IMMUNIZATION OF RATS WITH INFECTIVE LARVAE OF 60 CO IRRADIATED STRONGYLOIDES-RATTI

A study was made of the behavior of rats immunized with 50 Kr dose 60 Co irradiated larvae of Strongyloides ratti. Two S. ratti strains maintained in laboratory rats (Rattus norvegicus albinus) and forty eight rats separated into four groups of twelve rats each were utilized to test each strain of S. ratti. EPG counts, white cell differential counts in peripheric blood, periodic necropsies and Ig G anti-S. ratti tests by the ELISA technique were made on the 6th day and at 5-day intervals after the initial infection. A better protection was observed in animals challenged with non-irradiated larvae of the 2 S. ratti strains on the 30th day. The Ig G anti-S. ratti serum titers were detected from the 10th day on, presenting peaks between the 15th and 25th days in all groups. There was a high percentage of lymphocytes from the 10th day until the 45th day in the stained blood film of the infected group in relation to the non-infected control group.