Phylogenetic analysis of urease-positive thermophilic Campylobacter (UPTC) strains based on the molecular characterization of the flaA gene

Molecular cloning, nucleotide sequencing, and characterization of the flaA gene from additional isolates of urease-positive thermophilic Campylobacter (UPTC) were performed. These isolates were obtained from the natural environment in Northern Ireland (n = 9 from mussels) and in England (n = 1 from sea water). All isolates carried the shorter flaA gene, [open reading frames (ORFs), 1,461 to 1,503 base pairs], without any internal termination codons, and did not carry any flaA pseudogenes. The UPTC isolates were well discriminated by the neighbor joining (NJ) phylogenetic tree constructed based on the putative flaA genes ORFs nucleotide sequence information. In addition, the NJ tree constructed based on the flaA-short variable region sequence information discriminated the Campylobacter lari isolates with a similar degree of discrimination power.