Browsing by Author "Burridge, M.J."
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Item Comparative Infectivity for Cattle of Stabilates of Theileria Lawrencei (Serengeti) Derived from Adult and Nymphal Ticks(1974) Purnell, R.E.; Young, A.S.; Brown, C.G.D.; Burridge, M.J.; Payne, R.C. ; East African Veterinary Research Organization P.O Box 32, Kikuyu KenyaLarval and nymphal Rhipicephalus appendiculatus ticks were fed simultaneously on steers reacting to the inoculation of an infective stabilate of cattle-passaged Theileria lawrencei (Serengeti). The larvae and nymphs dropped engorged from the steers when their intra-erythrocytic piroplasm parasitaemias were in excess of 14 per cent.: after the ticks had moulted, they were fed on rabbits and removed after 3 and 5 days respectively. Some of the ticks were processed for histological examination of their salivary glands whilst others were ground and stabilates were prepared from them. Examination of the salivary glands indicated that there was a higher infection rate in the nymphs than in the adults although this was not statistically significant: subsequent inoculation into susceptible cattle of titrated aliquots of the stabilates, however, showed that aliquots from a certain number of adult ticks were more infective than those from the equivalent number of nymphal ticks. The duration of the prepatent period in the susceptible cattle could be correlated with the infective dose. The possibility of obtaining stabilates of nymphal material by feeding larval ticks all over the body of an infected animal is discussed, since such stabilates may be more concentrated and more easily prepared than adult tick stabilates.Item Comparative Infectivity for Cattle of Stabilates of Theileria Lawrencei (Serengeti) Derived from Adult and Nymphal Ticks(1974) Purnell, R.E.; Young, A.S.; Brown, C.G.D.; Burridge, M.J.; Payne, R.C.; East African Veterinary Research Organization, P.O. Box 32, Kikuyu, KenyaLarval and nymphal Rhipicephalus appendiculatus ticks were fed simultaneously on steers reacting to the inoculation of an infective stabilate of cattle-passaged Theileria lawrencei (Serengeti). The larvae and nymphs dropped engorged from the steers when their intra-erythrocytic piroplasm parasitaemias were in excess of 14 per cent.: after the ticks had moulted, they were fed on rabbits and removed after 3 and 5 days respectively. Some of the ticks were processed for histological examination of their salivary glands whilst others were ground and stabilates were prepared from them. Examination of the salivary glands indicated that there was a higher infection rate in the nymphs than in the adults although this was not statistically significant: subsequent inoculation into susceptible cattle of titrated aliquots of the stabilates, however, showed that aliquots from a certain number of adult ticks were more infective than those from the equivalent number of nymphal ticks. The duration of the prepatent period in the susceptible cattle could be correlated with the infective dose. The possibility of obtaining stabilates of nymphal material by feeding larval ticks all over the body of an infected animal is discussed, since such stabilates may be more concentrated and more easily prepared than adult tick stabilates.Item Detection of Antibodies to Babesia Bigemina in Dried Blood Samples using the Indirect Fluorescent Antibody Test(1973) Burridge, M.J.; Kimber, C.D.; McHardy, N.; East African Veterinary Research Organization, Muguga, P.O. Kabete, Kenya. Wellcome Research Laboratory (EA), P.O. Kabete, KenyaThe indirect fluorescent antibody (IFA) test has been used to detect antibodies to Babesia bigemina in serum samples from cattle (Lohr and Ross, 1968; Ross and Lohr, 1968, 1970; Zwart et al., 1968; Brocklesby et al., 1971). However, preparation of serum from blood collected by venepuncture is time-consuming and may be difficult under field conditions. The value of dried blood on filter paper as a source of antibody for the sero- diagnosis of haemoprotozoan infections using the IFA technique has been demonstrated by Bray (1962), Sadun et al. (1963), Duxbury and Sadun (1964), Diggs and Sadun (1965), Bailey et al. (1967), Frank et al., (1971) and Kimber and Burridge (1972). This present study demonstrates the value of dried blood samples as a source of antibody to B. bigemina for the IFA test.Item Duration of Serological Response to the Indirect Fluorescent Antibody Test of Cattle Recovered from Thcilcria Parva Infection(1973) Burridge, M.J.; Kimber, C.D.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaUsing the indirect fluorescent antibody test, a significant antibody titre to Thcilcria parva cell culture schizont antigen was demonstrated until 12–73 weeks (mean 29·7 weeks) after infection in the sera of 35 cattle recovered from experimental East Coast fever. In the same animals a significant titre to T. parva piroplasm antigen was only detected until 7–25 weeks (mean 13·5 weeks) after infection. It is recommended, therefore, that the schizont antigen should be preferred to the piroplasm antigen when the indirect fluorescent antibody test is used in epizootiological studies of East Coast fever.Item East Coast Fever of Cattle: 60 Co Irradiation of Infective Particles of Theileria Parva(1973) Purnell, R.E.; Brown, C.G.D.; Cunningham, M.P.; Burridge, M.J.; Musoke, A.J.; Dargie, J.D.; East African Veterinary Research Organization, Muguga, P. O. Kabete, Kenya. Faculty of Veterinary Science, University of Nairobi, Nairobi, KenyaInfective particles (IPs) of Theileria parva, the causative organism of East Coast Fever of cattle, were harvested from the tick vector, Rhipicephalus appendiculatus, using an in vitro feeding technic. In a ranging experiment, pairs of cattle were inoculated with aliquots of suspensions of IPs irradiated at doses of 4–137.6 krad. Doses of irradiation in excess of 8 krad appeared to destroy the parasite. In the 2nd and 3rd experiments, groups of 5 cattle were inoculated with aliquots of suspensions containing low and high concentrations of IPs respectively, irradiated at doses of 4–32 krad. In the 2nd experiment, doses of irradiation in excess of 10 krad appeared to destroy the parasite. In the 3rd experiment, at least 1 animal became infected when inoculated with an aliquot of a suspension irradiated at 16 krad. In all experiments, it appeared that increasing doses of irradiation destroyed increasing numbers of IPs. There was no conclusive evidence that IPs which survived irradiation were attenuated, and it appears that vaccination of cattle against ECF is unlikely to be achieved by inoculation of irradiated IPs using the methods described.Item East Coast Fever: 60Co-Irradiation of Theileria Parva in Its Tick Vector, Rhipicephalus Appendiculatus(1974) Purnell, R.E.; Brown, C.G.D.; Burridge, M.J.; Cunningham, M.P.; Emu, H.; Irvin, A.D.; Ledger, M.A.; Njuguna, L.M.; Payne, R.C.; Radley, D.E.; East African Veterinary Research Organization, Muguga P.O. Box 32, Kikuyu, KenyaThree experiments were carried out in which Theileria parva was irradiated in its tick vector, Rhipicephalus appendiculatus. In the first experiment, infected unfed adult ticks were irradiated at doubling doses from 4 to 32 krad. Some of the ticks were then fed for 4, 5, 6, 7 and 8 days on rabbits, and the parasites in their salivary glands examined. Five male and 5 female ticks from each irradiation dose were put onto each of a pair of susceptible cattle, whose reactions were recorded. Increasing doses of irradiation resulted in progressive destruction of the parasites. All cattle receiving ticks irradiated at doses up to and including 16 krad died of East Coast fever (ECF), and one of the cattle receiving ticks irradiated at 32 krad died.Item East Coast fever: correlation between the morphology and infectivity of Theileria parva developing in its tick vector(1973) Purnell, R.E.; Brown, C.G.D.; Cunningham, M.P.; Burridge, M.J.; Kirimi, L.M.; Ledger, M.A.Rhipicephalus appendiculatus ticks, infected with Theileria parva, were fed on rabbits and removed at daily intervals for 9 days. Half of the ticks removed were dissected and their salivary glands processed and examined for parasites. The remaining ticks which had been removed were ground up and aliquots of the supernatant fluid thus obtained were injected into East Coast fever susceptible cattle. Cattle injected with supernatant fluids from ticks fed for 4-9 days became infected, and this could be correlated with the histological detection of mature parasites in the corresponding ticks. The most highly ineffective supernatant fluids were prepared from 5-day-fed ticks. In a second experiment it was shown that female ticks of a variety of weights contained ineffective particles of T.parva.Item East Coast Fever: The Infectivity for Cattle of Infective Particles of Theileria Parva Harvested in Various Substrates(1973) Cunningham, M.P.; Brown, C.G.D.; Burridge, M.J.; Joyner, L.P.; Purnel, R.E.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaFemale Rhipicephalus appendiculatus ticks infected with Theileria parva were pre-fed on rabbits for 4 days before being removed and restrained on ‘plasticine’. They were then fed for 2-h periods on capillary tubes containing various substrates, the contents of which were subsequently inoculated into East Coast fever-susceptible cattle. Using this technique, precolostral calf serum and Eagle's Minimum Essential Medium, with the addition of Bovine Albumin Powder, were selected as substrates suitable for further laboratory investigation on East Coast fever as they were acceptable to the ticks and supported the viability of the parasites.Item The Incidence of Theilerial Parasites in East African Buffalo (Syncerus caffer)(1978) Young, A.S.; Brown, C.G.D.; Burridge, M.J.; Grootenhuis, G.K.; Kanhau, G.K.; Purnell, R.E.; Stagg, D. A.; Immunological Research on Tick-borne Cattle Diseases and Tick Control Project; East African Veterinary Research Organization245 buffalo from 13 areas of East Africa were examined for theilerial infections, The vast majority of buffalo (97,1%) examined had piroplasms in their erythrocytes. Theileria lawrencei was isolated from the buffalo by tick feeding and cell culture and was found to be common in most of these buffalo populations. Also over 50% of the buffalo had indirect fluorescent antibody (IF A) titres to T. lawrencei. T. mutans was only isolated from 3 buffalo populations but is probably common.Item The incidence of Theilerial Parasites in East African Buffalo (Syncerus caffer).(1978) Young, A.S.; Brown, C.G.; Burridge, M.J.; Grootenhuis, J.G.; Kanhai, G.K.; Purnell, R.E.; Stagg, D.A.; Immunological Research on Tick-borne Cattle Diseases and Tick Control Project; East African Veterinary Research Organisation, Muguga245 buffalo from 13 areas of East Africa were examined for theilerial infections. The vast majority of buffalo (97.1%) examined had piroplasms in their erythrocytes. Theileria lawrencei was isolated from the buffalo by tick feeding and cell culture and was found to be common in most of these buffalo populations. Also over 50% of the buffalo had indirect fluorescent antibody (IFA) titres to T. lawrencei. T. mutans was only isolated from 3 buffalo populations but is probably common. Haematoxenus sp. was detected in the blood of 56% of the buffalo sampled. In the light of these results the role of buffalo as a reservoir of cattle pathogenic theilerioses in East Africa is discussed.Item The Indirect Fluorescent Antibody Test for Experimental East Coast Fever (Theileria parva Infection of Cattle). Evaluation of a Cell Culture Schizont Antigen(1972) Burridge, M.J.; Kimber, C.D.A schizont antige/l for the indirect fluorescent antibody test was prepared from all in vitro culture suspension of lymphoid cells infected with Theileria parva macroschizonts. The fluorescence of the intracellular schizonts was bright and specific with T. parva positive control serum, but absellt with either conjugate alone or negative cOlltrol serum. Background stailling of the cells was minimal. No serological cross-reaction was detected with sera from cattle infected with T. mutans piroplasms.Item The Indirect Fluorescent Antibody Test for Experimental East Coast Fever (Theileria Parva Infection of Cattle). Evaluation of Dried Blood Samples as a Source of Antibody(1972) Kimber, C.D.; Burridge, M.J.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaEluatesfrom blood collected and dried on filter paper were a reliable alternative to sera for use in the indirect fluorescent antibody test for experimental East Coast fever, since the paiten of antibody response was similar to that detected wi.h serum samples. The collection of blood on filter paper greatly simplified the procedure for the routine serological screening of cattle and it is suggested that this technique may have considerable application in epizootiological studies on East Coast fever.Item Observations on the Cross-Immunity between Theileria Lawrencei (Serengeti) and Theileria Parva (Muguga) in Cattle(1973) Young, A.S.; Brown, C.G.D.; Burridge, M.J.; Cunningham, M.P.; Kirimi, I.M.; Irvin, A.D.; East