The Association of Cell Division Regulated by DicC With the Formation of Viable but Non-culturable Escherichia coli O157:H7
The Association of Cell Division Regulated by DicC With the Formation of Viable but Non-culturable Escherichia coli O157:H7
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DicC 调控的细胞分裂与存活但不可培养的大肠杆菌 O157:H7 形成的关系
DOI：
10.3389/fmicb.2019.02850
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发表时间：
2019-12
影响因子：
5.2
通讯作者：
Xiaojun Liao
中科院分区：
文献类型：
--
作者：
Hanxu Pan;Kai Dong;Lei Rao;Liang Zhao;Yongtao Wang;Xiaojun Liao
细菌在常规培养基上不能生长但实际上是活的状态（viable but non- culable， VBNC）已被广泛认为是细菌应对压力环境的一种策略。然而，关于VBNC形成的分子机制知之甚少。在此，我们旨在阐明细胞分裂调节蛋白在VBNC大肠杆菌O157:H7形成过程中的具体作用和细胞生长速率。我们之前发现，与非VBNC细胞相比，VBNC大肠杆菌O157:H7中dicC的表达减少了20.08倍。除了DicC和DicA似乎通过调节细胞分裂抑制剂DicB的表达来调节细胞分裂外，对DicC知之甚少。首先，我们的研究结果表明，ΔdicC突变体和dica过表达菌株的VBNC细胞数量增加，而高压二氧化碳、酸和H2O2诱导的dicc过表达菌株的VBNC细胞数量减少。此外，dica过表达菌株和ΔdicC突变株的生长速度均高于对照菌株，而dicc过表达菌株的生长速度明显低于载体菌株。dicB基因受dicA和dicC调控并抑制细胞分裂，dicB基因在dicC过表达菌株中表达水平升高，在ΔdicC突变株和dicA过表达菌株中表达水平降低，与生长表型一致。通过扫描电镜（SEM）和透射电镜（TEM）观察ΔdicC突变株和dica过表达株的矮化细胞形态。综上所述，我们的研究表明DicC负向调控VBNC状态的形成，DicA增强了细胞进入VBNC状态的能力。此外，细胞生长速率和矮化细胞形态可能与VBNC状态的形成有关。
The viable but non-culturable (VBNC) state, in which bacteria fail to grow on routine culture media but are actually alive, has been widely recognized as a strategy adopted by bacteria to cope with stressful environments. However, little is known regarding the molecular mechanism of VBNC formation. Here, we aimed to elucidate the specific roles of cell division regulatory proteins and the cell growth rate during VBNC Escherichia coli O157:H7 formation. We have previously found that expression of dicC is reduced by 20.08-fold in VBNC E. coli O157:H7 compared to non-VBNC cells. Little is known about DicC except that it, along with DicA, appears to act as a regulator of cell division by regulating expression of the cell division inhibitor DicB. First, our results showed that the VBNC cell number increased in the ΔdicC mutant as well as the DicA-overexpressing strain but decreased in the DicC-overexpressing strain induced by high-pressure carbon dioxide, acid, and H2O2. Furthermore, the growth rates of both the DicA-overexpressing strain and the ΔdicC mutant were higher than that of the control strain, while DicC-overexpressing strain grew significantly more slowly than the vector strain. The level of the dicB gene, regulated by dicA and dicC and inhibiting cell division, was increased in the DicC-overexpressing strain and decreased in the ΔdicC mutant and DicA-overexpressing strain, which was consistent with the growth phenotypes. In addition, the dwarfing cell morphology of the ΔdicC mutant and DicA-overexpressing strain were observed by SEM and TEM. Taken together, our study demonstrates that DicC negatively regulates the formation of the VBNC state, and DicA enhances the ability of cells to enter the VBNC state. Besides, the cell growth rate and dwarfing cell morphology may be correlated with the formation of the VBNC state.
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DOI：
10.1016/0003-6870(82)90111-9
发表时间：
1979-06
期刊：
Aviation, space, and environmental medicine
影响因子：
--
作者：
R. Norman;P. Bishop;M. Pierrynowski;J. Pezzack
通讯作者：
R. Norman;P. Bishop;M. Pierrynowski;J. Pezzack
关于高压 CO2 诱导形成存活但不可培养的大肠杆菌 O157:H7 的新见解
影响因子：
6.4
作者：
Zhao F;Wang Y;An H;Hao Y;Hu X;Liao X
通讯作者：
Liao X
影响因子：
4.4
作者：
Gupte, AR;de Rezende, CLE;Joseph, SW
通讯作者：
Joseph, SW
影响因子：
36.8
作者：
J. Nataro;J. Kaper
通讯作者：
J. Nataro;J. Kaper
DOI：
10.1007/bf00425651
发表时间：
1985-01-01
期刊：
MOLECULAR AND GENERAL GENETICS
影响因子：
--
作者：
BEJAR, S;BOUCHE, JP
通讯作者：
BOUCHE, JP