Suitability of MALDI-TOF MS for the identification of Staphylococcus aureus and members of the Staphylococcus intermedius group (S.I.G) complex [Idoneidad del uso del MALDI-TOF MS para la identificación de Staphylococcus aureus y miembros del grupo de Staphylococcus intermedius (S.I.G.)]
- Alcalá, L. 46
- Simón, M.C. 46
- López-Calleja, A.I. 34
- Ferrer, I. 34
- Pereira, J. 34
- Ortega, C. 46
- Torres, C. 15
- Viguera, N. 34
- Gómez-Sanz, E. 24
- Revillo, M.J. 34
- Rezusta, A. 34
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1
Centro de Investigación Biomédica de La Rioja
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- 2 Environmental Genomics and Systems Biology Research Group, Institute of Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), Wädenswil, Switzerland
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3
Hospital Miguel Servet
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4
Instituto de Investigación Sanitaria Aragón
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Instituto de Investigación Sanitaria Aragón
Zaragoza, España
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5
Universidad de La Rioja
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6
Universidad de Zaragoza
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ISSN: 1695-7504
Año de publicación: 2015
Volumen: 16
Número: 1
Tipo: Artículo
beta Ver similares en nube de resultadosOtras publicaciones en: Revista Electrónica de Veterinaria
Resumen
Although Staphyolococcus spp. are commonly isolated from humans and animals, their identification is problematic. This study assessed the suitability of MALDI-TOF MS (Biotyper 3) for their identification, comparing the results obtained by using phenotypical methods, MALDI-TOF (with and without adding formic acid) and molecular identification. A collection of 37 strains identified by conventional method as S. aureus (n= 7), S. intermedius (n=1) and S. pseudintermedius (n=29), were analyzed. The isolates belonged to ill and healthy dogs (n=27) and humans (n=10), from different biological samples. All of them were also identified by molecular methods and pure cultures were processed with a MALDI-TOF MS. The information was computed using DAG-Stat. The estimated sensitivity, specificity, efficiency and kappa statistics with a 95% confidence interval were calculated separately for the three bacterial species by taking molecular identification as the gold standard. Estafilococos from 27 dogs and their owners were identified. Only a strain of S. intermedius was found, so parameters related to it, might be considered with caution. All S. aureus were correctly identified. By using MALDI-TOF MS adding formic acid, lower sensibility and good specificity were calculated for S. pseudintermedius. In this case, almost perfect agreement between tests was obtained for S. aureus and S. pseudintermedius, respectively. When no formic acid was added, total agreement was estimated for S. aureus and substantial agreement for S. pseudintermedius. This study demonstrates the validity, the usefulness and the reliability of MALDI-TOF MS in the identification of bacterial isolates belonging to Staphylococcus spp.