Obtenção de duas populações precoces de Eimeria maxima Tyzzer, 1929 e sua caracterização

by Boock Moretti., Maria Eliane

Abstract (Summary)
The objective of the present study was to obtain precocious lines from two field isolates of Eimeria maxima "Cu" and "L" as well as to compare the pathogenicity and pathology between parent and precocious lines of each isolate. Sensitivity tests of these isolates against eight most common anticoccidial drugs were performed to characterise the isolates. The precocious lines were obtained by repeated selection for the first oocysts to appear in the infected chickens. After 14 passages of E. maxima "Cu" oocysts in chickens, the pre-patent period for the first oocysts was reduced from 129h 45' to 114 hours and after 18 passages of E. maxima "L" oocysts in chickens this period was reduced from 127 to 103h 30'. The precocious line F10 was as pathogenic as the parent strain of E. maxima "Cu" while the precocious line F14 was less pathogenic than the parent strain of E. maxima "L" usíng as criteria weight gain, lesion score and oocyst production. The histopathologic observations for both isolates confirmed the degree of patogenicity of the isolates. The evaluation of the sensitivity tests of isolates "Cu" and "L" against eight drugs using the anticoccidial index as a criteria showed that E. maxima "Cu" was sensitive to four drugs and partially resistant to four others while E. maxima "L" was sensitive to one drug, partially resistant to four and resistant to three other drugs. Stability of precocious lines for pre-patent period of first oocysts in chickens seems to be reached for both strains studied by the observation in reduction of oocyst production when compared to the parent strains. The aUenuation of these precocious lines will be studied in future and once this character is confirmed the lines will be used as a vaccine for coccidiosis contraI
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Urara Kawazoe; Urara Kawazoe [Orientador]; Arthur Gruber; Luiz Augusto Magalhães

School:Universidade Estadual de Campinas

School Location:Brazil

Source Type:Master's Thesis

Keywords:patogenicidade patologia testes de sensibilidade coccidiose


Date of Publication:12/01/1997

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