Evaluation of immunization with gut membrane glycoproteins of Haemonchus contortus against Haemonchus placet e H. contortus experimental infection in calves

• Grant number: 09/52649-5
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2009
• End date: October 31, 2011
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Alessandro Francisco Talamini Do Amarante
• Grantee: Alessandro Francisco Talamini Do Amarante
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

This study will be conducted to evaluate the protection conferred by a vaccine consisting of purified proteins of the membrane of the intestine de Haemonchus contortus, against artificial infection by H. contortus or Haemonchus placei in calves. Forty male Holstein calves, raised worm free, will be used. The animals will be allocated into four experimental groups as follows: Group 1 (n = 10), vaccinated and subsequently infected with infective larvae (L3) of H. contortus, Group 2 (n = 10), control without vaccination and infected with L3 of H. contortus, Group 3 (n = 10), vaccinated and subsequently infected with L3 of H. placei and Group 4 (n = 10), control without vaccination and infected with L3 of H. placei. The animals of Groups 1 and 3 will receive 300 mg of the vaccine, diluted in QuilA adjuvant and the other will be inoculated only with the adjuvant. The vaccine will be administered three times at intervals of 21 days. Seven days after the last application of the vaccine, animals will be challenged with 8000 L3 of H. contortus or H. placei. After 42 days of the challenge, animals will be sacrificed, for collection and quantification of parasites in the abomasum. Weekly, fecal examinations will be carried out as well blood samples will be taken for determination of the packed cell volume, total plasma protein and the number of eosinophils. Serum samples will be collected for determination of serum levels of immunoglobulins by Elisa test. Data will be submitted to analysis of variance and the averages will be compared by Tukey test. (AU)