U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Dubey, Jitenderitem
                                            GOMEZ, JORGE - COLOMBIA, SOUTH AMERICAitem
                                            BEDOYA, ANGELA - COLOMBIA, SOUTH AMERICAitem
                                            LORA, FABIANA - COLOMBIA, SOUTH AMERICAitem
                                            VIANNA, M C B - ICD/FASitem
                                            Hill, Doloresitem
                                            Kwok, Oliveritem
                                            Shen, Samuelitem
                                            MARCET, P - CDCP CHAMBLEE GAitem
                                            LEHMANN, T - CDCP CHAMBLEE GA
  Submitted to: Veterinary Parasitology
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 9/1/2005
                                    Publication  Date: 10/30/2005
                                    Citation: Dubey, J.P., Gomez, J.E., Bedoya, A., Lora, F., Vianna, M., Hill, D.E., Kwok, O.C., Shen, S.K., Marcet, P.L., Lehmann, T. 2005. Genetic and biologic characteristics of toxoplasma gondii isolates in free-range chickens from Columbia, South America. Veterinary Parasitology. 134:67-72.Interpretive Summary: Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. It causes mental retardation and loss of vision in children, and abortion in livestock. Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. Humans become infected by eating undercooked meat from infected animals and food and water contaminated with oocysts. 

Scientists at the Beltsville Agricultural Research Center  and Univ. of Colombia, South America   report for the first time genetic characterization of Toxoplasma isolates from chickens from Colombia. The results will be of interest to biologists, parasitologists, and veterinarians.
                                Technical Abstract: The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 77 free-range chickens (Gallus domesticus) from Colombia, South America was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 32 (44.4 %) of 72  chickens with titers of 1:5 in 4, 1:10 in 3, 1:20 in 1, 1: 40 in 1, 1: 80 in 8, 1:160 in 8, 1:320 in 3, and  1: 640 or higher  in 4. Hearts and brains of 31 seropositive chickens were pooled and bioassayed in mice. Tissues from 32 (16+16) seronegative chickens were pooled and fed to two, T. gondii-free cats, and tissues from nine chickens without matching sera were fed to one T. gondii-free cat. Feces of cats were examined for oocysts. T. gondii oocysts were excreted by a cat that was fed tissues  of  16 seronegative chickens. T. gondii was isolated by bioassay in mice from 23 chickens with MAT titers of 1:20 or higher. All infected mice from 16 of the 23 isolates died of toxoplasmosis.  Overall, 82 (81.1%) of 101 mice that became infected after inoculation with chicken tissues died of toxoplasmosis.  Genotyping of these 24 isolates using polymorphisms at the SAG2 locus indicated that   seven T. gondii isolates were Type I, 17 were Type III, and none was Type II. Phenotypically, T. gondii isolates from chickens from Colombia were similar to isolates from Brazil but different from the isolates from North America; most isolates from chickens from Brazil and Colombia were lethal for mice whereas isolates from North America did not kill inoculated mice. Genetically, none of the T. gondii isolates from Colombia and Brazil was SAG2 Type II, whereas most isolates from chickens from North America were Type II. This is the first report of genetic characterization of T. gondii isolates from Colombia, South America


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov