Publications by authors named "Marcel A Behr"

Background: Prevention of drug-resistant tuberculosis is a global health priority. However, trials evaluating the effectiveness of treating infection among contacts of persons with drug-resistant tuberculosis are lacking.

Methods: We conducted a double-blind, randomized, controlled trial comparing 6 months of daily levofloxacin (weight-based doses) with placebo to treat infection.

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Nontuberculous mycobacteria (NTM) are emerging human pathogens linked to severe pulmonary diseases. Current treatments involve the prolonged use of multiple drugs and are often ineffective. Bacterial dihydrofolate reductase (DHFR) is a key enzyme targeted by antibiotics in Gram-negative bacterial infections.

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(Mtb), the pathogen responsible for tuberculosis (TB), is the leading cause of bacterial disease-related death worldwide. Current antibiotic regimens for the treatment of TB remain dated and suffer from long treatment times as well as the development of drug resistance. As such, the search for novel chemical modalities that have selective or potent anti-Mtb properties remains an urgent priority, particularly against multidrug-resistant (MDR) Mtb strains.

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In the lower respiratory tract, the alveolar spaces are divided from the bloodstream and the external environment by only a few microns of interstitial tissue. Alveolar macrophages (AMs) defend this delicate mucosal surface from invading infections by regularly patrolling the site. AMs have three behavior modalities to achieve this goal: extending cell protrusions to probe and sample surrounding areas, squeezing the whole cell body between alveoli, and patrolling by moving the cell body around each alveolus.

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Article Synopsis
  • Mycobacterium abscessus complex (MABC) is an opportunistic bacteria that can cause severe pulmonary infections, leading to a study investigating its transmission in healthcare settings in Montréal.
  • The research analyzed 221 bacterial isolates from 115 individuals between 2010-2018 for genetic similarities, revealing 28 sequence types and 210 pairs of isolates within a close genetic range, although no definitive person-to-person transmission was identified.
  • The study concluded that while genomic analysis is helpful, it’s not enough to confirm MABC transmission in healthcare, suggesting that infections likely aren't spread directly between patients in these environments.
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The complete genome sequence of the most ancestral type SI strain of subspecies 6756, isolated from a sheep, was determined. The genome was sequenced using PacBio technology, yielding a genome size of 4,830,294 nucleotides with no identified plasmids.

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Objectives: Heteroresistant infections are defined as infections in which a mixture of drug-resistant and drug-susceptible populations are present. In (), heteroresistance poses a challenge in diagnosis and has been linked with poor treatment outcomes. We compared the analytical sensitivity of molecular methods, such as GeneXpert and whole genome sequencing (WGS) in detecting heteroresistance when compared with the 'gold standard' phenotypic assay: the agar proportion method (APM).

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Bovine tuberculosis (bTB), traditionally associated with , presents significant public health and economic challenges worldwide. This study investigated the causative agents of bTB in slaughtered cattle and buffalo in Lahore, Pakistan. Of the 3,581 animals screened, 34 were identified with gross TB-like lesions.

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Reference-based alignment of short-reads is a widely used technique in genomic analysis of the complex (MTBC) and the choice of reference sequence impacts the interpretation of analyses. The most widely used reference genomes include the ATCC type strain (H37Rv) and the putative MTBC ancestral sequence of Comas both of which are based on a lineage 4 sequence. As such, these reference sequences do not capture all of the structural variation known to be present in the ancestor of the MTBC.

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Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis, a chronic gastrointestinal disease affecting ruminants. This disease remains widespread in part due to the limitations of available diagnostics and vaccines.

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A new tuberculosis vaccine is a high priority. However, the classical development pathway is a major deterrent. Most tuberculosis cases arise within 2 years after Mycobacterium tuberculosis exposure, suggesting a 3-year trial period should be possible if sample size is large to maximize the number of early exposures.

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Mycobacteria are responsible for several human and animal diseases. NOD2 is a pattern recognition receptor that has an important role in mycobacterial recognition. However, the mechanisms by which mutations in NOD2 alter the course of mycobacterial infection remain unclear.

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is a member of the complex (MTBC) and causes tuberculosis in a variety of animals, including humans in South Asia. Here, we describe the clinical features associated with 8 human cases of whole genome sequence (WGS) confirmed from a tertiary care hospital in South India during 2018-2019. The patient ages ranged from 9 to 51 years, with 5 females and 3 males included.

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Despite our best efforts to discover new antimicrobials, bacteria have evolved mechanisms to become resistant. Resistance to antimicrobials can be attributed to innate, inducible, and acquired mechanisms. is one of the most antimicrobial resistant bacteria and is known to cause chronic pulmonary infections within the cystic fibrosis community.

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