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1. Nationwide Harmonization Effort for Semi-Quantitative Reporting of SARS-CoV-2 PCR Test Results in Belgium

Author

Cuypers, Lize, primary, Bode, Jannes, additional, Beuselinck, Kurt, additional, Laenen, Lies, additional, Dewaele, Klaas, additional, Janssen, Reile, additional, Capron, Arnaud, additional, Lafort, Yves, additional, Paridaens, Henry, additional, Bearzatto, Bertrand, additional, Cauchie, Mathieu, additional, Huwart, Aline, additional, Degosserie, Jonathan, additional, Fagnart, Olivier, additional, Overmeire, Yarah, additional, Rouffiange, Arlette, additional, Vandecandelaere, Ilse, additional, Deffontaine, Marine, additional, Pilate, Thomas, additional, Yin, Nicolas, additional, Micalessi, Isabel, additional, Roisin, Sandrine, additional, Moons, Veronique, additional, Reynders, Marijke, additional, Steyaert, Sophia, additional, Henin, Coralie, additional, Lazarova, Elena, additional, Obbels, Dagmar, additional, Dufrasne, François E., additional, Pirenne, Hendri, additional, Schepers, Raf, additional, Collin, Anaëlle, additional, Verhasselt, Bruno, additional, Gillet, Laurent, additional, Jonckheere, Stijn, additional, Van Lint, Philippe, additional, Van den Poel, Bea, additional, Van der Beken, Yolien, additional, Stojkovic, Violeta, additional, Garrino, Maria-Grazia, additional, Segers, Hannah, additional, Vos, Kevin, additional, Godefroid, Maaike, additional, Pede, Valerie, additional, Nollet, Friedel, additional, Claes, Vincent, additional, Verschraegen, Inge, additional, Bogaerts, Pierre, additional, Van Gysel, Marjan, additional, Leurs, Judith, additional, Saegeman, Veroniek, additional, Soetens, Oriane, additional, Vanhee, Merijn, additional, Schiettekatte, Gilberte, additional, Huyghe, Evelyne, additional, Martens, Steven, additional, Lemmens, Ann, additional, Nailis, Heleen, additional, Laffineur, Kim, additional, Steensels, Deborah, additional, Vanlaere, Elke, additional, Gras, Jérémie, additional, Roussel, Gatien, additional, Gijbels, Koenraad, additional, Boudewijns, Michael, additional, Sion, Catherine, additional, Achtergael, Wim, additional, Maurissen, Wim, additional, Iliano, Luc, additional, Chantrenne, Marianne, additional, Vanheule, Geert, additional, Flies, Reinoud, additional, Hougardy, Nicolas, additional, Berth, Mario, additional, Verbeke, Vanessa, additional, Morent, Robin, additional, Vankeerberghen, Anne, additional, Bontems, Sébastien, additional, Kehoe, Kaat, additional, Schallier, Anneleen, additional, Ho, Giang, additional, Bafort, Kristof, additional, Raymaekers, Marijke, additional, Pypen, Yolande, additional, Heinrichs, Amelie, additional, Schuermans, Wim, additional, Cuigniez, Dominique, additional, Lali, Salah Eddine, additional, Drieghe, Stefanie, additional, Ory, Dieter, additional, Le Mercier, Marie, additional, Van Laethem, Kristel, additional, Thoelen, Inge, additional, Vandamme, Sarah, additional, Mansoor, Iqbal, additional, Vael, Carl, additional, De Sloovere, Maxime, additional, Declerck, Katrien, additional, Dequeker, Elisabeth, additional, Desmet, Stefanie, additional, Maes, Piet, additional, Lagrou, Katrien, additional, and André, Emmanuel, additional

Published
2022
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2. Nationwide Harmonization Effort for Semi-Quantitative Reporting of SARS-CoV-2 PCR Test Results in Belgium.

Author

UCL - (MGD) Laboratoire de biologie clinique, UCL - SSS/IREC/MONT - Pôle Mont Godinne, Cuypers, Lize, Bode, Jannes, Beuselinck, Kurt, Laenen, Lies, Dewaele, Klaas, Janssen, Reile, Capron, Arnaud, Lafort, Yves, Paridaens, Henry, Bearzatto, Bertrand, Cauchie, Mathieu, Huwart, Aline, Degosserie, Jonathan, Fagnart, Olivier, Overmeire, Yarah, Rouffiange, Arlette, Vandecandelaere, Ilse, Deffontaine, Marine, Pilate, Thomas, Yin, Nicolas, Micalessi, Isabel, Roisin, Sandrine, Moons, Veronique, Reynders, Marijke, Steyaert, Sophia, Henin, Coralie, Lazarova, Elena, Obbels, Dagmar, Dufrasne, François E, Pirenne, Hendri, Schepers, Raf, Collin, Anaëlle, Verhasselt, Bruno, Gillet, Laurent, Jonckheere, Stijn, Van Lint, Philippe, Van den Poel, Bea, Van der Beken, Yolien, Stojkovic, Violeta, Garrino, Maria-Grazia, Segers, Hannah, Vos, Kevin, Godefroid, Maaike, Pede, Valerie, Nollet, Friedel, Claes, Vincent, Verschraegen, Inge, Bogaerts, Pierre, Van Gysel, Marjan, Leurs, Judith, Saegeman, Veroniek, Soetens, Oriane, Vanhee, Merijn, Schiettekatte, Gilberte, Huyghe, Evelyne, Martens, Steven, Lemmens, Ann, Nailis, Heleen, Laffineur, Kim, Steensels, Deborah, Vanlaere, Elke, Gras, Jérémie, Roussel, Gatien, Gijbels, Koenraad, Boudewijns, Michael, Sion, Catherine, Achtergael, Wim, Maurissen, Wim, Iliano, Luc, Chantrenne, Marianne, Vanheule, Geert, Flies, Reinoud, Hougardy, Nicolas, Berth, Mario, Verbeke, Vanessa, Morent, Robin, Vankeerberghen, Anne, Bontems, Sébastien, Kehoe, Kaat, Schallier, Anneleen, Ho, Giang, Bafort, Kristof, Raymaekers, Marijke, Pypen, Yolande, Heinrichs, Amelie, Schuermans, Wim, Cuigniez, Dominique, Lali, Salah Eddine, Drieghe, Stefanie, Ory, Dieter, Le Mercier, Marie, Van Laethem, Kristel, Thoelen, Inge, Vandamme, Sarah, Mansoor, Iqbal, Vael, Carl, De Sloovere, Maxime, Declerck, Katrien, Dequeker, Elisabeth, Desmet, Stefanie, Maes, Piet, Lagrou, Katrien, André, Emmanuel, UCL - (MGD) Laboratoire de biologie clinique, UCL - SSS/IREC/MONT - Pôle Mont Godinne, Cuypers, Lize, Bode, Jannes, Beuselinck, Kurt, Laenen, Lies, Dewaele, Klaas, Janssen, Reile, Capron, Arnaud, Lafort, Yves, Paridaens, Henry, Bearzatto, Bertrand, Cauchie, Mathieu, Huwart, Aline, Degosserie, Jonathan, Fagnart, Olivier, Overmeire, Yarah, Rouffiange, Arlette, Vandecandelaere, Ilse, Deffontaine, Marine, Pilate, Thomas, Yin, Nicolas, Micalessi, Isabel, Roisin, Sandrine, Moons, Veronique, Reynders, Marijke, Steyaert, Sophia, Henin, Coralie, Lazarova, Elena, Obbels, Dagmar, Dufrasne, François E, Pirenne, Hendri, Schepers, Raf, Collin, Anaëlle, Verhasselt, Bruno, Gillet, Laurent, Jonckheere, Stijn, Van Lint, Philippe, Van den Poel, Bea, Van der Beken, Yolien, Stojkovic, Violeta, Garrino, Maria-Grazia, Segers, Hannah, Vos, Kevin, Godefroid, Maaike, Pede, Valerie, Nollet, Friedel, Claes, Vincent, Verschraegen, Inge, Bogaerts, Pierre, Van Gysel, Marjan, Leurs, Judith, Saegeman, Veroniek, Soetens, Oriane, Vanhee, Merijn, Schiettekatte, Gilberte, Huyghe, Evelyne, Martens, Steven, Lemmens, Ann, Nailis, Heleen, Laffineur, Kim, Steensels, Deborah, Vanlaere, Elke, Gras, Jérémie, Roussel, Gatien, Gijbels, Koenraad, Boudewijns, Michael, Sion, Catherine, Achtergael, Wim, Maurissen, Wim, Iliano, Luc, Chantrenne, Marianne, Vanheule, Geert, Flies, Reinoud, Hougardy, Nicolas, Berth, Mario, Verbeke, Vanessa, Morent, Robin, Vankeerberghen, Anne, Bontems, Sébastien, Kehoe, Kaat, Schallier, Anneleen, Ho, Giang, Bafort, Kristof, Raymaekers, Marijke, Pypen, Yolande, Heinrichs, Amelie, Schuermans, Wim, Cuigniez, Dominique, Lali, Salah Eddine, Drieghe, Stefanie, Ory, Dieter, Le Mercier, Marie, Van Laethem, Kristel, Thoelen, Inge, Vandamme, Sarah, Mansoor, Iqbal, Vael, Carl, De Sloovere, Maxime, Declerck, Katrien, Dequeker, Elisabeth, Desmet, Stefanie, Maes, Piet, Lagrou, Katrien, and André, Emmanuel

Abstract

From early 2020, a high demand for SARS-CoV-2 tests was driven by several testing indications, including asymptomatic cases, resulting in the massive roll-out of PCR assays to combat the pandemic. Considering the dynamic of viral shedding during the course of infection, the demand to report cycle threshold (Ct) values rapidly emerged. As Ct values can be affected by a number of factors, we considered that harmonization of semi-quantitative PCR results across laboratories would avoid potential divergent interpretations, particularly in the absence of clinical or serological information. A proposal to harmonize reporting of test results was drafted by the National Reference Centre (NRC) UZ/KU Leuven, distinguishing four categories of positivity based on RNA copies/mL. Pre-quantified control material was shipped to 124 laboratories with instructions to setup a standard curve to define thresholds per assay. For each assay, the mean Ct value and corresponding standard deviation was calculated per target gene, for the three concentrations (10, 10 and 10 copies/mL) that determine the classification. The results of 17 assays are summarized. This harmonization effort allowed to ensure that all Belgian laboratories would report positive PCR results in the same semi-quantitative manner to clinicians and to the national database which feeds contact tracing interventions.

Published
2022

3. Comparison of the quantitative DiaSorin Liaison antigen test to RT-PCR for the diagnosis of COVID-19 in symptomatic and asymptomatic outpatients

Author

Lefever, Stefanie, Indevuyst, Christophe, Cuypers, Lize, Dewaele, Klaas, Yin, Nicolas, Cotton, Frédéric, Padalko, Elizaveta, Oyaert, Matthijs, Descy, Julie, Cavalier, Etienne, Van Ranst, Marc, André, Emmanuel, Lagrou, Katrien, and Vermeersch, Pieter

Subjects
Anamnèse - diagnostic [biologie clinique], Médecine clinique [biologie clinique]
Abstract

Background: We evaluated the quantitative DiaSorin Liaison SARS-CoV-2 antigen test in symptomatic and asymptomatic individuals consulting their general practioner (GP) during a period of stable intense virus circulation (213/100,000 habitants per day). Methods: Left-over RT-PCR positive (n=204) and negative (n=210) nasopharyngeal samples were randomly selected among fresh routine samples collected from patients consulting their GP. Samples were tested on Liaison XL according to the manufacturer’s instructions. Equivocal results were considered positive. Results: Overall sensitivity and specificity of the Liaison antigen test compared to RT-PCR were 67.7% [95% confidence interval (CI): 60.9%-73.7%] and 100% [CI: 97.8%-100%]. Sensitivity in samples with a viral load ≥10 5 ,≥10 4 and ≥10 3 copies/mL was 100% [CI: 96.3%-100.0%], 96.5% [CI: 91.8%-98.7%] and 87.4% [CI: 81.3%-91.5%], respectively. All samples ≤10 3 copies/mL were antigen negative. The ratio of antigen concentration to viral load in samples ≥10 3 copies/mL was comparable in symptomatic and asymptomatic individuals ( p =0.58). The proportion of RT-PCR positive participants with a high viral load (≥10 5 copies/mL) was not significantly higher in symptomatic than in asymptomatic participants (63.9% [CI: 54.9%-72.0%] vs. 51.9% [CI: 41.1%-62.6%], p =0.11), but the proportion of participants with a low viral load (, info:eu-repo/semantics/published

Published
2021

4. Comparison of the Quantitative DiaSorin Liaison Antigen Test to Reverse Transcription-PCR for the Diagnosis of COVID-19 in Symptomatic and Asymptomatic Outpatients

Author

Lefever, Stefanie, primary, Indevuyst, Christophe, additional, Cuypers, Lize, additional, Dewaele, Klaas, additional, Yin, Nicolas, additional, Cotton, Frédéric, additional, Padalko, Elizaveta, additional, Oyaert, Matthijs, additional, Descy, Julie, additional, Cavalier, Etienne, additional, Van Ranst, Marc, additional, André, Emmanuel, additional, Lagrou, Katrien, additional, and Vermeersch, Pieter, additional

Published
2021
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5. Triazole-Resistance in Environmental Aspergillus fumigatus in Latin American and African Countries

Author

Resendiz-Sharpe, Agustin, Dewaele, Klaas, Merckx, Rita, Bustamante, Beatriz, Vega-Gomez, Maria Celeste, Rolon, Miriam, Jacobs, Jan, Verweij, P.E., Maertens, Johan, Lagrou, Katrien, Resendiz-Sharpe, Agustin, Dewaele, Klaas, Merckx, Rita, Bustamante, Beatriz, Vega-Gomez, Maria Celeste, Rolon, Miriam, Jacobs, Jan, Verweij, P.E., Maertens, Johan, and Lagrou, Katrien

Abstract

Contains fulltext : 233628.pdf (Publisher’s version ) (Open Access)

Published
2021

6. Comparison of the quantitative diasorin liaison antigen test to reverse transcription-pcr for the diagnosis of covid-19 in symptomatic and asymptomatic outpatients

Author

Lefever, Stefanie, Indevuyst, Christophe, Cuypers, Lize, Dewaele, Klaas, Yin, Nicolas, Cotton, Frédéric, Padalko, Elizaveta, Oyaert, Matthijs, Descy, Julie, Cavalier, Etienne, Van Ranst, Marc, André, Emmanuel, Lagrou, Katrien, Vermeersch, Pieter, Lefever, Stefanie, Indevuyst, Christophe, Cuypers, Lize, Dewaele, Klaas, Yin, Nicolas, Cotton, Frédéric, Padalko, Elizaveta, Oyaert, Matthijs, Descy, Julie, Cavalier, Etienne, Van Ranst, Marc, André, Emmanuel, Lagrou, Katrien, and Vermeersch, Pieter

Abstract

We evaluated the quantitative DiaSorin Liaison severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test in symptomatic and asymptomatic individuals consulting their general practitioners (GPs) during a period of stable intense virus circulation (213/100,000 habitants per day). Leftover reverse transcription-PCR (RT-PCR) positive (n=204) and negative (n=210) nasopharyngeal samples were randomly selected among fresh routine samples collected from patients consulting their GPs. Samples were tested on Liaison XL according to the manufacturer's instructions. Equivocal results were considered negative. The overall sensitivity and specificity of the Liaison antigen test compared to RTPCR were 65.7% (95% confidence interval [CI], 58.9% to 71.9%) and 100% (CI, 97.8% to 100%). Sensitivity in samples with viral loads of ≥105, ≥104, and ≥103 copies/ml were 100% (CI, 96.3% to 100.0%), 96.5% (CI, 91.8% to 98.7%), and 87.4% (CI, 81.3% to 91.5%), respectively. All samples with ≤103 copies/ml were antigen negative. The ratio of antigen concentration to viral load in samples with ≥103 copies/ml was comparable in symptomatic and asymptomatic individuals (P=0.58). The proportion of RT-PCR-positive participants with a high viral load (≥105 copies/ml) was not significantly higher in symptomatic than in asymptomatic participants (63.9% [CI, 54.9% to 72.0%] versus 51.9% [CI, 41.1% to 62.6%]; P=0.11), but the proportion of participants with a low viral load (,103 copies/ml) was significantly higher in asymptomatic than in symptomatic RT-PCR-positive participants (35.4% [CI, 25.8% to 46.4%] versus 14.3% [CI, 9.0% to 21.8%]; P<0.01). Sensitivity and specificity in samples with a viral load of ≥104 copies/ml were 96.5% and 100%. The correlation of antigen concentration with viral load was comparable in symptomatic and asymptomatic individuals., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2021

11. First case of Candida aurisinfection in Belgium in a surgical patient from Kuwait

Author

Dewaele, Klaas, Frans, Johan, Smismans, Annick, Ho, Erwin, Tollens, Tim, and Lagrou, Katrien

Abstract

ABSTRACTObjective and importance:Candida aurisis a relatively new yeast species and an emerging opportunistic pathogen. It was first reported in 2009 in East Asia, as a difficult-to-identify Candidaspecies of uncertain clinical relevance. In recent years, it has appeared globally as a cause of invasive infections, not infrequently eliciting nosocomial outbreaks. Species identification in clinical laboratories has been challenging, as traditional phenotypic and biochemical methods have been generally unreliable. Clinical management is often complicated by multidrug resistance in many isolates. Additionally, C. aurishas demonstrated an unusual ability for persistence in the hospital environment and in asymptomatic patients. We present the first Belgian case of C. aurisinfection along with a brief review of the literature.Clinical presentation: A patient was referred from Kuwait for surgical treatment after a complicated bariatric procedure. Few days after transferral, she developed a catheter-related blood stream infection with C. auris. We obtained a low-confidence identification of C. auriswith the Bruker Biotyper MALDI-TOF MS system (Bruker Corporation, Billerica, MA, U.S.A.), and of Candida haemuloniiwith the Vitek YST identification system, version 7.01 (bioMérieux, Marcy-L’Etoile, France). Definite identification was obtained using Internal Transcribed Spacer (ITS) sequencing. As most C. aurisisolates, our strain was resistant to fluconazole, and the patient was eventually treated with catheter removal and anidulafungin therapy. We documented persistence of C. aurisclones with acquired echinocandin resistance in our patient up to 18 months after the infection.Conclusion:Clinicians and microbiologists should be aware of this globally emerging yeast, that poses important challenges in identification, treatment and hospital infection control.

Published
2020
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12. Nationwide Harmonization Effort for Semi-Quantitative Reporting of SARS-CoV-2 PCR Test Results in Belgium

Author

Lize Cuypers, Jannes Bode, Kurt Beuselinck, Lies Laenen, Klaas Dewaele, Reile Janssen, Arnaud Capron, Yves Lafort, Henry Paridaens, Bertrand Bearzatto, Mathieu Cauchie, Aline Huwart, Jonathan Degosserie, Olivier Fagnart, Yarah Overmeire, Arlette Rouffiange, Ilse Vandecandelaere, Marine Deffontaine, Thomas Pilate, Nicolas Yin, Isabel Micalessi, Sandrine Roisin, Veronique Moons, Marijke Reynders, Sophia Steyaert, Coralie Henin, Elena Lazarova, Dagmar Obbels, François E. Dufrasne, Hendri Pirenne, Raf Schepers, Anaëlle Collin, Bruno Verhasselt, Laurent Gillet, Stijn Jonckheere, Philippe Van Lint, Bea Van den Poel, Yolien Van der Beken, Violeta Stojkovic, Maria-Grazia Garrino, Hannah Segers, Kevin Vos, Maaike Godefroid, Valerie Pede, Friedel Nollet, Vincent Claes, Inge Verschraegen, Pierre Bogaerts, Marjan Van Gysel, Judith Leurs, Veroniek Saegeman, Oriane Soetens, Merijn Vanhee, Gilberte Schiettekatte, Evelyne Huyghe, Steven Martens, Ann Lemmens, Heleen Nailis, Kim Laffineur, Deborah Steensels, Elke Vanlaere, Jérémie Gras, Gatien Roussel, Koenraad Gijbels, Michael Boudewijns, Catherine Sion, Wim Achtergael, Wim Maurissen, Luc Iliano, Marianne Chantrenne, Geert Vanheule, Reinoud Flies, Nicolas Hougardy, Mario Berth, Vanessa Verbeke, Robin Morent, Anne Vankeerberghen, Sébastien Bontems, Kaat Kehoe, Anneleen Schallier, Giang Ho, Kristof Bafort, Marijke Raymaekers, Yolande Pypen, Amelie Heinrichs, Wim Schuermans, Dominique Cuigniez, Salah Eddine Lali, Stefanie Drieghe, Dieter Ory, Marie Le Mercier, Kristel Van Laethem, Inge Thoelen, Sarah Vandamme, Iqbal Mansoor, Carl Vael, Maxime De Sloovere, Katrien Declerck, Elisabeth Dequeker, Stefanie Desmet, Piet Maes, Katrien Lagrou, Emmanuel André, Dufrasne, Francois/0000-0001-6288-7936, Yin, Nicolas/0000-0003-1706-6869, Van Laethem, Kristel/0000-0001-6036-2271, Micalessi, Isabel, Ory , Dieter, Dequeker, Elisabeth, CLAES , Vincent, Verhasselt, Bruno, Moons, Veronique, Soetens, Oriane, Godefroid, Maaike, Verschraegen, Inge, Pirenne, Hendri, Gillet, Laurent, Heinrichs, Amelie, Huwart, Aline, Vanhee, Merijn, Vandamme, Sarah, Maurissen, Wim, Laenen , Lies, Reynders , Marijke, Thoelen, Inge, Gras, Jeremie, Berth, Mario, Obbels, Dagmar, Vanheule, Geert, Maes, Piet, Bafort, Kristof, Flies, Reinoud, Janssen, Reile, van den Poel, Bea, Bontems, Sebastien, Schepers , Raf, Overmeire, Yarah, Boudewijns, Michael, van der Beken, Yolien, Cuypers , Lize, Bode, Jannes, Vos, Kevin, Paridaens, Henry, Achtergael, Wim, Saegeman, Veroniek, Rouffiange, Arlette, Dewaele, Klaas, Pypen, Yolande, Yin, Nicolas, Drieghe, Stefanie, Nailis, Heleen, Kehoe, Kaat, DE SMET, Stefanie, Verbeke, Vanessa, Vanlaere, Elke, Vael, Carl, Van Laethem, Kristel, Segers, Hannah, Pede, Valerie, Deffontaine, Marine, Martens , Steven, Lemmens, Ann, Vankeerberghen, Anne, Lagrou, Katrien, Iliano, Luc, Chantrenne, Marianne, Laffineur, Kim, Bearzatto, Bertrand, Vandecandelaere, Ilse, Sion, Catherine, Andre, Emmanuel, Cuigniez, Dominique, Pilate, Thomas, Capron, Arnaud, Nollet, Friedel, Roisin, Sandrine, Gijbels, Koenraad, Van Lint, Philippe, Bogaerts, Pierre, Lafort, Yves, Henin, Coralie, Van Gysel, Marjan, Huyghe, Evelyne, Lali, Salah Eddine, Roussel, Gatien, Garrino, Maria-Grazia, Schuermans, Wim, Steyaert, Sophia, Le Mercier, Marie, De Sloovere, Maxime, Leurs, Judith, STEENSELS, Deborah, Declerck, Katrien, Dufrasne, Francois E., Fagnart, Olivier, Ho, Giang, Lazarova, Elena, Schallier, Anneleen, Beuselinck, Kurt, Morent, Robin, Hougardy, Nicolas, Raymaekers, Marijke, Jonckheere, Stijn, Stojkovic, Violeta, Degosserie, Jonathan, Cauchie, Mathieu, Schiettekatte, Gilberte, Collin, Anaelle, Mansoor, Iqbal, Faculty of Economic and Social Sciences and Solvay Business School, Faculty of Medicine and Pharmacy, Supporting clinical sciences, Microbiology and Infection Control, Clinical Biology, Experimental Pharmacology, Department of Clinical Microbiology, Faculty of Psychology and Educational Sciences, UCL - (MGD) Laboratoire de biologie clinique, and UCL - SSS/IREC/MONT - Pôle Mont Godinne

Subjects
SARS-CoV-2, PCR, semi-quantitative reporting, RNA copies/mL, infectivity, COVID-19/diagnosis, COVID-19, Real-Time Polymerase Chain Reaction, mL, Infectious Diseases, Belgium, SARS-CoV-2/genetics, Virology, Humans, RNA copies, Human medicine, Belgium/epidemiology, Pandemics
Abstract

From early 2020, a high demand for SARS-CoV-2 tests was driven by several testing indications, including asymptomatic cases, resulting in the massive roll-out of PCR assays to combat the pandemic. Considering the dynamic of viral shedding during the course of infection, the demand to report cycle threshold (Ct) values rapidly emerged. As Ct values can be affected by a number of factors, we considered that harmonization of semi-quantitative PCR results across laboratories would avoid potential divergent interpretations, particularly in the absence of clinical or serological information. A proposal to harmonize reporting of test results was drafted by the National Reference Centre (NRC) UZ/KU Leuven, distinguishing four categories of positivity based on RNA copies/mL. Pre-quantified control material was shipped to 124 laboratories with instructions to setup a standard curve to define thresholds per assay. For each assay, the mean Ct value and corresponding standard deviation was calculated per target gene, for the three concentrations (10(7), 10(5) and 10(3) copies/mL) that determine the classification. The results of 17 assays are summarized. This harmonization effort allowed to ensure that all Belgian laboratories would report positive PCR results in the same semi-quantitative manner to clinicians and to the national database which feeds contact tracing interventions. UZ/KU Leuven: as National Reference Center for Respiratory Pathogens, is supported by Sciensano, which is gratefully acknowledged. We would like to acknowledge additional staff members of the participating laboratories that contributed to this study: Jean-Luc Gala, Benoit Kabamba, Elsa Wiam, Valentin Coste, Paul Blanpain, Jean Ruelle, Ari Serbetciyan, Nicolas Pinte, Ophélie Simon and the entire UCLouvain federal testing platform COVID-19 team (all affiliation 4), Aurore Demars (affiliation 7), Laura Vanden Daele (affiliation 9), Hanne Valgaeren (affiliation 22), Guillaume Bayon-Vicente (affiliation 23), Fabrice Bureau, Claire Gourzonès and Joey Schyns (affiliation 28), Stéphanie Evrard (affiliation 42), Clara Ceyssens (affiliation 58), Jorn Hellemans (affiliation 77), Bram Slechten (affiliation 86) and the entire team of the laboratory of microbiology of UZA (affiliation 89) and of the UZA Federal testing platform COVID-19 (affiliation 85) for their boundless dedication.

Published
2022

13. Single nucleotide variation catalog from clinical isolates mapped on tertiary and quaternary structures of ESX-1-related proteins reveals critical regions as putative Mtb therapeutic targets.

Author

Tzfadia O, Gijsbers A, Vujkovic A, Snobre J, Vargas R, Dewaele K, Meehan CJ, Farhat M, Hakke S, Peters PJ, de Jong BC, Siroy A, and Ravelli RBG

Subjects
Humans, Virulence genetics, Mutation, Genome, Bacterial genetics, Models, Molecular, Polymorphism, Single Nucleotide, Bacterial Proteins genetics, Bacterial Proteins metabolism, Bacterial Proteins chemistry, Mycobacterium tuberculosis genetics, Mycobacterium tuberculosis metabolism, Tuberculosis microbiology, Antigens, Bacterial genetics, Antigens, Bacterial metabolism, Antigens, Bacterial chemistry
Abstract

