Laboratoire TransDiag

Montpellier, France

Laboratoire TransDiag

Montpellier, France

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Belondrade M.,Laboratoire TransDiag | Nicot S.,Laboratoire TransDiag | Beringue V.,French National Institute for Agricultural Research | Coste J.,Laboratoire TransDiag | And 2 more authors.
PLoS ONE | Year: 2016

The prevalence of variant Creutzfeldt-Jakob disease (vCJD) in the population remains uncertain, although it has been estimated that 1 in 2000 people in the United Kingdom are positive for abnormal prion protein (PrPTSE) by a recent survey of archived appendix tissues. The prominent lymphotropism of vCJD prions raises the possibility that some surgical procedures may be at risk of iatrogenic vCJD transmission in healthcare facilities. It is therefore vital that decontamination procedures applied to medical devices before their reprocessing are thoroughly validated. A current limitation is the lack of a rapid model permissive to human prions. Here, we developed a prion detection assay based on protein misfolding cyclic amplification (PMCA) technology combined with stainless-steel wire surfaces as carriers of prions (Surf-PMCA). This assay allowed the specific detection of minute quantities (10-8 brain dilution) of either human vCJD or ovine scrapie PrPTSE adsorbed onto a single steel wire, within a two week timeframe. Using Surf-PMCA we evaluated the performance of several reference and commercially available prion-specific decontamination procedures. Surprisingly, we found the efficiency of several marketed reagents to remove human vCJD PrPTSE was lower than expected. Overall, our results demonstrate that Surf-PMCA can be used as a rapid and ultrasensitive assay for the detection of human vCJD PrPTSE adsorbed onto a metallic surface, therefore facilitating the development and validation of decontamination procedures against human prions. © 2016 Belondrade et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


PubMed | Laboratoire TransDiag, French National Institute for Agricultural Research and Montpellier University
Type: Evaluation Studies | Journal: PloS one | Year: 2016

The prevalence of variant Creutzfeldt-Jakob disease (vCJD) in the population remains uncertain, although it has been estimated that 1 in 2000 people in the United Kingdom are positive for abnormal prion protein (PrPTSE) by a recent survey of archived appendix tissues. The prominent lymphotropism of vCJD prions raises the possibility that some surgical procedures may be at risk of iatrogenic vCJD transmission in healthcare facilities. It is therefore vital that decontamination procedures applied to medical devices before their reprocessing are thoroughly validated. A current limitation is the lack of a rapid model permissive to human prions. Here, we developed a prion detection assay based on protein misfolding cyclic amplification (PMCA) technology combined with stainless-steel wire surfaces as carriers of prions (Surf-PMCA). This assay allowed the specific detection of minute quantities (10-8 brain dilution) of either human vCJD or ovine scrapie PrPTSE adsorbed onto a single steel wire, within a two week timeframe. Using Surf-PMCA we evaluated the performance of several reference and commercially available prion-specific decontamination procedures. Surprisingly, we found the efficiency of several marketed reagents to remove human vCJD PrPTSE was lower than expected. Overall, our results demonstrate that Surf-PMCA can be used as a rapid and ultrasensitive assay for the detection of human vCJD PrPTSE adsorbed onto a metallic surface, therefore facilitating the development and validation of decontamination procedures against human prions.


Paris S.,Etablissement Francais du Sang Rhone Alpes | Rigal D.,Etablissement Francais du Sang Rhone Alpes | Barlet V.,Etablissement Francais du Sang Rhone Alpes | Verdier M.,Etablissement Francais du Sang Rhone Alpes | And 4 more authors.
Journal of Molecular Diagnostics | Year: 2014

The poor suitability of standard hemagglutination-based assay techniques for large-scale automated screening of red blood cell antigens severely limits the ability of blood banks to supply extensively phenotype-matched blood. With better understanding of the molecular basis of blood antigens, it is now possible to predict blood group phenotype by identifying single-nucleotide polymorphisms in genomic DNA. Development of DNA-typing assays for antigen screening in blood donation qualification laboratories promises to enable blood banks to provide optimally matched donations. We have designed an automated genotyping system using 96-well DNA microarrays for blood donation screening and a first panel of eight single-nucleotide polymorphisms to identify 16 alleles in four blood group systems (KEL, KIDD, DUFFY, and MNS). Our aim was to evaluate this system on 960 blood donor samples with known phenotype. Study data revealed a high concordance rate (99.92%; 95% CI, 99.77%-99.97%) between predicted and serologic phenotypes. These findings demonstrate that our assay using a simple protocol allows accurate, relatively low-cost phenotype prediction at the DNA level. This system could easily be configured with other blood group markers for identification of donors with rare blood types or blood units for IH panels or antigens from other systems. © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology.


Vossier L.,Laboratoire TransDiag | Leon F.,Laboratoire TransDiag | Bachelier C.,Laboratoire TransDiag | Marchandin H.,Montpellier University | And 5 more authors.
Transfusion | Year: 2014

Background Human neutrophil peptides (HNPs) 1 to 3 are the major antimicrobial peptides of the azurophilic granules of neutrophils. They represent an important arm of the innate immune system. Their production by chemical synthesis and recombinant technologies is expensive and limited by technical constraints due to their composition and the presence of three disulfide bonds. Study Design and Methods We have developed an original approach based on the purification of the natural human defensins HNPs 1 to 3 from neutrophils trapped on leukoreduction filters used in blood processing. The purification of HNPs 1 to 3 from these filters is performed in two steps: extraction of HNPs 1 to 3 retained in the filters followed by their immunoprecipitation. Studies were performed to determine the stability of defensins in the filters stored at room temperature. The activity of HNPs 1 to 3 obtained by our rapid protocol was validated by determining minimal inhibitory concentrations (MICs) against six reference bacterial strains and 12 clinical isolates. Results The human defensins HNPs 1 to 3 extracted from leukoreduction filters displayed high antimicrobial activity against tested strains, with MIC values between 0.12 and 1 μg/mL. Kinetics assays showed the appearance of activity 15 minutes after peptide addition. Moreover, we found that the HNPs 1 to 3 purified from leukoreduction filters that had been stored for 45 days at room temperature remained active. Conclusion Leukoreduction filters provide a rich and safe source of active human defensins HNPs 1 to 3. Moreover, the stability of the peptides in filters stored at room temperature allows envisaging a large-scale development of the process. © Published 2013. This article is a U.S. Government work and is in the public domain in the USA.


