Localization of Haemophilus ducreyi in naturally acquired chancroidal ulcers

• Published in: Microbes and infection 2006-08, Vol.8 (9), p.2465-2468
• Main Authors: Bauer, Margaret E., Townsend, Carisa A., Ronald, Allan R., Spinola, Stanley M.
• Format: Article
• Language: English
• Subjects: Bacterial diseases; Bacterial diseases of the genital system; Bacterial localization; Bacteriology; Biological and medical sciences; Chancroid; Chancroid - blood; Chancroid - metabolism; Chancroid - microbiology; Fibrin - metabolism; Fundamental and applied biological sciences. Psychology; Genital ulcer; Haemophilus ducreyi; Haemophilus ducreyi - isolation & purification; Haemophilus ducreyi - metabolism; Haemophilus ducreyi - pathogenicity; Human bacterial diseases; Humans; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Neutrophils - microbiology; Ulcer - blood; Ulcer - metabolism; Ulcer - microbiology
• ISSN: 1286-4579; 1769-714X
• DOI: 10.1016/j.micinf.2006.06.001

Haemophilus ducreyi causes the sexually transmitted genital ulcer disease chancroid. In human inoculation experiments, bacteria colocalize with neutrophils and macrophages but remain extracellular. The organism also colocalizes with collagen and fibrin but not with keratinocytes, fibroblasts, laminin, or fibronectin. These relationships are established by 48 h postinoculation and persist through the pustular stage of disease. To extend these observations to the ulcerative stage of disease, and to compare results in the human model with those of natural disease, we obtained biopsies from patients with naturally acquired chancroid. All ulcers were culture positive for H. ducreyi and histologically very similar to pustules from the human model. Staining with H. ducreyi-specific monoclonal antibodies demonstrated H. ducreyi within 5 biopsies. The organism was chiefly found within the granulocytic infiltrate of the ulcer. Dual staining for H. ducreyi and eukaryotic tissue components showed that H. ducreyi colocalized with neutrophils and fibrin at the ulcerative stage of disease. No bacteria were associated with keratinocytes, fibroblasts, or collagen. Overall, these findings are consistent with results from the human model. This is the first reported study to localize bacteria specifically identified as H. ducreyi within naturally acquired chancroid.