Potential bacterial pathogens of external ocular infections and their antibiotic susceptibility pattern at Hawassa University Teaching and Referral Hospital, Southern Ethiopia

Abstract

Bacterial external ocular infection is a common health problem along with increase and spread of drug resistance in Ethiopia. The objective of this study was to identify potential bacterial isolate of external ocular infections and their antimicrobial susceptibility patterns in patients attending eye clinic of the Hawassa University Teaching and Referral Hospital, from December 2012 to April 2013. A total of 281 consecutive, non-repetitive ocular specimens were collected among conjunctivitis cases (n=140), blepharitis cases (n=55), keratitis cases (n=31), dacryocystitis cases (n=19), and other cases (n=36). All samples were processed for culture and identification by standard methods. Susceptibility testing was done by Kirby-Bauer method as per Clinical and Laboratory Standards Institute (CLSI) guideline. Out of 281 ocular specimens submitted to culture, 137 (48.8%) specimen were positive. The most common bacterial isolates were Gram positive cocci (n=88; 61.5%). The predominant bacterial species isolated was Staphylococcus aureus (n=30; 21.0%) followed by coagulase negative Staphylococci (CoNS) (n=26; 18.2%) and Streptococcus pneumoniae (n=20; 14.0%). In vitro ciprofloxacin was effective against 86% of isolated pathogen. Multi-drug resistance was observed in 69.9% of the bacterial isolates. Our study confirmed that S. aureus was the overall predominant isolated pathogen followed by CoNS, S. pneumoniae and Klebsiella spp. Gram positive isolates were more susceptible to amoxicillin-clavulanic acid and vancomycin, whereas Gram negative isolates were more susceptible to ciprofloxacin and gentamicin. Relatively, ciprofloxacin is effective against most isolated pathogen.

Ocular bacterial infections at Quiha Ophthalmic Hospital, Northern Ethiopia: an evaluation according to the risk factors and the antimicrobial susceptibility of bacterial isolates

“…Our observations were also higher than that seen in India (34.5%) [3], Japan (32.2%) [4], and Iran (37.5%) [45]; sociodemographic, geographical or climatic differences for the patient populations could partially explain this [38]. Similar to findings from India [46], Iran [9], and other studies in Ethiopia [6, 10, 11, 44], Gram-positive bacteria contributed to majority (60.7%) of the total bacterial isolates in our study. Overall, the predominant bacterial isolate was S. aureus (21.5%), as has been reported in Jimma (28.4%) [6], Gondar (21%) [10], Nigeria (23.7%) [23], and India (26.6%) [47].…”

“…Our assessment revealed that a high proportion of ocular infections (66.7%) were due to bacterial infections elsewhere in Ethiopia, lower proportions have been observed (48.8–60.8%) [10, 11, 44]; however, higher proportions (74.7%) have been observed in Jimma, Ethiopia [6]. This variation could be attributed to the inclusion of only exra-ocular infection in other studies.…”

“…Resistance to two or more antimicrobials was seen in 53.9% of the isolates, which is lower than that reported in other regions in Ethiopia (69.9–87.1%) [10, 11]. S. pneumoniae (87.5%), CoNS (87%) and S. aureus (82.5%) were the most resistant among Gram-positive isolates.…”

“…Bacterial infections (Both Gram-positive and Gram-negative) contribute to 32 to 74% of ocular infections globally [4–10]. Staphylococci are the leading ocular isolates worldwide among the Gram-positive bacteria, [9, 11–13]; while Pseudomonas aeruginosa , Klebsiella pneumoniae and Escherichia coli are the major Gram-negative bacteria isolated from ocular infections [3, 14, 15]. …”

In VitroBiofilm Formation and Antibiotic Susceptibility Patterns of Bacteria from Suspected External Eye Infected Patients Attending Ophthalmology Clinic, Southwest Ethiopia

“…Methicillin-resistant isolates were determined using cefoxitin disk (30 μg) by incubating at 34 ± 1°C as recommended by CLSI [17]. Multidrug resistance (MDR) is operationalized as a resistance of bacterium to at least one agent in three or more different classes of antibiotic drugs [18].…”