Antimicrobial agents and chemotherapy
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Antimicrob. Agents Chemother. · Nov 2010
Should moxifloxacin be used for the treatment of extensively drug-resistant tuberculosis? An answer from a murine model.
The prevalence of extensively drug-resistant tuberculosis (XDR-TB), defined as TB that is resistant to isoniazid, rifampin, fluoroquinolones, and aminoglycosides, is rising worldwide. The extent of Mycobacterium tuberculosis resistance to fluoroquinolones depends on the mutation in the DNA gyrase, the only target of fluoroquinolones. The MIC of moxifloxacin, the most active fluoroquinolone against M. tuberculosis, may be lower than its peak serum level for some ofloxacin-resistant strains of Mycobacterium tuberculosis. ⋯ Moxifloxacin reduced mortality in mice infected with mutant strain GyrA A90V with an intermediate MIC (2 μg/ml). However, it had no impact on the mutant strain GyrA D94G with the highest MIC (4 μg/ml). Our study underscores current WHO recommendations to use moxifloxacin when there is resistance to early-generation fluoroquinolones such as ofloxacin, restricting this recommendation to strains with moxifloxacin MICs of less than or equal to 2 μg/ml.
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Antimicrob. Agents Chemother. · Oct 2010
Randomized Controlled TrialEfficacy and safety of nemonoxacin versus levofloxacin for community-acquired pneumonia.
Nemonoxacin, a novel nonfluorinated quinolone, exhibits potent in vitro and in vivo activities against community-acquired pneumonia (CAP) pathogens, including multidrug-resistant Streptococcus pneumoniae. Patients with mild to moderate CAP (n = 265) were randomized to receive oral nemonoxacin (750 mg or 500 mg) or levofloxacin (500 mg) once daily for 7 days. Clinical responses were determined at the test-of-cure visit in intent-to-treat (ITT), clinical per protocol (PPc), evaluable-ITT, and evaluable-PPc populations. ⋯ Overall, oral nemonoxacin (both 750 mg and 500 mg) administered for 7 days resulted in high clinical and bacteriological success rates in CAP patients. Further, good tolerability and excellent activity against common causative pathogens were demonstrated. Nemonoxacin (750 mg and 500 mg) once daily is as effective and safe as levofloxacin (500 mg) once daily for the treatment of CAP.
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Antimicrob. Agents Chemother. · Oct 2010
Colistin dosing and nephrotoxicity in a large community teaching hospital.
Thirty adult patients who received intravenous colistin (5.1 ± 2.4 mg/kg/day) were reviewed to evaluate dosing with respect to nephrotoxicity, which occurred in 10 (33%) patients within the first 5 days of treatment. Excessive colistin dosing was frequent (47%), often (71%) resulted from the use of actual body weight in obese patients, and was associated with higher rates of nephrotoxicity (80% versus 30%, P = 0.019).
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Pentraxin 3 (PTX3) is an acute-phase glycoprotein with a nonredundant function in the host resistance to Aspergillus fumigatus. PTX3 activity was evaluated against pulmonary aspergillosis in rats immunosuppressed with cortisone acetate. PTX3 enhanced the survival rate and reduced the lung fungal burden of infected rats in both therapeutic and prophylactic modalities. Thus, we extended the protective activity of PTX3 in pulmonary aspergillosis to corticosteroid-induced immunodeficiency, which is a relevant clinical condition in graft-versus-host disease and in solid organ transplant.
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Antimicrob. Agents Chemother. · Sep 2010
Influence of empiric therapy with a beta-lactam alone or combined with an aminoglycoside on prognosis of bacteremia due to gram-negative microorganisms.
Evidence supporting the combination of aminoglycosides with beta-lactams for gram-negative bacteremia is inconclusive. We have explored the influence on survival of empirical therapy with a beta-lactam alone versus that with a beta-lactam-aminoglycoside combination by retrospectively analyzing a series of bacteremic episodes due to aerobic or facultative gram-negative microorganisms treated with single or combination therapy. The outcome variable was a 30-day mortality. ⋯ In patients with gram-negative bacteremia, we could not find an overall association between empirical beta-lactam-aminoglycoside combination therapy and prognosis. However, a survival advantage cannot be discarded for episodes presenting shock or neutropenia, hence in these situations the use of combination therapy may still be justified. Combination therapy also should be considered for patients at risk of being infected with resistant organisms, if only to increase the appropriateness of empirical therapy.