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Study Objective: The purpose of this study was to compare the imaging findings of nontuberculous mycobacterial (NTM) infection in patients with normal and abnormal cystic fibrosis (CF) genotypes, and normal and abnormal alpha1-antitrypsin (AAT) phenotypes. Design: A retrospective review of medical records and chest CT scans from 85 patients with microbiologically proven NTM infection was performed. All patients had undergone genotype analysis for CF mutations, and phenotypic evaluation for AAT status. Patients with homozygous CF or AAT were not included. Two independent observers assessed the patterns and distribution of disease, according to a standardized score sheet. In 52 patients, follow-up CT scans were obtained 1 to 46 months (mean duration, 8 months) following the initial CT scan. The CT scan findings on the follow-up scan were visually compared with those on the initial CT scan for progression or regression of abnormalities. Statistical analysis was performed to evaluate the relationship between the dominant CT scan pattern and CF/AAT status, and between CT scan pattern and radiologic change on follow-up. Results: Fifteen patients (18%) were found to carry a single CF mutation, and an abnormal AAT phenotype was seen in 13 patients (15%). Three patients (3%) were found to have both a heterozygous CF mutation and a heterozygous AAT phenotype. On the initial CT scans, bronchiectasis and nodules were the most frequent findings of NTM infection in all three groups (p > 0.05). The prevalence of nodules was slightly lower in the CF group, and the prevalence of linear scarring was greater in the AAT group than in the normal group (p < 0.05). Among the 52 patients who had a follow-up CT scan, 8 (15%) had a CF mutation and 6 (12%) had an abnormal AAT phenotype. The extent and pattern of abnormality seen on the initial CT scan did not predict change on follow-up evaluation. After treatment, 40 patients (56%) with a normal CF genotype had decrease in disease extent, compared with 4 patients (25%) with a CF mutation (p < 0.05). Bronchiectasis was improved in approximately 35% of those with normal genotype, but in none of those with a CF mutation. Conclusion: In patients with NTM infection, the CT scan findings show only minor differences according to phenotype and genotype. Initial CT scan findings do not predict change on follow-up CT scan evaluation. However, on follow-up CT scan, patients with CF mutations are less likely to improve, while those with AAT phenotype appear to have a radiographic outcome similar to those with normal phenotype. [ABSTRACT FROM AUTHOR]

Describes the first reported cases of blastomycosis acquired occupationally in Colorado in 1998. Medical conditions of the patients; Complaints from the patients; Factors that contributed to blastomycosis; Risk factors of blastomycosis.

From a high throughput screening of commercially available libraries against nontuberculous mycobacteria and Mycobacterium tuberculosis, numerous hits were identified with moderate activity. Extensive medicinal chemistry optimization has led to a series of potent benzothiazole amide antimycobacterial agents. Replacement of the adamantyl group with cyclohexyl derivatives and further development of this series resulted in an advanced lead compound, CRS400393, which demonstrated excellent potency and a mycobacteria-specific spectrum of activity. MIC values ranged from 0.03 to 0.12 μg/mL against Mycobacterium abscessus and other rapid-grower NTM, and 1-2 μg/mL against Mycobacterium avium complex. The preliminary mechanism of action studies suggested these agents may target MmpL3, a mycobacterial mycolic acid transporter. The series has demonstrated in vivo efficacy in a proof of concept mouse model of M. abscessus infection., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A novel slowly growing, non-chromogenic species of the class Actinobacteria was isolated from a human respiratory sample in Nebraska, USA, in 2012. Analysis of the internal transcribed spacer sequence supported placement into the genus Mycobacterium with high sequence similarity to a previously undescribed strain isolated from a patient respiratory sample from Oregon, USA, held in a collection in Colorado, USA, in 2000. The two isolates were subjected to phenotypic testing and whole genome sequencing and found to be indistinguishable. The bacteria were acid-fast stain-positive, rod-shaped and exhibited growth after 7-10 days on solid media at temperatures ranging from 25 to 42°C. Colonies were non-pigmented, rough and slightly raised. Analyses of matrix-assisted laser desorption ionization time-of-flight profiles showed no matches against a reference library of 130 mycobacterial species. Full-length 16S rRNA gene sequences were identical for the two isolates, the average nucleotide identity (ANI) between their genomes was 99.7 % and phylogenetic comparisons classified the novel mycobacteria as the basal most species in the slowly growing Mycobacterium clade. Mycobacterium avium is the most closely related species based on rpoB gene sequence similarity (92 %), but the ANI between the genomes was 81.5 %, below the suggested cut-off for differentiating two species (95 %). Mycolic acid profiles were more similar to M. avium than to Mycobacterium simiae or Mycobacterium abscessus. The phenotypic and genomic data support the conclusion that the two related isolates represent a novel Mycobacterium species for which the name Mycobacterium talmoniae sp. nov. is proposed. The type strain is NE-TNMC-100812T (=ATCC BAA-2683T=DSM 46873T).

