Abstract

Background and aims: Staphylococcus aureus is an opportunist that causes ocular infection and systemic infections in the human body. This organism increases its resistance to many types of antibiotics every day and becomes more resistant, and this led to a growing concern in this era. Given this fact, the aims of this study were to determine the frequency of S. aureus in external ocular infections and to determine the prevalence of MRSA strains and the sensitivity of isolated S. aureus to antibiotics, in patients who attended selected ophthalmology clinics in major public hospitals and private clinics in the city of Sana’a - Yemen. Subjects and methods: The study was conducted for a year, starting in September 2016 to October 2017, where a total of 197 patients with external eye infections were included in the study. Samples were collected and transferred to the National Center of Public Laboratories (NCPHL), in Sana’a. Possible bacterial pathogens have been isolated and identified using standard laboratory techniques. MRSA was determined by means of the disc diffusion method to 5 micrograms of methycillin disc and 1 micrograms of oxicillin disc; an antimicrobial sensitivity test was performed by means of disc diffusion method of selected antibiotics. The ocular infections include conjunctivitis, keratitis, blepharitis and blepharo-conjunctivitis. Results: Of a total of 197 cultured swabs, only 146 swabs produced a positive culture (74.1%). Gram-positive bacteria formed 52.1% of the total isolates where S. aureus was the predominant pathogen (30.1%). The prevalence of MRSA was 34.1%. There was a higher rate of antibiotic resistance tested in MRSA isolates compared to a lower rate of resistance in MSSA. Conclusion: It can be concluded, S. aureus was the most common bacterial isolate in external ocular infections, high rate of MRSA, the emergence of S. aureus isolates resistant to wide range of antibiotics have raised MRSA in ocular infections into a multi-drugresistant, making it more and more dangerous in ocular infections. Regular surveillance of ocular associated infections and monitoring antibiotic sensitivity pattern and strict drug policy for antibiotics are recommend.