Antimicrobial agents and chemotherapy
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Antimicrob. Agents Chemother. · Jul 2015
The SmeYZ efflux pump of Stenotrophomonas maltophilia contributes to drug resistance, virulence-related characteristics, and virulence in mice.
The resistance-nodulation-division (RND)-type efflux pump is one of the causes of the multidrug resistance of Stenotrophomonas maltophilia. The roles of the RND-type efflux pump in physiological functions and virulence, in addition to antibiotic extrusion, have attracted much attention. In this study, the contributions of the constitutively expressed SmeYZ efflux pump to drug resistance, virulence-related characteristics, and virulence were evaluated. ⋯ Inactivation of smeYZ resulted in attenuation of oxidative stress susceptibility, swimming, flagella formation, biofilm formation, and secreted protease activity. Furthermore, loss of SmeYZ increased susceptibility to human serum and neutrophils and decreased in vivo virulence in a murine model. These findings suggest the possibility of attenuation of the resistance and virulence of S. maltophilia with inhibitors of the SmeYZ efflux pump.
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Antimicrob. Agents Chemother. · Jul 2015
Multicenter StudyDetermination of appropriate weight-based cutoffs for empiric cefazolin dosing using data from a phase 1 pharmacokinetics and safety study of cefazolin administered for surgical prophylaxis in pediatric patients aged 10 to 12 years.
Despite over 40 years of worldwide usage, relatively few data have been published on the pharmacokinetics of cefazolin in pediatric surgical patients. The primary objectives of this study were to examine the pharmacokinetics and safety of cefazolin in children 10 to 12 years of age (inclusive) receiving 1 or 2 g of cefazolin, based on body weight. This multiple-center, open-label study enrolled pediatric patients electively scheduled for surgical procedures who required cefazolin as part of their routine clinical management. ⋯ Patients weighing 50 to 60 kg exhibited elevated cefazolin exposures. Observed pharmacokinetic parameters and simulation results indicated that a weight-based cutoff of 60 kg is predicted to provide cefazolin exposure consistent with that observed in normal, healthy adults at recommended doses for surgical prophylaxis. (This study has been registered at ClinicalTrials.gov under registration no. NCT01904357.).
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Antimicrob. Agents Chemother. · Jul 2015
Clinical TrialFluconazole population pharmacokinetics and dosing for prevention and treatment of invasive Candidiasis in children supported with extracorporeal membrane oxygenation.
Candida infections are a leading cause of infectious disease-related death in children supported by extracorporeal membrane oxygenation (ECMO). The ECMO circuit can alter drug pharmacokinetics (PK); thus, standard fluconazole dosing may result in suboptimal drug exposures. The objective of our study was to determine the PK of fluconazole in children on ECMO. ⋯ The final model included the effect of serum creatinine (SCR) level on CL and the effect of ECMO on V as follows: CL (in liters per hour) = 0.019 × weight × (SCR/0.4)(-0.29) × exp(ηCL) and V (in liters) = 0.93 × weight × 1.4(ECMO) × exp(ηV). The fluconazole V was increased in children supported by ECMO. Consequently, children on ECMO require a higher fluconazole loading dose for prophylaxis (12 mg/kg of body weight) and treatment (35 mg/kg) paired with standard maintenance doses to achieve exposures similar to those of children not on ECMO.
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Antimicrob. Agents Chemother. · Jul 2015
Challenges and solutions for clinical development of new antibacterial agents: results of a survey among pharmaceutical industry professionals.
As the number of antibacterial medicines in the pipeline remains low, we anonymously surveyed pharmaceutical industry professionals on challenges and solutions for clinical development of these agents. Challenges were reported primarily as financial and regulatory. For multidrug-resistant organisms, there are needs for rapid diagnostic tests, new regulatory guidance, and adaptation of endpoints/trial designs. Regulators and public/private initiatives are addressing these challenges to help ensure that proposed solutions have the support of all involved stakeholders.