Treatment of non-tuberculous mycobacterial lung disease (NTM-LD) is challenging for several reasons including the relative resistance of NTM to currently available drugs and the difficulty in tolerating prolonged treatment with multiple drugs. Yet-to-be-done, large, multicenter, prospective randomized studies to establish the best regimens will also be arduous because multiple NTM species are known to cause human lung disease, differences in virulence and response to treatment between different species and strains within a species will make randomization more difficult, the need to distinguish relapse from a new infection, and the difficulty in adhering to the prescribed treatment due to intolerance, toxicity, and/or drug-drug interactions, often necessitating modification of therapeutic regimens. Furthermore, the out-of-state resident status of many patients seen at the relatively few centers that care for large number of NTM-LD patients pose logistical issues in monitoring response to treatment. Thus, current treatment regimens for NTM-LD is largely based on small case series, retrospective analyses, and guidelines based on expert opinions. It has been nearly 10 years since the publication of a consensus guideline for the treatment of NTM-LD. This review is a summary of the available evidence on the treatment of the major NTM-LD until more definitive studies and guidelines become available., Competing Interests: Conflict of Interest Dr. Julie V. Philley, Dr. Jennifer R. Honda, Dr. Michael M. Chan, Dr. Shannon Kasperbauer, Dr. Nicholas D. Walter, and Dr. Edward D. Chan declare that they have no conflict of interest. Dr. Mary Ann DeGroote is a co-PI for the pre-clinical evaluation of new therapeutic entities for NTM therapeutics with Crestonepharma Inc. This is an SBIR phase II grant. There is no overlap with antimicrobial agents described in this review.

Mycobacterium chelonae is a rapidly growing opportunistic nontuberculous mycobacterial (NTM) species that causes infections in humans and other hosts. Here, we report the draft genome sequence of Mycobacterium chelonae type strain ATCC 35752, consisting of 4.89 Mbp, 63.96% G+C content, 4,489 protein-coding genes, 48 tRNAs, and 3 rRNA genes., (Copyright © 2015 Hasan et al.)

Background: The successful treatment of tuberculosis (TB) requires long-term multidrug chemotherapy. Clinical trials to evaluate new drugs and regimens for TB treatment are protracted due to the slow clearance of Mycobacterium tuberculosis (Mtb) infection and the lack of early biomarkers to predict treatment outcome. Advancements in the field of metabolomics make it possible to identify metabolic profiles that correlate with disease states or successful chemotherapy. However, proof-of-concept of this approach has not been provided for a TB-early treatment response biosignature (TB-ETRB)., Methods: Urine samples collected at baseline and during treatment from 48 Ugandan and 39 South African HIV-seronegative adults with pulmonary TB were divided into discovery and qualification sets, normalized to creatinine concentration, and analyzed by liquid chromatography-mass spectrometry to identify small molecule molecular features (MFs) in individual patient samples. A biosignature that distinguished baseline and 1 month treatment samples was selected by pairwise t-test using data from two discovery sample sets. Hierarchical clustering and repeated measures analysis were applied to additional sample data to down select molecular features that behaved consistently between the two clinical sites and these were evaluated by logistic regression analysis., Results: Analysis of discovery samples identified 45 MFs that significantly changed in abundance at one month of treatment. Down selection using an extended set of discovery samples and qualification samples confirmed 23 MFs that consistently changed in abundance between baseline and 1, 2 and 6 months of therapy, with 12 MFs achieving statistical significance (p < 0.05). Six MFs classified the baseline and 1 month samples with an error rate of 11.8%., Conclusions: These results define a urine based TB-early treatment response biosignature (TB-ETRB) applicable to different parts of Africa, and provide proof-of-concept for further evaluation of this technology in monitoring clinical responses to TB therapy.

