The use of culture-derived metacyclic trypanosomes in studies on the serological relationships of stocks of Trypanosoma brucei gambiense.

Metacyclic trypanosomes of five stocks of Trypanosoma brucei gambiense were produced in vitro in tsetse head-salivary gland explant cultures and used to infect rabbits. Sera were collected from the rabbits and monitored by agglutination tests for antibody production to nine serotype antigens of T. b. gambiense. In the case of a Nigerian stock of T. b. gambiense the sequences of antibody production were found to be similar in animals infected with the stock transmitted by tsetse flies and from culture. Many similarities were also found between the patterns of antibody production in rabbits infected with stocks of T. b. gambiense from Senegal, Nigeria, Zaire and Uganda. The occurrence of similar serotypes in geographically different stocks of T. b. gambiense provides further support for continuing efforts to develop improved serodiagnostic tests for sleeping sickness based on variable trypanosome antigens and to find techniques for immunoprophylaxis.