Random Amplified Polymorphic DNA Subtyping of Haemophilus influenzae from Middle Ear Effusion Fluid of Lebanese Patients with Otitis Media with Effusion

Abstract

Objective: In this study, we evaluated a RandomAmplified Polymorphic DNA (RAPD) method, in thesubtyping of H. influenzae in middle ear effusions(MEE), obtained from 33 patients with otitis media witheffusion (OME) admitted to 3 medical centers in Beirut,Lebanon.Method: RAPD was initially evaluated on 15 H.influenzae isolates using three 10 mer primers alongwith a 21 mer primer.Results: Primer 1 (10 mer) and Primer 2 (20 mer) werethe most discriminatory when used in conjunction andwere selected to be used on DNA lysates obtained from33 MEE samples positive for H. influenzae by PCR.Conclusion: Our data have shown that 4 RAPD patternswere obtained on DNA of H. influenzae isolates and asingle RAPD pattern was seen on H. influenzae DNAfrom MEE samples. This indicates that a single strainmay have been implicated in these infections. Studiesare underway to determine the prevalence of H.influenzae as the etiology of otitis media with effusionin Lebanon and subtype the organism to determine apossible multi-strain involvement.Key words: Otitis, PCR, subtyping