Premium
FAILURE OF VACCINE STRAINS OF BABESIA BOVIS TO REGAIN INFECTIVITY FOR TICKS DURING LONG‐STANDING INFECTIONS IN CATTLE
Author(s) -
Dalgliesh R. J.,
Stewart N. P.
Publication year - 1977
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1977.tb05491.x
Subject(s) - infectivity , biology , babesia bovis , babesiosis , babesia bigemina , virology , veterinary medicine , tick , cattle diseases , microbiology and biotechnology , vector (molecular biology) , larva , virus , medicine , ecology , biochemistry , gene , recombinant dna
SUMMARY Two strains of Babesia bovis that were known to have lost infectivity for the normal tick vector, Boophilus microplus , due to repeated blood passaging in cattle, were studied to determine whether the strains would regain infectivity for ticks during longstanding infections. Parasitaemlas were monitored in 4 chronically infected calves that were regularly infested with ticks. Two strains of ticks known to be susceptible to infection with unmodified strains of B. bovis were used. Adult female ticks that dropped from the calves on days that a parasitaemia was evident were tested for B. bovis infection. Sixty‐six batches of ticks collected up to 279 days after infection of the calves produced 14 pools of larvae, none of which transmitted infection. Primary infections established from the chronic infections by subinoculation at 200, 259 and 333 days after infection of the calves were also not transmitted by ticks.