Published Apr 08, 2026 | 12:41 PM ⚊ Updated Apr 08, 2026 | 12:41 PM
Representational image. Credit: iStock
Synopsis: Researchers at CSIR-CCMB and LV Prasad Eye Institute sequenced 291 bacterial genomes from eye infections, finding over 45% multidrug-resistant and 15% extensively drug-resistant strains. Fluoroquinolone resistance appeared in all pathogens, linked to over-the-counter eye drop misuse. A new vancomycin-resistant Staphylococcus aureus strain emerged, underscoring urgent need for antibiotic stewardship, genomic surveillance, and region-specific treatment guidelines.
A common habit across Indian households is quietly accelerating one of medicine’s gravest threats. Researchers in Hyderabad have found that bacteria causing eye infections now resist nearly every antibiotic available, and the eye drops people buy freely from pharmacies sit at the centre of that crisis.
The study, published in Communications Biology, comes from a collaboration between the CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB) and the LV Prasad Eye Institute (LVPEI). It represents the largest genomic analysis of eye infection-causing bacteria ever conducted in India.
The team sequenced 291 bacterial genomes collected from patients at LVPEI. More than 45 percent of those bacteria qualified as multidrug-resistant. Over 15 percent crossed into a category called extensively drug-resistant, meaning treatments run out fast.
Resistance to fluoroquinolones, the class of antibiotics that includes the eye drops sold freely at pharmacies, appeared across every single eye pathogen in the study. Not some. Every one.
“We found samples with vancomycin-resistant Staphylococcus aureus and extensively drug-resistant Klebsiella pneumoniae strains involved in eye infections,” said Dr Karthik Bharadwaj, clinician-scientist at CSIR-CCMB. “These findings are worrying because they can spread their AMR genes to other bacteria too. Also, these pathogens can infect other parts of our bodies.”
In India, fluoroquinolone eye drops such as gatifloxacin and moxifloxacin sell without prescriptions. People reach for them at the first sign of redness or irritation, often without completing the course or without needing antibiotics at all.
Every incomplete or unnecessary exposure gives bacteria a chance to adapt. The ones that survive develop resistance mechanisms and pass them on. The study found mutant resistance genes throughout the bacterial samples, a signal that bacteria have lived under sustained antibiotic pressure for a long time.
The authors note that ciprofloxacin, another fluoroquinolone, is routinely prescribed without waiting for test results. Gatifloxacin and moxifloxacin double as routine prophylaxis after cataract surgery. The pressure on these drugs never lets up.
Among the findings, researchers identified a strain nobody had catalogued before.
A type of Staphylococcus aureus, designated ST9578, resisted vancomycin and teicoplanin, two antibiotics doctors reach for when everything else fails. The strain also resisted linezolid, another last-resort drug, through a mutation in a gene that had not previously been linked to that resistance.
Genomic detective work traced its ancestry to a sample collected from a human in the United Kingdom in 2015.
It arrived in a Hyderabad eye clinic in 2026.
When a patient walks in with an eye infection, clinicians rarely wait for laboratory results before starting treatment. Results take days. Vision loss does not wait.
So doctors use what the study calls empirical therapy, selecting antibiotics most likely to work based on experience and judgment, then adjusting once results arrive.
The study argues that this approach now carries serious risk. With resistance spreading so widely, the antibiotics chosen empirically may no longer work by the time the patient needs them to.
“While genomic tools are not yet part of routine clinical workflows, the insights generated through this study provide a critical foundation for developing region-specific treatment guidelines and strengthening antimicrobial stewardship efforts in ophthalmology,” said Dr Joveeta Joseph, head of microbiology at LVPEI.
The researchers make a larger argument that extends well beyond ophthalmology.
Eye infections do not originate inside the eye. They travel in from skin, from surfaces, from the environment. The bacteria that cause them carry resistance patterns that reflect what is circulating in the community outside.
“This study positions the eye as a valuable site for AMR surveillance in the environment around us,” said Dr Prashant Garg, executive chair of LVPEI.
In other words, what scientists find in an eye clinic tells them what is spreading everywhere else.
The study stops short of calling for an immediate ban on over-the-counter eye drops. But it calls for urgent action on multiple fronts, tighter antibiotic stewardship in ophthalmology, region-specific treatment guidelines, and expanded genomic surveillance across India.
“To understand and solve a problem like AMR, it is essential for clinicians and scientists to come together and contribute through their expertise. This is not a problem to be solved with model organisms but rather with real patient samples,” said Dr Vinay K Nandicoori, director of CSIR-CCMB.
The authors also point toward falling costs of genome sequencing as an opening. As the technology grows cheaper, integrating it into routine clinical practice becomes possible, giving doctors a tool that matches the speed at which bacteria evolve.
Antimicrobial resistance already kills over a million people globally each year. India carries one of the heaviest burdens.
This study adds evidence that the resistance building in hospitals and communities does not stay contained. It moves, it spreads, and it turns up in places as close and as ordinary as your eye.
The next time you reach for those drops at the pharmacy counter, the scientists who conducted this study would want you to pause.
