Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases
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Clin. Microbiol. Infect. · Nov 2011
Colonization and infection by colistin-resistant Gram-negative bacteria in a cohort of critically ill patients.
In recent years there has been renewed interest in colistin for the treatment of infections by multidrug-resistant Gram-negative bacteria, causing concern that increasing use may be accompanied by the emergence of resistance. This is a retrospective cohort study of colonization and infection by colistin-resistant (CR) gram-negative bacteria in critically ill patients. Colonization data were based on surveillance culture results. ⋯ Among them, 30 (20%) were colonized by Klebsiella pneumoniae isolates and 51 (34%) were colonized by intrinsically resistant to colistin (CIR) enterobacteriaceae. Seven cases of infection were caused by CR K. pneumoniae and 12 cases by CIR strains. The main risk factor for colonization by CR pathogens was colistin treatment.
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Clin. Microbiol. Infect. · Nov 2011
Predictors of catheter-related gram-negative bacilli bacteraemia among cancer patients.
Gram-negative bacillary bacteraemia (GNB) is associated with high morbidity and mortality among cancer patients. We conducted this study to determine the risk factors that may predict the catheter as the source of GNB in cancer patients. From July 2005 to December 2006 all 266 cancer patients with GNB and central venous catheters (CVCs) at The University of Texas M. ⋯ On multivariate analysis, S. maltophilia bacteraemia (odds ratio (OR), 5.78; 95% confidence interval (CI), 1.47-22.78; p 0.045), polymicrobial bacteraemia (OR, 4.04; 95% CI, 1.56-10.44; p 0.042), and more than 1000 CFUs from CVC blood cultures (OR, 4.39; 95% CI, 2.02-9.27; p <0.01), were associated with CRBSI. Neutropenia was associated with non-CRBSI (OR, 0.26; 95% CI, 0.13-0.53; p <0.01). Several factors such as S. maltophilia bacteraemia, polymicrobial bacteraemia and more than 1000 CFUs from a blood culture drawn through the CVC may assist the clinicians in assessing whether an indwelling catheter is the source of a GNB and hence CVC removal may be considered.
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Clin. Microbiol. Infect. · Oct 2011
Comparative StudyReal-time PCR assay-based strategy for differentiation between active Pneumocystis jirovecii pneumonia and colonization in immunocompromised patients.
Diagnosis of pneumocystosis usually relies on microscopic demonstration of Pneumocystis jirovecii in respiratory samples. Conventional PCR can detect low levels of P. jirovecii DNA but cannot differentiate active pneumonia from colonization. In this study, we used a new real-time quantitative PCR (qPCR) assay to identify and discriminate these entities. ⋯ Two cut-off values of 120 and 1900 TFEq/mL were proposed to discriminate active pneumonia from colonization, with a grey zone between them. In conclusion, this qPCR assay discriminates active pneumonia from colonization. This is particularly relevant for patient management, especially in non-human immunodeficiency virus (HIV)-infected immunocompromised patients, who often present low-burden P. jirovecii infections that are not diagnosed microscopically.
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Clin. Microbiol. Infect. · Sep 2011
Aspergillus fumigatus colonization in cystic fibrosis: implications for lung function?
Aspergillus fumigatus is commonly found in the respiratory secretions of patients with cystic fibrosis (CF). Although allergic bronchopulmonary aspergillosis (ABPA) is associated with deterioration of lung function, the effects of A. fumigatus colonization on lung function in the absence of ABPA are not clear. This study was performed in 259 adults and children with CF, without ABPA. ⋯ After adjustment for confounders, there was no significant difference in lung function between patients colonized for 0 or 1 year and patients with 2-3 or more than 3 years of colonization (p 0.40 and p 0.64) throughout the study. There was no significant difference in lung function decline between groups. Although colonization with A. fumigatus is more commonly found in patients with more severe lung disease and increased treatment burden, it is not independently associated with lower lung function or more severe lung function decline over a 5-year period.
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Clin. Microbiol. Infect. · Sep 2011
Improved clinical laboratory identification of human pathogenic yeasts by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.
The key to therapeutic success with yeast infections is an early onset of antifungal treatment with an appropriate drug regimen. To do this, yeast species identification is necessary, but conventional biochemical and morphological approaches are time-consuming. The recent arrival of biophysical methods, such as matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), in routine diagnostic laboratories holds the promise of significantly speeding up this process. ⋯ A significant advantage of MALDI-TOF MS over biochemistry in the recognition of isolates novel to the system was observed. Although both MALDI-TOF MS systems employed different approaches in the database structure and showed different susceptibilities to errors in database entries, these were negligible in terms of clinical usefulness. The time-saving benefit of MALDI-TOF MS over biochemical identification will substantially improve fungal diagnostics and patient treatment.