Journal of clinical microbiology
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J. Clin. Microbiol. · Nov 2009
Case ReportsFalse-positive PCR detection of Tropheryma whipplei in cerebrospinal fluid and biopsy samples from a child with chronic lymphocytic meningitis.
We report the case of a teenager with chronic lymphocytic meningitis for whom Tropheryma whipplei 16S rRNA PCR results were positive in two cerebrospinal fluid samples and one duodenal biopsy specimen. PCR targeting another specific sequence of Tropheryma whipplei and sequencing of the initially amplified 16S rRNA fragment did not confirm the results.
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J. Clin. Microbiol. · Oct 2009
Molecular characterization of Capnocytophaga canimorsus and other canine Capnocytophaga spp. and assessment by PCR of their frequencies in dogs.
Capnocytophaga canimorsus can be a virulent pathogen, whereas C. cynodegmi is of low virulence. Heterogeneity within these species, their frequency in dogs, and pathogenicity factors are largely unknown. Strains from blood cultures from patients presumptively identified as C. canimorsus (n = 25) and as C. cynodegmi by rrs analysis (n = 4), blood cultures from dogs (n = 8), blood cultures from cats (n = 2), and cultures from swabs from dog mouths (n = 53) were analyzed. ⋯ The sequencing of rrs genes suggested the presence of different gene copies in a few strains, indicating that the method is less appropriate for species identification. Both species are present in the majority of dogs. Additional Capnocytophaga species occur in dogs' and cats' mouths.
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J. Clin. Microbiol. · Sep 2009
Efficacy of bilateral bronchoalveolar lavage for diagnosis of ventilator-associated pneumonia.
Ventilator-associated pneumonia (VAP) is a common nosocomial infection causing significant morbidity and mortality. The goal of this study was to determine the efficacy of bilateral versus unilateral bronchoalveolar lavage (BAL) for the detection of the causative bacterial agents of VAP. We retrospectively studied the quantitative bacterial cultures of 399 BAL sample pairs collected from 287 mechanically ventilated patients over a 5-year period at a U. ⋯ Unilateral sampling would have failed to recover one or more significant isolates in 11% of positive pairs had only the right lung been sampled and in 16.7% had only the left lung been sampled. Our study shows that preferential sampling of the right lung improves the diagnostic efficacy of unilateral BAL for the detection of the etiologic agents of VAP. If bilateral sampling is performed, our results also indicate that pooling left- and right-lung samples for a single quantitative culture is comparable to processing samples individually.
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J. Clin. Microbiol. · Sep 2009
Comparative StudyMatrix-assisted laser desorption ionization-time of flight mass spectrometry for fast and reliable identification of clinical yeast isolates.
The clinical impact of severe infections with yeasts and yeast-like fungi has increased, especially in immunocompromised hosts. In recent years, new antifungal agents with different and partially species-specific activity patterns have become available. Therefore, rapid and reliable species identification is essential for antifungal treatment; however, conventional biochemical methods are time-consuming and require considerable expertise. ⋯ After complementation of the database, all isolates were unambiguously identified. The established API ID 32C biochemical diagnostic system identified 244 isolates in the first round. Overall, MALDI-TOF MS proved a most rapid and reliable tool for the identification of yeasts and yeast-like fungi, with the method providing a combination of the lowest expenditure of consumables, easy interpretation of results, and a fast turnaround time.
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J. Clin. Microbiol. · Sep 2009
Comparative StudyField performance of a rapid diagnostic test for influenza in an ambulatory setting.
Provided test characteristics are adequate, point-of-care rapid antigen detection tests for influenza could improve the timeliness and appropriateness of clinical decisions. Our objective was to estimate the field sensitivity and specificity of the Quidel QuickVue Influenza A+B test in an ambulatory setting. The sensitivity and specificity of the Quidel QuickVue test was evaluated against reverse-transcriptase PCR (RT-PCR) on nasopharyngeal specimens collected over two consecutive influenza seasons from ambulatory patients consulting for influenza-like illness (ILI) within 7 days of ILI onset. ⋯ The sensitivity of the test was slightly but nonsignificantly higher for influenza B virus (23%) than for influenza A virus (18%). Despite its high specificity, the low sensitivity of the Quidel QuickVue Influenza A+B test is too poor to direct clinical decisions for ambulatory patients with ILI. Negative results cannot rule out the diagnosis of influenza, and in that context, this test is of questionable utility for routine application in the clinical setting.