Listeria costaricensis sp. nov

Area of Science:

• Microbiology
• Bacteriology
• Genomics

Background:

• The genus Listeria includes important foodborne pathogens.
• Accurate identification and classification of Listeria species are crucial for public health and food safety.
• Previous studies have identified various Listeria species, but ongoing research seeks to uncover novel strains.

Purpose of the Study:

• To characterize a novel bacterial isolate from a food processing environment.
• To determine the taxonomic placement of the isolate within the genus Listeria.
• To propose a new species designation based on comprehensive genomic and phenotypic data.

Main Methods:

• Phylogenetic analysis using 16S rRNA gene sequences.
• Core genome phylogenetic analysis.
• Whole-genome sequencing for average nucleotide blast identity (ANI) calculations.
• Pairwise amino acid identity (AAI) and percentage of conserved proteins (POCP) analysis.
• Biochemical characterization.

Main Results:

• The isolate belonged to the genus Listeria but was distinct from known species.
• Phylogenetic analyses placed the strain within the Listeria sensu lato clade.
• Genomic analyses (ANI<80%) confirmed the isolate represents a novel species.
• Biochemical tests supported the classification as a new species.

Conclusions:

• A novel Listeria species, Listeria costaricensis sp. nov., is proposed.
• The type strain CLIP 2016/00682T represents this new species.
• This finding contributes to the understanding of Listeria diversity and requires further investigation into its characteristics.