Dewhirst F E, Chien C C, Paster B J, Ericson R L, Orcutt R P, Schauer D B, Fox J G
Department of Molecular Genetics, Forsyth Dental Center, Boston, Massachusetts 02115, USA.
Appl Environ Microbiol. 1999 Aug;65(8):3287-92. doi: 10.1128/AEM.65.8.3287-3292.1999.
The "altered Schaedler flora" (ASF) was developed for colonizing germfree rodents with a standardized microbiota. The purpose of this study was to identify each of the eight ASF strains by 16S rRNA sequence analysis. Three strains were previously identified as Lactobacillus acidophilus (strain ASF 360), Lactobacillus salivarius (strain ASF 361), and Bacteroides distasonis (strain ASF 519) based on phenotypic criteria. 16S rRNA analysis indicated that each of the strains differed from its presumptive identity. The 16S rRNA sequence of strain ASF 361 is essentially identical to the 16S rRNA sequences of the type strains of Lactobacillus murinis and Lactobacillus animalis (both isolated from mice), and all of these strains probably belong to a single species. Strain ASF 360 is a novel lactobacillus that clusters with L. acidophilus and Lactobacillus lactis. Strain ASF 519 falls into an unnamed genus containing [Bacteroides] distasonis, [Bacteroides] merdae, [Bacteroides] forsythus, and CDC group DF-3. This unnamed genus is in the Cytophaga-Flavobacterium-Bacteroides phylum and is most closely related to the genus Porphyromonas. The spiral-shaped strain, strain ASF 457, is in the Flexistipes phylum and exhibits sequence identity with rodent isolates of Robertson. The remaining four ASF strains, which are extremely oxygen-sensitive fusiform bacteria, group phylogenetically with the low-G+C-content gram-positive bacteria (Firmicutes, Bacillus-Clostridium group). ASF 356, ASF 492, and ASF 502 fall into Clostridium cluster XIV of Collins et al. Morphologically, ASF 492 resembles members of this cluster, Roseburia cecicola, and Eubacterium plexicaudatum. The 16S rRNA sequence of ASF 492 is identical to that of E. plexicaudatum. Since the type strain and other viable original isolates of E. plexicaudatum have been lost, strain ASF 492 is a candidate for a neotype strain. Strain ASF 500 branches deeply in the low-G+C-content gram-positive phylogenetic tree but is not closely related to any organisms whose 16S rRNA sequences are currently in the GenBank database. The 16S rRNA sequence information determined in the present study should allow rapid identification of ASF strains and should permit detailed analysis of the interactions of ASF organisms during development of intestinal disease in mice that are coinfected with a variety of pathogenic microorganisms.
“改变的 Schaedler 菌群”（ASF）是为用标准化微生物群定殖无菌啮齿动物而开发的。本研究的目的是通过 16S rRNA 序列分析鉴定 ASF 的八种菌株中的每一种。根据表型标准，先前已将三种菌株鉴定为嗜酸乳杆菌（ASF 360 菌株）、唾液乳杆菌（ASF 361 菌株）和狄氏拟杆菌（ASF 519 菌株）。16S rRNA 分析表明，每种菌株与其推测的身份不同。ASF 361 菌株的 16S rRNA 序列与鼠乳杆菌和动物乳杆菌（均从小鼠分离）的模式菌株的 16S rRNA 序列基本相同，并且所有这些菌株可能属于单一物种。ASF 360 菌株是一种与嗜酸乳杆菌和乳酸乳杆菌聚集在一起的新型乳杆菌。ASF 519 菌株属于一个未命名的属，该属包含狄氏拟杆菌、粪拟杆菌、福赛斯坦纳菌和 CDC 组 DF - 3。这个未命名的属属于噬纤维菌 - 黄杆菌 - 拟杆菌门，并且与卟啉单胞菌属关系最密切。螺旋形菌株 ASF 457 属于弯曲杆菌门，并且与罗伯逊啮齿动物分离株具有序列同一性。其余四种 ASF 菌株是对氧极度敏感的梭形细菌，在系统发育上与低 G + C 含量革兰氏阳性细菌（厚壁菌门，芽孢杆菌 - 梭菌组）归为一类。ASF 356、ASF 492 和 ASF 502 属于柯林斯等人的梭菌 XIV 簇。在形态上，ASF 492 类似于该簇的成员，盲肠罗氏菌和多尾真杆菌。ASF 492 的 16S rRNA 序列与多尾真杆菌的序列相同。由于多尾真杆菌的模式菌株和其他存活的原始分离株已丢失，ASF 492 菌株是新模式菌株的候选者。ASF 500 菌株在低 G + C 含量革兰氏阳性系统发育树中分支较深，但与 GenBank 数据库中目前其 16S rRNA 序列的任何生物没有密切关系。本研究中确定的 16S rRNA 序列信息应能快速鉴定 ASF 菌株，并应能详细分析在感染多种致病微生物的小鼠肠道疾病发展过程中 ASF 生物体之间的相互作用。
