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Objective:To evaluate the diagnostic effects of Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology for rapid screening of rifampicin-resistant tuberculosis.Methods:The clinical data of 150 patients diagnosed with tuberculosis by Bactec MGIT 960 liquid culture drug susceptibility in Zhejiang Chinese Medicine and Western Medicine Integrated Hospital from September 2016 to August 2019 were collected, including Xpert MTB/RIF and gene chip results. The isolated and cultured strains from patients were subjected to fluorescence PCR melting curve detection. Using Bactec MGIT 960 drug susceptibility results as the reference, the diagnostic efficacy of Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology for rifampicin resistance were analyzed, and the receiver operating characteristic curve (ROC) was drawn for comparative analysis.Results:Take Bactec MGIT 960 as the gold standard, the sensitivity of Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology for rifampicin resistance were 88.89% (16/18), 94.44% (17/18), 88.89% (16/18) respectively; the specificity were 96.21% (127/132), 96.21% (127/132), 95.45% (126/132), respectively. There was no statistically significant difference in the sensitivity and specificity among the three detection methods ( P>0.05). The Kappa values of the three molecular methods for detecting rifampicin resistance were 0.794, 0.827 and 0.770, respectively. The three detection methods have good diagnostic value for rifampicin resistance ( P<0.01), but there is no statistically significant difference between the three methods ( P>0.05). There were 8 cases of inconsistent results between the three methods and Bactec MGIT 960 drug sensitivity. Conclusion:Xpert MTB/RIF, Fluorescence PCR melting curve and gene chip technology have comparable ability to detect rifampicin resistance, all of these have high sensitivity and specificity for detecting rifampicin resistance and are suitable for rapid screening.
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Objective To compare the application of PCR-fluorescence probe, Bactec MGIT960 and Xpert MTB／RIF in diagnosis of tuberculosis from non-respiratory specimens.Methods Non-respiratory specimens from 225 patients with suspected tuberculosis admitted in Zhejiang Hospital of Integrated Chinese Medicine and Western Medicine from October 2017 to August 2018 were collected.There were 177 cases of tuberculosis and 48 cases of non-tuberculosis confirmed by clinical diagnosis.All specimens were tested with PCR-fluorescence probe, Xpert MTB／RIF and Bactec MGIT960.The clinical diagnostic results were used as the gold standard, and the receiver operating characteristic curve ( ROC) was drawn to evaluate the diagnostic values of three methods.The consistency of PCR-fluorescence probe method with Xpert MTB／RIF assay was analyzed.Results The sensitivity of PCR-fluorescent probe, Xpert MTB／RIF and Bactec MGIT960 in diagnosis of tuberculosis was 53.67%(95／177), 58.76%(104／177) and 31.07%(55／177), respectively.The sensitivity of PCR-fluorescent probe and Xpert MTB／RIF was higher than that of Bactec MGIT 960 culture ( χ2 ＝17.60 and 27.41, P＜0.01), while there was no significant difference between the PCR-fluorescent probe and the Xpert MTB／RIF (χ2 ＝0.93, P＞0.05).The specificity of three methods were 100.00%(48／48), 100.00%(48／48) and 97.92%(47／48), respectively (F＝1.83, P＞0.05).ROC curve analysis showed that the area under the ROC curve ( AUC) of PCR-fluorescent probe, Xpert MTB／RIF, and Bactec MGIT960 was 0.768, 0.794, and 0.645, respectively.The diagnostic value of PCR-fluorescent probe and Xpert MTB／RIF for tuberculosis was significantly higher than that of Bactec MGIT960 (Z＝5.19 and 6.52, P＜0.01); while Xpert MTB／RIF was superior to PCR-fluorescence probe (Z＝2.8, P＜0.05).In various types of specimens , there was no significant difference in the detection rate of tuberculosis between PCR-fluorescent probe method and Xpert MTB／RIF (χ2 ＝0.73, P＞0.05).The PCR-fluorescent probe and Xpert MTB／RIF had a good consistency (kappa＝0.829).Conclusion Xpert MTB／RIF is superior to PCR-fluorescence probe in the detection of tuberculosis in non-respiratory specimens such as tissues and pus, but the two have good consistency.The PCR-fluorescence probe method is economical and practical , and easy to promote, which has a high clinical application prospects.
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Objective To compare the clinical features of pulmonary infections with Mycobacterium intracellulare and Mycobacterium abscessus in the tuberculosis intensive care unit (ICU).Methods Clinical data of 74 patients with non-tuberculous mycobacterial pulmonary infection (NTM) admitted in tuberculosis ICU of Hangzhou Red Cross Hospital from January 2012 to May 2017 were retrospectively analyzed.There were 54 patients infected with Mycobacterial abscesses, 16 patients with Mycobacterial intracellular, 2 patients with Mycobacterium avium and 2 patients with Mycobacterium kansasii.The clinical features, imaging manifestations, treatment and prognosis of patients with Mycobacterial intracellular and Mycobacterial abscesses lung infections were compared.SPSS 21.0 software was used for statistical analysis.Survival curve analysis was performed using GraphPad Prism V 5.01.Results Among 74 patients with NTM lung disease , the infection rate of Mycobacterium abscessus was 72.87%(54/74), and the infection rate of Mycobacterium intracellular was 21.62%( 16/74 ).The age of patients with Mycobacterium intracellularis pulmonary disease was younger and the length of ICU stay was shorter than those of patients with Mycobacterium abscessus (t＝－2.729 and －6.150, P＜0.05 or ＜0.01).There was no significant difference in the gender distribution and APACHE Ⅱ scores between the two groups ( both P＞0.05).The proportion of patients with chronic obstructive pulmonary disease ( COPD) in Mycobacterium intracellularis group was significantly lower and the proportion of patients with bronchiectasis was significantly higher than those in Mycobacterial abscesses group (χ2＝3.902, P＜0.05; χ2＝23.888, P＜0.01).The proportion of patients complicated with stroke sequelae , Parkinson's disease and other central nervous system diseases ( χ2＝14.872, P＜0.01) and diabetes (χ2＝3.902, P＜0.05) in Mycobacterial abscess group was significantly higher, and that of hemoptysis was significantly lower (χ2＝9.717, P＜0.01) than those in Mycobacterium intracellularis group.Respiratory failure (93.75%) and septic shock (6.25%) were the main reasons of ICU admission for patients with Mycobacterium intracellularis lung disease; while respiratory failure (90.74%), heart failure (11.11%) and renal failure (1.85%) were main reasons of ICU admission for patients with Mycobacterial abscesses; there were no significant differences in the causes of ICU admission between the two groups ( all P＞0.05).The proportion of NTM isolated from patients with Mycobacterial intracellular lung disease, prior to mechanical ventilation was significantly higher than that of patients with Mycobacterial abscess ( χ2＝30.366, P ＜0.01 ).In imaging, the proportion of bronchiectasis in Mycobacterium intracellularis lung disease group was significantly higher than that in Mycobacterial abscesses lung disease group (χ2＝23.888, P＜0.01).There was no significant difference in the 28-day mortality rate between the two groups (χ2＝3.244, P＞0.05), while the survival rate in patients with Mycobacterium intracellularis lung disease within 120 days was significantly higher than that in patients with Mycobacterial abscesses lung disease (χ2＝12.780, P＜0.01).Conclusion When critically ill patients are positive for acid-fast staining, the ICU physician should consider the possibility of NTM lung disease.For severe patients with long-term mechanical ventilation , Mycobacterium abscessus infection should be considered first.