Random amplified polymorphic DNA subtyping of Haemophilus influenzae from middle ear effusion fluid of lebanese patients with otitis media with effusion

In this study, we evaluated a Random Amplified Polymorphic DNA (RAPD) method, in the subtyping of H. influenzae in middle ear effusions (MEE), obtained from 33 patients with otitis media with effusion (OME) admitted to 3 medical centers in Beirut, Lebanon. Method: RAPD was initially evaluated on 15 H. influenzae isolates using three 10 mer primers along with a 21 mer primer. Results: Primer 1 (10 mer) and Primer 2 (20 mer) were the most discriminatory when used in conjunction and were selected to be used on DNA lysates obtained from 33 MEE samples positive for H. influenzae by PCR. Conclusion: Our data have shown that 4 RAPD patterns were obtained on DNA of H. influenzae isolates and a single RAPD pattern was seen on H. influenzae DNA from MEE samples. This indicates that a single strain may have been implicated in these infections. Studies are underway to determine the prevalence of H. influenzae as the etiology of otitis media with effusion in Lebanon and subtype the organism to determine a possible multi-strain involvement.