UNASSIGNED: Workup of bronchiectasis patients mandates microbiological characterization often being sought via Bronchoscopy. However, whether to perform bronchial or lung biopsies, is unknown, especially for the diagnosis of NTM pulmonary disease. We aimed to assess the current practice and yield of the different bronchoscopic procedures in this setting.
UNASSIGNED: Data from an adult cohort with bronchiectasis referred for bronchoscopy for microbiologic sampling was reviewed, including demographics, etiology, imaging and results of the different bronchoscopic procedures performed.
UNASSIGNED: 127 subjects were analyzed (mean age 61, 56% female). BAL culture was positive in 44%. Frequent pathogens were Hemophilus Influenza (20%), pseudomonas aeruginosa (8%) and Staphylococcus aureus (7%). NTM and tuberculosis were found in 6% and 1.5% respectively. BAL cytology was sent in 125 procedures, EBB was performed in 51 patients (40%) and TBLB in 38 patients (30%). BAL cytology and both EBB and TBB (including tissue cultures) had no benefit over BAL with respect to microbiological diagnosis, including identification of mycobacterial disease.
UNASSIGNED: In adult subjects with Non-CF bronchiectasis requiring bronchoscopy for microbiological characterization, BAL cytology and lung tissue biopsies were frequently performed but were of minimal additional benefit over BAL culture (including for mycobacterial pulmonary disease), and are most likely futile.

Mycobacterium abscessus is a fast-growing non-tuberculous mycobacteria complex causing pulmonary infections, comprising the subspecies abscessus, massiliense and bolletii. Differences are based predominantly on natural inducible macrolide resistance, active in most Mycobacterium abscessus spp abscessus species and in Mycobacterium abscessus spp bolletii but inactive in Mycobacterium abscessus spp massiliense. Therapy consists in long-term treatment, combining multiple antibiotics. Prognosis is poor, as only 40% of patients experience cure. Pharmacodynamic and pharmacokinetic data on M. abscessus have recently been published, showing that therapy ineffectiveness might be explained by intrinsic bacterial resistance (macrolides…) and by the unfavorable pharmacokinetics of the recommended antibiotics. Other molecules and inhaled antibiotics are promising.

Non-tuberculous mycobacteria are a heterogeneous group of environmental bacteria and other than the well-known Mycobacterium tuberculosis complex and Mycobacterium leprae. They could cause localized or disseminated infections. Mycobacterium chelonae and Mycobacterium fortuitum are among the most clinically relevant non-tuberculous mycobacteria species. The infections treatment is complex since they are resistant to antituberculosis drugs and the biofilm formation makes them impermeable to several antibiotics. Antimicrobial photodynamic therapy (aPDT) constitutes an alternative to eliminate pathogens, principally those antimicrobials resistant. Among explored photosensitizers, phthalocyanines are considered excellent, but with a disadvantage: a lack solubility in aqueous media. Consequently, several nanocarriers have been studied in the last years. In this work, a Zn-phthalocyanine into liposomes was evaluated to photoinactivate M. fortuitum and M. chelonae. The results show a higher photodynamic activity of ZnPc into liposomes respect to solution. Furthermore, M. fortuitum was more sensible to aPDT than M. chelonae.

Non-tuberculous mycobacterial infections (mycobacterium other than Mycobacterium tuberculosis and Mycobacterium leprae) are organisms that are commonly found in the environment such as water, soil, and dust. They may form difficult to eliminate biofilms and have been reported to cause significant infections in humans, especially in immunocompromised hosts. This article describes an interesting case of Mycobacterium abscessus in the lung.

Rapid growing mycobacteria have been increasingly recognized as pathogens, both in immunocompromised and immunocompetent population, and their incidence has increased over the last decade significantly. Pulmonary infections are the most common, however, any organ can be affected. The treatment of these infections is costly, prolonged, and often antimicrobial resistance poses a significant challenge to a successful outcome. The source control together with antimicrobials is the cornerstone of treatment. We report a case series of 3 patients with extrapulmonary rapid growing mycobacterial infections in whom the successful treatment was achieved with source control alone.

