Since the extremely nutritional fastidious of the causative agent, H. ducreyi, confirmation of chancroid by cultivation is not sensitive. Complicated medium with supplement has been reported without significant outcomes by many investigators. This dissertation aims to re-evaluate the cultivation methods using 3 different selective enriched media. Ulcer scrapings were collected from 127 chancroid patients at the Nang-Learng VD center, Department of CDC, during 1989 to 1990. Microscopic examination were performed by Unna s papenheim staining. Cultures were simultaneously established on the following media : GCHgs composed of GC agar base supplemented with 2% bovine hemoglobin, 1% isovitalex and 3 mg/L vancomycin

MH-HB composed of Mueller Hinton agar base supplemented with 5% chocolated horse blood, 1% isovitalex and 3 mg/L vancomycin

BH-HB composed of brain heart infusion agar supplemented with 5% Chocolate horse blood, 5% fetal bovine serum, 1% isovitalex and 3 mg/L vancomycin. Resu lts revealed that 20.5% (26 out of 127 specimens) were smear positive showing the characteristic "shool of fish" arrangements. The cultivation rate of GCHgS, MH-HB and BH-HB were 8.7%, 15.7% and 15.7%, respectively. Combinative detection with bimedia showed 21.3%, 20.5% and 25.2% on the combination of GCHgS and MH-HB, GCHgS and BH-HB, MH-HB and BH-HB, respectively. With trimedia, H. ducreyi was isolated 37 out of 127 patients (29.1%). Uncorrelation of cultivation versus microscopic evaluation was revealed. Inclusion of both cultivation and microscopic significantly increased the sensitivity for chancroid detection. Using the trimedia and smear detection rate grew up to 37.8%. Antimicrobial susceptibility test was performed on H . ducreyi isolates using agar dilution technique. All isolates were susceptible to ceftriaxone, erythromycin, norfloxacin, ofloxacin, ciprofloxacin and spectinomycin. They all were resisted to tetracycline, sulfamethoxazole. Majority 37 into 7 plasmid patterns. were performed upon E. coli. kb, 10 kb, 3.1 kb plasmids carried ampicillin resistant characteristic while the 4.7 Kb carried kanamycin resistance.