The purpose of this study was to evaluate the application value of targeted next-generation sequencing(tNGS)for rapid detection of Mycobacterium tuberculosis.From September 2021 to October 2024,1 178 clinical samples from hospitalized pa-tients at the Non-tuberculous Mycobacteria Disease Diagnosis and Treatment Center of Guangzhou Chest Hospital were collected,in-cluding 272 sputum samples,871 broncho alveolar lavage fluid(BALF)samples,and 35 other samples.These samples were analyzed with tNGS and the liquid culture+DNA microarray chip method(referred to as the"culture identification method"),and the detection results between methods were compared.The numbers of Mycobacterium tuberculosis complex(MTBC)samples identified with tNGS and the culture identification method were 172 and 127,respectively,and the numbers of non-tuberculous mycobacteria(NTM)samples detected were 517 and 474,respectively.The detection rate of Mycobacterium was 56.88%with tNGS and was significantly lower(49.49%)with the culture identification method(χ2=13.27,P<0.05).For NTM identification,when sputum was used,the detection rate of tNGS was higher than that of the culture identification method(χ2=24.14,P<0.05).However,when BALF was used,no significant difference in detection rates was observed between tNGS and the culture identification method(χ2=3.97,P=0.06).When different sample types from the same patient were analyzed with tNGS for NTM,BALF was found to be a better choice than sputum(χ2=4.05,P<0.05).However,with the culture identification method,we observed no significant difference between sample types(χ2=2.72,P=0.10).Furthermore,both the MTBC and NTM sequences detected with tNGS were significantly higher in the culture-positive group than the culture-negative group.With increasing sequence numbers,the proportion of cases in the culture-positive group progressively rose,whereas an inverse trend was observed in the culture-negative group.With clinical diagno-sis as the reference standard,the sensitivity,specificity,and Kappa value of tNGS and the culture identification method in identifying mycobacterial diseases were 85.41%,91.32%,0.74 and 74.73%,93.15%,0.63,respectively.Compared with the culture identifica-tion method,tNGS for rapid detection of Mycobacterium exhibited excellent sensitivity,specificity and consistency,and its timeliness should help clinicians make precise individualized treatment plans earlier.

The purpose of this study was to evaluate the application value of targeted next-generation sequencing(tNGS)for rapid detection of Mycobacterium tuberculosis.From September 2021 to October 2024,1 178 clinical samples from hospitalized pa-tients at the Non-tuberculous Mycobacteria Disease Diagnosis and Treatment Center of Guangzhou Chest Hospital were collected,in-cluding 272 sputum samples,871 broncho alveolar lavage fluid(BALF)samples,and 35 other samples.These samples were analyzed with tNGS and the liquid culture+DNA microarray chip method(referred to as the"culture identification method"),and the detection results between methods were compared.The numbers of Mycobacterium tuberculosis complex(MTBC)samples identified with tNGS and the culture identification method were 172 and 127,respectively,and the numbers of non-tuberculous mycobacteria(NTM)samples detected were 517 and 474,respectively.The detection rate of Mycobacterium was 56.88%with tNGS and was significantly lower(49.49%)with the culture identification method(χ2=13.27,P<0.05).For NTM identification,when sputum was used,the detection rate of tNGS was higher than that of the culture identification method(χ2=24.14,P<0.05).However,when BALF was used,no significant difference in detection rates was observed between tNGS and the culture identification method(χ2=3.97,P=0.06).When different sample types from the same patient were analyzed with tNGS for NTM,BALF was found to be a better choice than sputum(χ2=4.05,P<0.05).However,with the culture identification method,we observed no significant difference between sample types(χ2=2.72,P=0.10).Furthermore,both the MTBC and NTM sequences detected with tNGS were significantly higher in the culture-positive group than the culture-negative group.With increasing sequence numbers,the proportion of cases in the culture-positive group progressively rose,whereas an inverse trend was observed in the culture-negative group.With clinical diagno-sis as the reference standard,the sensitivity,specificity,and Kappa value of tNGS and the culture identification method in identifying mycobacterial diseases were 85.41%,91.32%,0.74 and 74.73%,93.15%,0.63,respectively.Compared with the culture identifica-tion method,tNGS for rapid detection of Mycobacterium exhibited excellent sensitivity,specificity and consistency,and its timeliness should help clinicians make precise individualized treatment plans earlier.

We compared the MGIT 960 method,the reference,and the broth microdilution method for detecting the susceptibility of Mycobacterium tuberculosis isolates to protionamide (PTO).We performed drug susceptibility testing for 248 M.tuberculosis clinical isolates to PTO using MGIT 960 and broth microdilution method.In addition,a total of 117 isolates were randomly selected for further evaluation of the consistency of the minimal inhibitory concentrations determined by these two methods,and eleven concentrations of PTO had been involved accordingly (0.062 5,0.125,0.25,0.5,1,2,4,8,16,32,64 μg/mL).The MGIT method showed an average detection time of 10.1 days,while the detection period of broth microdilution method was 8 days,and the difference was statistically significant (P＜0.001).In addition,the rate of the sensitivity,specificity and concordance between these two methods was 96.5％ (55/57),93.2％ (178/191),and 94.0％ (233/248),respectively.The Kappa value was 0.84.Comparison of the MIC values detected by different methods revealed that the overall concordance rate was 81.2％ (95/117).For the isolates harboring low MIC values (MIC＜8.0 μg/mL),the concordance rate was 86.3％ (82/95),while that of the isolates with high MIC values was only 59.1％ (13/22).In conclusion,our data demonstrate that the broth microdilution method showed excellent concordance with MGIT method for detecting the resistance rate of M.tuberculosis isolates to PTO,indicating that the broth microdilution method with available performance,short turn-around time and convenient manual operation was suitable for rapid detection of M.tuberculosis to PTO.