Rapid detecting familiar pathogens in lower respiratory tract infections with universal primers PCR and RFLP

Abstract

Objective To explore the value of the polymerase chain reaction(PCR) and restriction fragment length polymorphism(RFLP) on rapid diagnose of bacteria in lower respiratory tract infections. Methods One hundred and twenty-five sputum samples of inpatients with lower respiratory tract infections were checked out. Every sputum sample was divided into two parts. One part was cultured for bacteria test, the other was detected by way of bacterial 16S rRNA gene PCR with universal primers, and the PCR products were digested by different restriction enzymes(HaeⅢ, Mn1Ⅰ, AluI,DdeⅠ and BstBⅠ) and analyzed by RFLP. Bacterial pathogens were identified from the different patterns and the outcomes compared between two methods. Results In 125 sputum samples,the positive rate of the way of the PCR and RFLP(68.0%) was visible higher than that of sputum culture (57.6%)(P<0.01). The positive rates of PCR and RFLP for examining S. pneumoniae and H. influenxae were higher also, but the positive rate of S. haemoliticus, S. epidermidis and E. faecium was lower than that of the sputum culture. Conclusions The method of PCR coupled with RFLP has the advantage of rapidity and sensitivity in detecting bacterial pathogens. It has also clinical application value for quick diagnosis of pathogens. Key words: Lower respiratory tract infections; Universal primers; Polymerase chain reaction; Restriction fragment length polymorphism; 16SrRNA gene