Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 2000  (2)
  • Bacterial Outer Membrane Proteins
  • American Society for Microbiology (CrossRef)  (2)
  • 1
    In: Infection and Immunity, 2000, Vol. 68(11), p.6441
    Description: Haemophilus ducreyi expresses a peptidoglycan-associated lipoprotein (PAL) that exhibits extensive homology to Haemophilus influenzae protein 6. We constructed an isogenic PAL mutant (35000HP-SMS4) by the use of a suicide vector that contains lacZ as a counterselectable marker. H. ducreyi 35000HP-SMS4 and its parent, 35000HP, had similar growth rates in broth and similar lipooligosaccharide profiles. 35000HP-SMS4 formed smaller, more transparent colonies than 35000HP and, unlike its parent, was hypersensitive to antibiotics. Complementation of the mutant in trans restored the parental phenotypes. To test whether expression of PAL is required for virulence, nine human volunteers were experimentally infected. Each subject was inoculated with two doses (41 to 89 CFU) of live 35000HP and one dose of heat-killed bacteria on one arm and with three doses (ranging from 28 to 800 CFU) of live 35000HP-SMS4 on the other arm. Papules developed at similar rates at sites inoculated with the mutant or parent but were significantly smaller at mutant-inoculated sites than at parent-inoculated sites. The pustule formation rate was 72% (95% confidence interval [CI], 46.5 to 90.3%) at 18 parent sites and 11% (95% CI, 2.4 to 29.2%) at 27 mutant sites (P 〈 0.0001). The rates of recovery of H. ducreyi from surface cultures were 8% (n = 130; 95% CI, 4.3 to 14.6%) for parent-inoculated sites and 0% (n = 120; 95% CI, 0.0 to 2.5%) for mutant-inoculated sites (P 〈 0.001). H. ducreyi was recovered from six of seven biopsied parent-inoculated sites and from one of three biopsied mutant-inoculated sites. Confocal microscopy confirmed that the bacteria present in a mutant inoculation site pustule lacked a PAL-specific epitope. Although biosafety regulations precluded our testing the complemented mutant in humans, these results suggest that expression of PAL facilitates the ability of H. ducreyi to progress to the pustular stage of disease.
    Keywords: Bacterial Outer Membrane Proteins ; Proteoglycans ; Haemophilus Infections -- Etiology ; Haemophilus Ducreyi -- Pathogenicity ; Lipoproteins -- Metabolism ; Peptidoglycan -- Metabolism;
    ISSN: 0019-9567
    ISSN: 00199567
    E-ISSN: 10985522
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    In: Infection and Immunity, 2000, Vol. 68(5), p.2602
    Description: Haemophilus ducreyi expresses 2 OmpA homologs, designated MOMP and OmpA2, whose genes are arranged in tandem on the chromosome. Northern blot analysis indicated that momp and ompA2 are transcribed independently. Sequences of the momp open reading frame (ORF) lacking the transcriptional start site were amplified by PCR, and an Omega-Km2 cassette was ligated into the ORF. A plasmid containing this construction was electroporated into H. ducreyi 35000HP, and an isogenic MOMP-deficient mutant (35000HP-SMS2) was generated by allele exchange. In Southern blotting, 35000HP-SMS2 contained one copy of the Omega-Km2 cassette in momp. 35000HP and 35000HP-SMS2 had similar outer membrane protein (OMP) and lipooligosaccharide profiles and growth rates except for up-regulation of a putative porin protein in the mutant. Five subjects were inoculated with three doses of live 35000HP-SMS2 on one arm and two doses of live 35000HP and one dose of a heat-killed control on the other arm in a double-blind escalating dose-response trial. Pustules developed at 7 of 10 sites inoculated with 35000HP and at 6 of 15 sites inoculated with 35000HP-SMS2 (P = 0.14). 35000HP and 35000HP-SMS2 were recovered at similar rates from daily surface cultures and semiquantitative cultures. The data suggest that expression of MOMP is not required for pustule formation by H. ducreyi in the human model of infection.
    Keywords: Medicine ; Biology;
    ISSN: 0019-9567
    ISSN: 00199567
    E-ISSN: 10985522
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages