Mycoplasma iowae: relationships among oxygen, virulence, and protection from oxidative stress.
Mycoplasma iowae: relationships among oxygen, virulence, and protection from oxidative stress.
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DOI：
10.1186/s13567-015-0170-7
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发表时间：
2015-03-21
影响因子：
4.4
通讯作者：
Balish MF
中科院分区：
文献类型：
--
作者：
Pritchard RE;Balish MF
与家禽相关的细菌爱荷华支原体定植于胚胎的多个部位，导致疾病或死亡。尽管爱荷华分枝杆菌在肠道中积聚，但它不会在该部位引起疾病，而只会在暴露于大气氧气的组织中引起疾病。由 katE 编码的 M. iowae 过氧化氢酶的活性能够快速去除溶液中的破坏性 H2O2，并且 katE 使鸡毒支原体 katE 转化体在甘油存在下产生的 H2O2 量大幅减少。由于产生过氧化氢酶的细菌通常对患有炎症性肠病的宿主有益，因此我们探讨了爱荷华分枝杆菌是否对秀丽隐杆线虫模型中的产生 H2O2 的细菌具有独特的保护作用，其保护性是否会随着 O2 水平的变化而变化，以及参与 H2O2 代谢和毒力的基因表达是否会随着 O2 水平的变化而变化。我们观察到，M. iowae 实际上对产生 H2O2 的肺炎链球菌有保护作用，但对产生 HCN 的铜绿假单胞菌没有保护作用，并且在 1% O2 中生长的 M. iowae 细胞比在大气 O2 中生长的 M. iowae 细胞更能促进秀丽隐杆线虫的存活。在低氧气条件下生长的细胞中，编码肺炎支原体 CARDS 毒素同源物的爱荷华分枝杆菌基因的转录水平降低了 5 倍。这些数据表明，代表肠道环境的氧气减少会触发爱荷华分枝杆菌降低其毒力能力，从而实现从致病模式到潜在有益模式的转变。
The poultry-associated bacterium Mycoplasma iowae colonizes multiple sites in embryos, with disease or death resulting. Although M. iowae accumulates in the intestinal tract, it does not cause disease at that site, but rather only in tissues that are exposed to atmospheric O2. The activity of M. iowae catalase, encoded by katE, is capable of rapid removal of damaging H2O2 from solution, and katE confers a substantial reduction in the amount of H2O2 produced by Mycoplasma gallisepticum katE transformants in the presence of glycerol. As catalase-producing bacteria are often beneficial to hosts with inflammatory bowel disease, we explored whether M. iowae was exclusively protective against H2O2-producing bacteria in a Caenorhabditis elegans model, whether its protectiveness changed in response to O2 levels, and whether expression of genes involved in H2O2 metabolism and virulence changed in response to O2 levels. We observed that M. iowae was in fact protective against H2O2-producing Streptococcus pneumoniae, but not HCN-producing Pseudomonas aeruginosa, and that M. iowae cells grown in 1% O2 promoted survival of C. elegans to a greater extent than M. iowae cells grown in atmospheric O2. Transcript levels of an M. iowae gene encoding a homolog of Mycoplasma pneumoniae CARDS toxin were 5-fold lower in cells grown in low O2. These data suggest that reduced O2, representing the intestinal environment, triggers M. iowae to reduce its virulence capabilities, effecting a change from a pathogenic mode to a potentially beneficial one.
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影响因子：
4.2
作者：
Hallamaa, Katri M.;Tang, Sen-Lin;Ficorilli, Nino;Browning, Glenn F.
通讯作者：
Browning, Glenn F.
影响因子：
15.3
作者：
Avery, OT;Neil, JM
通讯作者：
Neil, JM
影响因子：
2.4
作者：
JORDAN, FTW;AMIN, MM
通讯作者：
AMIN, MM
影响因子：
2.8
作者：
CASTRIC, PA
通讯作者：
CASTRIC, PA
影响因子：
14.9
作者：
Himmelreich, R;Hilbert, H;Herrmann, R
通讯作者：
Herrmann, R