Nontuberculous Mycobacteria In Patients Research Articles

Employing Multicolor Melting Curve Analysis to Rapidly Identify Non-Tuberculous Mycobacteria in Patients with Bronchiectasis: A Study from a Pulmonary Hospital in the Fuzhou District of China, 2018-2022.

Non-tuberculous mycobacteria (NTM) infection is common in bronchiectasis, with rising incidence globally. However, investigation into NTM in bronchiectasis patients in China remains relatively limited. This work aimed to identify and understand the features of NTM in bronchiectasis patient in Fuzhou district of China. The pulmonary samples were collected from 281 bronchiectasis patients with suspected NTM infection in Fuzhou, 2018-2022. MPB64 antigen detection was employed for the preliminary evaluation of NTM. Further NTM identification was realized using gene chip and gene sequencing. Among 281 patients, 172 (61.21%) patients were NTM-positive (58.72%) according to MPB64 antigen detection, with females (58.72%) outnumbering males (41.28%) and the highest prevalence in the age group of 46-65 years. In total, 47 NTM single infections and 3 mixed infections (1 Mycobacterium tuberculosis complex-M. intracellulare, 1 M. avium-M. intracellulare, and 1 M. abscessus-M. intracellulare) were identified through multicolor melting curve analysis (MMCA), which was compared with gene sequencing results. Both methods suggested Mycobacterium (M.) intracellulare, M. abscessus, and M. avium as the primary NTM species affecting bronchiectasis patients. M. intracellulare and M. abscessus were more frequent in females than males with the highest prevalence in the age group of 46-65 years according to MMCA. This research provides novel insights into the epidemiological and clinical features of NTM in bronchiectasis patients in Southeastern China. Significantly, M. intracellulare, M. abscessus, and M. avium were identified as the major NTM species, contributing to a better understanding and management of bronchiectasis accompanied by NTM infection.

Molecular Identification of Non-tuberculous Mycobacteria in Suspected Tuberculosis Cases in Central India.

Introduction Mycobacterium tuberculosis complex (MTBC), the primary cause of tuberculosis (TB), must be accurately identified to implement effective patient management and control strategies. Non-tuberculous mycobacteria (NTM) in suspected TB cases can result in erroneous diagnoses and needless treatment. Objective The study aimed to identify NTM in patients suspected of TB at a tertiary care hospital in central India using molecular methods. Methods This prospective study enrolled 400 suspected pulmonary and extra-pulmonary TB patients. Patients between the age of two to 90 years, of either gender, new and previously treated cases, Culture positive, patients with immune-compromised status, patients not responding to ATT, HIV positive and negative, and willing to give consent were included in the study. Liquid culture via the Mycobacterial growth indicator tube (MGIT) system was used to culture mycobacteria from clinical samples. The SD Bioline Ag MPT64 Test (Standard Diagnostics, South Korea) and in-house multiplex-PCR (mPCR) were used to differentiate between Mycobacterium tuberculosis complex and NTM species for the molecular identification of NTM GenoType® Mycobacterium Common Mycobacteria (CM) assay kit (HAIN Life Science, Nehren, Germany) was used following the manufacturer's protocol. Results Only 59/400 (14.7%) of the samples produced a positive result in MGIT culture, indicating the presence of mycobacteria, and 85.25% of the remaining 341 samples were negative for mycobacterial growth. Further investigation of these 59 cultures with mPCR and SD Bioline Ag MPT64 test showed that 12 (20.33%) cultures were determined to be NTM, while the remaining 47 (79.67%) were identified as MTBC. Genotype characterization with GenoType® mycobacterium CM assay kit revealed that five of the 12 NTM isolates (41.67%) showed patterns that were consistent with Mycobacterium (M.) fortuitum, three (25%) showed patterns that were consistent with M. abscessus, and four (33.33%) showed patterns that were consistent with M. tuberculosis. Conclusion These resultsemphasizethe value of molecular methods for precisely identifying mycobacterial species, particularly in suspected TB cases. The high prevalence of NTM in positive cultures emphasizes the significance of differentiating between MTBC and NTM to prevent misdiagnosis and ensure proper care. Understanding the epidemiology and clinical significance of these organisms in central India is made possible by the identification of particular NTM species.

Nontuberculous mycobacteria in patients of a specialty hospital.

