Abstract
Purpose :
Antimicrobial resistance (AMR) globally threatens the treatment outcomes of patients with any medical condition. AMR surveillance programs have been recommended by the World Health Organisation (WHO) to support disease prevention and control strategies. A bacterial ocular surveillance program (BOSS) was initiated in Sydney, Australia in 2016. We aimed to report the spectrum and AMR of bacteria isolated from corneal scrapings in bacterial keratitis in 2017 from different areas of the Sydney metropolitan area.
Methods :
A retrospective analysis of bacteria isolated from corneal scrapings from patients with bacterial keratitis from four centers across Sydney, New South Wales, Australia, from January 1 to December 31, 2017 was conducted. Sydney Eye and Prince of Wales Hospitals are in the east side of the city, and Westmead and Liverpool Hospitals in the west side. All specimens were processed at NSW Health Pathology. Antimicrobial resistance data were available for specimens from the eastern hospitals.
Results :
There were 288 episodes of clinical bacterial keratitis. Of these, 161 inoculated plates isolated 189 organisms (positive culture rate of 56%). There were 127 (67%) Gram-positive organisms and 62 (33%) Gram-negative organisms. Most of the episodes (n = 155, 82%) presented to the eastern hospitals.
Coagulase-negative staphylococci (CoNS) 37% (70/189), Staphylococcus aureus 12% (23/189), including four methicillin-resistant (MRSA), and Pseudomonas aeruginosa 18% (34/189) were the most common organisms.
AMR was found for: CoNS to cefalotin 18%, chloramphenicol 15%, gentamicin 9%, and ciprofloxacin 3%; methicillin-sensitive Staphylococcus aureus (MSSA) to chloramphenicol 8%; MRSA to ciprofloxacin 75% and gentamicin 25%; and Corynebacterium spp. to chloramphenicol 40%, and ciprofloxacin 40%. All Gram-positive organisms were susceptible to vancomycin. Pseudomonas aeruginosa isolates were susceptible to ciprofloxacin, gentamicin, and tobramycin
Conclusions :
CoNS were the most commonly culprit of bacterial keratitis and of these, about one-fifth were resistant to cefalotin, a common antibiotic used to initially treat bacterial keratitis. Most MRSA were resistant to ciprofloxacin. Although the BOSS was established in Sydney, a wider system should be implemented across Australia for providing more comprehensive data from different geographic areas to inform both clinical decision-making and empiric treatment strategies
This is a 2021 ARVO Annual Meeting abstract.