Clinical Significance, Species Distribution, and Temporal Trends of Nontuberculous Mycobacteria, Denmark, 1991-2022.

Nontuberculous mycobacteria (NTM) are emerging as notable causative agents of opportunistic infections. To examine clinical significance, species distribution, and temporal trends of NTM in Denmark, we performed a nationwide register-based study of all unique persons with NTM isolated in the country during 1991-2022. We categorized patients as having definite disease, possible disease, or isolation by using a previously validated method. The incidence of pulmonary NTM increased throughout the study period, in contrast to earlier findings. Mycobacterium malmoense, M. kansasii, M. szulgai, and M. avium complex were the most clinically significant species based on microbiologic findings; M. avium dominated in incidence. This study shows the need for surveillance for an emerging infection that is not notifiable in most countries, provides evidence to support clinical decision-making, and highlights the importance of not considering NTM as a single entity.

Evaluation of the STANDARD M10 MDR-TB and MTB/NTM assays for the detection of Mycobacterium tuberculosis, rifampicin and isoniazid resistance, and nontuberculous mycobacteria in a low-incidence setting.

Rapid detection is crucial for tuberculosis (TB) control. GeneXpert (Cepheid) is a widely used PCR system, known for its simplicity, random access, and point-of-care compatibility. SD BIOSENSOR recently introduced a similar system, STANDARD M10, including a Mycobacterium tuberculosis (MTB) and rifampicin (RIF) and isoniazid resistance (herein, MDR-TB) assay and an MTB/nontuberculous mycobacteria (NTM) assay. We evaluated these assays for the potential to replace the established Xpert MTB/RIF Ultra assay in a low-TB incidence setting. We analyzed 160 clinical respiratory samples (45 MTB-positive and 35 NTM-positive) and further 24 drug-resistant MTB, 30 mycobacterial species (2 MTB, 28 NTM), and 37 non-mycobacterial isolates. Compared with culture, clinical sensitivities and specificities for MTB detection were 88.9% (95% confidence interval [CI] = 76.1-95.6%) and 97.4% (CI = 92.3-99.4%) with Xpert Ultra, 88.9% (95% CI = 76.1-95.6%) and 98.3% (CI = 93.5-99.9%) with M10 MDR-TB, and 84.4% (CI = 70.9-94.4%) and 98.3% (CI = 93.5-99.9%) with M10 MTB/NTM, respectively. For NTM detection, M10 MTB/NTM showed sensitivity and specificity of 65.7% (CI = 49.1-79.2%) and 96.8% (CI = 91.8-99.0%). Compared with phenotypic drug susceptibility testing (DST), sensitivity and specificity for detecting RIF resistance were 100% (CI = 77.3-100%) and 95.6% (CI = 84.4-99.6%) with Xpert Ultra, and 100% (CI = 74.9-100%) and 95.5% (CI = 84.0-99.6%) with M10 MDR-TB. M10 MDR-TB showed 92.3% sensitivity (CI = 74.7-99.0%) and 100% specificity (CI = 87.3-100%) for detecting isoniazid resistance. All discrepancies in DST by PCR were concordant with whole-genome sequencing. While M10 MDR-TB demonstrated great potential as an alternative to Xpert Ultra, M10 MTB/NTM had limitations in NTM screening. Additionally, the M10 sputum pretreatment did not inactivate MTB efficiently, which should be considered in process risk assessment. IMPORTANCE: The molecular diagnostic STANDARD M10 system is highly analogous to the widely established GeneXpert system, which significantly increases the relevance of this evaluation study in the field of rapid detection of M. tuberculosis. To our knowledge, this is the first clinical evaluation describing the performance of the STANDARD M10 MDR-TB and MTB/NTM assays, including an extensive analytical specificity panel (inclusivity and exclusivity) for the detection of M. tuberculosis, drug resistance, and nontuberculous mycobacteria.

Source-to-tap investigation of the occurrence of nontuberculous mycobacteria in a full-scale chloraminated drinking water system.

