotics, in all eye pathogens, challenging reliance on empirical therapy. “There is a need to periodically revisit empirical therapy. Surveillance data should guide which antibiotics are used,” Dr Bharadwaj explained.
“While genomic tools are not yet part of routine clinical workflows, the insights from this study provide a critical foundation for region-specific treatment guidelines and stronger antimicrobial stewardship,” said Dr Joseph.