In drug development, there are typically a series of preclinical studies that must be completed with new compounds or regimens before use in humans. A sequence of in vitro assays followed by in vivo testing in validated animal models to assess the activity against Mycobacterium tuberculosis, pharmacology and toxicity is generally used for advancing compounds against tuberculosis in a preclinical stage. A plethora of different assay systems and conditions are used to study the effect of drug candidates on the growth of M. tuberculosis, making it difficult to compare data from one laboratory to another. The Bill and Melinda Gates Foundation recognized the scientific gap to delineate the spectrum of variables in experimental protocols, identify which of these are biologically significant, and converge towards a rationally derived standard set of optimized assays for evaluating compounds. The goals of this document are to recommend protocols and hence accelerate the process of TB drug discovery and testing. Data gathered from preclinical in vitro and in vivo assays during personal visits to laboratories and an electronic survey of methodologies sent to investigators is reported. Comments, opinions, experiences as well as final recommendations from those currently engaged in such preclinical studies for TB drug testing are being presented. Certain in vitro assays and mouse efficacy models were re-evaluated in the laboratory as head-to-head experiments and a summary is provided on the results obtained. It is our hope that this information will be a valuable resource for investigators in the field to move forward in an efficient way and that key variables of assays are included to ensure accuracy of results which can then be used for designing human clinical trials. This document then concludes with remaining questions and critical gaps that are in need of further validation and experimentation., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Here we describe an experimental murine model that allows for aerosolized antituberculosis drug efficacy testing. Intrapulmonary aerosol delivery of isoniazid, capreomycin, and amikacin to mice with pulmonary infection of Mycobacterium tuberculosis demonstrated efficacy in reducing pulmonary bacterial loads similar to that seen by standard drug delivery methods, even when lower concentrations of drugs and fewer doses were used in the aerosolized drug regimens. Interestingly, intrapulmonary delivery of isoniazid also reduced the bacterial load in the spleen.

The emergence of multidrug-resistant tuberculosis (MDR-TB) has led to a renewed interest in the use of second-line antibiotic agents. Unfortunately, there are currently dearths of information, data, and computational models that can be used to help design rational regimens for administration of these drugs. To help fill this knowledge gap, an exploratory physiologically based pharmacokinetic (PBPK) model, supported by targeted experimental data, was developed to predict the absorption, distribution, metabolism, and excretion (ADME) of the second-line agent capreomycin, a cyclic peptide antibiotic often grouped with the aminoglycoside antibiotics. To account for interindividual variability, Bayesian inference and Monte Carlo methods were used for model calibration, validation, and testing. Along with the predictive PBPK model, the first for an antituberculosis agent, this study provides estimates of various key pharmacokinetic parameter distributions and supports a hypothesized mechanism for capreomycin transport into the kidney.

