title: Isolation and genetic characterization of Toxoplasma gondii from alpaca (Vicugna pacos) and sheep (Ovis aries).
abstract: Alpacas are important to the economy of several countries. Little is known of Toxoplasma gondii infection in alpacas worldwide. In the present study, T. gondii was isolated and genetically characterized from alpacas for the first time. Alpacas (n = 16) and rams (n = 12) pastured on a farm in Virginia, USA, were examined at necropsy. Antibodies to T. gondii were determined by the modified agglutination test (MAT, 1:25) and found in 6 of 16 alpacas with titers of 1:100 (2 alpaca), 1:400 (2 alpacas), 1:800 (1 alpaca), and 1:1,600 (1 alpaca), and 5 of 12 rams in titers of 1:50 in one, 1:400 in one, 1:800 in one, 1:1,600 in one, and 1:3,200 in one. Tissues of all 16 alpacas were bioassayed in mice or in cats. Muscles (heart, skeletal muscle) of nine alpacas with MAT titers of 1:25 were fed to T. gondii-free cats; the cats did not shed oocysts. Viable T. gondii was isolated from tissues of two of six seropositive alpacas by bioassay in mice. Viable T. gondii was isolated from three of three seropositive sheep by bioassay in mice. Genotyping using cell-cultured tachyzoites revealed four genotypes, including one for ToxoDB PCR-RFLP genotype #2 (type III), one for genotype #3 (type II variant), one for genotype #170, and two for a new genotype designated as ToxoDB PCR-RFLP genotype #230. Thus, four of the five T. gondii isolates in the present study belonged to different genotypes. These results indicate a higher genetic diversity among T. gondii isolates circulating in the USA than previously realized.
authors.affiliation: Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Beltsville, MD, 20705-2350, USA, Jitender.dubey@ars.usda.gov.
authors.forename: Jitender Prakash
authors.initials: JP
authors.lastname: Dubey
authors.forename: Sarah Jane
authors.initials: SJ
authors.lastname: Casey
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Zajac
authors.forename: Stephen Arthur
authors.initials: SA
authors.lastname: Wildeus
authors.forename: David Scott
authors.initials: DS
authors.lastname: Lindsay
authors.forename: Shiv Kumar
authors.initials: SK
authors.lastname: Verma
authors.forename: Solange
authors.initials: S
authors.lastname: Oliveira
authors.forename: Oliver Chun Hung
authors.initials: OC
authors.lastname: Kwok
authors.forename: Chunlei
authors.initials: C
authors.lastname: Su
mesh_terms: D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000913:Antibodies, Protozoan; D002161:Camelids, New World / Q000469:parasitology*; D016054:DNA, Protozoan / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D051379:Mice; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology*; D014122:Toxoplasma / Q000235:genetics*; D014124:Toxoplasmosis, Animal / Q000469:parasitology*
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan
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