Current pattern of antibiotic resistance of clinical isolates among conjunctival swabs

Objectives: To identify the etiological agent in bacterial conjunctivitis and to determine the antibiogram of bacterial isolates.

Methodology: This observational study was conducted at Dr. Essa’s Laboratory over a period of 12 months ending in March 2012. Two hundred samples taken from conjunctiva of patients with conjunctivitis were cultured on routine medium and the antibiograms of bacterial isolates were determined by Kirby- Bauer disc diffusion method.

Results: The analysis of the culture showed that 41% were cultured positive with gram positive bacteria Staphylococcus aureus 52.5% and Staphylococcus epidermidis 30.1% and Micrococci 8.3%. However, 9.1% were gram negatives with Klebsiella pneumoniae 5.14% and Pseudomonas aeruginosa 2.6% and 1.36% were others (Acinetobacter, Haemophilus , E.coli and Moraxella) keeping in view the increasing use of contact lens and unclean fingers. The overall antibiograms of bacterial isolates indicate aminoglycosides (gentamicin, tobramicin) and the newer quinolones as apparent drug of choice for empirical therapy, followed by chloramphenicol, since drug fussy gram-negatives such as Pseudomonas, Acinetobacter and E.coli were among the conjunctival isolates. Resistance profile of gram positive isolates shows cefixime 91.4%, doxycycline 57.9%, cotrimoxazole 29.3%, ampicillin 22.9%, ciprofloxacin 13.4%, cephradine 8.3%, cefuroxime 7.1%, fosfomycin 4.7%, ceftriaxone 3.6%, co-amoxiclav 3.6%, cefotaxime 3.5%, vancomycin 2.6%.

Conclusion: Resistance to all conventionally used antibiotics is increasing, therefore identification of etiological agent and antibiogram is important to treat conjunctivitis and to avoid complications.