Abstract
The carbon storage regulator A (CsrA) controls a wide variety of bacterial processes, including metabolism, adherence, stress responses, and virulence. Haemophilus ducreyi, the causative agent of chancroid, harbors a homolog of csrA. Here, we generated an unmarked, in-frame deletion mutant of csrA to assess its contribution to H. ducreyi pathogenesis. In human inoculation experiments, the csrA mutant was partially attenuated for pustule formation compared to its parent. Deletion of csrA resulted in decreased adherence of H. ducreyi to human foreskin fibroblasts (HFF); Flp1 and Flp2, the determinants of H. ducreyi adherence to HFF cells, were downregulated in the csrA mutant. Compared to its parent, the csrA mutant had a significantly reduced ability to tolerate oxidative stress and heat shock. The enhanced sensitivity of the mutant to oxidative stress was more pronounced in bacteria grown to stationary phase compared to that in bacteria grown to mid-log phase. The csrA mutant also had a significant survival defect within human macrophages when the bacteria were grown to stationary phase but not to mid-log phase. Complementation in trans partially or fully restored the mutant phenotypes. These data suggest that CsrA contributes to virulence by multiple mechanisms and that these contributions may be more profound in bacterial cell populations that are not rapidly dividing in the human host.
| Original language | English |
|---|---|
| Pages (from-to) | 608-617 |
| Number of pages | 10 |
| Journal | Infection and Immunity |
| Volume | 81 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2013 |
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ASJC Scopus subject areas
- Immunology
- Microbiology
- Parasitology
- Infectious Diseases
Cite this
Carbon storage regulator a contributes to the virulence of haemophilus ducreyi in humans by multiple mechanisms. / Gangaiah, Dharanesh; Li, Wei; Fortney, Kate R.; Janowicz, Diane; Ellinger, Sheila; Zwickl, Beth; Katz, Barry; Spinola, Stanley.
In: Infection and Immunity, Vol. 81, No. 2, 02.2013, p. 608-617.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Carbon storage regulator a contributes to the virulence of haemophilus ducreyi in humans by multiple mechanisms
AU - Gangaiah, Dharanesh
AU - Li, Wei
AU - Fortney, Kate R.
AU - Janowicz, Diane
AU - Ellinger, Sheila
AU - Zwickl, Beth
AU - Katz, Barry
AU - Spinola, Stanley
PY - 2013/2
Y1 - 2013/2
N2 - The carbon storage regulator A (CsrA) controls a wide variety of bacterial processes, including metabolism, adherence, stress responses, and virulence. Haemophilus ducreyi, the causative agent of chancroid, harbors a homolog of csrA. Here, we generated an unmarked, in-frame deletion mutant of csrA to assess its contribution to H. ducreyi pathogenesis. In human inoculation experiments, the csrA mutant was partially attenuated for pustule formation compared to its parent. Deletion of csrA resulted in decreased adherence of H. ducreyi to human foreskin fibroblasts (HFF); Flp1 and Flp2, the determinants of H. ducreyi adherence to HFF cells, were downregulated in the csrA mutant. Compared to its parent, the csrA mutant had a significantly reduced ability to tolerate oxidative stress and heat shock. The enhanced sensitivity of the mutant to oxidative stress was more pronounced in bacteria grown to stationary phase compared to that in bacteria grown to mid-log phase. The csrA mutant also had a significant survival defect within human macrophages when the bacteria were grown to stationary phase but not to mid-log phase. Complementation in trans partially or fully restored the mutant phenotypes. These data suggest that CsrA contributes to virulence by multiple mechanisms and that these contributions may be more profound in bacterial cell populations that are not rapidly dividing in the human host.
AB - The carbon storage regulator A (CsrA) controls a wide variety of bacterial processes, including metabolism, adherence, stress responses, and virulence. Haemophilus ducreyi, the causative agent of chancroid, harbors a homolog of csrA. Here, we generated an unmarked, in-frame deletion mutant of csrA to assess its contribution to H. ducreyi pathogenesis. In human inoculation experiments, the csrA mutant was partially attenuated for pustule formation compared to its parent. Deletion of csrA resulted in decreased adherence of H. ducreyi to human foreskin fibroblasts (HFF); Flp1 and Flp2, the determinants of H. ducreyi adherence to HFF cells, were downregulated in the csrA mutant. Compared to its parent, the csrA mutant had a significantly reduced ability to tolerate oxidative stress and heat shock. The enhanced sensitivity of the mutant to oxidative stress was more pronounced in bacteria grown to stationary phase compared to that in bacteria grown to mid-log phase. The csrA mutant also had a significant survival defect within human macrophages when the bacteria were grown to stationary phase but not to mid-log phase. Complementation in trans partially or fully restored the mutant phenotypes. These data suggest that CsrA contributes to virulence by multiple mechanisms and that these contributions may be more profound in bacterial cell populations that are not rapidly dividing in the human host.
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UR - http://www.scopus.com/inward/citedby.url?scp=84873032519&partnerID=8YFLogxK
U2 - 10.1128/IAI.01239-12
DO - 10.1128/IAI.01239-12
M3 - Article
VL - 81
SP - 608
EP - 617
JO - Infection and Immunity
JF - Infection and Immunity
SN - 0019-9567
IS - 2
ER -