Microarray identification of Clostridium difficile core components and divergent regions associated with host origin

Area of Science:

• Microbiology
• Genomics
• Infectious Diseases

Background:

• Clostridium difficile is a gram-positive, spore-forming anaerobe causing significant human infections.
• Increasing incidence and severity of human C. difficile infections necessitate further research.

Purpose of the Study:

• To evaluate the genomic content of C. difficile strains from various hosts.
• To identify core genes and explore host-specific genetic diversity.
• To provide insights into host adaptation mechanisms.

Main Methods:

• Comparative genomic hybridization using microarrays.
• Analysis of 73 C. difficile strains from humans, horses, cattle, and pigs.
• Utilizing the C. difficile strain 630 genome as a reference.

Main Results:

• Approximately 16% of genes in strain 630 were conserved across all tested strains, defining the core genome.
• Absent or divergent genes were found across the genome and functional categories.
• Certain genes showed conservation within specific host origins, indicating potential host adaptation.

Conclusions:

• The study defines a core gene set for C. difficile, crucial for understanding its biology.
• Genomic divergence among strains suggests adaptation to different hosts.
• The identified core gene list is a foundational step for developing diagnostic arrays for C. difficile.