Developing a <i>Pseudomonas aeruginosa</i> keratitis model in Swiss albino mice for clinical assessment

Background & objectives Pseudomonas aeruginosa is a leading cause of bacterial keratitis, known for its rapid progression, severe corneal damage, and resistance to treatment. Existing animal models exist to study disease mechanisms and therapeutic options require specialised conditions or complex procedures. This study aimed to develop a simplified, cost-effective, and reproducible murine model of P. aeruginosa keratitis using Swiss albino mice for translational research applications. Methods Four female Swiss albino mice (6-8 wk old) were maintained under standard conditions. Baseline ocular evaluation was done using a handheld slit lamp. The left corneas were abraded with a sterile 26G needle and inoculated topically with 10 μL of P. aeruginosa (1.0 × 10⁶ CFU/mL, ATCC 19660). The right eyes served as uninfected controls. Clinical signs were assessed on days 1, 2, and 3 using a standardised 0-4 scoring scale. Infection was confirmed through culture, biochemical tests, and PCR targeting the exotoxin A gene. Statistical analysis was performed using one-way ANOVA with Tukey's post hoc test. Results All infected eyes developed progressive keratitis marked by lid swelling, corneal haze, and stromal involvement. Control eyes remained unaffected. Clinical scores increased significantly over time (P< 0.05). Culture and molecular analyses confirmed successful infection. Interpretation & conclusions This simplified Swiss albino mouse model effectively mimics human P. aeruginosa keratitis and enables cost-efficient study of pathogenesis and therapeutic testing. It can facilitate standardised ophthalmic infection research.