Short Communication

24 Haemophilus parasuis is the causative agent of Glässer’s disease and a commensal 25 coloniser of the porcine upper respiratory tract. Multiple complex factors, including the early 26 weaning of piglets and the management of high health status farms, make it a re-emerging 27 agent, responsible for a recent increase in the prevalence and severity of disease in pigs in 28 China. However, little genetic information is known about Chinese epidemic isolates. In this 29 study, a phylogenetic method for genotyping the H. parasuis population with available 30 Chinese epidemic isolates and reference strains from different origins is presented. 31 Phylogenetic analysis confirmed that there are at least two different genotypes in H. parasuis 32 population and a unique Chinese lineage with virulence results in the previous epidemics. 33 34