Abstract
Two strains ofBabesia bovis that had been serially blood passaged in splenectomized calves 27 to 33 times, a procedure known to have reduced their virulence for normal cattle, were shown to have low pathogenicity for replete, femaleBoophilus microplus. In comparison with a strain ofB. bovis unmodified by repeated blood passage, the two modified strains infected higher proportions of ticks and produced comparable numbers of morphologically similar parasites in their haemolymph, but killed significantly fewer of them. Red discolouration of haemolymph was observed in many ticks infected with the unmodified strain, but in none of those infected with the modified strains. It is suggested that the modified strains have lost a quality causing pathological effects on the gut cells of infected ticks.
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References
Callow LL (1977) Vaccination against bovine babesiosis. In: Miller LH, Pino JA, McKelvey JJ (eds) Immunity to blood parasites of animals and man, Plenum Press, New York, p 121
Callow LL, Hoyte HMD (1961) Transmission experiments usingBabesia bigemina Theileria mutans, Borrelia sp. and the cattle tick,Boophilus microplus. Aust Vet J 37:381–390
Callow LL, Mellors LT, McGregor W (1979) Reduction in virulence ofBabesia bovis due to rapid passage in splenectomized cattle. Int J Parasitol 9:333–338
Dalgliesh RJ, Stewart NP (1977) Failure of vaccine strains ofBabesia bovis to regain infectivity for ticks during long-standing infections in cattle. Aust Vet J 53:429–431
Friedhoff K, Scholtyseck E (1969) Feinstrukturen der Merozoiten vonBabesia bigemina im Ovar vonBoophilus microplus undBoophilus decoloratus. Z Parasitenkd 32:266–283
Hoffman G (1971) Infizierbarkeit verschiedenerBoophilusstämme mitBabesia bigemina sowie Beeinflussung der Zecken durch Wirt oder Parasit. Tropenmed Parasitol 22:270–284
Potgieter FT (1977) The life-cycle ofBabesia bovis andBabesia bigemina in ticks and cattle in South Africa. Ph D Thesis, Rand Afrikaans University, South Africa
Riek RF (1966) The lifecycle ofBabesia bigemina (Smith and Kilborne 1893) in the tick vectorBoophilus microplus (Canestrini).Aust J Agric Res 15:802–821
Riek RF (1966) The lifecycle ofBabesia argentina (Lignieres 1903) (Sporozoa: Piroplasmidea) in the tick vectorBoophilus microplus (Canestrini). Aust J Agric Res 17:247–254
Stewart NP (1978) Differences in the lifecycle between a vaccine strain and an unmodified strain ofBabesia bovis (Babes, 1889) in the tickBoophilus microplus (Canestrini). J Protozool 25:497–501
Stewart NP (1979) The life-cycle of transmissible and non-transmissible strains ofBabesia bovis in the tickBoophilus microplus. Thesis, Department of Primary Industries, Queensland Australia
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Dalgliesh, R.J., Stewart, N.P. & Duncalfe, F. Reduction in pathogenicity ofBabesia bovis for its tick vector,Boophilus microplus, after rapid blood passage in splenectomized calves. Z. Parasitenkd. 64, 347–351 (1981). https://doi.org/10.1007/BF00927381
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DOI: https://doi.org/10.1007/BF00927381