Occurrence of bacteria potentially pathogenic to humans in a harvested intertidal sea snail

ABSTRACT

Microbes associated with marine invertebrates play a key role in the physiological and biochemical processes of the host, and can be responsible for food-borne diseases in humans. Raw invertebrates are a common component of coastal gastronomy worldwide and their consumption could represent a potential risk to humans if their microbiome hosts infectious bacteria. However, these species’ microbiome composition is usually unknown. In this study, we sequenced the 16S gene to characterise the microbiome of the digestive system and gonads of the commercially-exploited sea snail Phorcus sauciatus from the Macaronesian islands and mainland Portugal. The goal was to identify bacteria that might pose a threat to humans. In total, 910 OTUs were identified, thirty-two of which were found to be classified as Risk level-1 and -2 species. Among these, twenty pathogenic bacterial strains were found in high relative abundance and identified as potential drivers of human diseases, including Micrococcus luteus and Serratia marcescens. Here, we discuss how our findings on the occurrence of these bacteria could seriously affect humans. Our results are relevant beyond the scope of this study, as this work might also pave the way for uncovering further implications on the raw consumption of other shellfish and invertebrate species.

KEYWORDS:

• Microbiome
• foodborne diseases
• pathogens
• invertebrates
• intertidal
• Atlantic Ocean

Acknowledgements

The authors are grateful to the DSEIMar of the Regional Directorate of Sea of the Autonomous Region of Madeira. We are also grateful to Madalena Gaspar for revising the English language of the manuscript. We also thank the Associate Editor and the two anonymous reviewers whose suggestions helped improve and clarify this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Statement of contribution

RS: Sampling collection and preparation of the first draft of the manuscript. JV: Sampling processing. Revision of the first draft of the manuscript. IVE: Analysis of results and writing the Material and Methods section. RR: Coordinating the revised version of the manuscript. Writing the discussion section. All authors revised the last version of the manuscript.

Additional information

Funding

The first author (RS) was supported by a grant from ARDITI OOM/2016/010 (M1420-01-0145-FEDER-000001-Observatório Oceânico da Madeira-OOM), and the second author (JV) by a grant from Fundação para a Ciência e Tecnologia - FCT (SFRH/BSAB/143056/2018. This study was also supported by the UE FEDER in the framework of the Projects MARISCOMAC (MAC/2.3d/097) and MACAROFOOD (MAC/2.3d/015), the Regional Government of Madeira and by FCT, through the strategic project UID/MAR/04292/2019 granted to MARE.