Osmoregulated periplasmic glucans of Salmonella enterica serovar Typhimurium are required for optimal virulence in mice
Osmoregulated periplasmic glucans of Salmonella enterica serovar Typhimurium are required for optimal virulence in mice
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DOI：
10.1099/mic.0.023747-0
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发表时间：
2009-01-01
期刊：
影响因子：
2.8
通讯作者：
Smith, Allen
中科院分区：
文献类型：
--
作者：
Bhagwat, Arvind A.;Jun, Won;Smith, Allen
我们从鼠伤寒沙门氏菌血清型中纯化了β-调节性周质葡聚糖（OPG），发现它们由100%葡萄糖组成，2-连接葡萄糖是最丰富的残基，末端葡萄糖、2，3-连接葡萄糖和2，6-连接葡萄糖也大量存在。用于OPG生物合成的两个结构基因opgG和opgH形成双顺反子操纵子，并且将卡那霉素抗性基因盒插入该操纵子中导致缺乏OPG的菌株。在低渗透压条件下，opgGH突变株的运动性和生长受损。与野生型菌株SL 1344相比，opgGH突变还导致小鼠中的LD 50增加2个对数。不能合成OPG对生物体的脂多糖模式或其在抗微生物肽、洗涤剂、pH和营养应激条件下存活的能力没有显著影响。我们观察到，opgGH缺陷型菌株在酸性生长条件（pH 5.0）下呼吸速率降低，并且与野生型菌株相比ATP水平较低。这些数据表明，S.鼠伤寒沙门氏菌有助于小鼠毒力以及在低渗透压生长条件下的生长和运动。
We purified osmoregulated periplasmic glucans (OPGs) from Salmonella enterica serovar Typhimurium and found them to be composed of 100% glucose with 2-linked glucose as the most abundant residue, with terminal glucose, 2,3-linked and 2,6-linked glucose also present in high quantities. The two structural genes for OPG biosynthesis, opgG and opgH, form a bicistronic operon, and insertion of a kanamycin resistance gene cassette into this operon resulted in a strain devoid of OPGs. The opgGH mutant strain was impaired in motility and growth under low osmolarity conditions. The opgGH mutation also resulted in a 2 log increase in the LD50 in mice compared to the wild-type strain SL1344. Inability to synthesize OPGs had no significant impact on the organism's lipopolysaccharide pattern or its ability to survive antimicrobial peptides-, detergent-, pH- and nutrient-stress conditions. We observed that the opgGH-defective strain respired at a reduced rate under acidic growth conditions (pH 5.0) and had lower ATP levels compared to the wild-type strain. These data indicate that OPGs; of S. Typhimurium contribute towards mouse virulence as well as growth and motility under low osmolarity growth conditions.