Multi-omics informed mathematical model for meropenem and tobramycin against hypermutable Pseudomonas aeruginosa.

Hypermutable P. aeruginosa isolates frequently display resistance emergence during treatment. Mechanisms of such resistance emergence have not been explored using dynamic hollow-fiber studies and multi-omics-informed mathematical modeling.

Cold Exposure and Oral Delivery of GLP-1R Agonists by an Engineered Probiotic Yeast Strain Have Antiobesity Effects in Mice.

Advanced microbiome therapeutics (AMTs) holds promise in utilizing engineered microbes such as bacteria or yeasts for innovative therapeutic applications, including the delivery of therapeutic peptides. Glucagon-like peptide-1 receptor agonists, such as Exendin-4, have emerged as potential treatments for type 2 diabetes and obesity. However, current administration methods face challenges with patient adherence and low oral bioavailability.

Effects of broad-spectrum antibiotics on the colonisation of probiotic yeast Saccharomyces boulardii in the murine gastrointestinal tract.

Mouse models are commonly used to study the colonisation profiles of microorganisms introduced to the gastrointestinal tract. Three commonly used mouse models include conventional, germ-free, and antibiotic-treated mice. However, colonisation resistance in conventional mice and specialised equipment for germ-free mice are usually limiting factors in their applications.

Unique mechanistic insights into pathways associated with the synergistic activity of polymyxin B and caspofungin against multidrug-resistant .

is an opportunistic Gram-negative pathogen causing nosocomial infections. rapidly acquires antibiotic resistance and is known as a reservoir for resistance genes. Polymyxins remain effective as a last-line therapy against infections caused by multidrug-resistant (MDR) ; however, resistance to polymyxins emerges rapidly with monotherapy.

Evaluation of Tobramycin and Ciprofloxacin as a Synergistic Combination Against Hypermutable Strains via Mechanism-Based Modelling.

Hypermutable strains have a greatly increased mutation rate and are prevalent in chronic respiratory infections. Initially, we systematically evaluated the time-course of total and resistant populations of hypermutable (PAO∆) and non-hypermutable (PAO1) strains in 48-h static concentration time-kill studies with two inocula. Both strains were exposed to clinically relevant concentrations of important antibiotics (aztreonam, ceftazidime, imipenem, meropenem, tobramycin, and ciprofloxacin) in monotherapy.

Characterization of Hypermutator Pseudomonas aeruginosa Isolates from Patients with Cystic Fibrosis in Australia.

Hypermutable isolates (hypermutators) have been identified in patients with cystic fibrosis (CF) and are associated with reduced lung function. Hypermutators display a greatly increased mutation rate and an enhanced ability to become resistant to antibiotics during treatment. Their prevalence has been established among patients with CF, but it has not been determined for patients with CF in Australia.

Meropenem Combined with Ciprofloxacin Combats Hypermutable Pseudomonas aeruginosa from Respiratory Infections of Cystic Fibrosis Patients.

Hypermutable organisms are prevalent in chronic respiratory infections and have been associated with reduced lung function in cystic fibrosis (CF); these isolates can become resistant to all antibiotics in monotherapy. This study aimed to evaluate the time course of bacterial killing and resistance of meropenem and ciprofloxacin in combination against hypermutable and nonhypermutable Static concentration time-kill experiments over 72 h assessed meropenem and ciprofloxacin in mono- and combination therapies against PAO1 (nonhypermutable), PAOΔ (hypermutable), and hypermutable isolates CW8, CW35, and CW44 obtained from CF patients with chronic respiratory infections. Meropenem (1 or 2 g every 8 h [q8h] as 3-h infusions and 3 g/day as a continuous infusion) and ciprofloxacin (400 mg q8h as 1-h infusions) in monotherapies and combinations were further evaluated in an 8-day hollow-fiber infection model study (HFIM) against CW44.

Optimization of a Meropenem-Tobramycin Combination Dosage Regimen against Hypermutable and Nonhypermutable Pseudomonas aeruginosa via Mechanism-Based Modeling and the Hollow-Fiber Infection Model.

Hypermutable strains are prevalent in patients with cystic fibrosis and rapidly become resistant to antibiotic monotherapies. Combination dosage regimens have not been optimized against such strains using mechanism-based modeling (MBM) and the hollow-fiber infection model (HFIM). The PAO1 wild-type strain and its isogenic hypermutable PAOΔ strain (MIC of 1.

Resistance suppression by high-intensity, short-duration aminoglycoside exposure against hypermutable and non-hypermutable Pseudomonas aeruginosa.

Objectives: Hypermutable bacteria are causing a drastic problem via their enhanced ability to become resistant. Our objectives were to compare bacterial killing and resistance emergence between differently shaped tobramycin concentration-time profiles at a given fAUC/MIC, and determine the tobramycin exposure durations that prevent resistance.

Methods: Static concentration time-kill studies over 24 h used Pseudomonas aeruginosa WT strains (ATCC 27853 and PAO1) and hypermutable PAOΔmutS.

Shape does matter: short high-concentration exposure minimizes resistance emergence for fluoroquinolones in Pseudomonas aeruginosa.

Objectives: For fluoroquinolones, the area under the free plasma concentration-time curve divided by the MIC (fAUC/MIC) best predicts bacterial killing in mice and outcomes in patients. However, it is unknown whether the shape of the antibiotic concentration profile affects resistance emergence. Our objective was to compare killing and resistance between ciprofloxacin concentration profiles with different shapes at the same fAUC/MIC and identify the durations of ciprofloxacin exposure that minimize resistance emergence.