In recent year，the iatrogenic infections and outbreaks caused by Mycobacterium abscessus complex（MABC）have been increasingly reported. Studies indicate that MABC accounts for 65%-80% of rapidly growing non-tuberculosis Mycobacterium（NTM）-related pulmonary diseases. As a clinically significant NTM pathogen，MABC exhibits rapid proliferation and intrinsic resistance to multiple antimicrobial agents. Notably，the 16S rDNA sequences among MABC subspecies share 100% homology，posing challenges for subspecies-level differentiation. Rapid and precise identification of MABC at the species or subspecies level is therefore critical for effective clinical management and outbreak control. Conventional biochemical methods for NTM identification are time-consuming and prone to inaccuracies，whereas molecular biology techniques offer superior speed and specificity，and have been widely used clinically. This review highlights the clinical implications of molecular biological techniques in MABC identification and its pivotal role in guiding therapeutic strategies.

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.

In recent year，the iatrogenic infections and outbreaks caused by Mycobacterium abscessus complex（MABC）have been increasingly reported. Studies indicate that MABC accounts for 65%-80% of rapidly growing non-tuberculosis Mycobacterium（NTM）-related pulmonary diseases. As a clinically significant NTM pathogen，MABC exhibits rapid proliferation and intrinsic resistance to multiple antimicrobial agents. Notably，the 16S rDNA sequences among MABC subspecies share 100% homology，posing challenges for subspecies-level differentiation. Rapid and precise identification of MABC at the species or subspecies level is therefore critical for effective clinical management and outbreak control. Conventional biochemical methods for NTM identification are time-consuming and prone to inaccuracies，whereas molecular biology techniques offer superior speed and specificity，and have been widely used clinically. This review highlights the clinical implications of molecular biological techniques in MABC identification and its pivotal role in guiding therapeutic strategies.

Objective To investigate the clinical efficacy of bronchoscopic MMC topical spraying for the treatment of tuberculous cicatricial stenosis of the central airway. Methods 45 patients with t tuberculous cicatricial stenosis of the central airway were randomly divided into a control group (14 patients), treatment group 1 (group1, 15 patients), or treatment group 2 (group 2, 16 patients), who received bronchial balloon dilatation alone, bronchial balloon dilatation combined with topical MMC spraying for one time, and for twice, respectively . The clinical efficacy was observed by using the MRC score and measuring airway diameter at the time points before treatment, end of treatment, and 3, 6, and 12 months after treatment, respectively. Results For the MRC scores at different time points, the MRC scores in group 2 (0.06 ± 0.25) and group 1 (0.33 ± 0.617) were significantly lower than those in the control group at 3 months after treatment (P < 0.05 for all comparisons);there were nosignificant differences at the other time points among the three groups. For the airway mean diameters at the different time points, the airway mean diameter was higher in group 2 than in the control group at 3 and 6 months after treatment (P < 0.01), and in group 1 at 3, 6, and 12 months (P < 0.05). No statistical differences were found in the other time points among three groups (P > 0.05). Conclusions Bronchial balloon dilatation combined with topical MMC spraying has certain short-term and long-term efficacy for improving dyspnea and maintaining the airway diameter after dilatation.

Objective To explore the impact of peripheral blood CD4 + T cells on nutritional status of patients with non-tuberculosis mycobacteria (NTM) lung disease. Methods A retrospective analysis was performed including 78 patients with NTM lung disease from January 2008 to December 2012 in Guangzhou Chest Hospital, who were divided into cellular immunocompromised group with 43 cases and control group including 35 cases and then the impact of malnutrition on cellular immune function decline was explored. Results Peripheral blood CD4+T cells were positively correlated with CD3+T cells, CD8+T cells, CD4+/CD8+T cell ratio in all of the included patients(P<0.05), while there was no correlation among peripheral blood CD4+T cells, ALB and PA (P>0.05). Compared with those in control group, TLC count was obviously lower while there were more patients with bronchiectasis in cellular immunocompromised group, which indicated statistical significance (P < 0.05). Conclusions Most of NTM patients are associated with malnutrition and NTM patients of cellular immunocompromised are associated with bronchiectasis easily and obvious reducing of TLC, but CD4+T cells and serum proteins levels are not necessarily correlated. The severity of NTM is commonly caused by such factors as basic pathologic change, cellular immunization, nutrition and infection.

Objective To evaluate the biological effect of endothelin (ET) antagonist on cultured B16 murine melanoma cells. Methods B16 murine melanoma cells were cultured in the presence of various concentrations (31.25, 62.5, 125, 250, 500 μg/mL) of ET antagonist or licoflavone. Then, melanoma cells were harvested for the detection of tyrosinase activity and melanin content. The proliferation rate of melanoma cells was measured with MTT method. The effect of ET antagonist was compared with that of licoflavone. Results Licoflavone had a concentration-dependent inhibition on melanogenesis. The ET antagonist selectively suppressed the ET-induced stimulation of tyrosinase and cell differentiation of B16 cells, but had no direct inhibitory effect on melanogenesis in culture, and little influence on melanocyte viability. The addition of ET antagonist at 200 μg/mL could significantly inhibit ET (0.5 μg/mL)-induced melanogenesis in Bl6 cells. The cytotoxity of the antagonist was relatively lower than that of licoflavone. Conclusions The results suggest that the ET antagonist is a safe skin-whitening ingredient, and may have a wide application perspective in the prevention of endothelin-induced skin pigmentation after UVB irradiation.