Smith M D, Angus B J, Wuthiekanun V, White N J
Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Infect Immun. 1997 Oct;65(10):4319-21. doi: 10.1128/iai.65.10.4319-4321.1997.
Two distinct types of Burkholderia pseudomallei, differentiated by the ability to assimilate L-arabinose but with similar morphologies and antigenicities, can be isolated from soil in Thailand. Approximately 25% of soil isolates from northeast Thailand were arabinose assimilators (Ara+), but in 1,200 sequentially studied patients, only arabinose "nonassimilators" (Ara-) caused melioidosis (P < 0.0001). In a murine model, there was a striking difference in virulence between Ara- and Ara+ B. pseudomallei. The mean (standard deviation) 50% lethal dose (LD[50]) inoculum for Ara- isolates was 182 (111) CFU/mouse compared with approximately 10(9) CFU/mouse for Ara+ soil isolates. There was no significant difference between the LD(50)s for clinical and soil Ara- isolates. All attempts to convert the biochemical phenotype by selective culture failed, which suggests that the biotype is stable.
从泰国土壤中可分离出两种不同类型的类鼻疽伯克霍尔德菌，它们可通过同化L-阿拉伯糖的能力来区分，但形态和抗原性相似。泰国东北部约25%的土壤分离株是阿拉伯糖同化菌（Ara+），但在1200例连续研究的患者中，只有阿拉伯糖“非同化菌”（Ara-）引起类鼻疽（P<0.0001）。在小鼠模型中，Ara-和Ara+类鼻疽伯克霍尔德菌的毒力存在显著差异。Ara-分离株的平均（标准差）半数致死剂量（LD50）接种量为182（111）CFU/小鼠，而Ara+土壤分离株约为109CFU/小鼠。临床和土壤Ara-分离株的LD50之间没有显著差异。通过选择性培养改变生化表型的所有尝试均失败，这表明生物型是稳定的。
