Phylogenomic analysis for Campylobacter fetus ocurring in Argentina

Area of Science:

• Veterinary microbiology
• Genomics
• Population genetics

Background:

• Campylobacter fetus causes bovine genital campylobacteriosis, leading to significant economic losses in Argentina's livestock industry.
• Understanding the genomic relationships of C. fetus strains is crucial for disease control.

Purpose of the Study:

• To establish genomic relationships of C. fetus strains from Argentina at local and global levels.
• To evaluate multi-locus sequence typing (MLST) as a C. fetus typing technique.

Main Methods:

• Whole genome sequencing of 34 local C. fetus strains and 265 global strains.
• Construction of local and global core genome maximum likelihood phylogenetic trees.
• In silico MLST analysis for sequence type determination.

Main Results:

• Local phylogenetic analysis revealed two major and one minor cluster, suggesting a clonal population structure (82% of strains).
• MLST identified ST4 (31 strains), ST5 (1 strain), and a novel ST70.
• Global analysis showed local strains clustering separately, with some related to strains from Uruguay and Brazil; ST5 was divergent.

Conclusions:

• Genomic data suggests active animal movement within Argentina and with neighboring countries.
• MLST showed limited concordance with phylogenetic analysis and is not a reliable subtyping method for C. fetus in Argentina.
• The study provides a foundation for future C. fetus research.