Nontuberculous mycobacteria (NTM) in drinking water are a significant public health concern. However, an incomplete understanding of the factors that influence the occurrence of NTM in drinking water limits our ability to characterize risk and prevent infection. This study sought to evaluate the influence of season and water treatment, distribution, and stagnation on NTM in drinking water. Samples were collected source-to-tap in a full-scale, chloraminated drinking water system approximately monthly from December 2019 to November 2020. NTM were characterized using culture-dependent (plate culture with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry [MALDI-TOF MS] isolate analysis) and culture-independent methods (quantitative PCR and genome-resolved metagenomics). Sampling locations included source waters, three locations within the treatment plant, and five buildings receiving water from the distribution system. Building plumbing samples consisted of first draw, 5-min flush, and full flush cold-water samples. As the study took place during the COVID-19 pandemic, the influence of reduced water usage in three of the five buildings was also investigated. The highest NTM densities source-to-tap were found in the summer first draw building water samples (107 gene copies/L), which also had the lowest monochloramine concentrations. Flushing was found to be effective for reducing NTM and restoring disinfectant residuals, though flush times necessary to improve water quality varied by building. Clinically relevant NTM species, including Mycobacterium avium, were recovered via plate culture, with increased occurrence observed in buildings with higher water age. Four of five NTM metagenome-assembled genomes were identified to the species level and matched identified isolates.IMPORTANCENTM infections are increasing in prevalence, difficult to treat, and associated with high morbidity and mortality rates. Our lack of understanding of the factors that influence NTM occurrence in drinking water limits our ability to prevent infections, accurately characterize risk, and focus remediation efforts. In this study, we comprehensively evaluated NTM in a full-scale drinking water system, showing that various steps in treatment and distribution influence NTM presence. Stagnant building water contained the highest NTM densities source-to-tap and was associated with low disinfectant residuals. We illustrated the differences in NTM detection and characterization obtained from culture-based and culture-independent methods, highlighting the complementarity between these approaches. We demonstrated that focusing NTM mitigation efforts in building plumbing systems, which have the highest NTM densities source-to-tap, has potential for immediate positive effects. We also identified steps during treatment that increase NTM levels, which provides beneficial information for utilities seeking to reduce NTM in finished water.

Application of a new designed high resolution melting analysis for mycobacterial species identification.

The Non-tuberculous mycobacterial (NTM) isolates should be distinguished from tuberculosis and identified at the species level for choosing an appropriate treatment plan. In this study, two molecular methods were used to differentiate NTM species, including a new designed High Resolution Melting (HRM) and Multilocus Sequence Analysis (MLSA). Seventy-five mycobacterial isolates were evaluated by sequencing four genes ( MLSA) and a HRM assay specifically targeting atpE was designed to rapidly and accurately identify and differentiate mycobacterium species. Out of 70 NTM isolates, 66 (94.3%), 65 (92.9%), 65 (92.9%) and 64 (91.4%) isolates were identified to the species level by PCR of atpE, tuf, rpoB and dnaK genes. We could identify 100% of the isolates to the species level (14 different species) by MLSA. By using HRM assay, all NTM isolates were identified and classified into eight groups, in addition, Mycobacterium tuberculosis and Nocardia were also detected simultaneously. The MLSA technique was able to differentiate all 14 species of NTM isolates. According to the results, the HRM assay is a rapid and beneficial method for identifying NTM, M. tuberculosis (MTB), and Nocardia isolates without sequencing.

Comparison of the sputum microbiome between patients with stable nontuberculous mycobacterial pulmonary disease and patients requiring treatment.

BACKGROUND: We evaluated whether the sputum bacterial microbiome differs between nontuberculous mycobacteria pulmonary disease (NTM-PD) patients with stable disease not requiring antibiotic treatment and those requiring antibiotics. METHODS: We collected sputum samples from 21 clinically stable NTM-PD patients (stable group) and 14 NTM-PD patients needing antibiotic treatment (treatment group). We also obtained 13 follow-up samples from the stable group. We analyzed the 48 samples using 16S rRNA gene sequencing (V3-V4 region) and compared the groups. RESULTS: In the linear discriminant analysis effect size (LEfSe) analysis, the species Porphyromonas pasteri, Haemophilus parahaemolyticus, Prevotella nanceiensis, and Gemella haemolysans were significantly more prevalent in the sputum of the stable group compared to the treatment group. No taxa showed significant differences in alpha-/beta-diversity or LEfSe between the 21 baseline and 13 follow-up sputum samples in the stable group. In the stable group, the genus Bergeyella and species Prevotella oris were less common in patients who achieved spontaneous culture conversion (n = 9) compared to those with persistent NTM positivity (n = 12) (effect size 3.04, p = 0.039 for Bergeyella; effect size 3.64, p = 0.033 for P. oris). In the treatment group, H. parainfluenzae was more common in patients with treatment success (n = 7) than in treatment-refractory patients (n = 7) (effect size 4.74, p = 0.013). CONCLUSIONS: Our study identified distinct bacterial taxa in the sputum of NTM-PD patients based on disease status. These results suggest the presence of a microbial environment that helps maintain disease stability.