The Mycobacterium abscessus complex can cause fatal pulmonary disease, especially in cystic fibrosis patients. Diagnosing M. abscessus complex pulmonary disease is challenging. Immunologic assays specific for M. abscessus are not available. In this study seven clinical M. abscessus complex strains and the M. abscessus reference strain ATCC19977 were used to find species-specific proteins for their use in immune assays. Six strains showed rough and smooth colony morphotypes simultaneously, two strains only showed rough mophotypes, resulting in 14 separate isolates. Clinical isolates were submitted to whole genome sequencing. Proteomic analysis was performed on bacterial lysates and culture supernatant of all 14 isolates. Species-specificity for M. abscessus complex was determined by a BLAST search for proteins present in all supernatants. Species-specific proteins underwent in silico B- and T-cell epitope prediction. All clinical strains were found to be M. abscessus ssp. abscessus. Mutations in MAB_4099c as a likely genetic basis of the rough morphotype were found in six out of seven clinical isolates. 79 proteins were present in every supernatant, of which 12 are exclusively encoded by all members of M. abscessus complex plus Mycobacterium immunogenum. In silico analyses predicted B- and T-cell epitopes in all of these 12 species-specific proteins.

BACKGROUND: Hot tub lung is a hypersensitivity pneumonitis (HP) due to exposure to inhaled non-tuberculous mycobacteria, the most frequent being Mycobacterium avium complex (MAC).
METHODS: A French couple developed typicalHP in the context of a repeated use of hot tubs. The husband had a severe hypoxemic form whereas his wife had a micronodular form with patchy ground glass on the thoracic scan, with less severe functional impairment. MAC was recovered in the hot tub water, but not in broncho-alveolar lavage fluid, and serologies were negative. Samples taken at home showed unusual exposure to Aureobasidium pullulans and Aspergillus flavus, as well as the presence of potentially responsible domestic molds. Blood precipitins for these microorganisms were identified. The evolution was favorable after removal of the hot tub.
CONCLUSIONS: These cases represent two of the typical presentations of hot tub lung, with a possible HP to an antigen other than MAC, which may have been enhanced by chronic exposure to multiple microorganisms.

Clinical isolates of Mycobacterium tuberculosis and Mycobacterium bovis are differentially susceptible to 2-Thiophen Hydrazide (TCH); however its mechanism of action or the reasons for that difference are unknown. We report herein that under our experimental conditions, TCH inhibits M. tuberculosis in solid but not in liquid medium, and that in spite of resembling Isoniazid and Ethionamide, it does not affect mycolic acid synthesis. To understand the mechanisms of action of TCH we isolated M. tuberculosis TCH resistant mutants which fell into two groups; one resistant to TCH and Isoniazid but not to Ethionamide or Triclosan, and the other resistant only to TCH with no, or marginal, cross resistance to Isoniazid. A S315T katG mutation conferred resistance to TCH while katG expression from a plasmid reduced M. tuberculosis MIC to this drug, suggesting a possible involvement of KatG in TCH activation. Whole genome sequencing of mutants from this second group revealed a single mutation in the alkylhydroperoxide reductase ahpC promoter locus in half of the mutants, while the remaining contained mutations in dispensable genes. This is the first report of the genetics underlying the action of TCH and of the involvement of ahpC as the sole basis for resistance to an anti-tubercular compound.

Non-tuberculous mycobacteria (NTM) are composed of mycobacterial species other than the Mycobacterium tuberculosis complex. Initially thought to be mere contaminants when isolated from clinical specimens, literature is increasing by the day showing NTM as proven pathogens. Due to the difference in antimicrobial susceptibility of different species, it becomes imperative for the microbiology laboratory to identify them to the species level. Molecular methods are available for rapid and accurate identification, but in a resource limited nation, phenotypic methods, albeit time consuming, are of paramount importance. By means of this article, the authors intend provide a concise summary of the basic biochemical reactions which can be done to identify most commonly isolated NTM.

UNASSIGNED: Non-tuberculous mycobacteria (NTM) are environmental bacteria capable of causing an opportunistic myriad of infections. Mycobacterium kansasii, one such NTM, is responsible for causing pulmonary disease in immunocompromised patients. Rare extrapulmonary manifestations such as lymphadenitis, osteoarticular manifestations, and skin and soft tissue infections are also observed.
UNASSIGNED: Here, we report an unusual case of sternoclavicular joint and elbow joint infection with M. kansasii in a relatively immunocompetent patient. Histopathology did not show classic granulomas and mycobacterial infection was not initially considered as a possibility. However repeat biopsies were sent for mycobacterial cultures which then grew M. kansasii.
UNASSIGNED: Diagnosis of M. kansasii in such cases can be difficult and culture-positive results may not necessarily imply positive diagnosis as they can be environmental contaminants. Furthermore, M. kansasii can cause infections without the characteristic granuloma formation, which can further complicate tissue diagnosis. This underlines the importance of ensuring that tissue samples obtained are cultured for mycobacteria.