The rapid molecular identification of 16 common coagulase negative Staphylococcus / 中华微生物学和免疫学杂志

ABSTRACT

ObjectiveTo establish the rapid molecular diagnosis of 16 common coagulase negative Staphylococcus(CNS).MethodsDNA sequencing of 16 CNS would be obtained with gap gene.After the alignment gap gene sequences which were available in the GenBank,the bacteria were identified with homological alignment and phylogenetic tree,and compared with the 16S rRNA gene.ResultsThe sequence similarity of the gap sequences ranged from 39% to 98% in 16 CNS.There were the highest similarity (98%) between S.hominis and S.hominis subsp,and the lowest(39% ) between S.saprophyticus and S.xylosus.The sequence similarity of the 16S rRNA sequences ranged from 96 to 98%,at least two species of bacteria similar rate of 99% and the most four species similar rate of 99%.Phylogenetic homology analysis showed that it was a high confidence(99% ) in the detection ofS.xylosus and S.lentus,S.chromogenes and S.intermedius,S.hominis and S.hominis subsp,but for 10 other species of bacteria,gap homology analysis has less unreliable confidence(49%,56% ) and 16S rRNA has more unreliable confidence(43%,43%,50%,56%,63%,65%,76% ).ConclusionAnalysis of gap sequence could identify 16 CNS timely and accurately,with higher confidence than 16S rRNA.