Distribution of nontuberculous mycobacteria in dental unit waterlines: A potential health hazard in the dental office.

BACKGROUND: It is essential to control the microbiology of dental unit water lines (DUWs) to prevent the spread of nontuberculous mycobacteria (NTM) and associated oral diseases. Therefore, the objective of this study was to quantify the presence of NTM in the water of 112 DUWs from dental centers and 57 DUWs from individual dental offices in Tehran, Iran. METHODS: A total of 169 water samples were collected from DUWs. After filtration through a 0.45 µm membrane, the samples were decontaminated with 0.005 % cetylpyridinium chloride and then cultured on two Lowenstein-Jensen media, incubated at 25 °C and 37 °C for 8 weeks. Positive cultures for mycobacteria were analyzed using phenotypic tests, and the NTM species were identified through 16S rDNA, rpoB, and hsp65 genes analysis. Drug resistance was also assessed. RESULTS: Of the total isolates, 38 (34.5 %) were classified as slow-growing mycobacteria (SGM), while 72 (65.5 %) were categorized as rapid-growing mycobacteria (RGM). NTM isolates were identified using molecular tests, including M. chelonae, M. abscessus, M. lentiflavum, M. mucogenicum, M. fortuitum, M. kansasii, M. simiae, M. gordonae, M. conceptionense, M. phocaicum, M. porcinum, and M. aurum. The NTM counts ranged from 50 to >500 CFU/500 mL across these 188 samples, with a median of 350 CFU/500 mL. Additionally, we reported two cases of intraoral infection caused by M. abscessus and M. chelonae, where the source of infection was traced to NTM-contaminated DUWs. CONCLUSIONS: The study found that most DUWs contained water contaminated with NTM, posing a potential health risk to humans. This research underscores the necessity of stringent quality control and certification of DUW water, with particular emphasis on ensuring the absence of NTM.

Phenotypical characteristics of nontuberculous mycobacterial infection in patients with bronchiectasis.

BACKGROUND: The global mortality and morbidity rates of bronchiectasis patients due to nontuberculous mycobacteria (NTM) pulmonary infection are on a concerning upward trend. The aims of this study to identify the phenotype of NTM-positive individuals with bronchiectasis. METHODS: A retrospective single-center observational study was conducted in adult patients with bronchiectasis who underwent bronchoscopy in 2007-2020. Clinical, laboratory, pulmonary function, and radiological data were compared between patients with a positive or negative NTM culture. RESULTS: Compared to the NTM-negative group (n=677), the NTM-positive group (n=94) was characterized (P ≤0.05 for all) by older age, greater proportion of females, and higher rates of gastroesophageal reflux disease and muco-active medication use; lower body mass index, serum albumin level, and lymphocyte and eosinophil counts; lower values of forced expiratory volume in one second, forced vital capacity, and their ratio, and lower diffusing lung capacity for carbon monoxide; higher rates of bronchiectasis in both lungs and upper lobes and higher number of involved lobes; and more exacerbations in the year prior bronchoscopy. On multivariate analysis, older age (OR 1.05, 95% CI 1.02-1.07, P=0.001), lower body mass index (OR 1.16, 95% CI 1.16-1.07, P <0.001), and increased number of involved lobes (OR 1.26, 95% CI 1.01-1.44, P=0.04) were associated with NTM infection. CONCLUSIONS: Patients with bronchiectasis and NTM pulmonary infection are more likely to be older and female with more severe clinical, laboratory, pulmonary function, and radiological parameters than those without NTM infection. This phenotype can be used for screening patients with suspected NTM disease.

Retrospective and prospective evaluation of the FluoroType®-Mycobacteria VER 1.0 assay for the identification of mycobacteria from cultures in a French center.

