Spectrum and antibiotic susceptibility pattern of bacterial isolates from conjunctival swabs

Conjunctivitis is the most common disease of conjunctiva which occurs by exogenous or endogenous source. Bacterial conjunctivitis is the most common type of this infection for which emperical treatment is started without knowing the etiological agents because prior cultures are generally not taken. We conducted this survey to study the etiological agents of conjunctivitis in a total of 6763 swabs obtained over a period of four years (2001 to 2004). The prevalence of bacterial conjunctivitis was found to be 20.4% with a predominance of Staphylococcus aureus (87.2%) followed by Streptococcus pneumoniae (4.7%) and gram negative rods (E.coli + Klebsiella spp. + Pseudomonas spp.) in 8.1% swabs. For S. aureus, amikacin showed maximum sensitivity (73.2%) while for S. pneumoniae, cefotaxime (90.6%) and cefazolin (89%) were found to be highly sensitive drugs. For gram negative rods, ceftazidime (74.1%) and cefotaxime (67%) were found to be preferred options. Thus it is concluded that bacterial conjunctivitis in our hospital is predominated by S. aureus. The bacterial isolates obtained from conjunctiva have not yet attained a high level of antibiotic resistance and hence averts the need to unnecessarily start new/latest generations of antibiotic eyedrops or antibiotic combination which may lead to acquisition of resistance by these bacteria.