Establishment and application of DPO-based quadruple real-time PCR for detection of mycobacteria / 中华检验医学杂志

ABSTRACT

Objective To establish a rapid,accurate and specific method to detect the common mycobacteria based on multiplex real-time PCR.Methods The dual priming oligonucleotide ( DPO)primers and TaqMan probes labeled with FAM,ROX,HEX or JOE fluoresceins at 5' end and eclipse at 3' end respectively were designed to detect the 16S rRNA of mycobacteria.Both specificity and sensitivity were estimated on multiplex real-time PCR detecting genome DNA from 4 mycobacterial model species.Sixty eight early morning sputum specimens collected from hospitalized patients in the Red Cross Hospital of Hangzhou were detected by multiplex real-time PCR,bacterial culture and smear microscopy simultaneously.The positive rates were analyzed by chi-square.Results Mycobacteria including Mycobacterium tuberculosis and three common non-tuberculosis mycobacteria spp.were identified by multiplex real-time PCR accurately and specifically,with the limited load at 101 cfu/ml.In 68 sputum specimens,31 were positive (positive rate 45.6％ ) by this method,which was significant higher than that by smear microscopy ( positive rate 14.7％,x2 =15.4,P ＜0.05 ).The positive cases were identified as 28 Mycobacterium tuberculosis,1 Mycobacterium avium and 2 Mycobacterium intracellulare in agreement with the culture results.One case,which is detected by culture,but not by PCR,was identified as Mycobacterium chelonae by sequencing.Conclusion The multiplex real-time PCR characterizing as sensitive,specific and time-saving for Mycobacterium tuberculosis and common non-tuberculosis mycobacteria could be chosen as the rapid laboratory test of mycobacterial infection.