Exosome secretome and mediated signaling in breast cancer patients with nontuberculous mycobacterial disease.

Bronchiectasis Nontuberculous mycobacterium (NTMnb) infection is an emerging health problem in breast cancer (BCa) patients. We measured sera exosome proteome in BCa-NTMnb subjects and controls by Mass Spectroscopy. Extracellular matrix protein 1 (ECM1) was detected exclusively in the circulating exosomes of 82% of the BCa-NTMnb cases. Co-culture of ECM1+ exosomes with normal human mammary epithelial cells induced epithelial to mesenchymal transition accompanied by increased Vimentin/CDH1 expression ratio and Glutamate production. Co-culture of the ECM1+ exosomes with normal human T cells modulated their cytokine production. The ECM1+ exosomes were markedly higher in sera obtained from BCa-NTMnb subjects. Exclusive expression of APN, APOC4 and AZGP1 was evident in the circulating exosomes of these BCa-NTMnb cases, which predicts disease prevalence independent of the body max index in concert with ECM1. Monitoring ECM1, APN, APOC4 and AZGP1 in the circulating exosomes could be beneficial for risk assessment, monitoring and surveillance of BCa-NTMnb.

Emergence of mmpT5 Variants during Bedaquiline Treatment of Mycobacterium intracellulare Lung Disease.

Bedaquiline (BDQ), a diarylquinoline antibiotic that targets ATP synthase, is effective for the treatment of Mycobacterium tuberculosis infections that no longer respond to conventional drugs. While investigating the off-label use of BDQ as salvage therapy, seven of 13 patients with Mycobacterium intracellulare lung disease had an initial microbiological response and then relapsed. Whole-genome comparison of pretreatment and relapse isolates of M. intracellulare uncovered mutations in a previously uncharacterized locus, mmpT5 Preliminary analysis suggested similarities between mmpT5 and the mmpR5 locus, which is associated with low-level BDQ resistance in M. tuberculosis Both genes encode transcriptional regulators and are adjacent to orthologs of the mmpS5-mmpL5 drug efflux operon. However, MmpT5 belongs to the TetR superfamily, whereas MmpR5 is a MarR family protein. Targeted sequencing uncovered nonsynonymous mmpT5 mutations in isolates from all seven relapse cases, including two pretreatment isolates. In contrast, only two relapse patient isolates had nonsynonymous changes in ATP synthase subunit c (atpE), the primary target of BDQ. Susceptibility testing indicated that mmpT5 mutations are associated with modest 2- to 8-fold increases in MICs for BDQ and clofazimine, whereas one atpE mutant exhibited a 50-fold increase in MIC for BDQ. Bedaquiline shows potential for the treatment of M. intracellulare lung disease, but optimization of treatment regimens is required to prevent the emergence of mmpT5 variants and microbiological relapse.

Mycobacterium arupense, Mycobacterium heraklionense, and a Newly Proposed Species, "Mycobacterium virginiense" sp. nov., but Not Mycobacterium nonchromogenicum, as Species of the Mycobacterium terrae Complex Causing Tenosynovitis and Osteomyelitis.

Mycobacterium terrae complex has been recognized as a cause of tenosynovitis, with M. terrae and Mycobacterium nonchromogenicum reported as the primary etiologic pathogens. The molecular taxonomy of the M. terrae complex causing tenosynovitis has not been established despite approximately 50 previously reported cases. We evaluated 26 isolates of the M. terrae complex associated with tenosynovitis or osteomyelitis recovered between 1984 and 2014 from 13 states, including 5 isolates reported in 1991 as M. nonchromogenicum by nonmolecular methods. The isolates belonged to three validated species, one new proposed species, and two novel related strains. The majority of isolates (20/26, or 77%) belonged to two recently described species: Mycobacterium arupense (10 isolates, or 38%) and Mycobacterium heraklionense (10 isolates, or 38%). Three isolates (12%) had 100% sequence identity to each other by 16S rRNA and 99.3 to 100% identity by rpoB gene region V sequencing and represent a previously undescribed species within the M. terrae complex. There were no isolates of M. terrae or M. nonchromogenicum, including among the five isolates reported in 1991. The 26 isolates were susceptible to clarithromycin (100%), rifabutin (100%), ethambutol (92%), and sulfamethoxazole or trimethoprim-sulfamethoxazole (70%). The current study suggests that M. arupense, M. heraklionense, and a newly proposed species ("M. virginiense" sp. nov.; proposed type strain MO-233 [DSM 100883, CIP 110918]) within the M. terrae complex are the major causes of tenosynovitis and osteomyelitis in the United States, with little change over 20 years. Species identification within this complex requires sequencing methods.

Mycobacterium abscessus. "Pleased to meet you, hope you guess my name...".

Mycobacterium abscessus is a formidable and difficult-to-treat mycobacterial pathogen with multiple drug-resistance mechanisms. The most important of these mechanisms is the presence of an inducible erythromycin methylase (erm) gene, because it confers macrolide resistance. It has recently been found that "M. abscessus" can be split into three species or subspecies based on gene sequence analysis other than the 16S rRNA gene and the presence or absence of a functional erm(41) gene. Several names have been applied to these three organisms, including M. abscessus or M. abscessus subsp. abscessus, Mycobacterium massiliense or M. abscessus subsp. massiliense, and Mycobacterium bolletii or M. abscessus subsp. bolletii. No universally accepted or recognized species or subspecies designations have emerged, and no names have been universally adopted for these organisms. This uncertainty has led to inconsistencies in the medical literature and understandable confusion by clinicians about the appropriate labels for "M. abscessus" isolates. We discuss the complexities involved in mycobacterial species/subspecies identification and taxonomy and suggest possible ways to improve the present state of uncertainty surrounding the labels for "M. abscessus" clinical isolates. We also suggest necessary changes in mycobacterial laboratory processing and reporting procedures for mycobacterial isolates.

