Abstract
A bactericidal assay was developed in order to test the effect of hyperimmune rabbit sera on the viability of serum-resistant Haemophilus ducreyi 35000HP. Testing of several lots of rabbit complement and time course experiments showed that the serum-sensitive H. ducreyi CIPA77 was killed efficiently by 25% complement at 35°C in 3 h. We hypothesized that incubation of 35000HP under these conditions with the appropriate bactericidal antibody would kill this strain. A panel of high titre rabbit antisera was developed and tested against 35000HP. The panel included antisera raised to whole cells, total membranes, Sarkosyl-insoluble outer membrane proteins, the H. ducreyi lipoprotein, and the peptidoglycan-associated lipoprotein. None of the antisera convincingly showed bactericidal activity. The bactericidal assay was also used to determine the effect of normal human serum (NHS) on isogenic mutants of 35000HP. 35000HP-RSM2, an Ωkan insertion mutant that expresses a truncated lipooligosaccharide, was as resistant to NHS as its parent. A mutant deficient in expression of the major outer membrane protein (35000.60) was sensitive to NHS. We conclude that 35000HP is relatively resistant to normal and hyperimmune sera, and that the major outer membrane protein contributes to this resistance.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 93-102 |
| Number of pages | 10 |
| Journal | Microbial Pathogenesis |
| Volume | 26 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1999 |
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Keywords
- Bactericidal activity
- Chancroid
- Haemophilus ducreyi
ASJC Scopus subject areas
- Microbiology
- Infectious Diseases
Cite this
Effect of normal and immune sera on Haemophilus ducreyi 35000HP and its isogenic MOMP and LOS mutants. / Hiltke, Thomas J.; Bauer, Margaret E.; Klesney-Tait, Julia; Hansen, Eric J.; Munson, Robert S.; Spinola, Stanley M.
In: Microbial Pathogenesis, Vol. 26, No. 2, 02.1999, p. 93-102.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of normal and immune sera on Haemophilus ducreyi 35000HP and its isogenic MOMP and LOS mutants
AU - Hiltke, Thomas J.
AU - Bauer, Margaret E.
AU - Klesney-Tait, Julia
AU - Hansen, Eric J.
AU - Munson, Robert S.
AU - Spinola, Stanley M.
PY - 1999/2
Y1 - 1999/2
N2 - A bactericidal assay was developed in order to test the effect of hyperimmune rabbit sera on the viability of serum-resistant Haemophilus ducreyi 35000HP. Testing of several lots of rabbit complement and time course experiments showed that the serum-sensitive H. ducreyi CIPA77 was killed efficiently by 25% complement at 35°C in 3 h. We hypothesized that incubation of 35000HP under these conditions with the appropriate bactericidal antibody would kill this strain. A panel of high titre rabbit antisera was developed and tested against 35000HP. The panel included antisera raised to whole cells, total membranes, Sarkosyl-insoluble outer membrane proteins, the H. ducreyi lipoprotein, and the peptidoglycan-associated lipoprotein. None of the antisera convincingly showed bactericidal activity. The bactericidal assay was also used to determine the effect of normal human serum (NHS) on isogenic mutants of 35000HP. 35000HP-RSM2, an Ωkan insertion mutant that expresses a truncated lipooligosaccharide, was as resistant to NHS as its parent. A mutant deficient in expression of the major outer membrane protein (35000.60) was sensitive to NHS. We conclude that 35000HP is relatively resistant to normal and hyperimmune sera, and that the major outer membrane protein contributes to this resistance.
AB - A bactericidal assay was developed in order to test the effect of hyperimmune rabbit sera on the viability of serum-resistant Haemophilus ducreyi 35000HP. Testing of several lots of rabbit complement and time course experiments showed that the serum-sensitive H. ducreyi CIPA77 was killed efficiently by 25% complement at 35°C in 3 h. We hypothesized that incubation of 35000HP under these conditions with the appropriate bactericidal antibody would kill this strain. A panel of high titre rabbit antisera was developed and tested against 35000HP. The panel included antisera raised to whole cells, total membranes, Sarkosyl-insoluble outer membrane proteins, the H. ducreyi lipoprotein, and the peptidoglycan-associated lipoprotein. None of the antisera convincingly showed bactericidal activity. The bactericidal assay was also used to determine the effect of normal human serum (NHS) on isogenic mutants of 35000HP. 35000HP-RSM2, an Ωkan insertion mutant that expresses a truncated lipooligosaccharide, was as resistant to NHS as its parent. A mutant deficient in expression of the major outer membrane protein (35000.60) was sensitive to NHS. We conclude that 35000HP is relatively resistant to normal and hyperimmune sera, and that the major outer membrane protein contributes to this resistance.
KW - Bactericidal activity
KW - Chancroid
KW - Haemophilus ducreyi
UR - http://www.scopus.com/inward/record.url?scp=0033083061&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033083061&partnerID=8YFLogxK
U2 - 10.1006/mpat.1998.0250
DO - 10.1006/mpat.1998.0250
M3 - Article
C2 - 10090856
AN - SCOPUS:0033083061
VL - 26
SP - 93
EP - 102
JO - Microbial Pathogenesis
JF - Microbial Pathogenesis
SN - 0882-4010
IS - 2
ER -