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

Jiao Tan; Yachun Wang; Zheng Li; Shuang Xia; Zhen Guo; Wenbo Li; Yingying Yuan; Jingcai Gao; Wei Wang

doi:10.1016/j.heliyon.2024.e28665

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

Heliyon. 2024 Mar 27;10(7):e28665. doi: 10.1016/j.heliyon.2024.e28665. eCollection 2024 Apr 15.

Authors

Jiao Tan¹, Yachun Wang¹, Zheng Li¹, Shuang Xia¹, Zhen Guo¹, Wenbo Li¹, Yingying Yuan¹, Jingcai Gao¹, Wei Wang¹

Affiliation

¹ Medical Laboratory, Henan Provincial Chest Hospital, Zhengzhou University, Henan Province Clinical Medical Research Center for Infectious Diseases (Tuberculosis), Zhengzhou, 450000, Henan, China.

Abstract

Background: This study analyzed the laboratory diagnosis results and drug resistance of patients infected with non-tuberculous mycobacterium (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 mycobacteria (a detection rate of 87.19%), among which Mycobacterium intracellulare (66.53%), Mycobacterium avium (15.70%), and Mycobacterium chelonei/abscessus 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 Mycobacterium avium 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 Mycobacterium chelonei/abscessus 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 Mycobacterium intracellulare 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.

Keywords: Drug resistance analysis; Laboratory tests; Non-tuberculous mycobacterium; Specificity; Strain identification.