鸡白痢沙门氏菌活的非可培养状态相关基因ybbB和rh1B的鉴定

Identifition of viable but non-culturable state related genes ybbB and rh1B in Salmonella pullorum

为鉴定细菌活的非可培养状态(VBNC)下的转录基因,本研究采用液体LB培养基在4℃条件下诱导鸡白痢沙门氏菌(S.pullorum)CVCC578株进入VBNC状态,并利用mRNA差异显示RT-PCR技术(DDRT-PCR)分析S.pullorum VBNC状态与正常状态所表达的差异基因。结果表明,在S.pullorum的VBNC状态下克隆得到两个转录基因片段,分别为422 bp和573 bp。序列分析表明:422 bp的cDNA片段与不同沙门氏菌株的tRNA硒尿核苷合成酶(tRNA 2-selenouridine synthase)的ybbB基因的核苷酸和氨基酸同源性均为99%;573 bp的cDNA片段则与不同菌株S.pullorum的ATP依赖性的RNA解旋酶基因(rh1B)的核苷酸同源性为95%～100%,氨基酸同源性为98%以上。在VBNC状态下这两个转录基因的发现,将为S.pullorum的VBNC机理研究奠定基础。

To identify the gene expression of Salmonell pullorum under viable but non-culturable state（VBNC）,two cDNA fragments were cloned and identified by mRNA differential display RT-PCR and dot blot from S.pullorum in VBNC induced by culturing in LB medium at 4 ℃.The sequencing analysis showed that the 2 cDNA fragments were 422 bp and 573 bp,respectively.The alignment analysis results indicated that the 422 bp cDNA had over 99% identity to tRNA 2-selenouridine synthase ybbB gene in S.pullorum at both nucleotide and deduced amino aicd level,and the 573 bp cDNA showed 95% to 100% at nucleotide level and over 98% at amino acid level to ATP-dependent RNA helicases rh1B gene of S.pullorum reference strains,respectively,which suggested the 2 genes were important for S.pullorum in VBNC.These finding would be useful to further study the mechanism of bacteria in VBNC.