Campylobacter cuniculorum sp. nov., from rabbits

Area of Science:

• Microbiology
• Veterinary Science
• Bacteriology

Background:

• Campylobacter species are significant pathogens in both animals and humans.
• Thermophilic Campylobacter species are commonly found in poultry and other food-producing animals.
• The diversity of Campylobacter in lagomorphs remains incompletely understood.

Purpose of the Study:

• To characterize novel thermotolerant Campylobacter strains isolated from rabbit caecal contents.
• To determine the phylogenetic relationship of these isolates to known Campylobacter species.
• To propose a new species designation for these unique rabbit-associated bacteria.

Main Methods:

• Isolation and cultivation of thermotolerant bacteria from rabbit caecal samples.
• Identification using genus-specific and species-specific Polymerase Chain Reaction (PCR).
• Morphological characterization, including flagellation and cell shape changes.
• Phylogenetic analysis using 16S rRNA, rpoB, and groEL gene sequences.
• Whole-cell protein electrophoresis for comparative analysis.

Main Results:

• Eight thermotolerant Campylobacter strains were isolated from rabbit caeca.
• These strains were identified as Campylobacter genus but did not match known thermophilic species via PCR.
• Morphological analysis revealed spiral cells with bipolar flagella, becoming coccoid upon prolonged incubation.
• Phylogenetic analyses showed the isolates formed a distinct clade, with Campylobacter helveticus as the closest neighbor (96.6% 16S rRNA similarity).
• Whole-cell protein electrophoresis confirmed the distinctness of these isolates.

Conclusions:

• The isolated strains represent a novel thermotolerant Campylobacter species.
• The proposed name for this new species is Campylobacter cuniculorum sp. nov.
• The type strain is 150B(T), with proposed accession numbers LMG 24588(T) and CCUG 56289(T).