Abstract
Vibrio vulnificus is a halophilic estuarine bacterium while it causes fatal septicemia or necrotizing wound infections in humans. This pathogen secretes the metalloprotease (V. vulnificus protease: VVP) and the cytolysin (V. vulnificus hemolysin: VVH) as protein toxins; however, their production was coordinated in response to the bacterial cell density. This regulation is termed quorum sensing (QS) and is mediated by the small diffusible molecule called autoinducer 2 (AI-2). In the present study, we investigated effects of disruption of luxO encoding a central response regulator of the QS circuit, as well as effects of temperature and growth phase, on the toxin production by V. vulnificus. Disruption of luxO was found to increase VVP production and expression of its gene vvpE. The expression of smcR, crp and rpoS, of which products positively regulate vvpE expression, and luxS encoding the AI-2 synthetase were also significantly increased. On the other hand, the luxO disruption resulted in reduction of VVH production and expression of its gene vvhA. Expression of other two genes affecting the QS circuit, luxT and rpoN, were also significantly decreased. The regulation systems of VVP production were found to exert their action during the stationary phase of the bacterial growth and to be operated strongly at 26 °C. By contrast, those of VVH production apparently started at the log phase and were operated more effectively at 37 °C.
| Original language | English |
|---|---|
| Pages (from-to) | 681-691 |
| Number of pages | 11 |
| Journal | World Journal of Microbiology and Biotechnology |
| Volume | 30 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 2014 |
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Keywords
- Autoinducer
- Hemolysin
- Metalloprotease
- Quorum sensing
- Vibrio vulnificus
ASJC Scopus subject areas
- Biotechnology
- Physiology
- Applied Microbiology and Biotechnology
Cite this
Effects of temperature, growth phase and luxO-disruption on regulation systems of toxin production in Vibrio vulnificus strain L-180, a human clinical isolate. / Elgaml, Abdelaziz; Higaki, Kazutaka; Miyoshi, Shin-ichi.
In: World Journal of Microbiology and Biotechnology, Vol. 30, No. 2, 02.2014, p. 681-691.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of temperature, growth phase and luxO-disruption on regulation systems of toxin production in Vibrio vulnificus strain L-180, a human clinical isolate
AU - Elgaml, Abdelaziz
AU - Higaki, Kazutaka
AU - Miyoshi, Shin-ichi
PY - 2014/2
Y1 - 2014/2
N2 - Vibrio vulnificus is a halophilic estuarine bacterium while it causes fatal septicemia or necrotizing wound infections in humans. This pathogen secretes the metalloprotease (V. vulnificus protease: VVP) and the cytolysin (V. vulnificus hemolysin: VVH) as protein toxins; however, their production was coordinated in response to the bacterial cell density. This regulation is termed quorum sensing (QS) and is mediated by the small diffusible molecule called autoinducer 2 (AI-2). In the present study, we investigated effects of disruption of luxO encoding a central response regulator of the QS circuit, as well as effects of temperature and growth phase, on the toxin production by V. vulnificus. Disruption of luxO was found to increase VVP production and expression of its gene vvpE. The expression of smcR, crp and rpoS, of which products positively regulate vvpE expression, and luxS encoding the AI-2 synthetase were also significantly increased. On the other hand, the luxO disruption resulted in reduction of VVH production and expression of its gene vvhA. Expression of other two genes affecting the QS circuit, luxT and rpoN, were also significantly decreased. The regulation systems of VVP production were found to exert their action during the stationary phase of the bacterial growth and to be operated strongly at 26 °C. By contrast, those of VVH production apparently started at the log phase and were operated more effectively at 37 °C.
AB - Vibrio vulnificus is a halophilic estuarine bacterium while it causes fatal septicemia or necrotizing wound infections in humans. This pathogen secretes the metalloprotease (V. vulnificus protease: VVP) and the cytolysin (V. vulnificus hemolysin: VVH) as protein toxins; however, their production was coordinated in response to the bacterial cell density. This regulation is termed quorum sensing (QS) and is mediated by the small diffusible molecule called autoinducer 2 (AI-2). In the present study, we investigated effects of disruption of luxO encoding a central response regulator of the QS circuit, as well as effects of temperature and growth phase, on the toxin production by V. vulnificus. Disruption of luxO was found to increase VVP production and expression of its gene vvpE. The expression of smcR, crp and rpoS, of which products positively regulate vvpE expression, and luxS encoding the AI-2 synthetase were also significantly increased. On the other hand, the luxO disruption resulted in reduction of VVH production and expression of its gene vvhA. Expression of other two genes affecting the QS circuit, luxT and rpoN, were also significantly decreased. The regulation systems of VVP production were found to exert their action during the stationary phase of the bacterial growth and to be operated strongly at 26 °C. By contrast, those of VVH production apparently started at the log phase and were operated more effectively at 37 °C.
KW - Autoinducer
KW - Hemolysin
KW - Metalloprotease
KW - Quorum sensing
KW - Vibrio vulnificus
UR - http://www.scopus.com/inward/record.url?scp=84893145728&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84893145728&partnerID=8YFLogxK
U2 - 10.1007/s11274-013-1501-3
DO - 10.1007/s11274-013-1501-3
M3 - Article
C2 - 24068537
AN - SCOPUS:84893145728
VL - 30
SP - 681
EP - 691
JO - Mircen Journal of Applied Microbiology and Biotechnology
JF - Mircen Journal of Applied Microbiology and Biotechnology
SN - 0265-0762
IS - 2
ER -