Immunosuppressed patients without AIDS had longer time to treatment and a higher rate of death than did patients with AIDS.
The main objective of this study was to assess the diagnostic performance of a set of three Mucorales quantitative PCR assays in a retrospective multicentre study. Mucormycosis cases were recorded thanks to the French prospective surveillance programme (RESSIF network). The day of sampling of the first histological or mycological positive specimen was defined as day 0 (D0). Detection of circulating DNA was performed on frozen serum samples collected from D-30 to D30, using quantitative PCR assays targeting Rhizomucor, Lichtheimia, Mucor/Rhizopus. Forty-four patients diagnosed with probable (n = 19) or proven (n = 25) mucormycosis were included. Thirty-six of the 44 patients (81%) had at least one PCR-positive serum. The first PCR-positive sample was observed 9 days (range 0-28 days) before diagnosis was made using mycological criteria and at least 2 days (range 0-24 days) before imaging. The identifications provided with the quantitative PCR assays were all concordant with culture and/or PCR-based identification of the causal species. Survival rate at D84 was significantly higher for patients with an initially positive PCR that became negative after treatment initiation than for patients whose PCR remained positive (48% and 4%, respectively; p <10). The median time for complete negativity of PCR was 7 days (range 3-19 days) after initiation of l-AmB treatment. Despite some limitations due to the retrospective design of the study, we showed that Mucorales quantitative PCR could not only confirm the mucormycosis diagnosis when other mycological arguments were present but could also anticipate this diagnosis. Quantification of DNA loads may also be a useful adjunct to treatment monitoring.
An immunocapture assay was developed to detect Toxoplasma gondii-specific immunoglobulin E (IgE) in sera from adults with acute acquired infection or reactivation and from babies with congenital toxoplasmosis. The components of this assay were monoclonal antibody to human IgE, samples from patients, and T. gondii tachyzoites treated with Formalin. When T. gondu-specific IgE antibodies were present, visually detectable agglutination occurred. Sera, umbilical cord blood, fetal blood, cerebrospinal fluid, and amniotic fluid were tested by this method. Specific IgE antibodies were detected in sera from 25 (86%) of 29 adults who developed specific IgG antibody during pregnancy or had specific IgA and IgM antibodies. Specific IgE was present early during infection, at the time that IgM antibodies were present, and slightly preceding the presence of specific IgA antibodies. In 23 patients tested serially, IgE antibodies never persisted for longer than 4 months. No nonspecific anti-T. gondii IgE was detected in sera from uninfected individuals. Maternal IgE antibodies did not cross the placenta. In sera of patients with congenital toxoplasmosis, specific IgE antibodies were found at birth, during the first year of life, and during immunologic recrudescence following discontinuation of pyrimethamine-sulfonamide therapy. The IgE immunocapture assay is simple to perform. It is especially useful for determining when T. gondu was acquired by recently infected pregnant women.
Comparative studies of Candida albicans strains are essential for proving cross-infections in epidemiological investigations. Typing of C. albicans strains is mainly based on genotypic methods. Fourier-transform infrared (FTIR) spectroscopy is described in this study as a novel phenotypic approach to the typing of C. albicans. The first step in the approach was the standardization of sample preparation (culture conditions and sampling parameters) and acquisition and classification parameters (spectral acquisition, spectral window selection, classification algorithm, and heterogeneity threshold). The second step consisted of validating the established parameters with a set of 79 strains of C. albicans isolated over 4 months from nine patients hospitalized in two intensive care units. Strains were isolated from multiple anatomical sites with repeated sampling. FTIR spectroscopy results were compared to randomly amplified polymorphic DNA (RAPD) results; this analysis showed that the amplification patterns of strains isolated from a given patient were identical and that different patients had different profiles. FTIR spectroscopy data were analyzed by hierarchical clustering performed with the second-derivative spectra. This classification revealed nine groups, one per patient. Only one spectrum out of 79 was misclassified by the FTIR spectroscopy method. RAPD and FTIR spectroscopy results were in good agreement, showing that, when nosocomial candidiasis transmission is suspected and urgent information is needed, this technique may be useful as a quick identification tool to give solid clues before confirmation by a genotypic method.Fungal infections occur mainly in immunodeficient patients or those harboring several risk factors, such as broad-spectrum antibiotic therapy, digestive surgery, catheter implantation, or graft transplantation. Thus, intensive care unit (ICU) patients are high-risk patients since they generally have several of these factors. Candida spp. constitute the third or fourth most common cause of nosocomial infections in ICUs, according to data from the National Nosocomial Infections Surveillance System and the European Prevalence of Infection in Intensive Care (1,22). Candida albicans is generally responsible for up to 50 to 70% of the infections, and its endogenous origin is generally implicated (3,7,21,23). However, cases of exogenous contamination have been described (4,6,13,14,16). Demonstration of the exogenous origin of a contaminant pathogen is based on the identification and comparison of strains. Among the different techniques used, genotypic methods are favored over phenotypic methods. Randomly amplified polymorphic DNA (RAPD) and other DNA fingerprinting methods, PCR-restriction fragment length polymorphism analysis, multilocus enzyme electrophoresis, DNA sequencing, and pulsed-field gel electrophoresis are generally used to check strain identity. These techniques are successful but require time, expensive consumables, and highly trained staff to be performed adequately.In this study...
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