Rivera-Posada J A, Pratchett M, Cano-Gomez A, Arango-Gomez J D, Owens L
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4812, Australia.
Dis Aquat Organ. 2011 Sep 9;96(2):113-23. doi: 10.3354/dao02389.
We used a polyphasic approach for precise identification of bacterial flora (Vibrionaceae) isolated from crown-of-thorns starfish (COTS) from Lizard Island (Great Barrier Reef, Australia) and Guam (U.S.A., Western Pacific Ocean). Previous 16S rRNA gene phylogenetic analysis was useful to allocate and identify isolates within the Photobacterium, Splendidus and Harveyi clades but failed in the identification of Vibrio harveyi-like isolates. Species of the V harveyi group have almost indistinguishable phenotypes and genotypes, and thus, identification by standard biochemical tests and 16S rRNA gene analysis is commonly inaccurate. Biochemical profiling and sequence analysis of additional topA and mreB housekeeping genes were carried out for definitive identification of 19 bacterial isolates recovered from sick and wild COTS. For 8 isolates, biochemical profiles and topA and mreB gene sequence alignments with the closest relatives (GenBank) confirmed previous 16S rRNA-based identification: V. fortis and Photobacterium eurosenbergii species (from wild COTS), and V natriegens (from diseased COTS). Further phylogenetic analysis based on topA and mreB concatenated sequences served to identify the remaining 11 V harveyi-like isolates: V. owensii and V. rotiferianus (from wild COTS), and V. owensii, V. rotiferianus, and V. harveyi (from diseased COTS). This study further confirms the reliability of topA-mreB gene sequence analysis for identification of these close species, and it reveals a wider distribution range of the potentially pathogenic V. harveyi group.
我们采用了一种多相方法，以精确鉴定从澳大利亚大堡礁蜥蜴岛和美国西太平洋关岛的棘冠海星（COTS）中分离出的细菌菌群（弧菌科）。先前的16S rRNA基因系统发育分析有助于将分离株分配和鉴定到发光杆菌属、灿烂弧菌属和哈维氏弧菌属分支中，但未能鉴定出哈维氏弧菌样分离株。哈维氏弧菌组的物种具有几乎难以区分的表型和基因型，因此，通过标准生化试验和16S rRNA基因分析进行鉴定通常不准确。为了明确鉴定从患病和野生棘冠海星中回收的19株细菌分离株，我们对额外的topA和mreB管家基因进行了生化分析和序列分析。对于8株分离株，生化分析以及与最相近亲缘种（GenBank）的topA和mreB基因序列比对证实了先前基于16S rRNA的鉴定结果：强壮弧菌和欧氏发光杆菌（来自野生棘冠海星），以及敏捷弧菌（来自患病棘冠海星）。基于topA和mreB串联序列的进一步系统发育分析有助于鉴定其余11株哈维氏弧菌样分离株：欧文氏弧菌和轮虫弧菌（来自野生棘冠海星），以及欧文氏弧菌、轮虫弧菌和哈维氏弧菌（来自患病棘冠海星）。本研究进一步证实了topA-mreB基因序列分析在鉴定这些近缘物种方面的可靠性，并揭示了潜在致病性哈维氏弧菌组更广泛的分布范围。
