Polyphasic identification of Vibrio species from aquatic sources using mass spectrometry, housekeeping gene sequencing and whole genome analysis.

Accurate bacterial identification is essential for determining the causative agent of an infection, thus facilitating appropriate treatment and management strategies in both human and animal health contexts. Some species in the Vibrio genus are recognized pathogens, associated with a variety of infections. However, identification of these bacteria is oftentimes controversial. Therefore, we aimed to evaluate different identification approaches in terms of their reliability in distinguishing Vibrio species. To achieve this, we selected a set of 40 Vibrio isolates previously recovered from water and floating plastic samples in a large bay environment and identified them employing MALDI-TOF mass spectrometry, and rrs and pyrH gene sequencing. A subset of isolates was also submitted to whole genome sequencing. Overall, MALDI-TOF was found to be a fast-screening methodology for identification, notably at genus-level. However, for better species discrimination, pyrH gene sequencing stood out as a more reliable tool in contrast to rrs gene sequencing and MALDI-TOF, as corroborated by whole genome sequencing analysis.