The incidence and clinical characteristics of NTM diseases in Brazil remain relatively unknown. The present study describes the diagnosis of NTM isolates, the clinical presentation and treatment outcomes. We analyzed NTM isolates in patients of a tertiary hospital in the Southeast region of Brazil, from January 2008 to July 2019. The ATS/IDSA criteria for diagnosis and treatment of these patients was applied. Mycobacterium kansasii were identified in 13/113 (11.5%) patients. In 59/113 (52.2%) patients who met the ATS criteria for disease, 29/59 (49.1%) received treatment, and 22/29 (75.8%) were cured. The major species identified was M. kansasii. The most frequent symptoms among the treated patients were dyspnea and cough, and the proportion of cured patients was high.

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

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. 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. 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%. 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 patient population in Hainan.

TNF inhibitors increase the risk of nontuberculous mycobacteria in patients with seropositive rheumatoid arthritis in a mycobacterium tuberculosis endemic area

The aim of this study is to examine the impact of tumor necrosis factor inhibitors (TNFI) on nontuberculous mycobacterium (NTM) infection in rheumatoid arthritis (RA) patients in a mycobacterium tuberculosis (MTB) endemic area. We selected 1089 TNFI-treated RA patients and 4356 untreated RA patients using propensity-matching analysis according to age, gender, and Charlson comorbidity index using the Korean National Health Insurance Service database from July 2009 to December 2010. Both groups were followed-up until the end of 2016 to measure the incidence of mycobacterial diseases. The incidence rate of NTM in TNFI-treated RA group was similar to those of MTB (328.1 and 340.9 per 100,000 person-years, respectively). The adjusted hazard ratio (aHR) of NTM for TNFI-treated RA compared to untreated RA was 1.751(95% CI 1.105–2.774). The risk of TNFI-associated NTM in RA was 2.108-fold higher among women than men. The age-stratified effects of TNFI on NTM development were significantly high in RA patients aged 50–65 years (aHR 2.018). RA patients without comorbidities had a higher incidence of NTM following TNFI treatment (aHR 1.742). This real-world, observational study highlights the need to increase awareness of NTM in TNFI-treated RA patients in an MTB endemic area.

Distribution of nontuberculous mycobacteria in patients with and without HIV/AIDS in Chongqing.

In this study, the distribution of nontuberculous mycobacteria (NTM) strains in patients with and without HIV/AIDS in Chongqing, China was evaluated. A retrospective study was performed in January-December 2020 at Chongqing Public Health Medical Center. NTM strains were assessed by a multi locus phylogenetic analysis. The distribution of NTM strains in HIV/AIDS and non-HIV/AIDS groups was compared. CD4+ cell counts, imaging changes, and characteristics of mycobacterial species were determined. In total, 324 patients with NTM infection (50 patients with HIV/AIDS and 274 patients without HIV/AIDS) were included. The most common etiological agent was M.abscessus (29%), followed by M.paraintracellulare (12%) andM.colombiense (11%). Predominant NTM species were M.avium (26%), M.colombiense (24%), and M.kansasii (18%) in patients with HIV/AIDS and wereM.abscessus (32%), M.paraintracellulare (13%), M.fortuitum (10%), and M. intracellulare (10%) in patients without HIV/AIDS. For a CD4+ cell count of <200/μl, the predominant species were M.aviumin the HIV/AIDS group and M.abscessus in the non-HIV/AIDS group. With respect to radiologic characteristics, different NTM strains were associated with distinct imaging manifestations; for example, M.marseillense, M.kansasii, and M.parasenchytosis were more likely to induce cavities. Imaging cavities, bronchiectasis, and acinar-like changes were more common in the non-HIV/AIDS groups. The infection rates of HIV and NTM in Chongqing are high, while M.abscessus, M.paraintracellulare, and M.colombiense are the main pathogens causing NTM diseases in Chongqing, and NTM strains differed significantly between patients with and without HIV/AIDS. Monitoring these indicators can help develop prevention strategies.

The Potential of Digital Polymerase Chain Reaction for Improving Diagnostic Yield of Nontuberculous Mycobacteria Pulmonary Disease.

IntroductionMany patients with nontuberculous mycobacteria pulmonary disease are asymptomatic. The disease diagnosis is confirmed in only a small proportion of patients with radiological findings suspicious for nontuberculous mycobacteria pulmonary disease. Thus, many patients remained undiagnosed. Here, we evaluated the diagnostic value of digital polymerase chain reaction (PCR) in nontuberculous mycobacteria pulmonary disease.MethodsWe prospectively evaluated 123 patients with radiological findings suspicious for nontuberculous mycobacteria pulmonary disease. Digital PCR was performed using bronchial lavage fluid, sputum, saliva, blood, and urine.ResultsThe culture of bronchial washing fluid was positive for nontuberculous mycobacteria in 53 patients and negative in 70. The positive detection rate of nontuberculous mycobacteria by digital PCR in patients with positive culture (n = 53) was as follows: bronchial lavage fluid 100%, sputum 62.9%, saliva 41.5%, blood 7.5%, and urine 3.8%. All patients with two or more positive partitions for nontuberculous mycobacteria in the digital PCR of bronchial lavage fluid showed nontuberculous mycobacteria growth in the bronchial lavage fluid culture. The digital PCR analysis of the bronchial lavage fluid showed a high sensitivity (100%), specificity (85.7%), positive predictive value (84.1%), negative predictive value (100%), and a high concordance rate (91.9%) with the bronchial lavage fluid culture results. In addition, the culture of bronchial lavage fluid was positive for nontuberculous mycobacteria in patients with two or more positive partitions in the digital PCR of sputum and saliva with a combined positive predictive value of 81.1%.ConclusionDigital PCR analysis of nontuberculous mycobacteria in bronchial lavage fluid shows a high concordance rate with the bronchial lavage fluid culture results and a high positive predictive value using both sputum and saliva, suggesting the potential usefulness of dPCR for diagnosis of nontuberculous mycobacteria pulmonary disease in clinical practice.

Prevalence and Clinical Characteristics of Nontuberculous Mycobacteria in Patients with Bronchiectasis: A Systematic Review and Meta-Analysis

Background: Although international bronchiectasis guidelines recommended screening of nontuberculous mycobacteria (NTM) both at initial evaluation and prior to administration of macrolide treatment, data regarding NTM in bronchiectasis remain elusive. Objective: To establish the prevalence, species, and clinical features of NTM in adults with bronchiectasis. Methods: We searched PubMed, Embase, and Web of Science for studies published before April 2020 reporting the prevalence of NTM in adults with bronchiectasis. We only included studies with bronchiectasis confirmed by computed tomography and NTM identified by mycobacteria culture or molecular methods. Random-effects meta-analysis was employed. Results: Of the 2,229 citations identified, 21 studies, including 12,454 bronchiectasis patients were included in the final meta-analysis. The overall pooled prevalence of NTM isolation and pulmonary NTM disease were 7.7% (5.0%–11.7%) (n/N = 2,677/12,454) and 4.1% (1.4%–11.4%) (n/N = 30/559), respectively, with significant heterogeneity (I2 = 97.7%, p < 0.001 and I2 = 79.9%, p = 0.007; respectively). The prevalence of NTM isolation varied significantly among different geographical regions with the highest isolation at 50.0% (47.3%–52.7%) reported in the United States. Mycobacterium avium complex and Mycobacterium abscessus complex accounted for 66 and 16.6% of all species, respectively. Some clinical and radiological differences were noted between patients with and without the presence of NTM isolation although the results are inconsistent. Conclusions: Heterogeneity in prevalence estimates of NTM isolation indicated that both local surveys to inform development of clinical services tailored to patients with bronchiectasis and population-based studies are needed. The clinical features associated with NTM in bronchiectasis and their incremental utility in studying the association is unknown and merits further investigation.

Nontuberculous mycobacteria in patients registered in a tuberculosis control program in Southwestern Colombia, 2014-2017

Introduction: Pulmonary disease produced by nontuberculous mycobacteria and pulmonary tuberculosis can share clinical signs and symptoms. It is important to discern one from the other in order to provide the proper treatment and programmatic management.&#x0D; Objective: To describe the frequency of nontuberculous mycobacteria isolated from patients registered in the tuberculosis control program in Cali.&#x0D; Methods: We conducted a descriptive study to know what extent of the pulmonary tuberculosis load in Cali-Colombia corresponds to nontuberculous mycobacteria, in a four-year period, 2014-2017. Demographic (sex, age, health insurance), clinical (diagnosis dates, laboratory data, comorbidities) and programmatic data (tuberculosis treatment initiation and duration) was collected for statistical analysis.&#x0D; Results: Of 3,651 patients registered in the local tuberculosis program with an initial diagnosis of pulmonary tuberculosis, 2,904 had sputum culture and among them 1.5% (43/2904) had nontuberculous mycobacteria isolation rather than Mycobacterium tuberculosis. Most of the nontuberculous mycobacteria isolates were not identified at the species level; M. fortuitum and M. abscessus were the most common species identified. 86% of patients initiated unnecessary tuberculosis treatment. &#x0D; Conclusion: Nontuberculous mycobacteria isolation from pulmonary samples could be frequent in patients registered in the tuberculosis program in Cali, Colombia. The lack of clinical suspicion, the limited laboratory infrastructure, and the absence of a reporting system could be contributing factors to underestimate the importance of nontuberculous mycobacteria in this setting. We recommend that nontuberculous mycobacteria identification should be considered for public health intervention.

