Streptococcus canis transcriptomic modifications in host cell entry environments of human keratinocytes

Area of Science:

• Microbiology
• Genomics
• Infectious Diseases

Background:

• Streptococcus canis is a commensal bacterium in companion animals.
• It can infect humans through skin/soft tissue, particularly via dog bites.
• Understanding its pathogenic mechanisms in human cells is crucial.

Purpose of the Study:

• To investigate the transcriptomic changes of Streptococcus canis during invasion of human keratinocytes.
• To identify key genes and pathways affected during host cell interaction.

Main Methods:

• Selected a S. canis isolate (FU1) based on cell invasion ability and cytotoxicity.
• Performed RNA-sequencing at baseline and post-inoculation (2h/5h) in human keratinocytes.
• Utilized principal component analysis (PCA), k-means clustering, and differential gene expression (DEG) analysis.
• Validated findings using quantitative reverse transcription-polymerase chain reaction (qRT-PCR).

Main Results:

• RNA-sequencing revealed significant gene expression alterations in S. canis upon keratinocyte invasion.
• Gene ontology analysis indicated widespread downregulation of metabolism-associated genes (energy, carbohydrate, amino acid, nucleotide transport/metabolism).
• Upregulated genes were primarily associated with transcription.
• qRT-PCR confirmed the downregulation of pgk and opuAA, and upregulation of slo and kdpB genes.

Conclusions:

• S. canis downregulates metabolism-related gene expression when interacting with human keratinocytes.
• These transcriptomic shifts suggest a potential for latent infection.
• Further research is required to fully understand the mechanisms of S. canis latent infection in human cells.