title: Striking Divergence in Toxoplasma ROP16 Nucleotide Sequences From Human and Meat Samples.
abstract: BACKGROUND
  ROP16 is a protein kinase of Toxoplasma gondii identified in the mouse model as a virulent marker, but it is unknown whether this finding is relevant in human toxoplasmosis.
  
  
  METHODS
  We obtained the Toxoplasma ROP16 locus DNA sequence in samples from 12 patients with ocular toxoplasmosis, 1 sample from a patient with congenital toxoplasmosis, 22 samples from soldiers operating in the jungle, 2 samples from urban soldiers, and 10 samples from meat for human consumption. An enzyme-linked immunosorbent assay specific for antibodies against the ROP16 mouse-virulent peptide was performed in 46 serum specimens from patients with ocular toxoplasmosis and in 28 serum specimens from patients with chronic asymptomatic infection, of whom 19 had congenital infection and 11 had toxoplasmic lymphadenitis.
  
  
  RESULTS
  We found a striking divergence of the ROP16 nucleotide sequences. Ten of 12 sequences (83.3%) from patients with ocular toxoplasmosis clustered with those of mouse-virulent strains, whereas 7 of 7 ROP16 sequences (100%) from meat were clustered with those of mouse-avirulent strains. Only 11 of 104 serum specimens (10.5%) had specific antibodies against the mouse-virulent peptide, and there was no association between clinical forms and positive results of serological assays.
  
  
  CONCLUSIONS
  The majority of ROP16 nucleotide sequences from Colombian patients with ocular toxoplasmosis belonged to the group of mouse-virulent strains.
authors.affiliation: Grupo de Estudio en Parasitología Molecular, Centro de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad del Quindio, Armenia Grupo Toxoplasmosis y Parasitología General, CIMPAT, Universidad de los Andes.
authors.forename: Catalina
authors.initials: C
authors.lastname: Alvarez
authors.affiliation: Grupo de Estudio en Parasitología Molecular, Centro de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad del Quindio, Armenia Departamento de Ciencias Básicas, Universidad del Rosario, Bogotá, Colombia.
authors.forename: Alejandra
authors.initials: A
authors.lastname: de-la-Torre
authors.affiliation: Grupo de Estudio en Parasitología Molecular, Centro de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad del Quindio, Armenia.
authors.forename: Mónica
authors.initials: M
authors.lastname: Vargas
authors.affiliation: Grupo Toxoplasmosis y Parasitología General, CIMPAT, Universidad de los Andes Department of Tropical Medicine, Tulane University, School of Public Health and Tropical Medicine, New Orleans, Louisiana.
authors.forename: Claudia
authors.initials: C
authors.lastname: Herrera
authors.affiliation: Grupo de Estudio en Parasitología Molecular, Centro de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad del Quindio, Armenia.
authors.forename: Lored Dayana
authors.initials: LD
authors.lastname: Uribe-Huertas
authors.affiliation: Grupo de Estudio en Parasitología Molecular, Centro de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad del Quindio, Armenia.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Lora
authors.affiliation: Grupo de Estudio en Parasitología Molecular, Centro de Investigaciones Biomédicas, Facultad de Ciencias de la Salud, Universidad del Quindio, Armenia.
authors.forename: Jorge Enrique
authors.initials: JE
authors.lastname: Gómez-Marín
mesh_terms: D002648:Child; D003105:Colombia; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D008460:Meat / Q000469:parasitology*; D011247:Pregnancy; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014122:Toxoplasma / Q000235:genetics* / Q000302:isolation & purification*; D014123:Toxoplasmosis / Q000469:parasitology*
chemical_list: D015800:Protozoan Proteins; D011505:Protein-Tyrosine Kinases; C552524:Rop16 protein, Toxoplasma gondii
keywords: ROP16 protein; Toxoplasma; foodborne diseases; infectious uveitis; virulence