Multilocus Sequence Typing of the Guangdong Isolates of Riemerella anatipestifer from Ducks in China

It is a very important significance to explore the bacterial typing methods rapidly, accurately and understand the genetic relation between isolates for controlling effectively the disease and preventing the dissemination and diffusion of the pathogen. The changes in the genetic material nucleotide sequences result in variation and evolution of bacteria, the development of molecular biology and genomics make typing of bacteria from phenotype to molecular typing. Riemerella anatipestifer is the causative agent of polyserositis of ducks and geese. We studied 54 isolates of Riemerella anatipestifer from Guangdong in China by multicolor sequence typing (MLST). The result showed that 54 isolates of Riemerella anatipestifer were divided into 14 STs, and among E3, b12xiao and Cb1 three isolates have with independent of type STs. It was found that there was high homology of RA and low genetic variability in the same area. The synonymous mutation and non synonymous mutation rate: dN/dS in seven housekeeping genes was lower than 0.25. Cluster analysis showed that the 54 isolates were clustered into 5 groups. eBRUST analysis showed that all isolates were clustered into one Group. It also proved that the genetic relationship was very closed in duck plague pathogen in this area; the source may be the same ancestors.