Nontuberculous Mycobacteria in China-incidence and Antimicrobial Resistance Spectrum From a Nationwide Survey

Abstract

Background: Information on prevalence and resistance spectrum of nontuberculous mycobacteria (NTM) in China is mainly based on regional or local data. A national survey of NTM pulmonary disease was carried out based on acid-fast positive sputum samples collected in 2013.Methods: Sputum samples collected from enrolled presumptive cases were cultured using L-J medium in 72 nationwide tuberculosis surveillance sites from the 31 Chinese mainland provinces and isolates were sent to national tuberculosis reference laboratory (NTRL). The species of re-cultured strains were identified by MALDI-TOF MS and minimal inhibitory concentrations (MICs) were determined to evaluate the drug susceptibility of NTM isolates.Results: Of 4917 mycobacterial isolates cultured, 317 (6.4%, 95% CI, 5.8% to 7.2%) were confirmed as NTM, among which 287 (7.7%, 95% CI, 6.9% to 8.6%) were from the southern region. In inland and coastal China, 87.7% (95% CI, 78.7% to 93.2%) and 50.0% (95% CI, 43.7% to 56.3%) of isolates, respectively, were slow growing mycobacteria (SGM), with the remaining rapid growing mycobacteria (RGM). A total of 29 species were detected, M. abscessus had higher clarithromycin-inducible resistance rates than M. massiliense (65.67% vs 2.22%). M. kansasii was present lower resistance rates in linezolid and moxifloxacin than Mycobacterium avium-intracellulare complex and other SGM.Conclusions: More NTM pulmonary disease was observed in southern and coastal China (p<0.01). SGM was widely distributed, and more RGM are present in southern and coastal China (p<0.01). The antimicrobial resistance spectrum of different NTM species was significant different, accurate species identification would be facilitated to NTM pulmonary disease treatment.

In vitro assessment of 17 antimicrobial agents against clinical Mycobacterium avium complex isolates

“…As second-line drugs for MAC disease, the clinical efficacy of moxifloxacin and linezolid remains uncertain [40]. In our study, both had limited activity against MAC isolates, which is comparable with previous studies in Korea [41], Sweden [39], and China [42]. However, unlike the poor activity in vitro, a recent study has shown that fluoroquinolone-containing regimens could achieve similar clinical improvement with the standard regimen and could be an alternative for patients who cannot tolerate the standard regimen [43].…”

Characteristic clinical features and plasma cytokine profiles in patients infected with nontuberculous mycobacteria and Talaromyces marneffei due to anti–interferon-gamma autoantibodies

“…The most prevalent NTM subspecies are MAC and MABc, both of which were the most common NTMs in patients with anti-IFN-γ Abs in previous studies [11,19], as well as the most common pathogenic NTMs in China [20][21]. Other opportunistic infections were rare in our study.…”