Carlos Ruiz de Alegría-Puig1, Ana De-Malet-Pintos-Fonseca2, Itziar Angulo-López2, Jesús Agüero-Balbín3, Francesc Marco4, Rodrigo Cayô5, Ignasi Roca6, Jordi Vila4, Luis Martínez-Martínez7. 1. Microbiology Service, University Hospital Marqués de Valdecilla-IDIVAL, Santander, Spain. Electronic address: carlosrdap@hotmail.com. 2. Microbiology Service, University Hospital Marqués de Valdecilla-IDIVAL, Santander, Spain. 3. Microbiology Service, University Hospital Marqués de Valdecilla-IDIVAL, Santander, Spain; Department of Molecular Biology, School of Medicine, University of Cantabria, Santander, Spain. 4. ISGlobal, Hospital Clinic - Universitat de Barcelona, Barcelona, Spain; Department of Clinical Microbiology. Hospital Clinic-Universitat de Barcelona, Spain. 5. Universidade Federal de São Paulo (UNIFESP), Laboratório de Inmunologia e Bacteriologia (LIB), Setor de Biologia Molecular, Microbiologia e Inmunologia - Departamento de Ciências Biológicas (DCB), Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF), Diadema, SP, Brazil; Universidade Federal de São Paulo - UNIFESP, Laboratório Alerta, Disciplina de Infectología, Departamento de Medicina, Escola Paulista de Medicina - EPM, São Paulo, SP, Brazil. 6. ISGlobal, Hospital Clinic - Universitat de Barcelona, Barcelona, Spain. 7. Unit of Microbiology, University Hospital Reina Sofia, Cordoba, Spain; Department of Microbiology, University of Cordoba, Cordoba, Spain; Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Spain.
Abstract
INTRODUCTION: Acinetobacter is a genus that comprises a group of opportunistic pathogens responsible for a variety of nosocomial infections. The Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex includes some species of clinical importance, mainly A. baumannii, A. pittii and A. nosocomialis, which share phenotypic similarities that make it very difficult to distinguish between them using a phenotypic approach. The aim of this study was to evaluate two commercial matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems for the identification of different Acinetobacter species, with a special focus among those belonging to the Acb complex. METHODS: One hundred and fifty-six Acinetobacter spp. clinical strains, identified by amplified ribosomal DNA restriction analysis (ARDRA) and rpoB gene sequencing, were analysed by two different MALDI-TOF systems. RESULTS: Considering only the 144 strains of the Acb complex evaluated in this study, the Vitek-MS™ and Microflex LT™ systems correctly identified 129 (89.6%) and 143 (99.3%) strains, respectively. CONCLUSION: After analysing 156 strains belonging to Acinetobacter spp., both Vitek-MS™ and Microflex LT™ proved to be rapid and accurate systems for the identification of Acb complex species showing a good correlation. However, both manufacturers should improve their databases to include new species in them.
INTRODUCTION:Acinetobacter is a genus that comprises a group of opportunistic pathogens responsible for a variety of nosocomial infections. The Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex includes some species of clinical importance, mainly A. baumannii, A. pittii and A. nosocomialis, which share phenotypic similarities that make it very difficult to distinguish between them using a phenotypic approach. The aim of this study was to evaluate two commercial matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems for the identification of different Acinetobacter species, with a special focus among those belonging to the Acb complex. METHODS: One hundred and fifty-six Acinetobacter spp. clinical strains, identified by amplified ribosomal DNA restriction analysis (ARDRA) and rpoB gene sequencing, were analysed by two different MALDI-TOF systems. RESULTS: Considering only the 144 strains of the Acb complex evaluated in this study, the Vitek-MS™ and Microflex LT™ systems correctly identified 129 (89.6%) and 143 (99.3%) strains, respectively. CONCLUSION: After analysing 156 strains belonging to Acinetobacter spp., both Vitek-MS™ and Microflex LT™ proved to be rapid and accurate systems for the identification of Acb complex species showing a good correlation. However, both manufacturers should improve their databases to include new species in them.
Authors: Matthias Egger; Samuel Penziner; Karl Dichtl; Max Gornicec; Lisa Kriegl; Robert Krause; Ethan Khong; Sanjay Mehta; Milenka Vargas; Sara Gianella; Magali Porrachia; Jeffrey D Jenks; Iswariya Venkataraman; Martin Hoenigl Journal: J Clin Microbiol Date: 2022-03-30 Impact factor: 11.677