title: Diversity of Sarcocystis spp shed by opossums in Brazil inferred with phylogenetic analysis of DNA coding ITS1, cytochrome B, and surface antigens.
abstract: Although few species of Sarcocystis are known to use marsupials of the genus Didelphis as definitive host, an extensive diversity of alleles of surface antigen genes (sag2, sag3, and sag4) has been described in samples of didelphid opossums in Brazil. In this work, we studied 25 samples of Sarcocystis derived from gastrointestinal tract of opossums of the genus Didelphis by accessing the variability of sag2, sag3, sag4, gene encoding cytochrome b (cytB) and first internal transcribed spacer (ITS1). Reference samples of Sarcocystis neurona (SN138) and Sarcocystis falcatula (SF1) maintained in cell culture were also analyzed. We found four allele variants of cytB, seven allele variants of ITS1, 10 allele variants of sag2, 13 allele variants of sag3, and 6 allele variants of sag4. None of the sporocyst-derived sequences obtained from Brazilian opossums revealed 100% identity to SN138 at cytB gene, nor to SN138 or SF1 at ITS1 locus. In addition, none of the sag alleles were found identical to either SF1 or SN138 homologous sequences, and a high number of new sag allele types were found other than those previously described in Brazil. Out of ten sag2 alleles, four are novel, while eight out of 13 sag3 alleles are novel and one out of six sag4 alleles is novel. Further studies are needed to clarify if such a vast repertoire of allele variants of Sarcocystis is the consequence of re-assortments driven by sexual exchange, in order to form individuals with highly diverse characteristics, such as pathogenicity, host spectrum, among others or if it only represents allele variants of different species with different biological traits.
authors.affiliation: Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Samantha Y O B
authors.initials: SY
authors.lastname: Valadas
authors.affiliation: Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Juliana I G
authors.initials: JI
authors.lastname: da Silva
authors.affiliation: Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Estela Gallucci
authors.initials: EG
authors.lastname: Lopes
authors.affiliation: Department of Veterinary Medicine, University of São Paulo, SP, Brazil.
authors.forename: Lara B
authors.initials: LB
authors.lastname: Keid
authors.affiliation: Technical Division of Veterinary Medicine and Management of Wildlife, Secretariat of the Environment and Green, City of São Paulo, SP, Brazil.
authors.forename: Ticiana
authors.initials: T
authors.lastname: Zwarg
authors.affiliation: Technical Division of Veterinary Medicine and Management of Wildlife, Secretariat of the Environment and Green, City of São Paulo, SP, Brazil.
authors.forename: Alice S
authors.initials: AS
authors.lastname: de Oliveira
authors.affiliation: Technical Division of Veterinary Medicine and Management of Wildlife, Secretariat of the Environment and Green, City of São Paulo, SP, Brazil.
authors.forename: Thaís C
authors.initials: TC
authors.lastname: Sanches
authors.affiliation: Technical Division of Veterinary Medicine and Management of Wildlife, Secretariat of the Environment and Green, City of São Paulo, SP, Brazil.
authors.forename: Adriana M
authors.initials: AM
authors.lastname: Joppert
authors.affiliation: Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Hilda F J
authors.initials: HF
authors.lastname: Pena
authors.affiliation: Department of Veterinary Medicine, University of São Paulo, SP, Brazil.
authors.forename: Tricia M F S
authors.initials: TM
authors.lastname: Oliveira
authors.affiliation: Department of Veterinary Medicine, University of São Paulo, SP, Brazil.
authors.forename: Helena L
authors.initials: HL
authors.lastname: Ferreira
authors.affiliation: Department of Preventive Veterinary Medicine and Animal Health, University of São Paulo, São Paulo, SP, Brazil. Electronic address: rosoares@usp.br.
authors.forename: Rodrigo M
authors.initials: RM
authors.lastname: Soares
mesh_terms: D000483:Alleles; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics; D000954:Antigens, Surface / Q000235:genetics; D001938:Brazil; D045303:Cytochromes b / Q000235:genetics; D021901:DNA, Intergenic / Q000235:genetics; D016054:DNA, Protozoan / Q000737:chemistry* / Q000235:genetics; D048293:Didelphis / Q000469:parasitology*; D041981:Gastrointestinal Tract / Q000469:parasitology; D014644:Genetic Variation; D005838:Genotype; D046408:Melopsittacus; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000235:genetics; D011821:Raccoons; D012522:Sarcocystis / Q000145:classification* / Q000235:genetics; D012523:Sarcocystosis / Q000469:parasitology / Q000662:veterinary; D017422:Sequence Analysis, DNA
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D021901:DNA, Intergenic; D016054:DNA, Protozoan; D015800:Protozoan Proteins; D045303:Cytochromes b
keywords: Didelphis spp; Molecular characterization; Phylogeny; Sarcocystidae; Sarcocystis falcatula; Sarcocystis neurona