Bacterial Conjunctivitis: Microbiological Profile, Antimicrobial Susceptibility Patterns and Recommendations for Treatment

Conjunctivitis is one of the most common ocular infections, with bacterial infections accounting for 50-70% of all conjunctivitis cases. We conducted a study to determine the bacteria causing conjunctivitis and their antimicrobial susceptibility patterns at a large hospital and medical college in North India. Conjunctival swab specimens were obtained from 91 conjunctivitis patients attending the Ophthalmology out-patient department and were processed by Gram’s stain, culture and antimicrobial susceptibility testing. Of the 91 samples collected, 46 showed growth of bacterial isolates; yielding total of 49 isolates. Gram positive and Gram negative bacteria comprised 77.5% and 22.4% respectively; including Staphylococcus aureus (31%), Staphylococcus epidermidis (27%), Streptococcus pneumoniae (16%), Streptococcus pyogenes (4%), Pseudomonas aeruginosa (10%), Klebsiella (8%), E. coli (2%) and Proteus spp. (2%). Most bacteria were susceptible to the newer generation fluoroquinolones, particularly gatifloxacin, and hence may be used if the treatment is warranted. Amikacin can also be used if Gram negative organisms are suspected. However, the use of antibiotics must be minimized and choice should be made on the basis of microbiological report.