Watanabe Yusaku, Fujihara Masatoshi, Obara Hisato, Nagai Kazuya, Harasawa Ryô
Department of Veterinary Microbiology, Faculty of Agriculture, Iwate University, Morioka 020–8550, Japan.
J Vet Med Sci. 2011 Dec;73(12):1657-61. doi: 10.1292/jvms.11-0293. Epub 2011 Jul 29.
Only two hemoplasma species, Eperythrozoon parvum and Mycoplasma suis, have been recognized in pigs. Here we demonstrate the genetic variations among six hemoplasma strains detected from pigs, by analyzing the 16S rRNA and RNase P RNA (rnpB) genes, and propose a novel hemoplasma taxon that has not been described previously. Phylogenetic trees based on the nucleotide sequence of the 16S rRNA gene indicated that these six hemoplasmas were divided into two clusters representing M. suis and a novel taxon. We further examined the primary and secondary structures of the nucleotide sequences of the rnpB gene of the novel taxon, and found it distinct from that of M. suis. In conclusion, we unveiled a genetic cluster distinct from M. suis, suggesting a new swine hemoplasma species or E. parvum. Our findings also suggest that this novel cluster should be included in the genus Mycoplasma.
猪身上仅识别出两种血支原体，即微小附红细胞体和猪支原体。在此，我们通过分析16S rRNA和核糖核酸酶P RNA（rnpB）基因，展示了从猪身上检测到的六种血支原体菌株之间的遗传变异，并提出了一个先前未描述过的新型血支原体分类单元。基于16S rRNA基因核苷酸序列构建的系统发育树表明，这六种血支原体被分为两个簇，分别代表猪支原体和一个新型分类单元。我们进一步研究了新型分类单元rnpB基因核苷酸序列的一级和二级结构，发现它与猪支原体不同。总之，我们揭示了一个与猪支原体不同的遗传簇，提示存在一种新的猪血支原体物种或微小附红细胞体。我们的研究结果还表明，这个新型簇应归入支原体属。
