Open AccessLocalization of Haemophilus ducreyi at the Pustular Stage of Disease in the Human Model of Infection
Author(s) -
Margaret E. Bauer,
Stanley M. Spinola
Publication year - 2000
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.68.4.2309-2314.2000
Subject(s) - haemophilus ducreyi , antiserum , biology , polyclonal antibodies , bacterial outer membrane , microbiology and biotechnology , staining , monoclonal antibody , immunofluorescence , bacteria , antibody , pasteurellaceae , escherichia coli , haemophilus influenzae , immunology , biochemistry , genetics , gene , antibiotics
To localizeHaemophilus ducreyi in vivo, human subjects were experimentally infected withH. ducreyi until they developed a painful pustule or for 14 days. Lesions were biopsied, and biopsy samples were fixed in 4% paraformaldehyde, and cryosectioned. Sections were stained with polyclonal anti-H. ducreyi antiserum orH. ducreyi -specific monoclonal antibodies (MAbs) and fluorescently tagged secondary antibodies and examined by confocal microscopy. We identifiedH. ducreyi in 16 of 18 pustules but did not detect bacteria in the one papule examined.H. ducreyi was observed as individual cells and in clumps or chains. Staining with MAbs 2D8, 5C9, 3B9, 2C7, and 9D12 demonstrated thatH. ducreyi expresses the major pilus subunit, FtpA, the 28-kDa outer membrane protein Hlp, the 18-kDa outer membrane protein PAL, and the major outer membrane protein (MOMP) or OmpA2 in vivo. By dual staining with polyclonal anti-H. ducreyi antiserum and MAbs that recognize human skin components, we observed bacteria within the neutrophilic infiltrates of all positively staining pustules and in the dermis of 10 of 16 pustules. We were unable to detect bacteria associated with keratinocytes in the samples examined. The data suggest thatH. ducreyi is found primarily in association with neutrophils and in the dermis at the pustular stage of disease in the human model of infection.