A.O. Okesola and A.O. Salako

Department of Medical Microbiology and Parasitology, College of Medicine, University of Ibadan, University College Hospital, Ibadan, Nigeria


Objective: In bacterial conjunctivitis, clinical presentations are not diagnostic of the causative agent, therefore, microbiological analysis is mandatory for specific treatment option. This study was undertaken to determine the microbiology profile of bacterial conjunctivitis in our environment.

Methodology: This is a laboratory-based study carried out in the Medical Microbiology Laboratory of University College Hospital, Ibadan, Nigeria. Conjunctival swabs collected from 365 patients with clinically diagnosed conjunctivitis, were analysed by standard bacteriological methods.

Results: Bacterial pathogens were detected in 342 (93.7%) conjunctival samples while 23(6.3%) were sterile. Of the pathogens, 256 (74.9%) were Staphylococcus aureus, 35(10.2%) Coagulase- negative staphylococci, 22 (6.4%) Pseudomonas aeruginosa , 11(3.2%) Escherichia coli, 7(2.1%) Klebsiella species, 5(1.5%) Streptococcus pneumoniae , 4(1.2%) Haemophilus influenzae, 1(0.3%) Proteus mirabilis and 1(0.3%)Neisseria gonorrhoeae . The highest rate of conjunctivitis 96(26.3%) was found among infants and children (0-10years).Resistance rates to most of the tested antibiotics were high. However, 67% of them were susceptible to ceftriaxone while only 39.2% were susceptible to chloramphenicol.

Conclusions: This study has recorded high antibiotic resistance in bacterial pathogens of conjunctivitis in this environment; therefore, determining the susceptibility pattern of these pathogens to available antibiotics is crucial to effective management of bacterial conjunctivitis.

Keywords: Conjunctivitis, bacteria, microbiological profile


Dr. A.O. Okesola,
Dept. of Medical Microbiology and Parasitology,
College Of Medicine,
University College Hospital,
Ibadan, Nigeria, West Africa.
Phone: 234- 803-305-0593
E- mail: abiolaokesola@yahoo.com


Bacterial conjunctivitis is common and affects all age groups. They are mainly caused by bacteria such as Streptococcus pneumoniae, Haemophilus influenzae , Staphylococcus aureus and Neisseria gonorrhoeae in the normal host. In the new born, who often get this infection from the vaginal fluids of their mothers during birth, N.gonorrhoea and Chlamydia trachomatis are the most common causes1,2. S.pneumoniae, P.aeruginosa, and S.aureus may also cause acute conjunctivitis in neonates or children3 In sexually active teenagers and adults, C.trachomatis and N.gonorrhoea have been implicated. In young children, H.influenzae can cause severe conjunctivitis. 4 In adults, isolates are S.pneumoniae, S.aureus, and Staphylococcus epidermidis5, Serratia marscences,6 S.pneumoniae, P.aeruginosa7 and Moraxella species have been implicated in institutional outbreaks of bacterial conjunctivitis. Gonococcal conjunctivitis rarely occurs without sexual transmission, and suspicion for possible sexual abuse should be maintained in prepubertal children.8 Neisseria meningitidis, however, is an uncommon cause of acute bacterial conjunctivitis.

Typically, transmission of the infection involves exogenous routes of infection via airborne fomites, handto- eye contact, contact with genital secretions and contact with upper respiratory tract infection secretions. Less frequently, infection may spread to the conjunctiva from the eyelids, lacrimal drainage apparatus, face, or paranasal sinuses. Hematogenous route of infection is however rare. The most common presentation is a red eye and the main tasks are to exclude potentially serious causes of a red eye and then decide whether the conjunctivitis is infective, allergic, or due to other causes, so that a suitable management could be instituted. Clinical presentations are not diagnostic of the causative agent, therefore microbiological analysis, with cytology, cultures, and microbial susceptibilities are mandatory. The specific antimicrobial therapy should then be based on the laboratory findings.9 This study was therefore designed to determine the prevalence and pattern of antibiotic susceptibility among bacterial pathogens of conjunctivitis in our environment.