PURPOSE: Rapid, reliable identification of mycobacteria from positive cultures is essential for patient management, particularly for the differential diagnosis of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) species. The aim of the present study was to evaluate a new "In-Vitro-Diagnostic"-certified PCR kit, FluoroType®-Mycobacteria VER 1.0 (Hain Lifescience GmbH) for NTM and MTBC identification from cultures. METHODS: Mycobacteria identification isolated from positive cultures during routine practice at the Lyon university hospital mycobacteria laboratory obtained by hsp65 amplification/sequencing were compared retrospectively and prospectively to those obtained by and the FluoroType®-Mycobacteria VER 1.0 kit. RESULTS: The overall agreement between hsp65 amplification/sequencing and the FluoroType®-Mycobacteria VER 1.0 kit was 88.4% (84/95); 91.2% (52/57) for the retrospective period and 84.2% (32/38) for the prospective period. There were 9 (9.5%) minor discrepancies (species in the FluoroType®-Mycobacteria VER 1.0 database and identified at genus level): 4 during the retrospective period, 5 during the prospective period; and 2 (2.1%) major discrepancies (species in the FluoroType®-Mycobacteria VER 1.0 database and identified incorrectly to species level): 1 during the retrospective period (M. kumamotonense identified as M. abscessus subsp massiliense by the kit) and 1 during the prospective period (M. chimaera identified as M. smegmatis by the kit). Including concordant results at genus level and minor discrepancies, 17.9% (17/95) of strains were identified as Mycobacterium sp. by the FluoroType®-Mycobacteria-VER 1.0 kit. CONCLUSION: The good performance of the FluoroType®-Mycobacteria-VER 1.0 kit with few major discrepancies could enable its use for first-line identification of positive mycobacteria cultures. However, an alternative identification method at least for reference laboratories is needed owing to the non-negligible proportion of NTM strains were identified at genus level.

Prevalence and risk factors of non-tuberculous mycobacterial pulmonary isolates and infection in interstitial lung disease associated with systemic autoimmune disease.

OBJECTIVES: Non-tuberculous mycobacterial (NTM) lung disease (NTM-LD) prevalence is increasing worldwide. In this study, we aimed to evaluate the clinical significance of NTM pulmonary isolates (NTM-PI) and NTM-LD in patients with systemic autoimmune disease (SAD) who had a concurrent interstitial lung disease (ILD) diagnosis. METHODS: We retrospectively identified patients with SAD who had a concurrent ILD diagnosis (SAD-ILD) and from whom clinically indicated sputum specimens were collected for NTM culture between 2003 and 2018 at a tertiary referral hospital. We analysed the prevalence and risk factors of NTM pulmonary isolates (NTM-PI; ≥1 positive culture) and NTM-LD (≥2 positive cultures). RESULTS: This study included 258 patients. Rheumatoid arthritis and Sjögren's syndrome were the most common SADs (32.2% and 26.7%, respectively). The NTM-negative subgroup had 204 patients (79.1%) and the NTM-PI subgroup had 54 patients (20.9%). In the NTM-PI subgroup, 33 patients had one NTM positive set of specimens (NTM 1+, 12.8% of the entire sample) and 21 had NTM-LD (8.1% of the entire sample). In a multivariable analysis, chronic kidney disease (CKD; adjusted odds ratio [aOR]: 3.10 [1.53, 6.29]) and chronic obstructive pulmonary disease (COPD; aOR: 2.59 [1.16, 5.78]) were significantly associated with NTM-PI. For NTM-LD, CKD (aOR: 2.79 [1.00, 7.76]) and COPD (aOR: 3.70 [1.23, 10.72]) remained significant risk factors. CONCLUSIONS: In patients with SAD-ILD, the NTM-PI and NTM-LD prevalence rates were 20.9% and 8.1%, respectively. COPD and CKD were independent risk factors of both NTM-PI and NTM-LD. Previous use of biological agents was associated with NTM-PI.

Usefulness of the mini nutritional assessment short-form for evaluating nutritional status in patients with nontuberculous mycobacterial pulmonary disease: a prospective cross-sectional study.

