Development of a heminested polymerase chain reaction assay for the detection of Haemophilus ducreyi in clinical specimens

Detection of Haemophilus ducreyi in genital ulcer specimens by culture lack s sensitivity. To enhance detection, a heminested polymerase chain reaction (PCR) assay was developed targeting the nucleotide sequence of a gene, des ignated p27, which encodes for a 27 kDa H. ducreyi-specific protein. The p2 7 PCR assay detected all (37/37) H. ducreyi strains tested and gave no ampl ified product from DNA extracts of any of 31 other microorganisms, from 30 non-genital ulcer specimens, or from 29 urethral and vaginal swab specimens collected from nonchancroid STD patients. In genital ulcer disease specime ns, compared to combined positive results obtained by culture and a previou sly described PCR assay, the P27 PCR assay showed a sensitivity of 91% (48/ 53). The p27 PCR assay provides a specific and a sensitive detection of H. ducreyi in clinical specimens.