Drug resistance of Haemophilus ducreyi
Rutanarugsa, A.; Vorachit, M.; Polnikorn, N.; Jayanetra, P.
Southeast Asian Journal of Tropical Medicine and Public Health 21(2): 185-193
1990
ISSN/ISBN: 0125-1562 PMID: 2237585 Document Number: 350091
Chancroid, the disease caused by Haemophilus ducreyi is one of the common sexually transmitted disease (STD) in Thailand and other tropical countries. In Thailand, the diagnosis of chancroid is still based on clinical appearance which may be confused with other STD manifested by genital ulcers. In recent years the increasing resistance strains of H. ducreyi to these antimicrobial agents has been reported so that cultivation and antimicrobial susceptibility tests of this organism have become more important. This study showed that MBV is the best medium for isolation with a success rate of 48%. All strains tested from isolates of this study were resistant to ampicillin, due to production of beta-lactamase. Approximately 99% of the strains were resistant to tetracycline 92% of strains were resistant to sulfamethoxazole and 32% were resistant to trimethoprim. All isolates were susceptible to chloramphenicol, ceftriaxone, erythromycin and the fluorinated quinolones ciprofloxacin, norfloxacin, ofloxacin and pefloxacin. Beta-lactamase enzymes produced by 37 strains of H. ducreyi were determined for their isoelectric point (pI). All had pI of 5.4, indicative of plasmid-mediated betalactamase type TEM-1.