Browsing by Author "Kimber, C.D."
Now showing 1 - 18 of 18
- Results Per Page
- Sort Options
Item Adaptation and Possible Attenuation of Theileria Parva-Infected Cells Grown in Irradiated Mice(1976) Irvin, A.D.; Brown, C.G.D.; Stagg, D.A.; Kanhai, G.K.; Kimber, C.D.; Radley, D.E.; East African Veterinary Research Organisation, Muguga, P.O. Box 32, Kikuyu, KenyaTheileria parva-infected bovine lymphoid cells were taken from 8 cattle immediately after death from East Coast fever (ECF). Cells were inoculated into groups of irradiated Swiss and athymic nude mice. Cells became established in one group of Swiss mice and 2 groups of athymic mice. Development of cells in mice only occurred if cells concurrently established in culture; when establishment in culture was delayed, cells failed to develop in mice. Cells from one of the isolates in athymic mice were passaged 6 times through further mice. On inoculation of these mouse-passaged cells into cattle, the animals underwent mild reactions and subsequently resisted a lethal ECF challenge. The possibility of vaccinating cattle against ECF by means of mouse passaged cells merits further study.Item Correlation between the morphology and infectivity of Theileria lawrencei developing in the tick Rhipicephalus appendiculatus(1975) