Platelet transfusion refractoriness and anti-HLA immunization.

Platelet transfusion refractoriness (PTR), defined as an unsatisfactory post-transfusion platelet count increment, is a common complication of patients receiving multiple transfusions. Different strategies are described in the management of PTR. In this work, we demonstrate the efficacy of the detection and identification of anti-HLA antibodies in the recipient using a threshold of 3000 mean fluorescence intensity (MFI), and the seek of donors not expressing HLA antigens against which the patient is immunized.

Detection of Achromobacter xylosoxidans in hospital, domestic, and outdoor environmental samples and comparison with human clinical isolates.

Achromobacter xylosoxidans is an aerobic nonfermentative Gram-negative rod considered an important emerging pathogen among cystic fibrosis (CF) patients worldwide and among immunocompromised patients. This increased prevalence remains unexplained, and to date no environmental reservoir has been identified. The aim of this study was to identify potential reservoirs of A. xylosoxidans in hospital, domestic, and outdoor environments and to compare the isolates with clinical ones. From 2011 to 2012, 339 samples were collected in Dijon's university hospital, in healthy volunteers' homes in the Dijon area, and in the outdoor environment in Burgundy (soil, water, mud, and plants). We designed a protocol to detect A. xylosoxidans in environmental samples based on a selective medium: MCXVAA (MacConkey agar supplemented with xylose, vancomycin, aztreonam, and amphotericin B). Susceptibility testing, genotypic analysis by pulsed-field gel electrophoresis, and blaOXA-114 sequencing were performed on the isolates. A total of 50 strains of A. xylosoxidans were detected in hospital (33 isolates), domestic (9 isolates), and outdoor (8 isolates) samples, mainly in hand washing sinks, showers, and water. Most of them were resistant to ciprofloxacin (49 strains). Genotypic analysis and blaOXA-114 sequencing revealed a wide diversity among the isolates, with 35 pulsotypes and 18 variants of oxacillinases. Interestingly, 10 isolates from hospital environment were clonally related to clinical isolates previously recovered from hospitalized patients, and one domestic isolate was identical to one recovered from a CF patient. These results indicate that A. xylosoxidans is commonly distributed in various environments and therefore that CF patients or immunocompromised patients are surrounded by these reservoirs.