Smrdel Katja Strasek, Petrovec Miroslav, Furlan Stanka Lotric, Zupan Tatjana Avsic
Faculty of Medicine, Institute of Microbiology and Immunology, Ljubljana, Slovenia.
FEMS Immunol Med Microbiol. 2012 Feb;64(1):123-5. doi: 10.1111/j.1574-695X.2011.00891.x.
Anaplasma phagocytophilum is an emerging tick-borne pathogen. Great genetic diversity of A. phagocytophilum has been described in animals and ticks. The present study is focused on the genetic variability of the groESL operon of A. phagocytophilum in human patients in Slovenia. During 1996–2008, there were 66 serologically confirmed patients with human granulocytic anaplasmosis. Of these, 46 were tested with a screening PCR for a small part of the 16S rRNA gene of A. phagocytophilum and 28 (60.9%) were positive. Positive samples were additionally tested with a PCR targeting the groESL operon and a larger fragment of the 16S rRNA gene. All amplicons were further sequenced and analyzed. The homology search and the alignment of the groESL sequences showed only one genetic variant. Sequence analysis of the 16S rRNA gene revealed 100% identity among amplicons. Slovenia is a small country with diverse climate, vegetation, and animal representatives. In previous studies in deer, dogs, and ticks, great diversity of the groESL operon was found. In contrast, in wild boar and in human patients from this study, only one genetic variant was detected. The results suggest that only one genetic variant might be pathogenic for humans or is competent enough to replicate in humans. To support this theory, other genetic markers and further studies need to be performed.
嗜吞噬细胞无形体是一种新出现的蜱传病原体。在动物和蜱中已发现嗜吞噬细胞无形体具有高度的遗传多样性。本研究聚焦于斯洛文尼亚人类患者中嗜吞噬细胞无形体groESL操纵子的遗传变异性。1996年至2008年期间，有66例血清学确诊的人类粒细胞无形体病患者。其中，46例接受了针对嗜吞噬细胞无形体16S rRNA基因一小部分的筛查PCR检测，28例（60.9%）呈阳性。对阳性样本进一步用靶向groESL操纵子和16S rRNA基因更大片段的PCR进行检测。所有扩增子均进一步测序和分析。groESL序列的同源性搜索和比对仅显示一种遗传变异。16S rRNA基因的序列分析显示扩增子之间100%同源。斯洛文尼亚是一个小国，气候、植被和动物种类多样。在之前对鹿、狗和蜱的研究中，发现groESL操纵子具有高度多样性。相比之下，在本研究的野猪和人类患者中，仅检测到一种遗传变异。结果表明，可能只有一种遗传变异对人类具有致病性或有足够能力在人类体内复制。为支持这一理论，需要进行其他遗传标记和进一步研究。
