Flagella are virulence determinants of Burkholderia pseudomallei
Flagella are virulence determinants of Burkholderia pseudomallei
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DOI：
10.1128/iai.71.4.1622-1629.2003
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发表时间：
2003-04-01
影响因子：
3.1
通讯作者：
Gan, YH
中科院分区：
文献类型：
--
作者：
Chua, KL;Chan, YY;Gan, YH
类鼻疽伯克霍尔德氏菌是一种产鞭毛的革兰氏阴性菌，是人类类鼻疽病的病原体。鞭毛通常被认为是细菌病原体表达的重要毒力决定因素，因为这些细胞器赋予的运动表型通常与生物体引起疾病的能力相关。我们使用了一种B的强毒分离物。pseudomallei，KHW，通过基因置换转座子诱变构建具有鞭毛蛋白基因突变（fliC）的等基因缺失突变体。KHWDeltafliCKm突变体在半固体琼脂中无鞭毛且不运动。与野生型相比，同基因KHWDeltafliCKm突变体在培养的人肺细胞中侵袭和复制的能力没有受损。在涉及秀丽隐杆线虫的慢杀试验中，它也具有同样的毒性，但在BALB/c小鼠的鼻内感染过程中是无毒的。从KHWDeltaflCKm感染小鼠的肺和脾中分离出的细菌（如果有的话）非常少。相比之下，肺和脾中的细菌负荷在感染KHW的小鼠和感染互补突变体KHWDeltafliCKm/pUCP 28 TfliC的小鼠中是相似的。与叙利亚仓鼠或糖尿病大鼠感染模型不同，B。在BALB/c小鼠腹腔感染过程中，类鼻疽鞭毛蛋白也是一种毒力因子。在这项研究中，所有感染KHWDeltafliCKm的动物都保持健康，无论感染途径如何，都没有死于疾病。因此，鞭毛是B的重要和必要的毒力决定因子。在小鼠鼻内和腹腔内感染期间，
Burkholderia pseudomallei, a facultatively intracellular pathogen, is a flagellated and motile gram-negative bacterium and is the causative agent of melioidosis in humans. Flagella are commonly recognized as important virulence determinants expressed by bacterial pathogens since the motility phenotype imparted by these organelles often correlates with the ability of an organism to cause disease. We used a virulent isolate of B. pseudomallei, KHW, to construct an isogenic deletion mutant with a mutation in the flagellin gene (fliC) by gene replacement transposon mutagenesis. The KHWDeltafliCKm mutant was aflagellate and nonmotile in semisolid agar. The isogenic KHWDeltafliCKm mutant was not impaired in terms of the ability to invade and replicate in cultured human lung cells compared with the wild type. It was also equally virulent in slow-killing assays involving Caenorhabditis elegans, but it was avirulent during intranasal infection of BALB/c mice. Very few bacteria, if any, were isolated from the lungs and spleens of KHWDeltafliCKm-infected mice. In contrast, the bacterial loads in the lungs and spleens were similar in mice infected with KHW and in mice infected with the complemented mutant, KHWDeltafliCKm/pUCP28TfliC. Unlike the Syrian hamster or diabetic rat models of infection, the B. pseudomallei flagellin was also a virulence factor during intraperitoneal infection of BALB/c mice. In this study, all animals infected with KHWDeltafliCKm remained healthy and did not succumb to disease regardless of the route of infection. The flagellum is therefore an important and necessary virulence determinant of B. pseudomallei during intranasal and intraperitoneal infection of mice.