Prevotella mikamonis sp. nov., isolated from equine clinical specimens.

Overview

• Researchers identified and characterized a new species of bacteria, named Prevotella mikamonis, isolated from clinical samples collected from horses in Japan.

Research Context and Purpose

• The study focused on five bacterial strains that were anaerobic, Gram-negative, and rod-shaped, collected from horse clinical specimens.
• The aim was to characterize these strains in detail to determine if they represented a new bacterial species.

Methods and Analysis

• Phenotypic Characterization: Physical and biochemical traits of the bacteria were examined to identify distinguishing features.
• Genotypic Characterization:
  • 16S rRNA gene sequencing was performed to determine the evolutionary relationships.
  • Phylogenetic trees showed that the five strains formed a distinct cluster apart from close relatives.
• Genomic Analysis:
  • The DNA G+C content was measured at 46.7 mol%, an important taxonomic feature.
  • Major cellular fatty acids identified included C, 3-OH-C, and 3-OH-iso-C, which contribute to the bacteria’s membrane properties.
  • Whole-genome comparisons involved Average Nucleotide Identity (ANIb) and digital DNA-DNA hybridization (dDDH). These methods quantify genetic similarity to known species.
  • The ANIb values were below 73.1%, and dDDH values were below 28.6% when compared with closely related species, which are below thresholds for classifying bacteria as the same species.

Findings and Conclusion

• The phenotypic, phylogenetic, and genomic data confirmed that these five strains are different enough from known species to warrant a new species classification.
• The proposed name of the new species is Prevotella mikamonis sp. nov.
• The type strain for this species is designated as GTC17253 (CCUG77931), serving as the reference for future studies.
• This discovery expands the understanding of bacterial diversity in equine clinical environments.