Oxidase reagent

Biochemical tests were performed using a Biolog GEN III MicroPlate test panel (Biolog Inc., Hayward, CA, USA) according to the manufacturer’s instructions. Briefly, bacteria were enriched on blood agar plates and homogenously mixed with IF-C inoculation fluid until the turbidity reached 65%. The inoculate was added to the microplate and cultured at 37°C in a candle jar. Color-change analyses and interpretation of the results were conducted using Biolog Microbial Identification Systems software (Biolog Inc.) at 24 and 48 h after incubation. The system compared the test strain results against an established database and used similarity indices to determine the species ID; otherwise, the genus ID or no ID was shown.
Oxidase and catalase tests were performed on each isolated Capnocytophaga strain. The catalase tests were performed using 3% hydrogen peroxide solution (Union Chemical, Hsinchu, Taiwan) and the oxidase tests were performed using oxidase reagent (Becton, Dickinson and Company).

Biochemical characteristics of the strains were investigated using API ZYM, 20A and 50CH strips (BioMérieux) according to the manufacturer's instructions. A 20‐min‐thermic shock of fresh colonies at 80°C was done in order to test sporulation. Catalase (BioMerieux) activity was determined in 3% hydrogen peroxide solution and oxidase activity was assessed using an oxidase reagent (Becton‐Dickinson).
Cellular fatty acid methyl ester (FAME) analysis was performed by gas chromatography/mass spectrometry (GC/MS). Two samples were prepared with approximately 17 mg of bacterial biomass per tube for strain Marseille‐P2849^T and 5 mg per tube for strain Marseille‐P3277^T. Briefly, fatty acid methyl esters were separated using an Elite 5‐MS column and monitored by mass spectrometry (Clarus 500—SQ 8 S, Perkin Elmer, Courtaboeuf, France) as previously described (Dione et al., 2016). Spectral database search was performed using MS Search 2.0 operated with the Standard Reference Database 1A (NIST, Gaithersburg, USA) and the FAMEs mass spectral database (Wiley, Chichester, UK).
Antibiotic susceptibility was tested using the E test gradient strip method (BioMerieux) to determine the minimal inhibitory concentration (MIC) of each tested antibiotic on blood Colombia agar media (BioMerieux, France).