Jangid Kamlesh, Kong Richard, Patole Milind S, Shouche Yogesh S
Molecular Biology Unit, National Centre for Cell Science, University of Pune, Pune- 411007, Maharashtra, India.
BMC Microbiol. 2007 Oct 23;7:93. doi: 10.1186/1471-2180-7-93.
Aeromonas spp. have been regarded as "emerging pathogens". Aeromonads possess multifactorial virulence and the production of many of these virulence determinants is associated with high cell density, a phenomenon that might be regulated by quorum sensing. However, only two species of the genus are reported to possess the luxRI quorum sensing gene homologs. The purpose of this study was to investigate if the luxRI homologs are universally present in the Aeromonas strains collected from various culture collections, clinical laboratories and field studies.
Of all the 73 Aeromonas strains used in the study, seventy-one strains elicited acyl-homoserine lactone-mediated response in multiple biosensor strains. However, dot blot hybridization revealed that the luxRI homologs are present in all the strains. PCR amplification and sequencing revealed that the luxRI homologs shared a very high percentage sequence similarity. No evidence for lateral gene transfer of the luxRI homologs between aeromonads and other genera was noted.
We propose that the luxRI quorum sensing gene homologs are universally present in the genus Aeromonas independently from their origin. This study is the first genus-wide report of the taxonomic distribution of the luxRI homologs.
气单胞菌属被视为“新兴病原体”。气单胞菌具有多种毒力因子，其中许多毒力决定因素的产生与高细胞密度有关，这种现象可能受群体感应调控。然而，据报道该属中只有两个物种拥有luxRI群体感应基因同源物。本研究的目的是调查从各种菌种保藏中心、临床实验室和实地研究中收集的气单胞菌菌株中是否普遍存在luxRI同源物。
在本研究使用的所有73株气单胞菌菌株中，有71株在多种生物传感器菌株中引发了酰基高丝氨酸内酯介导的反应。然而，斑点杂交显示luxRI同源物存在于所有菌株中。PCR扩增和测序表明，luxRI同源物具有非常高的序列相似百分比。未发现气单胞菌与其他属之间luxRI同源物横向基因转移的证据。
我们提出luxRI群体感应基因同源物普遍存在于气单胞菌属中，与它们的来源无关。本研究是关于luxRI同源物分类分布的首个全属范围报告。
