Diagnostic microbiology and infectious disease
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Diagn. Microbiol. Infect. Dis. · Nov 2010
Randomized Controlled TrialComparison of 30-min and 3-h infusion regimens for imipenem/cilastatin and for meropenem evaluated by Monte Carlo simulation.
Imipenem/cilastatin and meropenem are carbapenem antibiotics that are infused intravenously (IV) over 30 to 45 min. We evaluated probability of target attainment and cumulative probability of target attainment of 30-min and 3-h infusions for imipenem/cilastatin and meropenem. Eighteen healthy adults in a randomized, 4-phase, crossover study received 1000 mg of imipenem/cilastatin or meropenem as a single-dose IV over 30 min or 3 h. ⋯ Monte Carlo simulations using various dosage regimens at steady-state and 30-min and 3-h infusion rates were performed to evaluate the probabilities of attaining 20% (bacteriostatic), 30%, and 40% (maximum kill) time above the MIC. Three-hour infusions of imipenem/cilastatin and meropenem improved the cumulative probability of target attainment for a variety of populations of microorganisms compared to 30-min infusions. Prolonged infusions have the potential to optimize efficacy of imipenem/cilastatin and meropenem.
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Diagn. Microbiol. Infect. Dis. · Nov 2010
Case ReportsSelection and viral load kinetics of an oseltamivir-resistant pandemic influenza A (H1N1) virus in an immunocompromised patient during treatment with neuraminidase inhibitors.
Prolonged viral excretion in immunocompromised hosts leads to long oseltamivir treatment and to the subsequent development of oseltamivir-resistant pandemic influenza virus selection. We report the selection and nasopharyngeal shedding kinetics of an oseltamivir-resistant strain in a hospitalized immunocompromised patient with prolonged influenza illness. Viral load quantification and genotyping methods were performed from 7 serial nasopharyngeal samples. ⋯ Twelve days after the onset of symptoms, an oseltamivir-resistant strain was selected. After 12 days of inhaled zanamivir treatment, the patient was discharged asymptomatic. The study emphasizes the importance of viral load quantification and surveillance of emergence of resistant strains prospectively because the information provided has important implications in the clinical management of the patient.
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Diagn. Microbiol. Infect. Dis. · Nov 2010
Case ReportsThe limitations of polymerase chain reaction in the setting of possible recurrent tuberculosis: 2 instructional cases.
The interpretation of a positive result for Mycobacterium tuberculosis by nucleic acid amplification such as polymerase chain reaction (PCR) can be challenging. We present 2 cases that illustrate the limitations of tuberculosis PCR on respiratory secretions in previously treated patients, even years after the previous disease episode.
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Diagn. Microbiol. Infect. Dis. · Oct 2010
Clinical utility and prognostic value of bronchoalveolar lavage galactomannan in patients with hematologic malignancies.
We conducted a single-center retrospective cohort study to determine the performance characteristics of the galactomannan (GM) assay in bronchoalveolar lavage (BAL) in patients with hematologic malignancies. Patients were classified as proven, probable, possible, or no invasive pulmonary aspergillosis (IPA), according to international guidelines. A total of 173 BAL samples from 145 patients were included. ⋯ Using a GM index cutoff of ≥ 2.0, the sensitivity and NPV remained 100%, but specificity and PPV increased to 93% and 50%, respectively. The BAL GM assay is a highly sensitive screening test for IPA in patients with hematologic malignancies. Increasing the cutoff value to 2.0 would improve the performance of this assay.
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Diagn. Microbiol. Infect. Dis. · Jul 2010
Metallo-beta-lactamase-producing imipenem-resistant Pseudomonas aeruginosa clinical isolates in a university teaching hospital in Malaysia: detection of IMP-7 and first identification of IMP-4, VIM-2, and VIM-11.
Ninety (n = 90) imipenem-resistant Pseudomonas aeruginosa (IRPA) clinical isolates collected randomly during 2005 to 2008 from University Malaya Medical Center were assessed for the presence of different variants of metallo-beta-lactamase (MBL) genes. Polymerase chain reaction (PCR) assay detected 32 (n = 32) MBL gene PCR-positive isolates with the presence of bla(IMP) gene in 14 (n = 14) and bla(VIM) in 18 (n = 18) isolates. Four allelic variants, bla(IMP-7) (12 isolates), bla(IMP-4) (2 isolates), bla(VIM-2) (17 isolates), and bla(VIM-11) (1 isolate), of MBL genes were identified. This study is the first report of detection of bla(IMP-4), bla(VIM-2), and bla(VIM-11) MBL genes from IRPA clinical isolates in Malaysia.