Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, 117597, Singapore.
BMC Microbiol. 2010 Jan 29;10:28. doi: 10.1186/1471-2180-10-28.
Burkholderia pseudomallei is the causative agent for melioidosis, a disease with significant mortality and morbidity in endemic regions. Its versatility as a pathogen is reflected in its relatively huge 7.24 Mb genome and the presence of many virulence factors including three Type Three Secretion Systems known as T3SS1, T3SS2 and T3SS3. Besides being a human pathogen, it is able to infect and cause disease in many different animals and alternative hosts such as C. elegans.
Its host range is further extended to include plants as we demonstrated the ability of B. pseudomallei and the closely related species B. thailandensis to infect susceptible tomato but not rice plants. Bacteria were found to multiply intercellularly and were found in the xylem vessels of the vascular bundle. Disease is substantially attenuated upon infection with bacterial mutants deficient in T3SS1 or T3SS2 and slightly attenuated upon infection with the T3SS3 mutant. This shows the importance of both T3SS1 and T3SS2 in bacterial pathogenesis in susceptible plants.
The potential of B. pseudomallei as a plant pathogen raises new possibilities of exploiting plant as an alternative host for novel anti-infectives or virulence factor discovery. It also raises issues of biosecurity due to its classification as a potential bioterrorism agent.
类鼻疽伯克霍尔德菌是类鼻疽病的病原体，在流行地区该病具有较高的死亡率和发病率。其作为病原体的多功能性反映在其相对巨大的 7.24 Mb 基因组和存在许多毒力因子上，包括三个已知的 III 型分泌系统（T3SS1、T3SS2 和 T3SS3）。除了是人类病原体外，它还能够感染和引起许多不同动物和替代宿主（如秀丽隐杆线虫）的疾病。
我们证明了类鼻疽伯克霍尔德菌和密切相关的物种泰国伯克霍尔德菌能够感染易感的番茄但不能感染水稻植物，其宿主范围进一步扩大到包括植物。细菌被发现在细胞间繁殖，并存在于维管束的木质部导管中。感染 T3SS1 或 T3SS2 缺陷的细菌突变体后，疾病明显减轻，感染 T3SS3 突变体后疾病略有减轻。这表明 T3SS1 和 T3SS2 在易感植物中的细菌发病机制中都很重要。
类鼻疽伯克霍尔德菌作为植物病原体的潜力为利用植物作为新型抗感染药物或毒力因子发现的替代宿主提供了新的可能性。由于其被归类为潜在的生物恐怖主义制剂，因此也引发了生物安全问题。
