Evalutaion Of The Rapid Of Detection Of Mycobacterium Tuberculosis Based On Phage Amplified Biologically Assay From Sputum

ObjectiveTo detect sputum specimens by both conventional methods (direct auramine smear miscroscopy and concentrated auramine smear miscroscopy) and culture in Bactec MGIT 960 and Phage amplified biologically assay. And to evaluate the value in detection of Mycobacterium Tuberculosis by Phage amplified biologically assay.MaterialsMaterials : Sputum specimens ( n = 53 ) were obtained from 53 suspects for pulmonary tuberculosis in Shen Yang Chest Hospital. Sputum specimens stored in plastic bottle were normally collected from each patient in morning.Methods1. FAST Plaque TB testing was performed according to the pack insert.2. Direct auramine smear miscroscopy and concentrated auramine smear miscroscopy testing were performed according to Mycobacterium Tuberculosis detection rules.3. BACTEC MGIT960 method was performed according to the pack insert.4. BACTEC MGIT960 detection apparatus,FAST Plaque TB^TM. Analysis of statistics: Chi - square test using by counting data.ResultThe study was completed on 53 samples. FAST Plaque TBpositive is 24,direct smear miscroscopy positive is 11, concentrated smear miscroscopy positive is 17, BACTEC MGIT960 method positive is 22;out of 22 culture positive , 3 is negative for FAST Plaque TB.The positive rates of BACTEC MGIT960 result from + to + + + + are 60. 0% ^66. 7% N100% . 100% in PhaB;The number of Plaque is increasing with the + in culture.DiscussionThere are significant differences in direct smear miscroscopy and concentrated smear miscroscopy positive rates;There are significant differences in PhaB test and concentrated smear miscroscopy positive rates;There are not significant differences in PhaB test and BACTEC MGIT960 method positive rates.Compared to culture it has sensitivity of 86.4% and specificity of 83. 9% , positive predictive value of 79. 2% and negative predictive value of 89. 7 %;It has a good sensitivity and specificity . Using PhaB test and concentrated smear miscroscopy detect sputum, their sensitivity is 90. 9% , specificity is 83. 9% , they can increase sensitivity ,decrese misdiagnosis rate. 3 of the 22 culture -positive specimens tested PhaB - negative, They are valid to TB treatment . It i-dentify that PhaB can get false - negative in speciments few Mycobacterium tuberculosis;5 of the 31 culture - negative and smear - negative tested PhaB -positive , 2 cultures out of 5 are positive in another specimens from them, They are valid to TB treatment , and show the PhaB sensitivity in the 2 cases is higher than culture. Add the 2 cases to culture positive and calculate again, the sensitivity of PhaB is 0. 88, specificity is 0. 90. PhaB - positive rates is increasing with the quantity in culture. The number of Plaque can estimate the infectional level in Mycobacterium tuberculosis, it is a judgement - guide in clinical treatment.ConclusionPhage amplified biologically assay is a simple test that can detect viable mycobacterium in 1 days. The sensitivity of PhaB test is better than direct aura-mine smear miscroscopy and concentrated auramine smear miscroscopy . It can be useful in the rapid diagnosis of tuberculosis . PhaB test associating with concentrated smear miscroscopy can increase sensitivity , decrese misdiagnosis rate, it is a screening to suspected cases.