Huys G, Coopman R, Janssen P, Kersters K
Laboratorium voor Microbiologie, Universiteit Gent, Belgium.
Int J Syst Bacteriol. 1996 Apr;46(2):572-80. doi: 10.1099/00207713-46-2-572.
We investigated the ability of a recently developed genomic fingerprinting technique, named AFLP, to differentiate the 14 currently defined DNA hybridization groups (HGs) in the genus Aeromonas. We also determined the taxonomic positions of the phenospecies Aeromonas allosaccharophila, Aeromonas encheleia, Aeromonas enteropelogenes, and Aeromonas ichthiosmia, which have not been assigned to HGs yet. A total of 98 Aeromonas type and reference strains were included in this study. For the AFLP analysis, the total genomic DNA of each strain was digested with restriction endonucleases ApaI and TaqI. Subsequently, restriction fragments were selectively amplified under high-stringency PCR conditions. The amplification products were electrophoretically separated on a polyacrylamide gel and visualized by autoradiography. Following high-resolution densitometric scanning of the resulting band patterns, AFLP data were further processed for a computer-assisted comparison. A numerical analysis of the digitized fingerprints revealed 13 AFLP clusters which, in general, clearly supported the current Aeromonas taxonomy derived from DNA homology data. In addition, our results indicated that there is significant genotypic heterogeneity in Aeromonas eucrenophila (HG6), which may lead to a further subdivision of this species. A. allosaccharophila and A. encheleia did not represent a separate AFLP cluster but were found to be genotypically related to HG8/10 and HG6, respectively. In addition, the results of the AFLP analysis also confirmed the phylogenetic findings that A. enteropelogenes and A. ichthiosmia are in fact identical to Aeromonas trota (HG13) and Aeromonas veronii (HG8/10), respectively. The results of this study clearly show that the AFLP technique is a valuable new high-resolution genotypic tool for classification of Aeromonas species and also emphasize that this powerful DNA fingerprinting method is important for bacterial taxonomy in general.
我们研究了一种最近开发的名为AFLP的基因组指纹技术区分气单胞菌属中目前定义的14个DNA杂交组（HG）的能力。我们还确定了嗜异糖气单胞菌、鳗气单胞菌、肠栖气单胞菌和鱼嗅气单胞菌等表型种的分类地位，这些表型种尚未被归入杂交组。本研究共纳入98株气单胞菌类型菌株和参考菌株。对于AFLP分析，用限制性内切酶ApaI和TaqI消化各菌株的总基因组DNA。随后，在高严格度PCR条件下选择性扩增限制性片段。扩增产物在聚丙烯酰胺凝胶上进行电泳分离，并通过放射自显影进行可视化。对所得条带模式进行高分辨率光密度扫描后，对AFLP数据进行进一步处理以进行计算机辅助比较。对数字化指纹的数值分析揭示了13个AFLP聚类，总体上明确支持了源自DNA同源性数据的当前气单胞菌分类法。此外，我们的结果表明嗜泉气单胞菌（HG6）存在显著的基因型异质性，这可能导致该物种的进一步细分。嗜异糖气单胞菌和鳗气单胞菌并不代表一个单独的AFLP聚类，而是分别被发现与HG8/10和HG6基因型相关。此外，AFLP分析结果还证实了系统发育研究结果，即肠栖气单胞菌和鱼嗅气单胞菌实际上分别与豚鼠气单胞菌（HG13）和维氏气单胞菌（HG8/10）相同。本研究结果清楚地表明，AFLP技术是一种用于气单胞菌属分类的有价值的新型高分辨率基因型工具，同时也强调了这种强大的DNA指纹技术对一般细菌分类学的重要性。
