International journal of antimicrobial agents
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Int. J. Antimicrob. Agents · Apr 2018
Case ReportsGenotypic variations between wild-type and small colony variant of Staphylococcus aureus in prosthetic valve infectious endocarditis: a comparative genomic and transcriptomic analysis.
Staphylococcus aureus small colony variants (SCVs) can cause persistent infections. However, the genomes and transcriptomes of S. aureus SCVs remain poorly understood. A pair of isogenic wild-type and SCV methicillin-resistant S. aureus (MRSA) strains (IE1 and IE2, respectively) were isolated from a patient with prosthetic valve infectious endocarditis. ⋯ Most of the differentially expressed genes were involved in metabolism. Expression levels of several genes involved in the pathways to which plsY, deoC, eap and sstD belonged were changed, associated with the metabolism and virulence of S. aureus. In conclusion, the reduced growth rate and decreased virulence of MRSA SCV strains may be related to mutations in and downregulation of genes associated with metabolism and virulence, especially plsY, deoC, eap and sstD.
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Int. J. Antimicrob. Agents · Mar 2018
Observational StudyAssociation between augmented renal clearance, antibiotic exposure and clinical outcome in critically ill septic patients receiving high doses of β-lactams administered by continuous infusion: a prospective observational study.
This study assessed whether augmented renal clearance (ARC) impacts negatively on antibiotic concentrations and clinical outcomes in patients treated by high-dose β-lactams administered continuously. Over a 9-month period, all critically ill patients without renal impairment treated by one of the monitored β-lactams for a documented infection were eligible. During the first 3 days of antibiotic therapy, every patient underwent 24-h CLCr measurements and therapeutic drug monitoring. ⋯ Mean CLCr values ≥170 mL/min were significantly associated with subexposure<4xMIC [OR = 10.1 (2.4-41.6); P = 0.001]. Patients with subexposure<4×MIC presented higher rates of therapeutic failure [OR = 6.3 (1.2-33.2); P = 0.03]. Mean CLCr values ≥170 mL/min remain a risk factor for subexposure to β-lactams despite high doses of β-lactams administered continuously. β-Lactam subexposure was associated with higher rates of therapeutic failure in septic critically ill patients.
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Int. J. Antimicrob. Agents · Mar 2018
Observational StudyCo-infection with influenza-associated acute respiratory distress syndrome requiring extracorporeal membrane oxygenation.
The co-infection frequency and impact among influenza-associated acute respiratory distress syndrome (ARDS) patients requiring extracorporeal membrane oxygenation (ECMO) are not known. This retrospective observational analysis concerned data prospectively collected from patients admitted to our medical intensive care unit (ICU) who received ECMO support for influenza-associated ARDS between 2009-2016. Co-infection was defined as occurring within 48 h following ICU admission. ⋯ In conclusion, co-infection is frequent in ECMO-treated patients with influenza-associated ARDS, affecting ca. 50%, and is independently associated with poor outcome. Staphylococcus aureus was the most frequently identified pathogen, with a high rate of PVL-positive S. aureus. Whether specific therapy targeting PVL-producing S. aureus should be given remains to be determined.
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Int. J. Antimicrob. Agents · Feb 2018
Ceftolozane/tazobactam activity against drug-resistant Enterobacteriaceae and Pseudomonas aeruginosa causing healthcare-associated infections in the Asia-Pacific region (minus China, Australia and New Zealand): report from an Antimicrobial Surveillance Programme (2013-2015).
The aim of this study was to evaluate the in vitro activity of ceftolozane/tazobactam and comparator agents tested against Enterobacteriaceae and Pseudomonas aeruginosa isolates from patients in the Asia-Pacific (APAC) region with healthcare-associated infections. Ceftolozane/tazobactam is an antipseudomonal cephalosporin combined with a well-established β-lactamase inhibitor. A total of 1963 Gram-negative organisms (489 P. aeruginosa and 1474 Enterobacteriaceae) were consecutively collected using a prevalence-based approach from 14 medical centres in the APAC region. ⋯ Ceftolozane/tazobactam was the most potent (MIC50/90, 0.5/4 µg/mL) β-lactam agent tested against P. aeruginosa isolates, inhibiting 90.8% at an MIC of ≤4 µg/mL. Pseudomonas aeruginosa exhibited high rates of susceptibility to amikacin [91.2/89.4% (CLSI/EUCAST)] and colistin [98.4/100.0% (CLSI/EUCAST)]. Ceftolozane/tazobactam was the most active β-lactam agent tested against P. aeruginosa and demonstrated higher in vitro activity than available cephalosporins when tested against Enterobacteriaceae.
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Int. J. Antimicrob. Agents · Jan 2018
Review Meta AnalysisInhaled colistin monotherapy for respiratory tract infections in adults without cystic fibrosis: a systematic review and meta-analysis.
Inhaled colistin is becoming increasingly popular against respiratory tract infections caused by multidrug resistant (MDR) Gram-negative bacteria because it may overcome the problems associated with intravenous (IV) administration. ⋯ Inhaled colistin monotherapy may deserve further consideration as a mode for colistin administration for the treatment of respiratory tract infections caused by MDR A. baumannii and P. aeruginosa.