Epidemiological risk factors and the geographical distribution of eight Mycobacterium species.

BACKGROUND: Nontuberculous mycobacteria (NTM) are environmental bacterium that may cause and/or compound respiratory diseases in humans. There are over a hundred NTM species with varying pathogenicity's Therefore, it is necessary to characterize the populations at risk for each species. METHODS: Demographic (age, sex, and state of residence) and microbiological data from 2014 were extracted from Mississippi, Missouri, and Ohio disease surveillance systems. NTM species with > 50 reports were included in the analysis. Patient sex, age, and incidence rates were generated for each of the following NTM species: M. abscessus, M. avium complex (MAC), M. chelonae, M. fortuitum, M. gordonae, M. kansasii, M. mucogenicum, and M. peregrinum. RESULTS: Analysis by sex showed that M. chelonae,M. fortuitum, M. gordonae,and M. kansasii had significantly higher rates in males than females. Age was not associated with patient rates for several specific NTM species e.g., M. chelonae. Mississippi had the highest patient' rates for M. avium, M. gordonae, M. kansasii, and M. chelonae. Ohio had the highest patient' rates for M. abscessus, M. mucogenicum, and M. peregrinum. The highest patient's rate for M. fortuitum was observed in Missouri. CONCLUSION: This study showed that NTM infection occurred more frequently in males. The highest rates were observed in Mississippi for most of the NTMs studied. Age was not a strong risk factor for some of the NTM species.

Prospective evaluation of nontuberculous mycobacteria disease in cystic fibrosis: The design of the PREDICT study.

BACKGROUND: Nontuberculous mycobacteria (NTM) are an important cause of airway infections in people with cystic fibrosis (pwCF). Isolation of NTM from respiratory specimens of pwCF do not mandate treatment in the absence of clinical and radiologic features of NTM pulmonary disease (NTM-PD), as some pwCF clear the infection without treatment and others do not appear to progress to NTM-PD despite persistent infection. An evidence-based protocol to standardize diagnosis of NTM-PD is needed to systematically identify pwCF who may benefit from treatment. METHODS: In this multicenter observational study, eligible pwCF who are 6 years of age and older and who have had a recent positive NTM culture are systematically evaluated for NTM-PD. Participants are identified based on positive NTM culture results obtained during routine clinical care and following enrollment are evaluated for NTM-PD and CF-related comorbidities. Participants are followed in PREDICT until they meet NTM-PD diagnostic criteria and are ready to initiate NTM treatment, or until study termination. Active participants who have not met these criteria are re-consented every 5 years to enable long-term participation. RESULTS: The primary endpoint will summarize the proportion of participants who meet the NTM-PD diagnosis definition. The time from enrollment to NTM-PD diagnosis will be derived from Kaplan-Meier estimates. CONCLUSION: A prospective protocol to identify NTM-PD in pwCF will test if this standardized approach defines a cohort with signs and symptoms associated with NTM-PD, to assist with clinical decision making and to build a framework for future therapeutic trials. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02073409.

Immunological and microbial shifts in the aging rhesus macaque lung during nontuberculous mycobacterial infection.

Nontuberculous mycobacteria (NTM) are environmentally ubiquitous organisms that predominately cause NTM pulmonary disease (NTMPD) in individuals over the age of 65. The incidence of NTMPD has increased in the U.S., exceeding that of Mycobacterium tuberculosis. However, the mechanisms leading to higher susceptibility and severity of NTMPD with aging are poorly defined in part due to the lack of animal models that accurately recapitulate human disease. Here, we compared bacterial load, microbial communities, and host responses longitudinally between three young (two female and one male) and two aged (two female) rhesus macaques inoculated with Mycobacterium avium subsp. hominissuis (MAH) in the right caudal lobe. Unilateral infection resulted in a low bacterial load in both young and aged animals confined to the infected side. Although a robust inflammatory response was only observed in the inoculated lung, immune cell infiltration and antigen-specific T cells were detected in both lungs. Computed tomography, gross pathology, and histopathology revealed increased disease severity and persistence of bacterial DNA in aged animals. Additional analyses showed the translocation of gut and oral-pharyngeal bacterial DNA into the lower respiratory microbiome. Finally, single-cell RNA sequencing revealed a heightened inflammatory response to MAH infection by alveolar macrophages in aged animals. These data are consistent with the model that increased disease severity in the aged is mediated by a dysregulated macrophage response that may be sustained through persistent antigen presence. IMPORTANCE: Nontuberculous mycobacteria (NTM) are emerging as pathogens of high consequence, as cases of NTM pulmonary disease (NTMPD) have exceeded those of Mycobacterium tuberculosis. NTMPD can be debilitating, particularly in patients over 65 years of age, as it causes chronic cough and fatigue requiring prolonged treatments with antibiotics. The underlying mechanisms of this increased disease severity with age are poorly understood, hampering the development of therapeutics and vaccines. Here, we use a rhesus macaque model to investigate the impact of age on host-NTM interactions. This work shows that aging is associated with increased disease severity and bacterial persistence in aged rhesus macaques, thus providing a preclinical model to develop and test novel therapeutics and interventions.

Non-tuberculous mycobacteria disease pre-lung transplantation: A systematic review of the treatment regimens and duration pre- and post-transplant.

BACKGROUND: There is lack of consensus on non-tuberculous mycobacteria pulmonary disease (NTM-PD) treatment regimen and duration in patient listed for lung transplantation (LTx). We conducted a systematic review on treatment regimen and duration pre- and directly post-LTx, for patients with known NTM-PD pre-LTx. Additionally, we searched for risk factors for NTM disease development post-LTx and for mortality. METHODS: Literature was reviewed on PubMed, Embase and the Cochrane Library, for articles published from inception to January 2022. Individual patient data were sought. RESULTS: Sixteen studies were included reporting 92 patients. Most frequent used agents were aminoglycosides and macrolides for Mycobacterium abscessus (M. abscessus) and macrolides and tuberculostatic agents for Mycobacterium avium complex (M. avium complex). The median treatment duration pre-LTx was 10 months (IQR 6-17) and 2 months (IQR 2-8) directly post-LTx. Longer treatment duration pre-LTx was observed in children and in patients with M. abscessus. 46% of the patients with NTM-PD pre-LTx developed NTM disease post-LTx, related mortality rate was 10%. Longer treatment duration pre-LTx (p < 0.001) and sputum non-conversion pre-LTx (p = 0.003) were significantly associated with development of NTM-disease post-LTx. Longer treatment duration pre-LTx (p = 0.004), younger age (p < 0.001) and sputum non-conversion (p = 0.044) were risk factors for NTM related death. CONCLUSIONS: The median treatment duration pre-LTx was 10 months (IQR 6-17) and 2 months (IQR 2-8) directly post-LTx. Patients with longer treatment duration for NTM-PD pre-LTx and with sputum non-conversion are at risk for NTM disease post-LTx and for NTM-related death. Children were particularly at risk for NTM related death.

Comparative analysis of phenotypic and genotypic antibiotic susceptibility patterns in Mycobacterium avium complex.

OBJECTIVE: Phenotypic (Sensititre Myco, pDST) and genotypic drug susceptibility testing (GenoType NTM DR, gDST) in M. avium complex (MAC) have become available as standardized assays, but comparable data is needed. This study aimed to investigate the phenotypic and genotypic drug susceptibility patterns in MAC clinical isolates. METHODS: Overall, 98 isolates from 85 patients were included. pDST and gDST were performed on all isolates and results compared regarding specificity and sensitivity using pDST as a reference method. The impact of drug instability on pDST results was studied using a biological assay over 14 days. In addition, the evolution of antimicrobial resistance was investigated in sequential isolates of 13 patients. RESULTS: Macrolide resistance was rare, 1.2% (95% CI 0.7-7.3) of isolates in the base cohort. No aminoglycoside resistances were found, but 14.1% of the studied isolates (95% CI 7.8-23.8) showed intermediate susceptibility. The GenoType NTM DR identified two out of four macrolide-resistant isolates. Antibiotic stability was demonstrated to be poor in rifampicin, rifabutin, and doxycycylin. CONCLUSIONS: pDST results in NTM for unstable antibiotics must be interpreted with care. A combination of pDST and gDST will be useful for the guidance of antimicrobial therapy in MAC-disease.

Mycobacterium avium complex: Adherence as a way of life.

Mycobacterium avium complex (MAC) organisms are waterborne, opportunistic pathogens whose source is natural waters and soils and proliferates and persists in premise plumbing, for example household and hospital plumbing. M. avium complex and other environmental mycobacteria grow slowly, not because their metabolism is slow, but because they synthesize long chain (C60-C80) fatty acids that make up its hydrophobic and impermeable outer membrane. There are costs and benefits to the presence of that lipid-rich outer membrane. One benefit is that cell-surface hydrophobicity drives M. avium complex cells to adhere to surfaces to reduce their interaction with charged ions in suspension; they are likely "biofilm pioneers", adhering to a wide variety of surface materials. The result is that the slow-growing M. avium complex cells (1 gen/day at 37 °C) will not be washed out of any flowing system, whether a stream or plumbing in the built environment. Although the slow permeation of nutrients in M. avium complex organisms limits growth, they are also resistant to disinfectants, thus increasing their survival in water distribution systems, premise plumbing, and medical equipment. There are three components to the antimicrobial resistance of M. avium complex in biofilms: (1) innate resistance due to the hydrophobic, impermeable outer membrane, (2) residence in a matrix of extracellular polysaccharide, lipid, DNA, and protein that prevents access of antimicrobials to M. avium cells, and (3) an adaptive and transient increased resistance of biofilm-grown M. avium cells grown in biofilms. As expected M. avium in biofilms will display neutral, antagonistic, or beneficial interactions with other biofilm inhabitants. Methylobacterium spp., the common pink-pigmented, waterborne bacteria compete with M. avium for surface binding, suggested an approach to reducing M. avium biofilm formation and hence persistence in premise plumbing.

How can we improve the outcome for transplant patients with nontuberculous mycobacterial infections?

Nontuberculous mycobacteria (NTM) are environmental organisms that are rapidly emerging as pathogens in the transplant population. The prevalence of infection in transplant recipients remains unknown. While guidelines exist for treatment of NTM, neither the American Thoracic Society, the Infectious Diseases Society of America, nor the British Thoracic Society guidelines dictate the approach needed for transplant recipients. Here, we summarize risk factors, important diagnostic and treatment facts, and preventive measures to be taken to help improve outcomes of those infected with NTM infections.

A M. avium complex spondylodiscitis in a middle-aged woman with diabetes.

Spondylodiscitis, the inflammation of the vertebral bodies and the intervertebral disk space, is the reason for low back pain in a minority of cases. This is caused by various pathogens. Mycobacterium tuberculosis is responsible for 17-39% of all the cases of spondylodiscitis. On the contrast, spondylodiscitis from non tuberculous mycobacteria is extremely rare in literature. We describe a 68 -year old diabetic woman which is the first case of bone marrow involvement by M. intracellulare (member of M avium complex)with spondylodiscitis.

Natural isoflavone biochanin A as a template for the design of new and potent 3-phenylquinolone efflux inhibitors against Mycobacterium avium.

Mycobacterium avium is a difficult-to-treat pathogen able to quickly develop drug resistance. Like for other microbial species, overexpression of efflux pumps is one of the main mechanisms in developing multidrug resistance. Although the use of efflux pumps inhibitors (EPIs) represents a promising strategy to reverse resistance, to date few M. avium EPIs are known. Recently, we showed that in-house 2-phenylquinoline S. aureus NorA EPIs exhibited also a good activity against M. avium efflux pumps. Herein, we report a series of 3-phenylquinolones designed by modifying the isoflavone biochanin A, a natural EPI of the related M. smegmatis, taking into account some important SAR information obtained around the 2-phenylquinoline NorA EPIs. The 3-phenylquinolones inhibited M. avium efflux pumps with derivatives 1e and 1g that displayed the highest synergistic activity against all the strains considered in the study, bringing down (from 4- to 128-fold reduction) the MIC values of macrolides and fluoroquinolones.

Treatment and outcome of non-tuberculous mycobacterial pulmonary disease in a predominantly fibro-cavitary disease cohort.

BACKGROUND: The incidence of non-tuberculous mycobacterial pulmonary disease (NTM-PD) has increased in the Netherlands. The fibro-cavitary disease manifestation predominates, as elsewhere in Europe. We studied treatment and outcome of this disease manifestation, as such data are scarce. METHODS: We conducted a retrospective study of all patients diagnosed with NTM-PD according to the American Thoracic Society statement between 2008 and 2013 in a reference clinic. RESULTS: Sixty-three patients were included. Thirty-two (51%) were females and mean age was 60.8 years. Most patients had underlying COPD (73%). M. avium complex pulmonary disease (MAC-PD) was most frequent (n = 38, 60.3%), followed by M. malmoense (n = 7) and M. kansasii (n = 6). Twenty-two patients had fibro-cavitary MAC-PD, 14 had nodular-bronchiectatic MAC-PD and 2 had other manifestations. Thirty-two (94%) patients treated for MAC-PD received a rifamycin-ethambutol-macrolide based regimen. Microbiological cure rates were lower for fibro-cavitary (52.4%) than for nodular bronchiectatic MAC-PD (100%; p = 0.03). Sixty-nine percent of treated patients experienced adverse events, most frequently gastrointestinal discomforts (71%), tinnitus (18%), hearing impairment (16%) and hepatotoxicity (18%). CONCLUSIONS: Fibro-cavitary NTM-PD remains predominant, but is now diagnosed more frequently in women. Fibro-cavitary disease is harder to cure than nodular-bronchiectatic disease. Adverse events are frequent and can necessitate cessation of treatment.

The prevalence of non-tuberculous mycobacterial infections in mainland China: Systematic review and meta-analysis.

Despite increasing attention towards the non-tuberculous mycobacterial (NTM) diseases, the overall epidemiological information remains unavailable for China. A systematic review and meta-analysis was conducted using data of 105 qualified publications from Chinese mainland. The assay demonstrated that the prevalence of NTM infections among tuberculosis suspects was 6.3% (5.4%-7.4%) in mainland, while the Southeastern region had the highest NTM prevalence at 8.6% (7.1%-10.5%). In Northern China, slow growing mycobacteria (SGM) consistituted 63.7% of all the NTM isolates, while this rate in Southern China was 53.0%. More rapid growing mycobacteria (RGM) were present in southern China than the northern (χ2 = 57.996, P < 0.001). According to the coastal provinces' data (from north to south), the NTM prevalence rate and the number of isolated NTM species increased apparently in accordance with geographic latitude. The information obtained in this assay will facilitate the NTM disease diagnosis and screening policy making in China.

Distribution of nontuberculous mycobacteria in treated patients with pulmonary disease in Greece - relation to microbiological data.

AIMS: The aim was to assess the distribution of nontuberculous mycobacteria (NTM) in treated patients with pulmonary disease (PD) in Greece. PATIENTS & METHODS: Patients treated for NTM PD at the two largest chest diseases hospitals in Greece, in the period 1990-2013 were investigated. For the years 2005-2013 data on NTM isolation frequency were recorded. RESULTS: M. avium complex (MAC) was the predominant cause of NTM PD disease followed by M. kansasii and rapid growing mycobacteria (RGM). The pathogenicity of RGM was significantly lower than this of MAC and M. kansasii. An increase was observed in the percentage of isolated NTM species that were considered clinically significant over the study period. CONCLUSIONS: The increasing number of NTM PD in Greece is a consequence of their isolation being more frequently considered as clinically relevant.

