ABSTRACT
Molecular beacon probe was designed based on a specific DNA sequence of Nocardia to PCR detection of thisbacterium.The strains of Nocardia、Gordina and Rhodococcus were inoculated in Brain Heart Infusion Agar medium separately,then the growth condition was observed,DNA was extracted as a template;the molecular beacon probe was designed based on the partial secA 1 gene sequences of Nocardia strains,and the probe was added into the reaction system of real time fluorescence quantitative PCR (RT-PCR),and the fluorescence signal was tested at the end of PCR.Showed that the amplified secA1 gene of Nocardia could produce positive fluorescence signal in RT-PCR,but those of Gordonia and Rhodococcus with control groups showed negative results because of no fluorescence signal.In conclusion as a housekeeping gene,secA1 is an ideal target molecule to identify the actinomycetes strains on the species level in the systematic evolution research,and the technique of fluorescence molecular beacon probe is accurate,rapid and sensitive for detecting the Nocardia strains with secA1 gene.