African Veterinary Research Organization, Muguga, P.O. Kabete,KenyaObservations on the cross-immunity between Theileria lawrencei (Serengeti) and Theileria parva (Muguga) in cattle. Internationaljournal for Parasitology3: 723–728. Cattle immunized against Theileria parva (Muguga) showed little resistance to Theileria lawrencei (Serengeti) stabilate challenge, while cattle immune to T. lawrencei (Serengeti) were fully resistant to challenge with T. parva (Muguga) stabilate. Cattle inoculated with cultured lymphoid cells infected with T. lawrencei (Serengeti) macroschizonts survived a subsequent T. lawrencei (Serengeti) stabilate challenge.Item A Pathogenic Theilerial Syndrome of Cattle in the Narok District of Kenya(1972) Burridge, M.J.; Kimber, C.D.A.; East African Veterinary Research Organization, P.O. Kabete, Muguga, KenyaTwo theilerial parasites, both pathogenic for cattle, which had been isolated during a field trial conducted in Kenya, were studied in the laboratory. One of the parasites was mechanically transmissible and the other tick-transmitted. The sera of two groups of cattle, each infected with one of these parasites, were studied by the indirect fluorescent antibody technique, using both standard Theileria parva and T. mutans antigens and antigens prepared from the infective parasites under study. From the results obtained it was concluded that in the indirect fluorescent antibody test the mechanically transmissible parasite behaved antigenically like T. mutans and the tick-transmitted parasite like T. parva.Item A Pathogenic Theilerial Syndrome Of Cattle In The Narok District Of kenya(1972) Irvin, A.D.; Brown, C.G.D.; Burridge, M.J.; Cunningham, M.P.; Musoke, A.J.; Pierce, M.A.; Radley, D.E.Two theilerial parasites, pathogenic for cattle, were isolated during a field trial conducted at Aitong in the Narok District of Kenya. In a series of laboratory experiments the first of these parasites was successfully transmitted to all of 18 cattle by syringe inoculation of piroplasm infected blood. Two lines were established which were passaged 5 and 3 times respectively_ The animals inoculated all underwent a haemolytic syndrome with anaemia and jaundice and 5 of them died. Macro- and microschizonts were seen in only one of these 18 animals, but piroplasms were present in large numbers. Animals which had recovered from infection and were challenged with Theileria parva all died and there was no evidence that previous infection had conferred any protection on them. This infection was not transmitted by ticks.Item Preliminary Observations on a Theilerial Species Pathogenic to Cattle Isolated from Buffalo (Syncerus Caffer) in Tanzania(1973) Young, A.S.; Branagan, D.; Brown, C.G.D.; Burridge, M.J.; Cunningham, M.P.; Purnell, R.E.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaA theilerial species, pathogenic to cattle, and resembling Theileria lawrencei, was isolated from two buffalo captured in the Serengeti National Park, Tanzania. When nymphal Rhicephalus appendiculatus ticks were fed on the buffalo, on four out of six occasions the resultant adults were shown to be capable of causing highly pathogenic T. lawrencei-type infections in cattle. Aspects of the life cycle of the parasite in both ticks and cattle were studied. Its development in the tick was apparently similar to that of T. parva, and, in cattle, only differed from T. parva by causing the host’s death when relatively few lymphocytes were infected with macroschizonts and when neither microschizonts nor piroplasms were detectable. The parasite was designated T. lawrencei (Serengeti).Item Preliminary Studies on an Atypical Strain of Bovine Theileria Isolated in Kenya(1974) Burridge, M.J.; Brown, C.G.D.; Crawford, J.G.; Kirimi, I.M.; Morzaria, S.P.; Payne, R.C.; East African Veterinary Research Organization, PO Box 32, Kikuyu, Kenya FAO/UNDP Project KEN 22, Veterinary Research Laboratory, PO Kabete, KenyaA theilerial parasite infective for cattle, Theileria sp. (Githunguri), was isolated from the Kiambu District of Kenya through Rhipicephalus appendiculatus ticks. Eight cattle were experimentally infected with Theileria sp. (Githunguri); their reactions were characterized by the production of low numbers of macroschizonts, no microschizonts, few or no piroplasms, and a transient febrile response. All these cattle recovered from clinically