Emergence of antibiotic-specific phenotypes during prolonged treatment of mice.

A major challenge in tuberculosis (TB) therapeutics is that antibiotic exposure leads to changes in the physiology of (), which may enable the pathogen to withstand treatment. While antibiotic-treated has been evaluated in experiments it is unclear if and how long-term treatment with diverse antibiotics with varying treatment-shortening activity (sterilizing activity) affects physiologic processes differently. Here, we used SEARCH-TB, a pathogen-targeted RNA-sequencing platform, to characterize the transcriptome in the BALB/c high-dose aerosol infection mouse model following 4 weeks of treatment with three sterilizing and three non-sterilizing antibiotics.

Emergence of antibiotic-specific phenotypes during prolonged treatment of mice.

A major challenge in tuberculosis (TB) therapeutics is that antibiotic exposure leads to changes in the physiologic state of () which may enable the pathogen to withstand treatment. While antibiotic-treated have been evaluated in short-term experiments, it is unclear if and how long-term treatment with diverse antibiotics with varying treatment-shortening activity (sterilizing activity) affect physiologic states differently. Here, we used SEARCH-TB, a pathogen-targeted RNA-sequencing platform, to characterize the transcriptome in the BALB/c high-dose aerosol infection mouse model following 4-week treatment with three sterilizing and three non-sterilizing antibiotics.

Transcriptional adaptation of that survives prolonged multi-drug treatment in mice.

A major reason that curing tuberculosis requires prolonged treatment is that drug exposure changes bacterial phenotypes. The physiologic adaptations of that survive drug exposure have been obscure due to low sensitivity of existing methods in drug-treated animals. Using the novel SEARCH-TB RNA-seq platform, we elucidated phenotypes in mice treated for with the global standard 4-drug regimen and compared them with the effect of the same regimen .

Lung microenvironments harbor phenotypes with distinct treatment responses.

Tuberculosis lung lesions are complex and harbor heterogeneous microenvironments that influence antibiotic effectiveness. Major strides have been made recently in understanding drug pharmacokinetics in pulmonary lesions, but the bacterial phenotypes that arise under these conditions and their contribution to drug tolerance are poorly understood. A pharmacodynamic marker called the RS ratio quantifies ongoing rRNA synthesis based on the abundance of newly synthesized precursor rRNA relative to mature structural rRNA.

Spiropyrimidinetriones: a Class of DNA Gyrase Inhibitors with Activity against Mycobacterium tuberculosis and without Cross-Resistance to Fluoroquinolones.

Described here is a series of spiropyrimidinetrione (SPT) compounds with activity against Mycobacterium tuberculosis through inhibition of DNA gyrase. The SPT class operates via a novel mode of inhibition, which involves Mg-independent stabilization of the DNA cleavage complex with DNA gyrase and is thereby not cross-resistant with other DNA gyrase-inhibiting antibacterials, including fluoroquinolones. Compound 22 from the series was profiled broadly and showed cidality as well as intracellular activity against M.

1,3-Diarylpyrazolyl-acylsulfonamides as Potent Anti-tuberculosis Agents Targeting Cell Wall Biosynthesis in .

Phenotypic whole cell high-throughput screening of a ∼150,000 diverse set of compounds against (Mtb) in cholesterol-containing media identified 1,3-diarylpyrazolyl-acylsulfonamide as a moderately active hit. Structure-activity relationship (SAR) studies demonstrated a clear scope to improve whole cell potency to MIC values of <0.5 μM, and a plausible pharmacophore model was developed to describe the chemical space of active compounds.

Comparative Analysis of Pharmacodynamics in the C3HeB/FeJ Mouse Tuberculosis Model for DprE1 Inhibitors TBA-7371, PBTZ169, and OPC-167832.

Multiple drug discovery initiatives for tuberculosis are currently ongoing to identify and develop new potent drugs with novel targets in order to shorten treatment duration. One of the drug classes with a new mode of action is DprE1 inhibitors targeting an essential process in cell wall synthesis of Mycobacterium tuberculosis. In this investigation, three DprE1 inhibitors currently in clinical trials, TBA-7371, PBTZ169, and OPC-167832, were evaluated side-by-side as single agents in the C3HeB/FeJ mouse model presenting with caseous necrotic pulmonary lesions upon tuberculosis infection.

Susceptibility of Mycobacterium abscessus to antimycobacterial drugs in preclinical models.

Over the last 10 years, Mycobacterium abscessus group strains have emerged as important human pathogens, which are associated with significantly higher fatality rates than any other rapidly growing mycobacteria. These opportunistic pathogens are widespread in the environment and can cause a wide range of clinical diseases, including skin, soft tissue, central nervous system, and disseminated infections; by far, the most difficult to treat is the pulmonary form. Infections with M.