Abstract
Purpose :
The purpose of this study was to identify in those patients over 65 years old, the microbiologic diagnosis, and antibiotic sensitivity, over a 5-year period in an ophthalmology institute in Mexico City.
Methods :
A retrospective analysis of all patients with the diagnosis of infectious keratitis examined between January 2013 to December 2017 was carried out at the Instituto de Oftalmología Conde de Valenciana in Mexico City. The database of the Department of Microbiology and Ocular Proteomics was analyzed to identify all the results of these patients
Results :
A total of 221 corneal scrapes were performed in the same number of patients. All the corneal scrapes were sent for culture. Positive cultures were obtained in 169 of the 221 corneal scrapings (77%). From the 169 positive cultures, there were a total of 199 pathogens isolated; 90% (180) were bacteria and 10% (19) were a fungus.
For the 180 bacteria, isolated Staphylococcus epidermidis was the most common Gram-positive pathogen isolated in 34% of the cases, Pseudomonas aeruginosa was the most common Gram-negative bacteria isolated 8% and for filamentous fungus Fusarium sp and for yeast Candida albicans were the most common pathogens that caused mycotic keratitis.
We observed that from the 199 pathogens isolated 16% were co-infections.
Regarding S. epidermidis isolates, 96.6% were sensitive to Vancomycin over the 5 year study period. However, we observed an increasing trend in resistance to Moxifloxacin from 0% to 29% respectively. However, S. Aureusisolates were 100% sensitive to Vancomycin and Moxifloxacin, but resistance to Ciprofloxacin rose from 33% in 2013 to 50% in 2016
Pseudomonas aeruginosa was the most common Gram-negative microorganism; Moxifloxacin, Gentamicin, Ciprofloxacin preserved their effectiveness against P. aeruginosa throughout the study period.
A sensitivity test was only carried out for yeast; 100% were sensitive to Fluconazole and 89% were sensitive to Voriconazole and Amphotericin B.
Conclusions :
We found some resistance to ciprofloxacin among the staphylococci isolated, but the majority remained sensitive.
Fluoroquinolone monotherapy should perhaps not be the first choice, given the resistance among some staphylococci, which was the most frequently identified organism in our series, although in vitro resistance does not necessitate lack of clinical response.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.