A multicentre evaluation of the NG-test DetecTool OXA-23 for the rapid detection of OXA-23 carbapenemase directly from blood cultures

Alexandra Vasilakopoulou; Thierry Naas; Camille Gonzalez; Jordi Vila; Dóra Szabo; Eleonora Riccobono; Katalin Kamotsay; Sophie Reissier; Dàmaris Berbel; Albert Zoltan Aszalos; Magda Rosenmoller; Milovan Stankov-Puges; Panagiota-Christina Georgiou; Sophia Vourli; Hervé Volland; Spyros Pournaras

doi:10.1093/jacamr/dlae029

A multicentre evaluation of the NG-test DetecTool OXA-23 for the rapid detection of OXA-23 carbapenemase directly from blood cultures

JAC Antimicrob Resist. 2024 Mar 7;6(2):dlae029. doi: 10.1093/jacamr/dlae029. eCollection 2024 Apr.

Authors

Alexandra Vasilakopoulou¹, Thierry Naas², Camille Gonzalez², Jordi Vila^{3

4

5}, Dóra Szabo⁶, Eleonora Riccobono^{7

8}, Katalin Kamotsay⁹, Sophie Reissier¹⁰, Dàmaris Berbel¹¹, Albert Zoltan Aszalos¹², Magda Rosenmoller¹³, Milovan Stankov-Puges¹⁴, Panagiota-Christina Georgiou¹, Sophia Vourli¹, Hervé Volland¹⁵, Spyros Pournaras¹

Affiliations

¹ Laboratory of Clinical Microbiology, Attikon University General Hospital, Medical School, National and Kapodistrian University, Athens, Greece.
² Team 'Resist', INSERM Unit 1184, Faculty of Medicine, Université Paris-Saclay, Bacteriology-Hygiene Unit, Assistance Publique-Hôpitaux de Paris, AP-HP Paris-Saclay, Bicêtre Hospital Le Kremlin-Bicêtre, Paris, France.
³ Department of Clinical Microbiology, Hospital Clinic of Barcelona, Barcelona, Spain.
⁴ Institute for Global Health (ISGlobal), University of Barcelona, Barcelona, Spain.
⁵ Department of Clinical Microbiology/CIBER de Enfermedades Infecciosas, University of Barcelona, Madrid, Spain.
⁶ Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary.
⁷ Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
⁸ Department of Medical Biotechnologies, University of Siena, Siena, Italy.
⁹ Central Microbiology Laboratory, Central Hospital of Southern Pest National Institute of Hematology and Infectious Diseases, Budapest, Hungary.
¹⁰ Department of Bacteriology, Amiens University Hospital, Amiens, France.
¹¹ Microbiology Department, Hospital de Bellvitge, IDIBELL, UB, CIBERES, Barcelona, Spain.
¹² Health Services Management Training Centre, Semmelweis University, Budapest, Hungary.
¹³ Department of Operations, Information and Technology, IESE Business School, Barcelona, Spain.
¹⁴ R&D Department, NG Biotech, Guipry, France.
¹⁵ Département Médicaments et Technologies Pour la Santé (DMTS), Université Paris Saclay, CEA, INRAE, SPI, 91191 Gif-sur-Yvette, Paris, France.

Abstract

Objectives: A multicentre study evaluating NG-Test DetecTool OXA-23 for the detection of OXA-23 carbapenemase directly from positive blood cultures (PBCs).

Methods: The NG-Test DetecTool OXA-23 is an immunoassay that integrates a sample preparation device. We evaluated NG-Test DetecTool OXA-23 on 189 spiked and 126 clinical PBCs. The clinical samples' standard-of-care procedure consisted of bacterial identification from the first day of positivity by MALDI-TOF MS, conventional culture and antimicrobial susceptibility testing. The immunoassay results were verified molecularly. The strains used for the spiked samples consisted of well-characterized Acinetobacter baumannii and Proteus mirabilis strains.

Results: The NG-Test DetecTool OXA-23 was evaluated on 315 PBCs and revealed sensitivity of 100% (95% CI: 98.21%-100.00%) and specificity of 100% (95% CI: 96.73%-100.00%). It provided 204 true-positive results for OXA-23 in 196 bottles with carbapenem-resistant A. baumannii (CRAB) and 8 bottles with carbapenem-resistant P. mirabilis and also provided 111 true-negative results. There were no false-positive and no false-negative results. Among the 315 PBCs studied, 83 clinical blood cultures collected in the ICU of a Greek university hospital, which were tested prospectively, all yielded CRAB, and OXA-23 was correctly detected in all samples from the first day of positivity using the NG-Test DetecTool OXA-23.

Conclusions: The NG-Test DetecTool OXA-23 has exhibited excellent sensitivity and specificity for OXA-23 detection in PBCs and can provide valuable information for appropriate selection of antibiotic therapy and early implementation of infection control measures.