Abstract:
Background: Ocular infections caused by different groups of bacteria are important public health
problems worldwide. The situation is more worsened by the alarmingly increasing rate of antibiotic
resistance.
Objectives: The aim of this study was to assess the magnitude of the bacterial isolates, associated risk
factors and their antimicrobial susceptibility patterns isolated from patients with external ocular
infection at Borumeda Hospital, Northeast Ethiopia.
Methods: A cross-sectional study was conducted at Borumeda Hospital from February to May, 2014.
A systematic random sampling technique was used. Socio-demographic data and possible risk factors
were collected using structured questionnaire. External ocular specimens were collected according to
standard operational procedure. After collection, specimens were inoculated on MacConkey agar,
chocolate agar, blood agar and Mannitol Salt Agar. Presumptive bacterial colonies were isolated using
a series of biochemical tests based on their Gram reaction. Kirey Bauer disk diffusion method was used
to determine the antimicrobial susceptibility pattern of the isolates. Data were entered and analyzed
using SPSS version 20. Descriptive statistics and logistic regression analysis was used to determine
dependant and independent variable. P value <0.05 were considered as statistically significant to all
test.
Results: Among 160 patients, males were 94(58.8 %). The mean age of study participants was 55.11
years. Majority was 95(59.4%) culture positive for 89 (93.7%) Gram positive and 6(3.8%) was Gram
negative. Coagulase negative Staphylococci were the predominant isolate 51(31.9%) followed by S.
aureus 21(13.1%) and S. pneumoniae 10 (6.2%). Total multidrug resistance shows in 48 (50.5 %) of
the isolates. All Gram positive isolates were susceptible for vancomycin but 60(46.1%) of them showed
resistance against amoxicillin. Resistance for tetracycline, norfloxacylin, ceftriaxon and ciprofloxacin 4
(66.7 %) for each, was observed among Gram negative bacterial isolates. Multivariate analysis shows
the predisposing risk factor were no statistical significant association with dependant variable.
Conclusion: The prevalence of bacterial isolates in external ocular samples was high in the study area
and the dominant bacterial isolate was coagulase negative staphylococci. Amoxicillin resistance among
Gram positive bacterial isolates was exceptionally high. Although the number of Gram negative
bacterial isolates were small, drug resistance was comparatively significant. Therefore, identification of
ophthalmic bacterial etiological agent and conducting drug susceptibility test could reduce drug
resistance and increase cure rate during treatment.