BACKGROUND: Although the Mini Nutritional Assessment (MNA) is recognized as a useful tool for evaluating nutritional status in patients with various diseases, its applicability in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) remains undetermined. METHODS: We designed a prospective cross-sectional study to investigate whether the MNA Short-Form (MNA-SF) score can serve as a screening tool to assess the nutritional status of patients with NTM-PD. The MNA-SF was conducted upon patient enrollment, and correlation analyses were performed to compare MNA-SF scores with other nutritional measurements and disease severity. Multivariable logistic regression analyses were conducted to evaluate the association between MNA-SF scores and NTM-PD severity. RESULTS: The 194 patients with NTM-PD included in the analysis had a median age of 65.0 (59.0-69.0) years; 59.3% (n = 115) had low MNA-SF scores (< 12). The low MNA-SF group exhibited a lower body mass index (19.7 vs. 22.4 kg/m2, p < 0.001) and fat-free mass index (14.7 vs. 15.6 kg/m2, p < 0.001) than the normal MNA-SF group, as well as higher incidences of sarcopenia (20.0% vs. 6.3%, p = 0.008) and adipopenia (35.7% vs. 5.1%, p < 0.001). However, no significant differences in calorie and protein intakes were observed between the two groups. Low MNA-SF scores were associated with radiographic severity (adjusted odds ratio 2.72, 95% confidence interval 1.38-5.36) but not with forced vital capacity. CONCLUSIONS: The MNA-SF can effectively assess the nutritional status of patients with NTM-PD and can serve as an important clinical indicator in NTM-PD where treatment timing is determined by clinical judgment.

Comparative analysis of non-tuberculous mycobacterial lung disease and lung colonization: a case-control study.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are common opportunistic pathogens, and the most common infection site is lung. NTM are found commonly in the environment. Many patients have NTM lung colonization (NTM-Col). NTM lung disease (NTM-LD) have no specific sympotms, though it is hard to differentiate NTM-LD and NTM-Col under this circumstance. The aim of this study is to explore the differences between NTM-LD and NTM-Col for future clinical diagnosis and treatment. METHODS: We retrospectively enrolled patients who had a history of NTM isolated from respiratory specimens in Peking Union Medical College Hospital (PUMCH) from January 1st, 2013 to December 31st, 2022. Patients were classified into NTM-LD group and NTM-Col group. Demographic characteristics, clinical manifestations, laboratory tests and imaging findings of the two groups were compared. Comparative analysis was also performed in peripheral blood lymphocyte subsets among three groups. RESULTS: A total of 127 NTM-LD patients and 37 NTM-Col patients were enrolled. Proportion of patients with bronchiectasis was higher in NTM-LD group than in NTM-Col group (P = 0.026). Predominant NTM isolates were Mycobacterium avium complex (MAC). NTM-LD group had a higher proportion of Mycobacterium intracellulare (P = 0.004). CD4+ T cells counts was lower in NTM-LD group (P = 0.041) than in NTM-Col group. Imaging finding of bronchiectasis (P = 0.006) was higher in NTM-LD group than in NTM-Col group. Imaging findings of bronchiectasis (OR = 6.282, P = 0.016), and CD4+ T cell count (OR = 0.997, P = 0.012) were independent associated factors for differential diagnosis between NTM-LD and NTM-Col. CONCLUSION: NTM isolates from both NTM-LD and NTM-Col patients were predominantly MAC, with a higher Mycobacterium intracellulare isolation rate in NTM-LD group. Imaging findings of bronchiectasis and lower peripheral blood CD4+ T cell count may be helpful to separate the diagnosis of NTM-LD from NTM-Col.

Prevalence of nontuberculous mycobacteria and the emergence of rare species in Henan Province, China.

Nontuberculous mycobacteria (NTM) is a large group of mycobacteria other than the Mycobacterium tuberculosis complex and Mycobacterium leprae. Epidemiological investigations have found that the incidence of NTM infections is increasing in China, and it is naturally resistant to many antibiotics. Therefore, studies of NTM species in clinical isolates are useful for understanding the epidemiology of NTM infections. The present study aimed to investigate the incidence of NTM infections and types of NTM species. Of the 420 samples collected, 285 were positive for M. tuberculosis, 62 samples were negative, and the remaining 73 samples contained NTM, including 35 (8.3%) only NTM and 38 (9%) mixed (M. tuberculosis and NTM). The most prevalent NTM species were Mycobacterium intracellulare (30.1%), followed by Mycobacterium abscessus (15%) and M. triviale (12%). M. gordonae infection was detected in 9.5% of total NTM-positive cases. Moreover, this study reports the presence of Mycobacterium nonchromogenicum infection and a high prevalence of M. triviale for the first time in Henan. M. intracellulare is the most prevalent, accompanied by some emerging NTM species, including M. nonchromogenicum and a high prevalence of M. triviale in Henan Province. Monitoring NTM transmission and epidemiology could enhance mycobacteriosis management in future.

Nontuberculous mycobacterial pulmonary disease (NTM PD) incidence trends in the United States, 2010-2019.

BACKGROUND: Nontuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that cause chronic lung disease. Rates of NTM pulmonary disease (NTM PD) have increased over the last several decades, yet national estimates in the United States (US) have not been assessed since 2015. METHODS: We used a nationally representative population of Medicare beneficiaries aged ≥ 65 years to assess rates of NTM PD in a high-risk population from 2010 to 2019. Poisson generalized linear models were used to assess the annual percent change in incidence in the overall population and among key demographic groups such as sex, geography, and race/ethnicity. We evaluated the relative prevalence of various comorbid conditions previously found to be associated with NTM PD. RESULTS: We identified 59,724 cases of incident NTM PD from 2010 to 2019 from an annual mean population of 29,687,097 beneficiaries, with an average annual incidence of 20.1 per 100,000 population. NTM PD incidence was overall highest in the South and among women, Asian individuals, and persons aged ≥ 80 years relative to other studied demographic groups. The annual percent change in NTM PD incidence was highest in the Northeast, at 6.5%, and Midwest, at 5.9%, and among women, at 6.5%. Several comorbid conditions were highly associated with concurrent NTM diagnosis, including allergic bronchopulmonary aspergillosis, bronchiectasis, and cystic fibrosis. CONCLUSIONS: Here we provide current estimates of NTM PD incidence and prevalence and describe increasing trends in the US from 2010 to 2019. Our study suggests a need for improved healthcare planning to handle an increased future caseload, as well as improved diagnostics and therapeutics to better detect and treat NTM PD in populations aged ≥ 65 years.

Impact of bacterial co-isolation on treatment initiation and long-term prognosis of patients with nontuberculous mycobacterial pulmonary disease: analysis of a prospective cohort study.

BACKGROUND: Nontuberculous mycobacterial pulmonary disease (NTM-PD), a chronic respiratory condition, presents a growing challenge globally. Uncertainties exist regarding the impact of concurrent bacterial co-isolation on treatment initiation and long-term prognosis. METHODS: This study analysed data from participants enrolled in an ongoing prospective observational cohort study on NTM-PD (NCT01616745) between 1 July 2011, and 31 December 2022, who provided sputum samples for bacterial culture at enrolment. Identification of potential pathogenic microorganisms (PPMs) was defined as a positive bacterial culture. Clinical characteristics were compared between NTM-PD patients with Pseudomonas, non-pseudomonal PPMs, and those without PPM co-isolation. Cox proportional hazard regression models were employed to assess the association of bacterial co-isolation with rates of NTM-PD treatment initiation and all-cause mortality. RESULTS: Overall, 453 patients (median age, 62 years; 30% male) were included in the analysis. PPMs were co-isolated in 77 patients (17%), including 13 with Pseudomonas species. Co-isolation of Pseudomonas was associated with a significantly higher erythrocyte sedimentation rate (P = 0.02) and St. George's Respiratory Questionnaire score (P = 0.01). Non-pseudomonal PPM co-isolation was significantly associated with a higher likelihood of NTM-PD treatment initiation (adjusted hazards ratio [aHR], 1.56, 95% confidence interval [CI], 1.03-2.36, P = 0.036), whereas co-isolation of Pseudomonas was independently correlated with increased all-cause mortality (aHR, 3.25, 95% CI, 1.08-9.84, P = 0.037). CONCLUSIONS: Our findings emphasize the importance of microbial surveillance, as bacterial co-isolation affects treatment initiation and prognosis in patients with NTM-PD.

Disseminated mycobacterium genavense infection with central nervous system involvement in an HIV patient: a case report and literature review.