Proteins encoded by the ESX-1 genes of interest are essential for full virulence in all Mycobacterium tuberculosis complex (Mtbc) lineages, the pathogens causing the highest mortality worldwide. Identifying critical regions in these ESX-1-related proteins could provide preventive or therapeutic targets for Mtb infection, the game changer needed for tuberculosis control. We analyzed a compendium of whole genome sequences of clinical Mtb isolates from all lineages from >32,000 patients and identified single nucleotide polymorphisms. When mutations corresponding to all non-synonymous single nucleotide polymorphisms were mapped on structural models of the ESX-1 proteins, fully conserved regions emerged. Some could be assigned to known quaternary structures, whereas others could be predicted to be involved in yet-to-be-discovered interactions. Some mutants had clonally expanded (found in >1% of the isolates); these mutants were mostly located at the surface of globular domains, remote from known intra- and inter-molecular protein-protein interactions. Fully conserved intrinsically disordered regions of proteins were found, suggesting that these regions are crucial for the pathogenicity of the Mtbc. Altogether, our findings highlight fully conserved regions of proteins as attractive vaccine antigens and drug targets to control Mtb virulence. Extending this approach to the whole Mtb genome as well as other microorganisms will enhance vaccine development for various pathogens., Importance: We mapped all non-synonymous single nucleotide polymorphisms onto each of the experimental and predicted ESX-1 proteins' structural models and inspected their placement. Varying sizes of conserved regions were found. Next, we analyzed predicted intrinsically disordered regions within our set of proteins, finding two putative long stretches that are fully conserved, and discussed their potential essential role in immunological recognition. Combined, our findings highlight new targets for interfering with Mycobacterium tuberculosis complex virulence., Competing Interests: The authors declare no conflict of interest.

Published
2024
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14. First case of Candida auris infection in Belgium in a surgical patient from Kuwait.

Author

Dewaele K, Frans J, Smismans A, Ho E, Tollens T, and Lagrou K

Subjects
Anastomotic Leak, Anidulafungin therapeutic use, Antifungal Agents therapeutic use, Belgium, Candida genetics, Candida isolation & purification, Candidiasis, Invasive drug therapy, Candidiasis, Invasive microbiology, Catheter-Related Infections drug therapy, Catheter-Related Infections microbiology, Drug Resistance, Fungal, Female, Humans, Ileum injuries, Intestinal Fistula complications, Intestinal Perforation complications, Kuwait, Microbial Sensitivity Tests, Middle Aged, Patient Transfer, Postoperative Complications drug therapy, Postoperative Complications microbiology, Surgical Wound Infection complications, Urinary Tract Infections complications, Candidiasis, Invasive diagnosis, Catheter-Related Infections diagnosis, Central Venous Catheters, Gastric Bypass, Postoperative Complications diagnosis
Abstract

Objective and importance: Candida auris is a relatively new yeast species and an emerging opportunistic pathogen. It was first reported in 2009 in East Asia, as a difficult-to-identify Candida species of uncertain clinical relevance. In recent years, it has appeared globally as a cause of invasive infections, not infrequently eliciting nosocomial outbreaks. Species identification in clinical laboratories has been challenging, as traditional phenotypic and biochemical methods have been generally unreliable. Clinical management is often complicated by multidrug resistance in many isolates. Additionally, C. auris has demonstrated an unusual ability for persistence in the hospital environment and in asymptomatic patients. We present the first Belgian case of C. auris infection along with a brief review of the literature. Clinical presentation: A patient was referred from Kuwait for surgical treatment after a complicated bariatric procedure. Few days after transferral, she developed a catheter-related blood stream infection with C. auris . We obtained a low-confidence identification of C. auris with the Bruker Biotyper MALDI-TOF MS system (Bruker Corporation, Billerica, MA, U.S.A.), and of Candida haemulonii with the Vitek YST identification system, version 7.01 (bioMérieux, Marcy-L'Etoile, France). Definite identification was obtained using Internal Transcribed Spacer (ITS) sequencing. As most C. auris isolates, our strain was resistant to fluconazole, and the patient was eventually treated with catheter removal and anidulafungin therapy. We documented persistence of C. auris clones with acquired echinocandin resistance in our patient up to 18 months after the infection. Conclusion: Clinicians and microbiologists should be aware of this globally emerging yeast, that poses important challenges in identification, treatment and hospital infection control.

Published
2020
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