黄喉拟水龟体表溃疡病原菌SG_(24)的分类鉴定

从患溃疡的黄喉拟水龟病灶中分离到一株病原菌SG24。对菌株SG24进行了常规生理生化测定和ATBExpression半自动细菌鉴定仪鉴定,并测定16S rRNA序列,分析其与相关细菌相应序列的同源性,构建了系统进化树。普通细菌学方法结果显示菌株SG24为黏质沙雷氏菌(Serratia marcescens)。以沙雷氏菌属的16S rRNA基因序列设计一对引物进行PCR扩增,获得了菌株SG24大小约950 bp的16S rRNA部分基因片段,测序结果显示菌株SG24与黏质沙雷氏菌同类,与已登录的黏质沙雷氏菌(S.marcescensDQ207558)的16S rRNA同源性大于99%。综合以上分类鉴定结果,确定菌株SG24属于沙雷氏菌属的黏质沙雷氏菌。药物敏感试验结果表明:菌株SG24对链霉素、庆大霉素、壮观霉素、强力霉素、卡那霉素、阿米卡星、诺氟沙星、氧氟沙星和复方新诺明敏感。

Identification of SG24 Strain,a Pathogenic Bacteria Causing Ulceration of Mauremys mutica cantor

A pathogenic bacterial strain SG24 was isolated from the exterior ulceration of Mauremys mutica cantor.According to the results of the traditional physiological and biochemical characteristics,the TAB Expression systematic identification,the strain SG24 was identified as Serratia marcescens.In addition,the 16S rRNA gene of strain SG24 was sequenced and compared with that of related strains,and the molecular phylogenetic dendrogram was constructed.About 950 bp fragments of the strain were amplified by PCR using two primers designed according to the 16S rRNA gene sequences of Serratia.Phylogenetic tree based on 16S rRNA gene showed that strain SG24 was clustered together with Serratia marcescens.The sequence analysis of 16S rRNA gene revealed that strain SG24 exhibited high similarity(greater than 99%) with that of Serratia marcescens(DQ207558) from GenBank database.Based on the results obtained,strain SG24 was identified as Serratia marcescens.Meanwhile,its sensitivity to chemotherapeutants was detected.The results showed that strain SG24 was sensitive to streptomycin,gentamycin,spectinomycin,doxycycline,kanamycin,amikanamycin,norfloxacin,ofloxacin,and trimethoprim.