Penicillin-binding proteins of Haemophilus ducreyi

Interactions of Yersinia pestis penicillin-binding proteins with beta-lactam antibiotics

The affinities of six major penicillin-binding proteins (PBPs) of Yersinia pestis EV76 to different beta-lactam antibiotics were determined. The results indicate that, similar to their counterparts in Escherichia coli, PBP2 and PBP3 are the lethal targets of amdinocillin and furazlocillin, respectively. The PBP contents of four additional Y. pestis strains and the morphological effects produced by some beta-lactam antibiotics are also reported.

Chancroid and the role of genital ulcer disease in the spread of human retroviruses

Chancroid is the most prevalent form of genital ulcer disease in developing countries and is undergoing a resurgence in industrialized countries. As a result of a nonspecificity of the clinical findings, the etiologic diagnosis of genital ulcer disease requires laboratory support. Genital ulcer disease is a risk factor for the transmission of human retroviral infections. An understanding of this interaction is emerging and will impact on the treatment and control programs for the agents causing genital ulcer disease.

Biology of Haemophilus ducreyi

The etiological agent of the sexually transmitted genital ulcer disease chancroid was first described in 1889 by Auguste Ducrey following repeated autoinoculation of purulent ulcer material from a series of patients. The organism was isolated on artificial media a decade later but has remained difficult to isolate consistently, resulting in controversy over its characteristics and role as the causative agent of chancroid. Because of its fastidious growth requirements, including unknown components in blood, the organism was included in the original description of the genus Haemophilus. Requirement for exogenous hemin and limited phenotypic characteristics, including structural and antigenic properties, suggested that Haemophilus ducreyi was a valid member of the genus Haemophilus. Recent studies of respiratory quinones, deoxyribonucleic acid hybridization, and competition for homologous transformation of the type species, H. influenzae, suggest that H. ducreyi is unrelated to any of the present species of the family Pasteurellaceae, which includes members of the genera Haemophilus, Actinobacillus, and Pasteurella. This review summarizes the early studies with H. ducreyi and our current knowledge of the microbiology of this important human pathogen.