Pidiyar Vyankatesh J, Jangid Kamlesh, Dayananda K M, Kaznowski Adam, Gonzalez Jose M, Patole Milind S, Shouche Yogesh S
Molecular Biology Unit, National Centre for Cell Science, University of Pune, Ganeshkhind, Pune, Maharashtra, India.
Syst Appl Microbiol. 2003 Jun;26(2):197-202. doi: 10.1078/072320203322346047.
We determined the gyrB gene sequences of all 17 hybridizations groups of Aeromonas. Phylogenetic trees showing the evolutionary relatedness of gyrB and 16S rRNA genes in the type strains of Aeromonas were compared. Using this approach, we determined the phylogenetic position of Aeromonas culicicola MTCC 3249(T), isolated from midgut of Culex quinquefasciatus. In the gyrB based-analysis A. culicicola MTCC 3249(T) grouped with A. veronii whereas, it grouped with A. jandaei in the 16S rRNA based tree. The number of nucleotide differences in 16S rRNA sequences was less than found with the gyrB sequence data. Most of the observed nucleotide differences in the gyrB gene were synonymous. The Cophenetic Correlation Coefficient (CCC) for gyrB sequences was 0.87 indicating this gene to be a better molecular chronometer compared to 16S rRNA for delineation of Aeromonas species. This strain was found to be positive for the cytolytic enterotoxin gene. PCR-Amplicon Sequence Analysis (PCR-ASA) of this gene showed that the isolate is affiliated to type I and is potentially pathogenic. These PCR-ASA results agreed in part with the gyrB sequence results.
我们测定了气单胞菌属所有17个杂交组的gyrB基因序列。比较了显示气单胞菌模式菌株中gyrB和16S rRNA基因进化相关性的系统发育树。采用这种方法，我们确定了从致倦库蚊中肠分离出的嗜库蚊气单胞菌MTCC 3249(T)的系统发育位置。在基于gyrB的分析中，嗜库蚊气单胞菌MTCC 3249(T)与维罗纳气单胞菌归为一组，而在基于16S rRNA的树中，它与詹氏气单胞菌归为一组。16S rRNA序列中的核苷酸差异数量少于gyrB序列数据中的差异数量。gyrB基因中观察到的大多数核苷酸差异是同义的。gyrB序列的协变相关系数（CCC）为0.87，表明与16S rRNA相比，该基因是用于气单胞菌属分类的更好的分子计时器。发现该菌株的细胞溶解性肠毒素基因呈阳性。对该基因的PCR扩增子序列分析（PCR-ASA）表明，该分离株属于I型，具有潜在致病性。这些PCR-ASA结果与gyrB序列结果部分一致。
