布鲁菌进化和分类学研究进展

Progress in the evolution and taxonomy of Brucella

布鲁菌属革兰氏阴性兼性胞内寄生菌,能感染多种宿主动物和人。该属可分为6个典型种,包括羊种、牛种、猪种、沙林鼠种、绵羊附睾种以及犬种布鲁菌等。此分类是基于其致病性以及宿主偏好性的差异划分。尽管6个种通过传统表型试验能区分,但布鲁菌种内采用DNA-DNA杂交证明DNA同源性高度一致(相似性大于90%)。因此有人提议布鲁菌由单一种组成,即布鲁菌属中只有羊种布鲁菌,其他种都是羊种菌的生物亚型之一。然而基于其他分子技术的基因分型表明其DNA多态性表现明显,说明目前对这个种的分型还是比较准确。而最近分离的海洋种布鲁氏菌分离株(鳍型和鲸型)采用传统分型标准和一些特异的分子标记也证明这种分型比较正确。本文对目前布鲁菌种属进化和分类学进行综述,希望对研究其进化和分类有所帮助。

Brucellae are Gram-negative,facultative intracellular bacteria that can infect many species of animals and man.Six species are currently recognized within the genus Brucella：B.melitensis,B.abortus,B.suis,B.neotomae,B.ovis,and B.canis.This classification is mainly based on differences in pathogenicity and in host preferences.Although the six species can be differentiated by conventional phenotypic tests,these species display a high degree of DNA homology in DNA-DNA hybridization assays（90% identity）.Therefore it has been proposed that the Brucella genus should comprise only one species i.e.B.melitensis and that the other species should be considered as biovars.However,several molecular genotyping methods have shown of significant DNA polymorphism Brucella species allowing the species to be correctly differentiated.This is also true for the recent marine mammal Brucella isolates,which two new species names have been proposed,i.e.B.pinnipediae and B.cetaceae,according to the classical criteria of host preferentialism（pinnipeds and cetaceans respectively） and specific molecular markers.This article reviews the evolution and taxonomy of Brucella.