Differentiation of Mycobacterium avium Complex Isolated in Korea by DT1-BT6 PCR

Recently, selective PCR method using DT1 and DT6 sequences was introduced to identify and differentiate the Mycobacterium avium complex (MAC) into M. intracellulare and M. avium. We applied this method to 49 MAC clinical isolates identified by biochemical tests. They were differentiated into 39 strains of M. intracelluare and 10 strains of M. avium. Compared to those results obtained by 16S rDNA sequencing, DT1-DT6 PCR method showed 100% specificity. While the sensitivity of DT6 PCR for M. avium was 100%, that of DT1 PCR for M. intracellulare was 84.6%. These results show heterogeneity of M intracellulare Korea clinical isolates from Korea. In conclusion, although the in-house DTl-DT6 PCR is an easy and convenient method in differentiating MAC members, other methods such as 16S rDNA sequencing analysis should be performed for the correct identification, especially of M intracellulare.

Perfil bacteriológico da tuberculose pulmonar na regiäo de Campinas e das Diretorias Regionais de Saúde XII, XV e XX - 1999/2000 / Bacteriologic profile of lung tuberculosis in the Campinas Region and XII, XV and XX Health Regional Department,-1999/2000

Com o objetivo de avaliar o diagnóstico bacteriológico e controle de tratamento da tuberculose, os autores analisaram, nos anos de 1999 e 2000, os exames processados pelo Instituto Adolfo Lutz de Campinas e laboratórios de sua abrangência das Diretorias Regionais de Saúde (DIR)-XII, XV e XX, que atendem 93 municípios. Neste período foram realizados 53.341 baciloscopias, em 3.781 (7,1 por cento) foram detectados a presença de BAAR com positividade 4,9 por cento para diagnóstico, 1,2 por cento para controle de tratamento e 1 por cento para o sem informação quanto ao quesito diagnóstico e ou controle de tratamento. Foram realizadas 7.603 (14,3 por cento) culturas, havendo isolamento de microbactérias em 1.134 (14,9 por cento) amostras, 13,2 por cento para diagnóstico, 1,4 por cento para controle de tratamento e 0,3 por cento para o sem informação. Foram identificadas 936 cepas pertencentes ao complexo Mycobacterium tuberculosis e 48 ao complexo M.avium. O perfil de sensibilidade de 381 cepas de M.tuberculosis demonstrou que 78,0 por cento foram sensíveis às drogas testadas e 22,0 por cento resistentes a pelo menos uma droga. As análises destes dados contribuem para as ações do Programa de Controle da Tuberculose, auxiliando na determinação do perfil epidemiológico da doença na regiäo de Campinas e nas DIRs envolvidas. (AU)

With the purpose of evaluating the bacteriological diagnosis and the tuberculosis treatmentcontrol, the authors analyzed, in the years of 1999/2000, the tests processed by the Adolfo Lutz Institutein Campinas (SP), Health Regional Department (DIRS) and laboratories related to it from XII, XV and XX,witch serve 93 towns. During that period 53.341 samples were undertaken, 3.781 (7,1%) detected thepresence of BAAR with positiveness of 4,9% for diagnosis, 1,2% for treatment control and 1,0% for theones without information regarding the diagnosis item or treatment control. 7.603(14,3%) cultures weregrown, with isolation of micobacteria taking place in 1.134 (14,9%); 13,2% for diagnosis, 1,4% for treatmentcontrol and 0,3% for the ones lacking information. 936 heathers belonging to Mycobacterium tuberculosiscomplex and 48 belonging do M. avium complex were identified. The profile of sensitiveness of 381heathers of M. tuberculosis showed that 78% were sensitive to tested drugs used and 22% resisted atleast one drug. That data analyses have contributed to the realizations of the Tuberculosis ControlProgram, helping to determining the epidemiological profile of the illness in the Campinas region andinvolved DIRs. (AU)