Antimicrobial agents and chemotherapy
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Antimicrob. Agents Chemother. · Sep 2015
Meropenem population pharmacokinetics in critically ill patients with septic shock and continuous renal replacement therapy: influence of residual diuresis on dose requirements.
Meropenem dosing in critically ill patients with septic shock and continuous renal replacement therapy (CRRT) is complex, with the recommended maintenance doses being 500 mg to 1,000 mg every 8 h (q8h) to every 12 h. This multicenter study aimed to describe the pharmacokinetics (PKs) of meropenem in this population to identify the sources of PK variability and to evaluate different dosing regimens to develop recommendations based on clinical parameters. Thirty patients with septic shock and CRRT receiving meropenem were enrolled (153 plasma samples were tested). ⋯ If 100% of the ƒ uT >MIC was chosen as the target, oligoanuric patients would require 500 mg q8h as a bolus over 30 min for the treatment of susceptible bacteria (MIC < 2 mg/liter), while patients with preserved diuresis would require the same dose given as an infusion over 3 h. If bacteria with MICs close to the resistance breakpoint (2 to 4 mg/liter) were to be treated with meropenem, a dose of 500 mg every 6 h would be necessary: a bolus over 30 min for oligoanuric patients and an infusion over 3 h for patients with preserved diuresis. Our results suggest that residual diuresis may be an easy and inexpensive tool to help with titration of the meropenem dose and infusion time in this challenging population.
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Antimicrob. Agents Chemother. · Aug 2015
Unprecedented Silver Resistance in Clinically Isolated Enterobacteriaceae: Major Implications for Burn and Wound Management.
Increased utilization of inorganic silver as an adjunctive to many medical devices has raised concerns of emergent silver resistance in clinical bacteria. Although the molecular basis for silver resistance has been previously characterized, to date, significant phenotypic expression of these genes in clinical settings is yet to be observed. Here, we identified the first strains of clinical bacteria expressing silver resistance at a level that could significantly impact wound care and the use of silver-based dressings. ⋯ This finding suggested that the isolates may neutralize ionic silver via reduction to elemental silver. Antimicrobial testing revealed both organisms to be completely resistant to many commercially available silver-impregnated burn and wound dressings. Taken together, these findings provide the first evidence of clinical bacteria capable of expressing silver resistance at levels that could significantly impact wound management.
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Antimicrob. Agents Chemother. · Aug 2015
The 8-Pyrrole-Benzothiazinones Are Noncovalent Inhibitors of DprE1 from Mycobacterium tuberculosis.
8-Nitro-benzothiazinones (BTZs), such as BTZ043 and PBTZ169, inhibit decaprenylphosphoryl-β-d-ribose 2'-oxidase (DprE1) and display nanomolar bactericidal activity against Mycobacterium tuberculosis in vitro. Structure-activity relationship (SAR) studies revealed the 8-nitro group of the BTZ scaffold to be crucial for the mechanism of action, which involves formation of a semimercaptal bond with Cys387 in the active site of DprE1. ⋯ These compounds inhibit DprE1 with 50% inhibitory concentration (IC50) values of <8 μM and present favorable in vitro absorption-distribution-metabolism-excretion/toxicity (ADME/T) and in vivo pharmacokinetic profiles. The most promising compound, PyrBTZ01, did not show efficacy in a mouse model of acute tuberculosis, suggesting that BTZ-mediated killing through DprE1 inhibition requires a combination of both covalent bond formation and compound potency.
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Antimicrob. Agents Chemother. · Aug 2015
Multicenter Study Clinical TrialEvidence of Plasmodium falciparum Malaria Multidrug Resistance to Artemisinin and Piperaquine in Western Cambodia: Dihydroartemisinin-Piperaquine Open-Label Multicenter Clinical Assessment.
Western Cambodia is recognized as the epicenter of Plasmodium falciparum multidrug resistance. Recent reports of the efficacy of dihydroartemisinin (DHA)-piperaquine (PP), the latest of the artemisinin-based combination therapies (ACTs) recommended by the WHO, have prompted further investigations. The clinical efficacy of dihydroartemisinin-piperaquine in uncomplicated falciparum malaria was assessed in western and eastern Cambodia over 42 days. ⋯ Our data show evidence of P. falciparum resistance to PP in western Cambodia, an area of widespread artemisinin resistance. New therapeutic strategies, such as the use of triple ACTs, are urgently needed and must be tested. (This study has been registered at the Australian New Zealand Clinical Trials Registry under registration no. ACTRN12614000344695.).