BACTERIAL SPECTRUM OF EXTERNAL OCULAR INFECTIONS: PREVALENCE AND ASSOCIATED IN VITRO ANTIMICROBIAL SUSCEPTIBILITY AND RESISTANCE IN A TERTIARY CARE HOSPITAL.

Abstract

Background: External ocular infections (EOI) can affect the lids, conjunctiva or cornea and may carry serious consequences including visual impairment if not correctly identified and treated. Empirical treatment is usually initiated using broad-spectrum antibiotics before concluding culture and susceptibility testing, this along with casual prescriptions, ineffective dosing and poor patient compliance have contributed to increasing bacterial resistance to commonly used topical antibiotics. Aims: Through this study we aim to establish the prevalence of bacterial EOI and their associated in vitro antimicrobial susceptibility and resistance profiles. Materials and Methods: This cross-sectional study reviewed consecutive microbiological reports of EOI from January 2015 to December 2016. Demographic data and bacterial organisms isolated as well as their susceptibility and resistance results to routine antibiotics used in culture testing were obtained and analyzed. Results: A total of 218 reports of bacterial EOI were attained from 165 patients. Gram-negative organisms represented 71% of all culture reports. H. influenza was the most common etiologic agent representing 26% of all organisms, followed by S. aureus (12%) and P. aeruginosa (10%). Gram-negative isolates had the highest In vitro susceptibility to Amikacin, Colistin and Meropenem. Gram-positive isolates had the highest In vitro susceptibility to Vancomycin. Resistance to multiple antibiotic classes was seen in 39% of cultures. Conclusion: The antimicrobials used in routine culture testing including topical antibiotics commonly used by ophthalmologists had high susceptibility rates overall, but In vitro resistance was encountered for various bacterial organisms. Susceptibility testing allows physician to choose the best antibiotic to avoid inadequate treatment and potential complications including visual impairment and blindness. Copy Right, IJAR, 2018,. All rights reserved.