Preliminary Results of Bedaquiline as Salvage Therapy for Patients With Nontuberculous Mycobacterial Lung Disease.

BACKGROUND: Bedaquiline is an oral antimycobacterial agent belonging to a new class of drugs called diarylquinolines. It has low equivalent minimal inhibitory concentrations for Mycobacterium tuberculosis and nontuberculous mycobacterial (NTM) lung disease, especially Mycobacterium avium complex (MAC) and Mycobacterium abscessus (Mab). Bedaquiline appears to be effective for the treatment of multidrug-resistant TB but has not been tested clinically for NTM disease. METHODS: We describe a case series of off-label use of bedaquiline for treatment failure lung disease caused by MAC or Mab. Only patients whose insurance would pay for the drug were included. Fifteen adult patients were selected, but only 10 (six MAC, four Mab) could obtain bedaquiline. The 10 patients had been treated for 1 to 8 years, and all were on treatment at the start of bedaquiline therapy. Eighty percent had macrolide-resistant isolates (eight of 10). The patients were treated with the same bedaquiline dosage as that used in TB trials and received the best available companion drugs (mean, 5.0 drugs). All patients completed 6 months of therapy and remain on bedaquiline. RESULTS: Common side effects included nausea (60%), arthralgias (40%), and anorexia and subjective fever (30%). No abnormal ECG findings were observed with a mean corrected QT interval lengthening of 2.4 milliseconds at 6 months. After 6 months of therapy, 60% of patients (six of 10) had a microbiologic response, with 50% (five of 10) having one or more negative cultures. CONCLUSIONS: This small preliminary report demonstrates potential clinical and microbiologic activity of bedaquiline in patients with advanced MAC or Mab lung disease but the findings require confirmation with larger studies.

The significance of Mycobacterium abscessus subspecies abscessus isolation during Mycobacterium avium complex lung disease therapy.

BACKGROUND: Isolation of Mycobacterium abscessus subspecies abscessus (MAA) is common during Mycobacterium avium complex (MAC) lung disease therapy, but there is limited information about the clinical significance of the MAA isolates. METHODS: We identified 53 of 180 patients (29%) treated for MAC lung disease who had isolation of MAA during MAC lung disease therapy. Patients were divided into those without (group 1) and those with (group 2) MAA lung disease. RESULTS: There were no significant demographic differences between patients with and without MAA isolation or between groups 1 and 2. Group 1 and 2 patients had similar total sputum cultures obtained (P = .7; 95% CI, -13.4 to 8.6) and length of follow-up (P = .8; 95% CI, -21.5 to 16.1). Group 2 patients had significantly more total positive cultures for MAA (mean±SD, 15.0 ± 11.1 vs 1.2 ± 0.4; P < .0001; 95% CI, -17.7 to -9.9), were significantly more likely to develop new or enlarging cavitary lesions while on MAC therapy (P > .0001), and were significantly more likely to meet all three American Thoracic Society diagnostic criteria for nontuberculous mycobacterial disease (21 of 21 [100%] vs 0 of 32 [0%]; P < .0001) compared with group 1 patients. Group 1 patients were significantly more likely to have single, positive MAA cultures than group 2 patients (25 of 31 vs 0 of 21; P < .0001). CONCLUSIONS: Microbiologic and clinical follow-up after completion of MAC lung disease therapy is required to determine the significance of MAA isolated during MAC lung disease therapy. Single MAA isolates are not likely to be clinically significant.

Mycobacterium abscessus: challenges in diagnosis and treatment.

PURPOSE OF REVIEW: Mycobacterium abscessus is the most common rapidly growing mycobacterium that causes lung disease. This review describes recently published literature regarding M. abscessus taxonomy, environmental niche, diagnosis, management and outcome in pulmonary disease in adults and adolescents with cystic fibrosis. RECENT FINDINGS: The classification of M. abscessus subsp. abscessus, M. abscessus subsp. massiliense and M. abscessus subsp. bolletii is useful clinically because of the discovery of the erm(41) gene, which is responsible for macrolide resistance in M. abscessus. Macrolide susceptibility is key for successful treatment of M. abscessus subsp. massiliense. The poor outcome and eradication of M. abscessus subsp. abscessus remains both a diagnostic and treatment challenge in approximately 80% of isolates that are macrolide resistant. Molecular studies, such as genotyping, may allow prediction of disease progression. Overall, there is a dearth of new literature surrounding M. abscessus. SUMMARY: New studies differentiating M. abscessus subsp. abscessus and M. abscessus subsp. massiliense based on the erm(41) gene demonstrate the latter to have a better prognosis and improved treatment outcomes. M. abscessus subsp. abscessus remains a formidable pathogen in diagnosis and treatment.

Laryngeal tuberculosis in the United States of America: a forgotten disease.

Laryngeal tuberculosis (TB) was a common manifestation of TB in the early twentieth century, but now represents only 1% of all cases. Most modern case series of laryngeal TB originate outside the USA. We report a case of laryngeal TB from our institution and review other US cases published between 1970 and 2012. One hundred twenty-seven cases were identified. The mean patient age was 49 y and 28% were female. The mean duration of symptoms was 19 weeks. Dysphonia and weight loss were the most common manifestations, seen in 96% and 47% of cases, respectively. These symptoms were usually attributed to malignancy initially. Most cases involved the vocal cords. Eighty-six percent of cases had underlying pulmonary involvement. Mortality was 3%. In the USA, laryngeal TB is rarely suspected and often confused with malignancy. This infection should be considered in patients with unexplained dysphonia and weight loss.