Attenuated virulence of a Burkholderia cepacia type III secretion mutant in a murine model of infection.
Attenuated virulence of a Burkholderia cepacia type III secretion mutant in a murine model of infection.
复制标题
洋葱伯克霍尔德菌 III 型分泌突变体在小鼠感染模型中的毒力减弱。
DOI：
10.1128/iai.71.3.1405-1415.2003
复制
发表时间：
2003
影响因子：
3.1
通讯作者：
Mohr,ChristianD
中科院分区：
文献类型：
--
作者：
Tomich,Mladen;Griffith,Adam;Herfst,ChristineA;Burns,JaneL;Mohr,ChristianD
Type III secretion systems are utilized by a number of gram-negative bacterial pathogens to deliver virulence-associated proteins into host cells. Using a PCR-based approach, we identified homologs of type III secretion genes in the gram-negative bacteriumBurkholderia cepacia, an important pulmonary pathogen in immunocompromised patients and patients with cystic fibrosis. One of the genes, designatedbscN, encodes a member of a family of ATP-binding proteins believed to generate energy driving virulence protein secretion. Genetic dissection of the regions flanking thebscNgene revealed a locus consisting of at least 10 open reading frames, predicted to encode products with significant homology to known type III secretion proteins in other bacteria. A defined null mutation was generated in thebscNgene, and the null strain and wild-type parent strain were examined by use of a murine model ofB. cepaciainfection. Quantitative bacteriological analysis of the lungs and spleens of infected C57BL/6 mice revealed that thebscNnull strain was attenuated in virulence compared to the parent strain, with significantly lower bacterial recovery from the lungs and spleens at 3 days postinfection. Moreover, histopathological changes, including an inflammatory cell infiltrate, were more pronounced in the lungs of mice infected with the wild-type parent strain than in those of mice infected with the isogenicbscNmutant. These results implicate type III secretion as an important determinant in the pathogenesis ofB. cepacia.