mild reactions to infection, but were fully susceptible to subsequent Theileria parva (Muguga) challenge. A cell culture isolate of Theileria sp. (Githunguri) was made from injected lymphoid cells of a reacting animal and, from the resultant in vitro culture suspension, a schizont antigen of the parasite was prepared for the indirect fluorescent antibody test. Serological studies on Theileria sp. (Githunguri), using this test, indicated that it was antigenically distinct from T. parva, T. lawrencei and T. mutans, but had some antigens in common with T. parva and T. lawrencei.Item The Specific Immunoglobulin Response in Cattle Immunized with Isolated Theileria Parva Antigens(1974) Wagner, G.G.; Duffus, W.P.H.; Burridge, M.J.; East African Veterinary Research Organization, Muguga, Kenya Veterinary Research Laboratory, Kabete, KenyaCattle were inoculated with purified Theileria parva piroplasm and/or schizont antigen. Two similar inoculations were given 10 days apart. Serum samples were regularly collected and the indirect haemagglutination (IHA), indirect immunofluorescence (IFA), complement-fixation (CF) and immunodiffusion (ID) tests were used to detect T. parva antibodies. Selected sera were separated by Sephadex G 200 and fractions examined for specific immunoglobulin activity. With the IHA test specific antibody first appeared 4 days post inoculation (dpi) and reached high titres by 8 dpi. With the IFA and CF tests specific antibody also appeared 4 dpi and reached high titres by 8–14 and 10–14 dpi respectively. Specific ID activity was detected as early as 6 dpi and persisted for the length of the experiment. On fractionation of the sera both the IHA and CF tests indicated a sequential production of T. parva IgM and 7S Ig. However, in cattle inoculated with schizont antigen only, a significant 7S Ig component was not detected by the IHA test until 16 dpi, but was demonstrated by the CF test 7 dpi. The IFA test, however, detected anti T. parva activity almost exclusively in the 7S Ig fractions. All cattle were challenged 35–42 dpi with infective T. parva stabilate and all cattle proved fully susceptible. The lack of protection by high titres of specific T. parva immunoglobulin is discussed, together with the data on the differential immunoglobulin response, in relation to previous results.Item Studies on Colostral Antibodies to Theileria Parva using the Indirect Fluorescent Antibody Test(1973) Burridge, M.J.; Kimber, C.D.; East African Veterinary Research Organization, Muguga, KenyaAt the time of calving, 2 of 10 Theileria parva-immune cattle had significant serum titres [1:40] to T. parva schizont antigen, but none had titres to T. parva piroplasm antigen. In contrast, colostrum from 8 of these cows had significant levels of antibodies to T. parva schizont antigen [1:40 to 1:640] and colostrum from 7 had significant levels to T. parva piroplasm antigen [1:640-1:2560]. Following ingestion of colostrum, 2 of the calves born to these cows showed significant rises in serum antibody titre to T. parva schizont antigen [1:40] and 1 showed a rise to T. parva piroplasm antigen [1:2560].Item Theileria Annulata: Cross-Reactions between a Cell Culture Schizont Antigen and Antigens of East African Species in the Indirect Fluorescent Antibody Test(1974) Burridge, M.J.; Brown, C.G.D.; Kimber, C.D.; East African Veterinary Research Organization, Muguga, P. O. Box 32, Kikuyu, KenyaA schizont antigen for the indirect fluorescent antibody test was prepared from an in vitro culture suspension of lymphoid cells infected with Theileria annulata macroschizonts. Two cattle recovered from T. annulata infection showed marked rises in antibody titer to this schizont antigen, with peak titers of 1:40,960 and 1:2560. Using sera from these recovered cattle, T. annulata cell culture schizont antigen was shown to cross-react markedly with Theileria parva and Theileria lawrencei cell culture schizonts and with Theileria mutans piroplasms in the indirect fluorescent antibody test. In contrast, using high-titer antisera to T. parva, T. lawrencei, and T. mutans, serological cross-reactions with T. annulata schizonts were only detected with T. parva and T. lawrencei antisera, and in both instances these were minimal. The value of the indirect fluorescent antibody test in the differential diagnosis of Theileria species pathogenic for cattle is discussed.