PubMed | Laboratoire TransDiag, Jean Monnet University and Etablissement francais du sang
Type: Journal Article | Journal: Presse medicale (Paris, France : 1983) | Year: 2015

Transfusion is a mixed discipline which includes the production of blood components, applied biology aiming in particular at establishing the highest compatibility for immunological characteristics between blood components to be delivered to patients and recipients, and, finally translational medicine to evaluate the effectiveness of the transfused products and to proactively avoid hazards, at least those that are preventible and can be anticipated. The whole chain takes place with the concern of continuous improvement of quality and safety. These two principles (quality/safety) have been and still are concerns of constant progress applicable to all the transfusion chain steps; they benefit from programs of Research and Development (R&D). Fundamental research, basic but also applied and clinical research, accompanies, in a constantly joint manner, scientific and medical progresses by providing new solutions to dampen the current problems and to prepare the future.


El Ichi S.,Laboratoire TransDiag | El Ichi S.,CNRS Institute of Analytical Sciences | Leon F.,Laboratoire TransDiag | Vossier L.,Laboratoire TransDiag | And 5 more authors.
Biosensors and Bioelectronics | Year: 2014

Blood safety is a global health goal. In developed countries, bacterial contamination of platelet concentrates is the highest infectious risk in transfusion despite the current preventive strategies. We aimed to develop a conductometric biosensor for the generic, rapid and sensitive detection of Gram-negative bacteria. Our strategy is based on immunosensors: addressable magnetic nanoparticles coupled with anti-LPS antibodies were used for the generic capture of Gram-negative bacteria. Bacterial capture was characterized by impedancemetric and microscopic measurements. The results obtained with conductometric measurements allowed real-time, sensitive detection of Escherichia coli or Serratia marcescens cultures from 1 to 103CFUmL-1. The ability of the immunosensor to detect Gram negative bacteria was also tested on clinically relevant strains. The conductometric immunosensor allowed the direct detection of 10-103CFUmL-1 of Pseudomonas aeruginosa and Acinetobacter baumannii strains that were undetectable using standard immunoblot methods. Results showed that the conductometric response was not inhibited in 1% serum. © 2013 Elsevier B.V.


PubMed | CNRS Institute of Analytical Sciences, Laboratoire TransDiag and Montpellier University
Type: | Journal: Biosensors & bioelectronics | Year: 2014

Blood safety is a global health goal. In developed countries, bacterial contamination of platelet concentrates is the highest infectious risk in transfusion despite the current preventive strategies. We aimed to develop a conductometric biosensor for the generic, rapid and sensitive detection of Gram-negative bacteria. Our strategy is based on immunosensors: addressable magnetic nanoparticles coupled with anti-LPS antibodies were used for the generic capture of Gram-negative bacteria. Bacterial capture was characterized by impedancemetric and microscopic measurements. The results obtained with conductometric measurements allowed real-time, sensitive detection of Escherichia coli or Serratia marcescens cultures from 1 to 10(3) CFU mL(-1). The ability of the immunosensor to detect Gram negative bacteria was also tested on clinically relevant strains. The conductometric immunosensor allowed the direct detection of 10-10(3) CFU mL(-1) of Pseudomonas aeruginosa and Acinetobacter baumannii strains that were undetectable using standard immunoblot methods. Results showed that the conductometric response was not inhibited in 1% serum.


PubMed | Laboratoire TransDiag
Type: Journal Article | Journal: Transfusion | Year: 2014

Human neutrophil peptides (HNPs) 1 to 3 are the major antimicrobial peptides of the azurophilic granules of neutrophils. They represent an important arm of the innate immune system. Their production by chemical synthesis and recombinant technologies is expensive and limited by technical constraints due to their composition and the presence of three disulfide bonds.We have developed an original approach based on the purification of the natural human defensins HNPs 1 to 3 from neutrophils trapped on leukoreduction filters used in blood processing. The purification of HNPs 1 to 3 from these filters is performed in two steps: extraction of HNPs 1 to 3 retained in the filters followed by their immunoprecipitation. Studies were performed to determine the stability of defensins in the filters stored at room temperature. The activity of HNPs 1 to 3 obtained by our rapid protocol was validated by determining minimal inhibitory concentrations (MICs) against six reference bacterial strains and 12 clinical isolates.The human defensins HNPs 1 to 3 extracted from leukoreduction filters displayed high antimicrobial activity against tested strains, with MIC values between 0.12 and 1g/mL. Kinetics assays showed the appearance of activity 15 minutes after peptide addition. Moreover, we found that the HNPs 1 to 3 purified from leukoreduction filters that had been stored for 45 days at room temperature remained active.Leukoreduction filters provide a rich and safe source of active human defensins HNPs 1 to 3. Moreover, the stability of the peptides in filters stored at room temperature allows envisaging a large-scale development of the process.

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