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
 Animal Parasitic Diseases Laboratory: Beltsville, MD
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Resources
                        Our ScientistsSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Northeast Area Beltsville, Maryland (BARC) Beltsville Agricultural Research Center Animal Parasitic Diseases Laboratory 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
                                            Jenkins, Mark
  Submitted to: Meeting Abstract
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 5/31/2014
                                    Publication  Date: N/A
                                    Citation: N/AInterpretive Summary:
                                Technical Abstract: Applying ionophore drugs and synthetic chemicals to poultry feed has been used for over 50 years to control avian coccidiosis.  While this strategy has been and continues to be effective, drug resistance has prompted alternatives such as drug rotation or vaccination with live Eimeria oocysts.  Often there is no a priori way of determining the level of drug resistance in the Eimeria population in litter until a decrease in performance or an increase in necrotic enteritis occurs.  The most common method of measuring drug resistance involves testing several anti-coccidial drugs in susceptible chickens, a process that is both time-consuming and labor-intensive.  The purpose of the present study was to develop an in vitro assay for testing ionophore sensitivity of E. tenella.  Preliminary dose titration experiments revealed an optimum concentration of monensin and salinomycin that did not affect host cell integrity, but inhibited invasion and development of E. tenella sporozoites.  These assay conditions were used to develop a rapid and highly sensitive polymerase chain reaction (PCR) for determining inhibitory effect of the ionophores on intracellular E. tenella.  Moreover, both assays showed excellent agreement with counting intracellular sporozoites.  Time-course studies revealed an optimum effect of monensin at 24 hr and salinomycin at 48 hr post-invasion.  The in vitro assay for ionophore sensitivity can be completed within 1 week after collection of oocysts from litter.  Studies are underway to assay E. tenella sensitivity to synthetic chemicals, and apply the assay to other Eimeria species, such as E. acervulina and E. maxima.


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