The Characterization of Complement Fixing Circulating Anti-Body by the Jird (Meriones Unguiculatus) in Response to Infection with Brugia Pahangi over an Extended Period of Time

Abstract

Male outbred jirds (Merione unguiculatus) were inoculated with doses of 100 or 200 infective Brugia pahangi larvae (1_3’s), and tested for complement fixing circulating antibody. Following innoculation, all test animals became positive for microfilaria in peripheral blood. Seventeen of 20 test animals developed patent, sustained infections within, or shortly after 60 days. The longest prepotent period was measured at 118 days. Readings of microfilarial densities were taken after the first month, through 12 months, with the final microfilarial reading between 12 and 21 months. Microfilarial densities vacillated through the course of infection. At the time of necropsy, adult worms were recovered from the testes, heart and pulmonary regions, pelt and carcass and viscera. Recovered adults were sexed and counted for their particular region of residence. The majority of the recovered adults were found in either the testicular region or the pulmonary region with small percentages in other areas. Total worm recovery was between 25% and 30% of the 1_3 dosage innoculated. Complement fixation reagent concentrations; Rabbit Hemolysin, Guinea Pig Complement, and B. pahangi antigen were titrated and standardized (HEW Technical Report, 1965). Complement fixation tests were performed with test sera from infected animals divided into 2 groups (A & B), Group A animals had consistently low microfilarial densities throughout the course of infection (<500) with Group B maintaining high densities throughout (>500). The lowest positive titer was determined at 1:4 with the highest titer observed at 1:256. Animals of Group A were demonstrated at having significantly greater mean antibody titers during the third, sixth and post twelve month periods with relation to Group B. The complement fixation titers showed a correlation between microfilarial densities and mean antibody titers, between the two test groups, at significant time periods.