Identification of Nontuberculous Mycobacteria in Patients with Pulmonary Diseases in Gyeongnam, Korea, Using Multiplex PCR and Multigene Sequence-Based Analysis.

Background Nontuberculous mycobacteria (NTM) are widely present in environments, such as soil and water, and have recently been recognized as important pathogenic bacteria. The incidence of NTM-related infections is steadily increasing. As the diagnosis and treatment of NTM infection should be distinguished from tuberculosis, and the treatment should be specific to the species of NTM acquired, accurate species identification is required. Methods In this study, two-step multiplex PCR (mPCR) and multigene sequence-based analysis were used to accurately identify NTM species in 320 clinical isolates from Gyeongsang National University Hospital (GNUH). In particular, major mycobacterial strains with a high isolation frequency as well as coinfections with multiple species were diagnosed through two-step mPCR. Multigene sequencing was performed to accurately identify other NTM species not detected by mPCR. Variable regions of the genes 16S rRNA, rpoB, hsp65, and 16S-23S rRNA internal transcribed spacer were included in the analysis. Results Two-step mPCR identified 234 (73.1%) cases of M. intracellulare, 26 (8.1%) cases of M. avium subsp. avium, and 13 (4.1%) cases of M. avium subsp. hominissuis infection. Additionally, 9 (2.8%) M. fortuitum, 9 (2.8%) M. massiliense, 2 (0.6%) M. abscessus, and 4 (1.2%) M. kansasii isolates were identified. Coinfection was identified in 7 (2.2%) samples. The sixteen samples not classified by two-step mPCR included 6 (1.9%) cases of M. chimaera, 4 (1.3%) M. gordonae, 1 (0.3%) M. colombiense, 1 (0.3%) M. mageritense, and 1 (0.3%) M. persicum identified by sequence analysis. Conclusions The results of this study suggest a strategy for rapid detection and accurate identification of species using two-step mPCR and multigene sequence-based analysis. To the best of our knowledge, this study is the first to report the identification of NTM species isolated from patients in Gyeongnam/Korea.

The Association of Long-term Macrolide Therapy and Nontuberculous Mycobacterial Culture Positivity in Patients With Bronchiectasis

The Association of Long-term Macrolide Therapy and Nontuberculous Mycobacterial Culture Positivity in Patients With Bronchiectasis

Prevalence of Nontuberculous Mycobacteria in Patients Suspected of Tuberculosis and Drug Resistant Tuberculosis

Prevalence of Nontuberculous Mycobacteria in Patients Suspected of Tuberculosis and Drug Resistant Tuberculosis

Impact of Bronchiectasis on Incident Nontuberculous Mycobacterial Pulmonary Disease: A 10-Year National Cohort Study

Impact of Bronchiectasis on Incident Nontuberculous Mycobacterial Pulmonary Disease: A 10-Year National Cohort Study

Profile of Nontuberculous Mycobacteria in Patients Suspected of Tuberculosis and Drug-Resistant Tuberculosis.

Objective Infections due to nontuberculous mycobacteria (NTM) is increasing globally and may present as drug-resistant tuberculosis (DRTB). In India, data on NTM prevalence and species diversity is limited. Present study was conducted to detect the prevalence and profile of NTM among patients suspected of DRTB using paraffin slide culture (PSC)and mycobacteria growth indicator tube (MGIT) culture methods for isolation of NTM. Material and Method A total of 2,938 samples suspected of TB/DRTB were cultured on PSC and MGIT960. Species identification of mycobacterial isolate was done by sequencing of 16s ribosomal RNA gene. Result Among 2938 samples, 35 (1.19%) were found positive for NTM by PSC and 9 (0.30%) were found positive by MGIT. The diversity of NTM species was high (13 species). Out of 35 NTM isolates by PSC, maximum 34.29% (12) isolates were found to be Mycobacterium fortuitum , followed by 11.43% (4) Mycobacterium abscessus and Mycobacterium chelonae , and 42.85% (15) were other species viz. 8.57% (3) were Mycobacterium intracellulare and Mycobacterium kansasii , 5.71% (2) were Mycobacterium peregrinum , and 2.85% (1) were Mycobacterium flavescens, Mycobacterium farcinogenes, Mycobacterium moriokanese, Mycobacterium wolinskyi, Mycobacterium simiae, Mycobacterium goodii , and Mycobacterium terrae each. Coinfection of Mycobacterium tuberculosis (MTB) and NTM was found in 60% (21) samples. Conclusion Prevalence of NTM was low among multidrug resistant tuberculosis/TB suspected patients, similar to other studies done in India. PSC was found better than MGIT for the isolation of NTM, though poor separation of NTM and MTB on subculture may have led to false negativity in cases of coinfection. About 13 species were isolated; M. fortuitum was the most common of all. Since coinfection of NTM and TB can also occur, samples of patients suspected of NTM should be cultured on PSC even if positive for MTB.

Shifting Paradigms Regarding the Role of Nontuberculous Mycobacteria in Patients with Cystic Fibrosis Advanced Lung Disease

Nontuberculous mycobacteria (NTM) are challenging pathogens in cystic fibrosis (CF). The best approach is unknown, in particular, in patients in need of a lung transplant (LTX). NTM sputum-positive patients were identified from all CF patients treated at the University Hospital of Zurich Adult CF Center. Course of disease and resistance to macrolide therapy was recorded. Of 6 patients who received a LTX, NTM patients were compared with patients without NTM for survival and development of chronic lung allograft dysfunction (CLAD). Of 111 CF patients, 43 (38.7%) patients grew at least one NTM culture of which 28 (25.2%) reached the stringent criteria for NTM positivity defined by three NTM positive cultures. With 32 (74.4%) isolates, M. abcessus spp. (MABSC) were the most frequent and acquired at an earlier age as compared to other NTM species (20 y [17-8] vs. 27 y [24-33]). NTM patients tended to be male and homozygous for PheF508del mutation, in particular, patients with MABSC, and more likely to require a LTX than patients without NTM (14.3% vs. 2.4%, p = 0.035). Of 28 MABSC patients with susceptibility testing, only three out of 16 (18.8%.) patients receiving treatment achieved long-term culture negativity. Treated patients were more likely to develop clarithromycin resistance than patients without treatment (68.8% vs. 16.7%, p = 0.019) with no difference in developing advanced lung disease (ALD), receiving a LTPL or death. 2 of the 6 patients undergoing LTX suffered from infection with MABSC, both of them being NTM positive before LTX. No difference in long-term survival nor in developing CLAD was observed. Two patients developed pulmonary and one extra-pulmonary infection. NTM patients are at greater risk of ALD and requiring LTX, with MABSC infection acquired at an earlier age and being more common in patients with PheF508del homozygous genotype. It is unclear whether this reflects a more rapid underlying course of CF. In MABSC patients, response to chemotherapy was poor and development of resistance common. NTM infection after LTX did not result in increased mortality or development of CLAD and BOS, but was associated with infection. Our experience supports that NTM infection should not generally be regarded as an absolute contraindication for LTX, but NTM eradication prior to LTX should be attempted.

Nontuberculous mycobacteria in patients with suspected tuberculosis and the genetic diversity of Mycobacterium avium in the extreme south of Brazil.

ABSTRACTObjective:Nontuberculous mycobacteria (NTM) are a heterogeneous group of bacteria that are widely distributed in nature and associated with opportunistic infections in humans. The aims of this study were to identify NTM in patients with suspected tuberculosis who presented positive cultures and to evaluate the genetic diversity of strains identified as Mycobacterium avium. Methods:We studied pulmonary and extrapulmonary samples obtained from 1,248 patients. The samples that tested positive on culture and negative for the M. tuberculosis complex by molecular identification techniques were evaluated by detection of the hsp65 and rpoB genes and sequencing of conserved fragments of these genes. All strains identified as M. avium were genotyped using the eight-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat method. Results:We found that NTM accounted for 25 (7.5%) of the 332 mycobacteria isolated. Of those 25, 18 (72%) were M. avium, 5 (20%) were M. abscessus, 1 (4%) was M. gastri, and 1 (4%) was M. kansasii. The 18 M. avium strains showed high diversity, only two strains being genetically related. Conclusions:These results highlight the need to consider the investigation of NTM in patients with suspected active tuberculosis who present with positive cultures, as well as to evaluate the genetic diversity of M. avium strains.

