Immunological relationships of Long Island isolates of Babesia microti
Benach, J.L.; White, D.J.; McGovern, J.P.; Jacovina, M.M.
American Journal of Tropical Medicine and Hygiene 28(4): 643-648
1979
ISSN/ISBN: 0002-9637 PMID: 88904 Document Number: 144498
Strain differences between 2 rodent-derived and one human-derived Babesia microti isolates from Long Island, USA, were investigated by 3 conventional methods. Homologous and heterologous superinfection experiments showed a cross-protection between the 3 isolates and resistance to increasing dosages was seen in all homologous and heterologous challenges. Intact and splenectomized Sprague-Dawley rats were susceptible to all strains; Swiss mice developed only slight transient parasitaemias; Nylar and CFW mice as well as CFW and Wistar intact and splenectomized rats were not susceptible to the strains. Indirect immunofluorescence tests using convalescent sera from 6 Long Island cases of babesiosis showed no titre differences with the 2 Long Island B. microti antigens and the Gray strain antigen. Indirect immunofluorescence studies showed that IgG antibody in hamsters appears early in the course of infection, rises rapidly concurrent with increasing parasitaemia and becomes stable at high titres for the duration of the infection. IgG antibody titres were unaffected by homologous superinfection challenges.