ABSTRACT
Objective To compare real-time PCR and gomori-methenamine silver stain in the diagnosis of pneumocystis peumonia (PCP).Methods 2 525 unrepeated specimens from suspected PCP patient admitted in Peaking Union Medical College Hospital were collected in 2014.2 492 samples were detected by gomori-methenamine silver stain,33 samples were detected by real-time PCR,and 429 samples were detected by both methods at the meanwhile.With clinical diagnosis as reference standard,the sensitivity,specificity,positive predictive value and negative predictive value of the two methods were analysised.Results Positive rate of gomori-methenamine silver stain was 1.2 ％ (30/2 492).The first three specimen types were sputum,tracheal intubation suction and bronchoalveolar lavage fluid,the positive rate was 0.70 ％ (13/1 845),4.00％ (10/250) and 2.72％ (7/257) respectively.Positive rate of realtime PCR was 34.20％ (158/462),and the positive rate of sputum and bronchoalveolar lavage fluid was 30.61％ (105/343) and 44.54％ (53/119) respectively.The sensitivity were 13.97％ vs 72.07％,specificity were 100％ vs 94.24％,positive predictive value were 100％ vs 92.14％ and negative predictive value were 55.36％ vs 78.26％ for gomori-methenamine silver stain and real-time PCR respectively.All of which were statistically significant analysed by x2 test for paired data.The x2 value and P alue were x2 =68.625,P＜0.01;x2 =4.296,P＜0.05;x2 =6.380,P＜0.01 and x2 =11.873,P＜0.01.Conclusion The real-time PCR had higher sensitivity,fewer interference factors and more clinical diagnostic value,so clinicians should make more use of real-time PCR to diagnose PCP earlier.
ABSTRACT
Objective To verify the feasibility of Chlamydia trachomatis(CT),Neisseria gonorrhoeae(NG),Ureaplasma urealyticum(UU)detection by automatic nucleic acid extraction workstation(MagX).Methods The test samples of CT (159),NG(128)and UU(144)were collected.The samples were extracted of nucleic acid two methods:manual extraction, which entailed manually preparing PCR reaction system and MagX automatic nucleic acid extraction workstation,which au-tomatically prepared the reaction system.The two parts of nucleic acids proceeded to the Simultaneous Amplification and Testing(SAT).The result of manual extraction was set as the golden standard and the Kappa consistency analysis was con-ducted.Meanwhile,the sensitivity,specificity,accuracy and carry pollution experiments of MagX were verified.Results The sensitivity of MagX automatic nucleic acids extraction workstation were 92.59%(CT),100.00%(NG)and 93.33%(UU).The specificity were 98.48%(CT),98.18%(NG)and 95.24%(UU).The accuracy were 97.48%(CT),98.44%(NG)and 94.44%(UU).The results of kappa consistency analysis were greater than 0.8(CT:Kappa=0.910 6,NG:Kap-pa=0.938 3,UU:Kappa=0.885 6).MagX detected the precision of CT,NG and UU:Coefficient of Variation(CV)<5%. There was no pollution phenomenon.Conclusion MagX automatic nucleic acids extraction workstation could be used to test three kinds of sexually transmitted pathogen in clinical settings.