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

Abstract

Background China has seen a drastic increase in the incidence of non-tuberculous mycobacteria (NTM) infection, which is a notable public health issue. Due to a lack of reliable epidemiological surveillance information, there is a need to gather accurate epidemiological and surveillance data, which can help clinicians effectively treat NTM patients. Moreover, drug susceptibility testing for NTM is not frequently performed in China. This retrospective study, therefore, determined the prevalence and resistance characteristics of NTM to provide a reference to control the NTM epidemic. Methods Sputum, alveolar lavage fluid, and other respiratory specimens were collected from 3025 patients with suspected pulmonary tuberculosis attending The Second Affiliated Hospital of Hainan Medical University from January 2014 to December 2021. Strain identification and species distribution of NTM were performed by DNA chip technology and gene sequencing, and the drug resistance of NTM isolates was evaluated by calculating the minimum inhibitory concentration through antimicrobial susceptibility testing for NTM. Results From 2014 to 2021, 373 strains of NTM were isolated and identified from respiratory specimens of 3025 suspected tuberculosis patients. Except in 2014, NTM-infected patients accounted for more than 10% of suspected tuberculosis patients in other years. The median age of patients with NTM infection was 62.0 years (53.0, 71.0), and the male-to-female ratio among these patients was 0.79:1. Among culture-positive strains, 12.3% (373/3040; 95% CI 11.1–13.4%) were identified as NTM comprising forty species of NTM. The forty species of NTM included 23 slow-growing mycobacteria (SGM) and 17 rapidly-growing mycobacteria (RGM). Among the NTM isolates, 58.7% (219/373; 95% CI 53.7–63.7%) were SGM and 41.3% (154/373; 95% CI 36.3–46.3%) were RGM. M.avium complex(MAC)(41.3%; 95% CI 36.3–46.3%) and M.abscessus complex (MABC)(33.2%; 95% CI 28.4–38.0%) were the most frequently detected species, followed by M.simiae Complex (11.8%; 95% CI 8.5–15.1%), M.fortuitum group (5.1%; 95% CI 2.9–7.3%), and others. Drug sensitivity test results showed that most of the NTM isolates were susceptible to amikacin and clarithromycin with a drug resistance rate of less than 10%. However, clarithromycin could induce drug resistance, followed by linezolid and moxifloxacin, and their drug resistance rate was less than 50%. Conclusion During 2014–2021, the number of NTM isolates detected in the respiratory specimens of the study patients in The Second Affiliated Hospital of Hainan Medical University increased year by year. M. intracellulare is the most common pathogenic NTM species, and there is a high incidence of NTM infection on Hainan Island. Our findings might be of great importance for diagnosing and treating this p...

Genotypic Characterization of Mycobacterium Tuberculosis Strains Resistant to Rifampicin, Isoniazid and Second-Line Antibiotics in Chad

“…online, using samples from 264 patients with tuberculosis from 2022 to 2023. Similar studies were reported in China in 2023 [21,22]. During this research, a total of 1050 sputum samples were meticulously collected and subjected to thorough examination using TB-LAMP, GeneXpert and Line Probe Assay diagnostic tests (Table 2).…”

Distribution, Prevalence, and Antibiotic Resistance of Non-Tuberculous Mycobacteria on Hainan Island

“…The present study identified five major groups of NTM, including MAC, MABC, M. simiae complex, M. fortuitum complex, and other NTMs. MAC, a common causative agent of human NTM diseases affecting various organs such as lungs, soft tissues, lymph nodes, and bone marrow, with MAC pulmonary disease being the most prevalent[18]∘, was also the primary NTM pathogen detected in our study from pulmonary disease cases in Hainan, with a total of 51 isolates (comprising M. intracellulare, M. paraintracellare, M. colombiense, M. timonense, M. avium). This aligns with previous reports by Zhong [12] and Wang [18] who identified 149 and 154 MAC isolates respectively, reinforcing the widespread distribution of MAC in Hainan.…”

“…Drug susceptibility testing of numerous NTM isolates indicates clarithromycin (CLR) and amikacin (AMK) as highly effective against MAC, serving as first-line agents [18]. MAC shows resistance to linezolid (LZD; 42.86%) and moxifloxacin (MFX; 25.32%), suggesting their use as second-line options.…”

Toward tuberculosis elimination by understanding epidemiologic characteristics and risk factors in Hainan Province, China

“…Fourthly, TB patients in Hainan Province were mainly found passively, with low positive detection rate and delay in seeking medical care. It is noticed that bacteriologically negative patients were more than positive patients, which still possess a certain degree of infectivity and may have a certain impact on TB prevalence in the community [ 32 ]. The median duration of patient delay in seeking medical attention for TB patients in Hainan Province was 30 (10, 61) days, higher than the national average [ 33 ].…”