Zeman Petr, Jahn Petr
Medical Laboratories, Konevova 205, 130 00 Prague 3, Czech Republic.
Equine Clinic, University of Veterinary and Pharmaceutical Sciences, Palackeho 1-3, 612 42 Brno, Czech Republic.
J Med Microbiol. 2009 Apr;58(Pt 4):423-429. doi: 10.1099/jmm.0.007831-0.
Anaplasma phagocytophilum is a tick-borne rickettsial pathogen that has measurable genetic heterogeneity across its geographical range and reservoir spectrum. In the present study, publicly available sequences of the genes that have prevailingly been used for typing A. phagocytophilum were analysed to identify the segments giving the highest resolution with respect to the predictability of host and geographical provenances of the strains. Selected partial sequences of 16S rRNA, groL, msp4 and ank genes were then employed in a tentative multilocus typing scheme used to characterize the strains causing equine granulocytic anaplasmosis (EGA). We were able to both identify alleles characteristic for equine strains of A. phagocytophilum and distinguish two unique genetic variants infecting horses in the Czech Republic. This resolution far exceeded the discriminatory potential of any of the four sequenced genes when used singly. The two novel A. phagocytophilum variants appeared to be phylogenetically closer to the strains reported as causing human disease in Slovenia than to strains thus far isolated from other European EGA cases. A decline in the quality of recently deposited A. phagocytophilum sequences was also demonstrated.
嗜吞噬细胞无形体是一种蜱传立克次氏体病原体，在其地理分布范围和宿主谱中具有可测量的遗传异质性。在本研究中，对主要用于嗜吞噬细胞无形体分型的基因的公开可用序列进行了分析，以确定在菌株宿主和地理来源的可预测性方面具有最高分辨率的片段。然后，将选定的16S rRNA、groL、msp4和ank基因的部分序列用于一个初步的多位点分型方案，以表征引起马粒细胞无形体病（EGA）的菌株。我们能够识别嗜吞噬细胞无形体马源菌株的特征等位基因，并区分在捷克共和国感染马匹的两种独特遗传变体。当单独使用时，这种分辨率远远超过了四个测序基因中任何一个的鉴别潜力。这两种新型嗜吞噬细胞无形体变体在系统发育上似乎更接近在斯洛文尼亚报道的引起人类疾病的菌株，而不是迄今为止从其他欧洲EGA病例中分离出的菌株。最近提交的嗜吞噬细胞无形体序列的质量也有所下降。