An evaluation of methods for the isolation of nontuberculous mycobacteria from patients with cystic fibrosis, bronchiectasis and patients assessed for lung transplantation

BackgroundRGM medium is an agar-based, selective culture medium designed for the isolation of nontuberculous mycobacteria (NTM) from the sputum of patients with cystic fibrosis (CF). We evaluated RGM medium for the detection of NTM in patients with CF (405 samples), bronchiectasis (323 samples) and other lung diseases necessitating lung transplantation (274 samples).MethodsIn total, 1002 respiratory samples from 676 patients were included in the study. Direct culture on RGM medium, with incubation at two temperatures (30 °C and 37 °C), was compared with conventional culture of decontaminated samples for acid-fast bacilli (AFB) using both a solid medium (Löwenstein-Jensen medium) and a liquid medium (the Mycobacterial Growth Indicator Tube; MGIT).ResultsFor all three patient groups, significantly more isolates of NTM were recovered using RGM medium incubated at 30 °C than by any other method (sensitivity: 94.6% vs. 22.4% for conventional AFB culture; P < 0.0001). Significantly more isolates of Mycobacterium abscessus complex were isolated on RGM at 30 °C than by AFB culture (sensitivity: 96.1% vs. 58.8%; P < 0.0001). The recovery of Mycobacterium avium complex was also greater using RGM medium at 30 °C compared to AFB culture (sensitivity: 83% vs. 70.2%), although this difference was not statistically significant and a combination of methods was necessary for optimal recovery (P = 0.21).ConclusionsIn the largest study of RGM medium to date, we reaffirm its utility for isolation of NTM from patients with CF. Furthermore; we show that it also provides an effective tool for culture of respiratory samples from patients with bronchiectasis and other lung diseases.

SPECIES DIVERSITY OF NON-TUBERCULOUS MYCOBACTERIA IN PATIENTS WITH MYCOBACTERIOSIS IN THE NORTH-WESTERN FEDERAL DISTRICT OF RUSSIA

The objective of the study: to analyze the structure and trends in non-tuberculous mycobacteria (NTBM) population causing diseases in the North-Western Federal District of the Russian Federation. Subjects and methods. 745 clinical NTBM strains were identified. All clinical strains of NTBM were isolated by culture from clinical samples (sputum, bronchial washings, bronchoalveolar lavage fluid, pus, stool, urine, surgical and biopsy specimens, and venous blood in case of sepsis). In 23 cases, NTBM were detected post mortem. Mycobacteria were cultured on solid media or by the automated system of Bactec MGIT 960 BD USA. Species of re-cultured mycobacteria were identified using the test system of GenoType® Mycobacterium CM/AS (Hain Lifescience, Germany). Results. Analysis of the structure of the NTBM population isolated from patients with mycobacteriosis in the North-West of Russia, for the period of 2012-2018 showed overall dominance of M. avium (56.4%). However, certain NTBM species were found to be prevailing in some regions: M. lentiflavum and M. gordonae dominated in the Komi Republic and Arkhangelsk respectively. Unlike other regions of Russia, in the North-Western region, there was a consistently low level of detection of M. кansasii and M. xenopi. For the last 12 years in Saint Petersburg and Leningrad region, the variety NTBM in patients with different immune status has been growing but the portion of M. avium remains to be stably high exceeding 50%.

Profile of isolates of non-tuberculous mycobacteria in patients treated in the municipal health network of Juiz de Fora - Minas Gerais (2015-2018)

Profile of isolates of non-tuberculous mycobacteria in patients treated in the municipal health network of Juiz de Fora - Minas Gerais (2015-2018)

Laboratory Diagnosis of Non-Tuberculous Mycobacterium Infections in Bronchiectasis Patients: Issues and Controversies

Non-tuberculous mycobacteria (NTM) are environmental microbes that can cause pulmonary infection and are especially problematic in bronchiectasis patients with or without cystic fibrosis (CF). Microbiological identification of NTM in these patients is difficult given the high microbial burden in the lungs and the need to differentiate between colonization and transient and true infection. Determining if and when to initiate antimicrobial treatment against this multi-drug-resistant group of organisms is also challenging. To address the changing landscape of care for these patients, the U.S. Cystic Fibrosis Foundation and the European Cystic Fibrosis Society convened an expert committee in 2016 and drafted new guidelines for the management of NTM in CF patients. These recommendations update the 2007 American Thoracic Society and Infectious Disease Society of America guidelines on the diagnosis and treatment of NTM pulmonary infections. Here, we provide data to support the new recommendations and discuss the advancements and ongoing challenges associated with NTM infections.