Study on the phylogenetic relationships of Sarcocystis in Rongshui County of Guangxi

Abstract

Objective To investigate and analyze the phylogenetic relationships of Sarcocystis from Rongshui County of Guangxi.Methods Pork and beef meats were collected at markets in Rongshui County.All samples were examined using microscope and Sarcocystis isolates were collected from positive samples.The genomic DNA was extracted from Sarcocystis.18S rRNA was amplified as the DNA marker by PCR and the amplicon was sequenced and analysis was carried out compared with that of GenBank.Phylogenetic trees were constructed by maximum likelihood method and neighbor-joining method.The phylogenetic relationships were analyzed.Results There were 3 isolates from Rongshui County.The similarity among isolates from Rongshui County and Sarcocystis sequences from GenBank were analyzed.Gongdong isolate was similar to S.suinominis with 99.8％ homology,Liangzai isolate 1 was similar to S.suinominis with 97.4％ homology,and the other isolate was similar to S.hominis with 93.5％ homology.In the phylogenetic tree constructed by maximum likelihood method,Gongdong isolate and S.suinominis from GenBank were located in one branch,Liangzai isolate 1 and S.miescheriana were located in another branch,while the isolate 2 from Liangzai were located in another branch,which was close to the branch with S.hominis and S.sinensis.In the other phylogenetic tree constructed by neighbor-joining method,Gongdong isolate and Liangzai isolates were located in the same branching situation similar to that constructed by maximum likelihood method,but Liangzai isolate 1 and S.miescheriana were located in separate branch respectively.Conclusion There were 3 isolates from Rongshui County with genetic variation,Gongdong isolate from Rongshui County was similar to S.suinominis.Liangzai isolate 1 was similar to S.miescheriana,while the Liangzai isolate 2 needed to be further identified. Key words: Sarcocystis; Prevalence; Phenogenetic relationship