Laboratory tests and analysis of drug resistance in non-tuberculous mycobacteria.

BACKGROUND

This study analyzed the laboratory diagnosis results and drug resistance of patients infected with (NTM).

METHODS

We collected information on patients with positive indicators of NTM infection at the Henan Provincial Chest Hospital from 2020 to 2022. Acid-fast smear, mycobacterium culture, QB-SPOT assay, GeneXpert MTB/RIF assay, immunoglobulin E test, tuberculosis antibody test, and microplate method for drug sensitivity test were analyzed using strain identification as the gold standard.

RESULTS

The 242 cases of NTM infection were predominantly detected with slow-growing (a detection rate of 87.19%), among which (66.53%), (15.70%), and complex (11.16%) ranked the top three in terms of the isolation rate. Males patients accounted for a higher proportion (58.26%) than females (41.74%), and the majority of them were over 60 years (50.83%). Among laboratory tests for patients with NTM infection, mycobacterium culture showed a highest detected rate (87.20%) among laboratory tests. The results of the drug sensitivity test demonstrated that the resistance rate of NTM was generally high. Moreover, the complex with the highest isolation rate showed 100% resistant to doxycycline and minocycline, but exhibited relatively high sensitivity to moxifloxacin (a resistance rate of 7.89%) and rifabutin (a resistance rate of 13.16%). The complex was 100% resistant to doxycycline and relatively sensitive to cefoxitin (29.17%) and clarithromycin (37.50%).

CONCLUSION

The NTM species isolated by the Henan Provincial Chest Hospital is dominated by and the highest positive rate is detected by mycobacterium culture among laboratory tests. NTM infection generally exhibits a high rate of drug resistance. Accordingly, the accurate diagnosis of NTM diseases requires enhanced drug sensitivity testing to provide patients with targeted combination drug treatment.