Bacterial profile and antimicrobial resistance in a Tertiary Hospital in Mexico

Objective: The objective of this study was to report the characteristics and the bacterial microbiological frequency of the etiological agents and the antibiotic sensitivity of the isolated pathogens in infectious keratitis in Mexico between 2012 and 2016. Methods: This was a retrospective, cross-sectional, and observational study; medical records of all patients who presented in the cornea department in Mexico with infectious keratitis from 2012 to 2016 were reviewed. Demographic data, Gram stain, and microorganisms obtained in the culture and antibiotic sensitivities were evaluated by disc diffusion test. Results: In the studied period, a total of 639 (40.67%) cases that had a positive culture were included; 54.5% were male with an average age of 48.50 ± 20.43. Gram-positive agents were the most frequent with 80.66% of cases. The most frequent causative agent was Staphylococcus epidermidis (36.61%). The most frequent Gram-negative agent was Pseudomonas aeruginosa (7.55%). The antibiotic with the highest sensitivity was netilmicin (90.3%), followed by moxifloxacin (82.3%) and gatifloxacin (81.3%). Among fortified antibiotics, ceftazidime had a sensitivity of 78% while vancomycin 43.8% (for Gram positive). Conclusion: Bacteria are the most common cause of infectious keratitis, Staphylococcus and Pseudomonas as the most common isolates. There was low resistance to netilmicin and fourth-generation fluoroquinolones for these isolates.