Antimicrobial agents and chemotherapy
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Antimicrob. Agents Chemother. · Aug 2013
Evaluation of a nisin-eluting nanofiber scaffold to treat Staphylococcus aureus-induced skin infections in mice.
Staphylococcus aureus is a virulent pathogen and a major causative agent of superficial and invasive skin and soft tissue infections (SSSTIs). Antibiotic resistance in S. aureus, among other bacterial pathogens, has rapidly increased, and this is placing an enormous burden on the health care sector and has serious implications for infected individuals, especially immunocompromised patients. Alternative treatments thus need to be explored to continue to successfully treat infections caused by S. aureus, including antibiotic-resistant strains of S. aureus. ⋯ The bacterial burden of wounds treated with nisin-containing nanofiber wound dressings was 4.3 × 10(2) CFU/wound, whereas wounds treated with control nanofiber wound dressings had 2.2 × 10(7) CFU/wound on the last day of the trial (day 7). Furthermore, the wound dressings stimulated wound closure of excisional wounds, and no adverse effects were observed by histological analysis. Nisin-containing nanofiber wound dressings have the potential to treat S. aureus skin infections and to potentially accelerate wound healing of excisional wounds.
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Antimicrob. Agents Chemother. · Jul 2013
Relationship of in vitro synergy and treatment outcome with daptomycin plus rifampin in patients with invasive methicillin-resistant Staphylococcus aureus infections.
We report the findings of a study examining the relationship between in vitro daptomycin-rifampin synergy and the therapeutic outcome of 12 patients with complex deep methicillin-resistant Staphylococcus aureus (MRSA) infections treated for prolonged periods with this combination. Checkerboard synergy was found in nine cases and was 100% predictive of therapeutic success; absence of synergy was found in three cases, two of which were therapeutic failures (P = 0.045). No relationship was observed between synergy and outcome by time-kill assessment. Checkerboard synergy may predict clinical response to daptomycin plus rifampin for complex invasive MRSA infections requiring prolonged treatment.
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Macrolide antibiotics are largely used in pregnancy for different bacterial infections. Their fetal safety has been studied by several groups, yielding opposing results. In particular, there have been studies claiming an association between macrolides and cardiovascular malformations. ⋯ Similarly, no associations were demonstrated with pyloric stenosis or intussusception. Use of macrolides in the first trimester of pregnancy is not associated with an increased risk of major malformations. Exposure in the third trimester is not likely to increase neonatal risks for pyloric stenosis or intussusception in a clinically meaningful manner.
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Antimicrob. Agents Chemother. · Jul 2013
Multicenter StudyAppropriateness of empirical treatment and outcome in bacteremia caused by extended-spectrum-β-lactamase-producing bacteria.
We studied clinical characteristics, appropriateness of initial antibiotic treatment, and other factors associated with day 30 mortality in patients with bacteremia caused by extended-spectrum-β-lactamase (ESBL)-producing bacteria in eight Dutch hospitals. Retrospectively, information was collected from 232 consecutive patients with ESBL bacteremia (due to Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae) between 2008 and 2010. In this cohort (median age of 65 years; 24 patients were <18 years of age), many had comorbidities, such as malignancy (34%) or recurrent urinary tract infection (UTI) (15%). ⋯ Further assessment of confounding and a stratified analysis for patients with UTI and non-UTI origins of infection did not reveal a statistically significant effect of inappropriate therapy on day 30 mortality, and these results were insensitive to the possible misclassification of patients who had received β-lactam-β-lactamase inhibitor combinations or ceftazidime as initial treatment. In conclusion, ESBL bacteremia occurs mostly in patients with comorbidities requiring frequent hospitalization, and 84% of episodes were health care associated. Factors other than inappropriate therapy within <24 h determined day 30 mortality.
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Antimicrob. Agents Chemother. · Jul 2013
Pharmacokinetics of first-line tuberculosis drugs in Tanzanian patients.
East Africa has a high tuberculosis (TB) incidence and mortality, yet there are very limited data on exposure to TB drugs in patients from this region. We therefore determined the pharmacokinetic characteristics of first-line TB drugs in Tanzanian patients using intensive pharmacokinetic sampling. In 20 adult TB patients, plasma concentrations were determined just before and at 1, 2, 3, 4, 6, 8, 10, and 24 h after observed drug intake with food to estimate the areas under the curve from 0 to 24 h (AUC0-24) and peak plasma concentrations (Cmax) of isoniazid, rifampin, pyrazinamide, and ethambutol. ⋯ A substantial proportion of patients had an isoniazid and/or rifampin Cmax below the reference range. Intake of TB drugs with food may partly explain these low drug levels, but such a drug intake reflects common practice. The finding of low TB drug concentrations is concerning because low concentrations have been associated with worse treatment outcome in several other studies.