Trends and Species Diversity of Non-tuberculous Mycobacteria Isolated From Respiratory Samples in Northern China, 2014–2021

Abstract

BackgroundPulmonary non-tuberculous mycobacteria (NTM) infection has become a public health concern in China and around the world. The objective of this study was to describe the longitudinal changes in the frequency and diversity of NTM in northern China.MethodsWe retrospectively analyzed data on mycobacterium species in Beijing Chest Hospital from January 2014 to December 2021. The isolates were identified to species level by targeted DNA sequencing.ResultsAfter excluding duplicates, 1,755 NTM strains were analyzed, which were from 27 provinces in China over 8 years. Among all mycobacteria, the proportion of NTM increased each year, from 4.24% in 2014 to 12.68% in 2021. Overall, 39 different NTM species were identified, including 23 slow growing mycobacteria (SGM) and 16 rapid growing mycobacteria (RGM). The most common species were M. intracellulare (51.62%), M. abscessus (22.22%), M. kansasii (8.32%), M. avium (7.75%) and M. fortuitum (2.05%). The number of NTM species identified also increased each year from 9 in 2014 to 26 in 2021. Most species showed stable isolation rates over the years; however, the proportion of M. avium increased from 3.85 to 10.42% during the study period. Besides, 81 non-mycobacteria strains, including Gordonia (21 isolates), Nocardia (19 isolates) and Tsukamurella (17 isolates), etc., were also discovered.ConclusionThe proportion of NTM and species diversity increased considerably in northern China from 2014 to 2021. M. intracellulare was the most common NTM isolated among respiratory specimens, followed by M. abscessus and M. kansasii. Rare NTM species and non-mycobacteria pathogens also need attention.

Prevalence of non-tuberculous mycobacteria among people presumed to have tuberculosis, positive for acid-fast bacilli in Mali

“…The MAC was the most common NTM detected. The predominance of MAC has been reported in pulmonary NTM infections in many countries around the world (26,27,40,41) 29,38,40,41. In Mali, between 2004 and 2013, M. avium was the most frequently identified species of the MAC complex (7,27,37).…”

Screening and Drug Resistance Analysis of Non-Tuberculous Mycobacteria in Patients with Suspected Pulmonary Tuberculosis on the Hainan Island, China

“…abscessus subspecies, which was consistent with earlier discoveries in the coastal regions of southern China, India, Japan, and other countries. 6 , 21–23 To the best of our knowledge, this is the first study on strain identification, drug sensitivity testing, and screening among patients with suspected TB due to NTM lung illness in the Hainan Province.…”

“…3–5 Thus far, more than 270 NTM species/subspecies have been identified, of which more than 60 are pathogenic. 6 The incidence of NTM infection has increased globally, with China alone seeing an increase from 4.9% in 1990 to 22.9% in 2010. 7 However, because most nations and territories do not have mandatory reporting of NTM infections, currently available epidemiological surveillance data are scarce and unreliable.…”

Comparative genome analysis reveals high-level drug resistance markers in a clinical isolate of Mycobacterium fortuitum subsp. fortuitum MF GZ001

“…The yearly incidence of lung infections caused by NTM has increased from 3.13 to 4.73 per 100000 people, whereas the prevalence of NTM rose dramatically from 4.24% in 2014 to 12.68% in 2021, indicating a significant increase in the NTM outbreak in China. ( Winthrop et al., 2020 ; Jia et al., 2021 ; Sun et al., 2022 ). The majority of NTM are rapidly growing species that have been associated with serious infectious diseases ( De Groote and Huitt, 2006 ).…”