Non-specific induction of increased resistance in mice toTrypanosoma congolenseandTrypanosoma bruceiby immunostimulants

Abstract

SUMMARYAdministration of the immunostimulantsCorynebacterium parvum, Bacillus Calmette-Guérin(BCG) orBordetella pertussisprior to, or at the same time as, challenge withTrypanosoma congolensesignificantly increased survival times in mice, both of trypano-susceptible (A/J) and trypano-resistant (C57Bl) strains. The increased survival time was associated with significant alterations in parasitaemia, which included lengthening of the pre-patent period, a delay in the time taken to reach the first peak of parasitaemia and a reduction in the level of parasitaemia. Similar results were obtained when these strains of mice were challenged withTrypanosoma bruceifollowing pre-treatment withC. parvum. Thus, by the use of immunostimulants it was possible to reduce the susceptibility of mice to trypanosomiasis and the hope is that this can also be achieved with domestic livestock.