Avgustin G, Wright F, Flint H J
Rowett Research Institute, Bucksburn, Aberdeen, United Kingdom.
Int J Syst Bacteriol. 1994 Apr;44(2):246-55. doi: 10.1099/00207713-44-2-246.
A high degree of genetic diversity among 29 strains of Prevotella (Bacteroides) ruminicola from the rumen was revealed by comparing restriction fragment length polymorphisms in 16S rRNA genes, sodium dodecyl sulfate-polyacrylamide gel profiles of total-cell proteins, and G + C contents of chromosomal DNAs. In order to obtain information on phylogenetic relationships, the sequences of a 389-bp region of the 16S rRNA gene, including variable regions 4 and 5, were compared for 10 strains. These 10 strains formed a single group when their sequences were compared with 16S ribosomal DNA sequences from other species, including Bacteroides spp. from the human colon. On the other hand, the great genetic distances between many P. ruminicola strains, including P. ruminicola subsp. brevis B(1)4 and GA33 and P. ruminicola 23T (T = type strain), support the hypothesis that these organisms should be reclassified into new species. We identified signature oligonucleotides based on 16S ribosomal DNA sequences that distinguished strains related to strains 23T, B(1)4, GA33, and M384, as well as an oligonucleotide that specifically recognized all but one of the Bacteroides and Prevotella strains tested. On the basis of the priming activities of these signature oligonucleotides in PCR reactions and on other criteria, we concluded that 12 of the original 29 strains were related to strain 23T, 4 were related to strain B(1)4, and 4 were related to strain GA33. While there are clear grounds for subdividing the species P. ruminicola on the basis of genotypic differences, it is appropriate to delay formal reclassification until further work on the phenotypic differentiation of the new groups is completed.
通过比较16S rRNA基因中的限制性片段长度多态性、全细胞蛋白的十二烷基硫酸钠-聚丙烯酰胺凝胶图谱以及染色体DNA的G+C含量，揭示了来自瘤胃的29株反刍普雷沃氏菌（拟杆菌属）之间高度的遗传多样性。为了获得系统发育关系的信息，对10株菌的16S rRNA基因389 bp区域（包括可变区4和5）的序列进行了比较。当将这些菌株的序列与其他物种（包括来自人类结肠的拟杆菌属）的16S核糖体DNA序列进行比较时，这10株菌形成了一个单一组。另一方面，许多反刍普雷沃氏菌菌株（包括短反刍普雷沃氏菌亚种B(1)4和GA33以及反刍普雷沃氏菌23T（T=模式菌株））之间的巨大遗传距离支持了这些生物体应重新分类为新物种的假设。我们基于16S核糖体DNA序列鉴定了区分与23T、B(1)4、GA33和M384菌株相关的菌株的特征寡核苷酸，以及一种特异性识别除一株测试的拟杆菌属和普雷沃氏菌属菌株外所有菌株的寡核苷酸。基于这些特征寡核苷酸在PCR反应中的引物活性及其他标准，我们得出结论，最初的29株菌中有12株与23T菌株相关，4株与B(1)4菌株相关，4株与GA33菌株相关。虽然有明确的理由根据基因型差异对反刍普雷沃氏菌进行细分，但在完成新组表型分化的进一步研究之前，推迟正式重新分类是合适的。
