title: Genetic diversity of porcine reproductive and respiratory syndrome virus in Thailand and Southeast Asia from 2008 to 2013.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) affects the swine industry worldwide. Annual surveillances taken from 2008 to 2013 revealed a 13.86% prevalence of PRRSVs in swine populations in Thailand. The selected positive samples were genetically characterized based on global systems and phylogenetic trees that were constructed using 967 ORF5 samples from this study, the collective sequences from Thailand and Southeast Asia and reference sequences. The results showed that both types I and II have been circulating in Thai swine and that genotype II was more prevalent than genotype I. Only type II was found in other countries in Southeast Asia. Type I PRRSVs from Thailand are clustered in subtype 1, clades A, D and H. Type II PRRSVs are topologically classified in lineage 1 and sublineages 5.1, 5.2 and 8.7, of which sublineage 8.7 was predominant, especially after 2010. PRRSVs in sublineage 8.7 are divided into two groups: classical NA and HP-PRRSV. An analysis of all HP-PRRSVs in Southeast Asia revealed four separate clades--A (SX2009-like), B (09HEN1-like), JXA1-like and GXFCH08-like--reflecting four different introductions of these viruses into Thailand, Lao PDR, Cambodia and Vietnam. HP-PRRSV first appeared in Thailand and Cambodia in 2008, 2 years before the first epidemic outbreaks. Recently, the genetics of PRRSVs in Southeast Asia have become more diverse. Thus, PRRSV genetics must be continually characterized and phylogenetically analyzed using global systematic classifications to provide annual genetic information for PRRS control and vaccine selection.
authors.affiliation: Department of Microbiology and Immunology, Kasetsart University, 50th Ngamwongwan Rd., Chatuchak, Bangkok 10900, Thailand; Interdisciplinary Graduate Program in Genetic Engineering, Kasetsart University, 50th Ngamwongwan Rd., Chatuchak, Bangkok 10900, Thailand.
authors.forename: Tippawan
authors.initials: T
authors.lastname: Jantafong
authors.affiliation: Department of Genetics, Faculty of Science, Kasetsart University, 50th Ngamwongwan Rd., Chatuchak, Bangkok 10900, Thailand.
authors.forename: Pradit
authors.initials: P
authors.lastname: Sangtong
authors.affiliation: Department of Microbiology and Immunology, Kasetsart University, 50th Ngamwongwan Rd., Chatuchak, Bangkok 10900, Thailand; Animal Health and Technical Service Office, 29/2 Zone 9, Suwindhawong, Nongchok, Bangkok 10530, Thailand.
authors.forename: Wimontiane
authors.initials: W
authors.lastname: Saenglub
authors.affiliation: Animal Health and Technical Service Office, 29/2 Zone 9, Suwindhawong, Nongchok, Bangkok 10530, Thailand.
authors.forename: Chatthapon
authors.initials: C
authors.lastname: Mungkundar
authors.affiliation: Animal Health and Technical Service Office, 29/2 Zone 9, Suwindhawong, Nongchok, Bangkok 10530, Thailand.
authors.forename: Narin
authors.initials: N
authors.lastname: Romlamduan
authors.affiliation: Department of Companion Animal Clinical Science, Faculty of Veterinary Medicine, Kasetsart University, 50th Ngamwongwan Rd., Chatuchak, Bangkok 10900, Thailand.
authors.forename: Chalermpol
authors.initials: C
authors.lastname: Lekchareonsuk
authors.affiliation: Department of Microbiology and Immunology, Kasetsart University, 50th Ngamwongwan Rd., Chatuchak, Bangkok 10900, Thailand; Interdisciplinary Graduate Program in Genetic Engineering, Kasetsart University, 50th Ngamwongwan Rd., Chatuchak, Bangkok 10900, Thailand; Center for Advanced Studies in Agriculture and Food, KU Institute for Advanced Studies, Kasetsart University, Bangkok 10900, Thailand. Electronic address: fvetptn@ku.ac.th.
authors.forename: Porntippa
authors.initials: P
authors.lastname: Lekcharoensuk
mesh_terms: D000818:Animals; D001210:Asia, Southeastern / Q000453:epidemiology; D001483:Base Sequence; D014644:Genetic Variation; D005838:Genotype; D005843:Geography; D008969:Molecular Sequence Data; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000453:epidemiology / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013552:Swine; D013785:Thailand / Q000453:epidemiology; D014744:Vietnam / Q000453:epidemiology
keywords: ORF5; PRRSV, Genetic diversity; Phylogenetic analysis; Porcine reproductive and respiratory syndrome virus