Schistosoma mansoni: cutaneous resistance in mice with primary infection

Abstract

Evaluation of the cutaneous resistance of mice to Schistosoma mansoni -was performed using the pinna of the ear as the site of infec-tion and recovery of schistosomules by incuba ting the ear fragments in Hepes-buffered. Elac medium. This method was found to be effective for counts of recovered schistosomules in normal and previously infected (immune) mice when compared with the technique of skin digestion in a collagenase containing medium. A decrease of 42% to 46% of the parasitism was shown to occur in immune mice from days 1 to 7. This resistance was observed in mice with bisexual (6-15 weeks) and unisexual (33-34 weeks) infections, as well as in inbred (C57 BL/IO, CBA and F, from CBA x CBA2 crossing) and outbred Swiss animals. Since the pinna of the ear proved to be very useful in the study of antischistosomotic resistance in mice, at skin level, it is suggested that it should be utilized as standard infection route to study the factors affecting the immunity to S. mansoni in mice.