Azithromycin is a potent macrolide antibiotic with poorly understood antiinflammatory properties. Long-term use of azithromycin in patients with chronic inflammatory lung diseases, such as cystic fibrosis (CF), results in improved outcomes. Paradoxically, a recent study reported that azithromycin use in patients with CF is associated with increased infection with nontuberculous mycobacteria (NTM). Here, we confirm that long-term azithromycin use by adults with CF is associated with the development of infection with NTM, particularly the multi-drug-resistant species Mycobacterium abscessus, and identify an underlying mechanism. We found that in primary human macrophages, concentrations of azithromycin achieved during therapeutic dosing blocked autophagosome clearance by preventing lysosomal acidification, thereby impairing autophagic and phagosomal degradation. As a consequence, azithromycin treatment inhibited intracellular killing of mycobacteria within macrophages and resulted in chronic infection with NTM in mice. Our findings emphasize the essential role for autophagy in the host response to infection with NTM, reveal why chronic use of azithromycin may predispose to mycobacterial disease, and highlight the dangers of inadvertent pharmacological blockade of autophagy in patients at risk of infection with drug-resistant pathogens.

Female BALB/cAnNCrl (n = 170; age, 6 to 9 wk) mice were infected by intravenous inoculation of 5 × 10(6) cfu Mycobacterium tuberculosis strain Erdman (ATCC 35801). Between day 52 and 5 mo after infection, 10 of the 170 mice infected according to this protocol developed torticollis, including mice in treatment groups that received combination antibiotic therapy of rifampin-pyrazinamide or moxifloxacin-rifampin-pyrazinamide. Torticollis did not develop in mice receiving isoniazid- rifampin-pyrazinamide therapy, nor was it present in the cohort of aerogenically infected mice. Affected mice were euthanized, and complete necropsy evaluation was performed on 4 mice. Gross necropsy evaluation revealed typical tuberculosis lesions in lungs of infected mice. Histologic evaluation of tissues revealed granulomatous otitis media with intralesional acid-fast bacilli consistent with Mycobacterium tuberculosis. These cases represent an unusual finding specific to the intravenous mouse model of Mycobacterium tuberculosis and may represent a model of a similar condition in humans that is known as tuberculous otitis media.

The continuing global epidemic of tuberculosis, the increasing rate of multidrug resistant (MDR) tuberculosis and the more recent emergence of extensively drug resistant (XDR) tuberculosis are great causes for concern. A major international effort is currently underway to optimize current drug therapies and to discover new drugs that are active against these organisms. This effort has created a pipeline of new candidate drugs at various stages of preclinical and early clinical evaluations. Major challenges still exist, however, varying from the standardization and application of current animal models and their application to drug discovery and characterization to the fact that our knowledge about the basic biology of the MDR and XDR strains of Mycobacterium tuberculosis is minimal at best.

We performed a retrospective cohort study of human immunodeficiency virus (HIV)-associated Mycobacterium avium complex (MAC) infection during 1997-2004 to assess for factors associated with initial macrolide resistance. Of 52 HIV-associated sterile-site MAC isolates, 9 (17%) were initially macrolide resistant. Prior MAC treatment and prolonged MAC prophylaxis with macrolides were associated with infection with a macrolide-resistant isolate; 2 (22%) of 9 patients had limited or no prior macrolide exposure. Initial MAC isolates in HIV-infected persons should routinely be tested for macrolide resistance.

Periplasmic Cu, Zn-cofactored superoxide dismutase (SodC) protects Gram-negative bacteria from exogenous oxidative damage. The virulent Salmonella typhimurium strain ATCC 14028s has been found to contain two discrete periplasmic Cu, Zn-SOD enzymes that are only 57% identical at the amino acid level. SodCI is carried by a cryptic bacteriophage, and SodCII is closely related to the Cu, Zn-superoxide dismutase of Escherichia coli. All Salmonella serotypes appear to carry the sodCII locus, but the phage-associated sodCI gene is found only in certain strains belonging to the most highly pathogenic serotypes. Expression of either sodC locus appears to be enhanced during stationary phase, but only sodCII is regulated by the alternative sigma factor sigmas (RpoS). Mutants lacking both sodC genes are less lethal for mice than mutants possessing either sodC locus alone, indicating that both Cu, Zn-SOD enzymes contribute to Salmonella pathogenicity. The evolutionary acquisition of an additional sodC gene has contributed to the enhanced virulence of selected Salmonella strains.