Objective To evaluate the value of GeneXpert MTB/RIF assay in the clinical diagnosis of tuberculosis and tuberculosis associated rifampin resistance. Methods A total of 851 patients admitted to the Guangxi Longtan Hospital from September 22, 2015 to May 25, 2016 were enrolled. The smear microscopic examination, solid culture test, and GeneXpert MTB/RIF assay was performed on each patient. Drug sensitivity test of rifampicin using proportion method was done on patients infected with mycobacterium tuberculosis isolated by solid culture, and rifampicin resistance detection was performed on GeneXpert MTB/RIF positive patients. Bacteriological positive consistency test was performed on GeneXpert MTB/RIF and solid culture, and rifampicin resistance detection was compared bwtween GeneXpert MTB/RIF and drug sensitivity using proportion method. Culture and drug susceptibility testing were used as the gold standard, and the MTB sensitivity and specificity of smear microscopic examination, solid culture, and GeneXpert MTB/RIF assay was compared. Results Culture was used as the gold standard. Compared with culture, the sensitivity, specificity, positive predictive value, and negative predictive value of GeneXpert MTB/RIF was 95.48%(211/241), 94.91%(559/569), 87.55%(211/241), and 98.24%(559/569) respectively. The sensitivity of Xpert MTB/RIF for culture positive smear positive specimens and culture positive smear negative specimens was 98.78% (162/164) and 85.96%(49/57) respectively. Drug susceptibility testing was used as the gold standard. Compared with drug susceptibility testing, the sensitivity, specificity, positive predictive value, and negative predictive value of rifampin resistance measured by GeneXpert MTB/RIF was 98.70%(152/154), 92.98%(53/57), 97.44%(152/156) and 96.36%(53/55) respectively. The consistency rate of GeneXpert MTB/RIF and solid culture was 93.83% (Kappa = 0.847), and that of GeneXpert MTB/RIF rifampin resistance detection and proportion method for drug sensitivity was 96.38% (Kappa = 0.904). Conclusions The GeneXpert MTB/RIF detection is easily operated with high sensitivity and specificity compared with smear microscopic examination and solid culture, and it also possesses good consistency with solid culture and traditional drug sensitivity. Moreover, it could also be applied to diagnose the resistance to rifampin, which is very promising in application.

Objective To evaluate the effect of ZOPOMED-60 mycobacterium tuberculosis microscanner on detecting acid-fast bacilli in sputum smears.Methods A total of 203 qualified sputum specimens from patients treated in Chest Hospital of Guangxi Zhuang Autonomous Region in May 2023 were collected.The samples were stained by using Ziehl-Neelsen staining and fluorecent staining,respectively,and the acid-fast bacillus was detected by the manual microscopy and ZOPOMED-60 mycobacterium tuberculosis microscanner.The sensitivity,specificity,positive predictive value and negative predictive value of acid-fast bacillus were calculated using different methods based on liquid culture of mycobacterium.Results The positive rates of manual reading and instrument intelligent reading of fluorecent staining were 12.3%and 18.7%,respectively,and the positive rates of manual reading and instrument intelligent reading of Ziehl-Neelsen staining were 13.3%and 17.7%,respectively.There was no significant difference between the four reading results(P>0.05).Based on the results of liquid culture of mycobacterium,sensitivity of manual reading and instrument intelligent reading of fluorecent staining and manual reading and instrument intelligent reading of Ziehl-Neelsen staining were 40.0%,45.0%,45.0%and 53.3%,specificity were 99.3%,92.3%,100.0%and 97.2%,positive predictive values were 96.0%,71.0%,100.0%and 88.9%,and negative predictive values were 79.8%,80.0%,81.2%and 83.2%,respectively.The consistency was good.Conclusion The performance of ZOPOMED-60 mycobacterium tuberculosis microscanner in the detection of acid-fast bacilli by two staining methods is good,and it is worth popularizing.