Histophilus somni Genomics and Genetics.

Area of Science:

• Bacteriology and Genomics
• Veterinary Infectious Diseases

Background:

• Histophilus somni is a significant bacterial pathogen in cattle and sheep, causing multisystemic diseases.
• Virulence factors such as lipooligosaccharide, apoptosis induction, and Fc-binding proteins are key to H. somni pathogenicity.
• Genomic sequencing of H. somni strains has opened new avenues for understanding its evolution and virulence.

Purpose of the Study:

• To analyze the genomes of H. somni strains to understand their evolution and identify novel genetic elements.
• To investigate the genetic basis for H. somni's adaptability and recalcitrance to natural transformation.
• To explore the potential of post-genomic approaches, including transcriptomics, for functional gene characterization.

Main Methods:

• Comparative genomic analysis of H. somni pneumonia strain 2336 and preputial strain 129Pt.
• Identification and characterization of horizontally transferred genetic elements, such as integrative and conjugative elements (ICEHso2336).
• Transcriptomic studies to identify novel genes and small noncoding RNAs.

Main Results:

• Comparative genomics revealed the role of horizontal gene transfer in H. somni evolution and identified an ICEHso2336 element conferring tetracycline resistance.
• Abundance of Haemophilus influenzae uptake signal sequences in H. somni genomes provides a genetic basis for natural transformation recalcitrance.
• Transcriptomic analyses have identified numerous small noncoding RNAs and previously unknown genes.

Conclusions:

• Genomic and post-genomic studies provide significant insights into H. somni virulence, evolution, and genetic adaptability.
• The findings highlight the importance of systems biology approaches for future in-depth investigations of H. somni.
• Continued research is crucial for developing effective strategies against H. somni infections in livestock.