[Usefulness of MALDI-TOF and REP-PCR against PFGE for the epidemiological study of Acinetobacter baumannii]

Rev Esp Quimioter. 2021 Jun;34(3):207-213. doi: 10.37201/req/142.2020. Epub 2021 Apr 8.
[Article in Spanish]

Abstract

Objective: To evaluate the ability of MALDI-TOF MS and rep-PCR to discriminate Acinetobacter baumannii clones.

Methods: A total of 21 strains of A. baumannii with different epidemiological and phenotipycal characteristics were included in the study. All isolates were analyzed in parallel by MALDI-TOF MS and rep-PCR and the spectra obtained were compared with each other and with the results obtained by pulsed field gel electrophoresis (PFGE). Isolates with a similarity equal to or greater than 87% were considered to be part of the same clonal group.

Results: The analysis of the 21 isolates included in the study, resulted in 8 clonal groups using PFGE, 3 groups by MALDI-TOF MS and 7 groups by rep-PCR analysis. The isolates that formed the different groups by the 3 techniques used were totally different, so it can be concluded that there is no equivalence between the results obtained with the three typing methods used.

Conclusions: Despite its simplicity, neither MALDI-TOF MS nor rep-PCR can at this time replace PFGE for the epidemiological study of A. baumannii.

Objetivo: Evaluar la capacidad de MALDI-TOF MS (Matrix-assisted Laser Desorption-Ionization Time Of Flight) y rep-PCR para discriminar diferentes clones de Acinetobacter baumannii.

Material y métodos: Se incluyeron en el estudio 21 aislados de A. baumannii con diferentes características epidemiológicas y fenotípicas. Todas las muestras se analizaron en paralelo por MALDI-TOF MS y rep-PCR y los espectros obtenidos se compararon entre ellos y con los resultados obtenidos mediante electroforesis en campo pulsado (PFGE). Se consideró que los aislados con una similitud igual o superior al 87% formaban parte del mismo grupo clonal.

Resultados: El análisis de los 21 aislados incluidos en el estudio, dio lugar a 9 grupos clonales en PFGE, 3 grupos en MALDI-TOF MS y 7 grupos en el análisis mediante rep-PCR. Los aislados que formaban los diferentes grupos por las 3 técnicas utilizadas eran totalmente diferentes, por lo que se puede concluir que no hay equivalencia entre los resultados obtenidos con los tres métodos de tipado utilizados.

Conclusiones: A pesar de su simplicidad ni MALDI-TOF MS ni rep-PCR pueden sustituir en este momento al PFGE para el estudio epidemiológico de A. baumannii.

Keywords: Acinetobacter baumannii; MALDI-TOF MS; carbapenemase; epidemiology; rep-PCR.

MeSH terms

  • Acinetobacter Infections* / epidemiology
  • Acinetobacter baumannii* / genetics
  • Electrophoresis, Gel, Pulsed-Field
  • Humans
  • Polymerase Chain Reaction
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization