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, Jitender
  Submitted to: Journal of Parasitology
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 2/22/2002
                                    Publication  Date: 3/22/2002
                                    Citation: Dubey, J.P. 2002. Tachyzoite-induced life cycle of toxoplasma gondii in cats. Journal of Parasitology 88:713-717.Interpretive Summary: Toxoplasma gondii is a single-celled parasite of livestock and humans.  It causes mental retardation in congenitally infected children and abortion in livestock.  There are 3 infectious stages of this parasite: tachyzoites, bradyzoites and oocysts.  Cats are the reservoir hosts of T. gondii because they are the only hosts that can excrete in their feces enviromentally-  resistant stage called oocysts.  Humans become infected by any of these 3 stages from oocysts. The lifecycle of Toxoplasma in the cat is known after ingesting bradyzoites and oocysts but not after ingesting tachyzoites.  A scientist at the Beltsville Agricultural Research Center has studied the lifecycle of Toxoplasma in cats after feeding tachyzoites.  The results will be of interest to veterinarians, parasitologists, and public health workers.
                                Technical Abstract: Tachyzoite-induced cycle of Toxoplasma gondii was studied in 46 cats. Tachyzoites of the M-7741 or Me-49 strains of T. gondii were administered orally to cats by pouring in the mouth or by stomach tube, or by intra- intestinal inoculation.  Ten weaned cats that had been inoculated with tachyzoites directly in intestine were killed 1, 3, 6, 9, 12, 15, 18, or 25 5days later and their tissues were studied histologically and bioassayed in mice.  Toxoplasma gondii was demonstrable in blood of 8 and in other tissues of all of these 10 cats.  Four of 5, 1-to-8-day-old cats fed tachyzoites by stomach tube became infected with T. gondii and 1 became ill due to toxoplasmosis.  All 19 weaned cats fed tachyzoites (poured in the mouth) became infected and 6 died of acute toxoplasmosis 9-15 days after feeding T. gondii.  Six of 12 weaned cats fed tachyzoites by a stomach tube became infected but were asymptomatic.  Overall, 12 of 26 cats observed for r19 days or more shed oocysts with prepatent periods of 19 days or more wit the sole exception of 1 cat that shed oocyst with a prepatent period of 5 days.  Entero-epithelial stages of T. gondii were not found in any cat before oocysts were shed.  Cats shed up to 360 million oocysts in a day and oocysts were shed for 4 to 6 days.


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