ISOLATION OF HAEMOPHILUS-DUCREYI - THE IM PORTANCE OF THE CHOICE OF THE GROWING MEDIUM - THE SENEGALESE EXPERIENCE

Genital ulcerations typify one of the major reasons clients seek STD c onsultation in developing countries. The usual etiologies are syphilis , chancroid and herpes. The ideal diagnostic approach is to undertake complete laboratory examination that are rarely possible in structure destitute of laboratory analysis possibilities which is the case for m ost of the STD transmission agents. Chancroid is caused by Haemophilus ducreyi, a short Gram negative bacteria. The bacteriological diagnosi s is based on direct examination, isolation and identification of the bacteria. The nutritive exigence of the bacteria required 3 medium of isolation (PPLO base Pasteur), GC base (GIBCO) and Muller Hinton base (Becton & Dickinson, with << chocolate >> agar) have been tested from the chancre samples of 108 male patients who had a median age of 31 ye ars. Direct exams were positive in 66 cases (61 %) and culture exams p ositive in 53 cases (49 %). The Muller Hinton base with << chocolate > > agar produced the best results and seems to be the medium of choice for isolated strains in Senegal. The culture mediums currently used in Europe are apparently inappropriate for the germ culture in Senegal. We have also observed that all the isolated strains were producers of beta-lactamase. Antibiotic treatment before the sample swab is taken s eems to have an inhibiting effect on the culture. Direct examination w ith a sensibility of 94,3 % and a specificity of 70,9 % remains suffic ient in routine presumptive diagnosis in endemic areas.