Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of human oral Capnocytophaga species

Anne Jolivet-Gougeon (1, 2) , Nicolas Helsens (1) , Elise Renard (1) , Zohreh Tamanai-Shacoori (1) , Martine Bonnaure-Mallet (1, 2)

1 NuMeCan - Nutrition, Métabolismes et Cancer
2 Centre Hospitalier Universitaire de Rennes [CHU Rennes] = Rennes University Hospital [Ponchaillou]

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was evaluated for rapid identification of cfxA PCR positive and negative Capnocytophaga strains. Colonies were grown on blood agar, incubated anaerobically at 37 °C for 48 h, and were then evaluated by MALDI-TOF MS and 16S rRNA gene sequencing. Both methods identified all colonies to the genus level. The MALDI-TOF MS method gave the same result, at the species level, as 16S rRNA gene sequencing for 41/53 Capnocytophaga sp. strains (77.4%), but the limit of this technique was the absence of some species (C. leadbetteri, C. AHN) in the Biotyper-Bruker® database used in this study. Distinction between the cefotaxime resistant and susceptible strains was unsuccessful using the MALDI-TOF MS method. This technique had low discriminatory power to rapidly detect beta-lactamase-producing Capnocytophaga strains in clinical samples. However, the results from a score-oriented dendrogram confirmed MALDI-TOF MS is a rapid, inexpensive, and reliable method for Capnocytophaga species identification. Enrichment of the reference database used (Biotyper®) will improve future results.

Mots clés: cfxA; Capnocytophaga; PCR; MALDI-TOF mass spectrometry; Dendrogram; 16S rRNA

Domaines: Bactériologie; Ingénierie biomédicale

Anne Jolivet-Gougeon, Nicolas Helsens, Elise Renard, Zohreh Tamanai-Shacoori, Martine Bonnaure-Mallet. Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of human oral Capnocytophaga species. Anaerobe, 2017, 48, pp.89-93. ⟨10.1016/j.anaerobe.2017.07.003⟩. ⟨hal-01619482⟩