BACKGROUND: Immunodeficient patients, particularly HIV patients, are at risk of opportunistic infections. Nontuberculous mycobacteria can cause severe complications in immunodeficient patients. CASE PRESENTATION: We describe a 57-year-old HIV patient, primarily presented with coughs and constitutional symptoms, with a unique Mycobacterium genavense abdominal, pulmonary, and central nervous system infection, accompanied by intracranial masses. CONCLUSION: The diagnosis of NTM, including M. genavense, must always be considered by clinicians in immunodeficient patients, especially those with HIV, who have a compromised immune system.

Facial cutaneous tuberculosis infected by non-tuberculous mycobacteria.

BACKGROUND: Cutaneous infections caused by non-tuberculous mycobacteria (NTM) are extremely rare, particularly when they are localized to the facial area. This condition presents significant diagnostic challenges due to its unusual presentation and the need for precise microbiological identification. CASE PRESENTATION: A two-year-old male patient presented with a progressively enlarging reddish-brown mass on the left side of his face. Despite the absence of systemic symptoms, the lesion's growth warranted investigation due to its growth. Ultrasonography showed a hypoechoic mass in the dermis, indicating an underlying abscess. The subsequent aspiration resulted in pale yellow pus, which upon testing and culture, confirmed the presence of Mycobacterium avium complex infection, a species of NTM. This case exemplifies the synergy between imaging modalities and microbiological analysis, highlighting the crucial role of both in achieving favorable clinical outcomes in patients with suspected cutaneous NTM infections. Ultrasound can expedite diagnosis, improve treatment planning, and enhance patient care by enabling targeted interventions and monitoring response to therapy in these scenarios. However, it is the combination of pathogen-specific diagnostics that ensures accurate etiological attribution and appropriate antimicrobial stewardship. CONCLUSION: Although rare, facial cutaneous infections caused by NTM still deserve thorough investigation to determine the exact cause. Ultrasound is used to identify cutaneous lesions, measure their extent, and guide surgical procedures. The ultimate diagnosis is based on microbiological confirmation.

Mycobacterium marseillense bloodstream infection combined with skin fungal infection: a case report and literature review.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are present widely in the natural environment and can invade the human body through the respiratory tract, gastrointestinal tract, and skin. Immunocompromised patients are particularly prone to infection, which primarily affects multiple organs, including the lungs, lymph nodes, and skin. However, cases of NTM bloodstream infections are rare. Here, we report a rare case of Mycobacterium marseillense bloodstream infection with concurrent skin fungal infection in a patient after kidney transplantation. Related literature was reviewed to enhance the understanding of this rare condition. CASE PRESENTATION: A 58-year-old male with a history of long-term steroid and immunosuppressant use after kidney transplantation presented with limb swelling that worsened over the past two months. Physical examination revealed redness and swelling of the skin in all four limbs, with a non-healing wound on the lower left limb. Skin tissue analysis by metagenomic next-generation sequencing (mNGS) and fungal culture indicated infection with Trichophyton rubrum. Blood culture results suggested infection with Mycobacterium marseillense. After receiving anti-NTM treatment, the patient's symptoms significantly improved, and he is currently undergoing treatment. CONCLUSION: Mycobacterium marseillense is a NTM. Gram staining suffered from misdetection, and the acid-fast staining result was positive. This bacterium was identified by mass spectrometry and mNGS analyses. Antimicrobial susceptibility tests for NTM were performed using the broth microdilution method. The results of the susceptibility test showed that Mycobacterium marseillense was sensitive to clarithromycin, an intermediary between moxifloxacin and linezolid. Bacterial clearance requires a combination of drugs and an adequate course of treatment. NTM bloodstream infections are relatively rare, and early identification and proactive intervention are key to their successful management.

Rapid lateral flow test for Mycobacterium tuberculosis complex and non-tuberculous mycobacteria differentiation.

The diagnosis of mycobacterial infections, including both the Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM), poses a significant global medical challenge. This study proposes a novel approach using immunochromatographic (IC) strip tests for the simultaneous detection of MTBC and NTM. Traditional methods for identifying mycobacteria, such as culture techniques, are hindered by delays in distinguishing between MTBC and NTM, which can affect patient care and disease control. Molecular methods, while sensitive, are resource-intensive and unable to differentiate between live and dead bacteria. In this research, we developed unique monoclonal antibodies (mAbs) against Ag85B, a mycobacterial secretory protein, and successfully implemented IC strip tests named 8B and 9B. These strips demonstrated high concordance rates with conventional methods for detecting MTBC, with positivity rates of 93.9% and 85.9%, respectively. For NTM detection, the IC strip tests achieved a 63.2% detection rate compared to culture methods, considering variations in growth rates among different NTM species. Furthermore, this study highlights a significant finding regarding the potential of MPT64 and Ag85B proteins as markers for MTBC detection. In conclusion, our breakthrough method enables rapid and accurate detection of both MTBC and NTM bacteria within the BACTEC MGIT system. This approach represents a valuable tool in clinical settings for distinguishing between MTBC and NTM infections, thereby enhancing the management and control of mycobacterial diseases. KEY POINTS: • Panel of mAbs for differentiating MTB versus NTM • IC strips for diagnosing MTBC and NTM after the BACTEC MGIT • Combined detection of MTP64 and Ag85B enhances diagnostic accuracy.

Challenges in diagnosing bovine tuberculosis through surveillance and characterization of Mycobacterium species in slaughtered cattle in Kolkata.

BACKGROUND: Tuberculosis in cattle is caused by Mycobacterium tuberculosis complex (MTBC) species. Apart from MTBC, different Nontuberculous Mycobacteria (NTM) species have also been isolated from cattle. The presence of NTM infection in bovines makes the diagnosis of bovine tuberculosis (bTB) a cumbersome task. Therefore, a cross sectional study was conducted to isolate and characterize different Mycobacterium spp. from a slaughterhouse situated in Kolkata, a city in the eastern part of India. RESULTS: Out of 258 morbid samples, 98 isolates were found to be positive for bacterial growth, and 35% (n = 34) were positive for Mycobacterium. 94% of Mycobacterial cultural isolates were NTM (n = 32), and the rest (n = 2) were found to be MTBC. Species-level identification of the isolates by hsp65 sequencing revealed that out of 32 isolates, 24 were M. fortuitum, three were M. abscessus, two each were M. chelonae and M. parascrofulaceum, and one was M. novocastrense. A phylogenetic tree with partial hsp65 gene sequences was also constructed to determine the relatedness of the unknown isolates to the reference strains. CONCLUSION: Both NTM species and MTBCs were identified from TB-like lesions in cattle that were slaughtered at the Kolkata abattoir. This discovery may indicate that NTM contributes to the development of lesions in cattle. Also, we recommend implication of more specific diagnostic tests for bTB.

Three Cases of Non-Tuberculosis Mycobacterium Skin Infection Outbreak in Beauty Institutions.

BACKGROUND: From June 2021 to July 2021, our hospital confirmed 3 cases of Mycobacterium infection in skin abscesses. All 3 patients underwent thread embedding and weight loss surgery at the same informal beauty institution, with a history of silk protein injection. None of the patients had any other underlying diseases or surgical history. Symptoms and signs show that the disease is acute and the course of the disease is short. All patients have found subcutaneous masses in different parts of the body. In most cases, the masses show redness and swelling, and some of the masses are accompanied by tenderness, wave sensation, and rupture. After some of the masses rupture, purulent secretions can be seen. METHODS: The pus secreted by the skin lesions of the three patients were cultured to a single bacterium, which was identified by MALDI-TOF MS. Multiple locus sequence typing (MLST) was performed using three specific genes (hsp65, rpoB, and secA1) and seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH). The results were queried through the MLST database of Mycobacterium abscess. RESULTS: All three strains of bacteria were Mycobacterium abscess type ST279 massiliense subtype. Three antibacterial drugs including cefmetazole, amikacin, and clarithromycin were administered in combination with 5-aminolevulinic acid photodynamic therapy (ALA-PDT). After 3 - 6 months, there was no obvious redness or swelling in the surrounding tissues of the wound, and no obvious purulent secretions were observed. All patients were cured and discharged from the hospital. After a follow-up of six months, there was no recurrence of the lesions. CONCLUSIONS: Medical institutions must strictly follow infection control guidelines and take preventive measures to prevent such incidents from happening again. ALA-PDT as a combination therapy for nontuberculous Mycobacterium (NTM) skin infections can improve treatment efficacy and shorten antibiotic usage time.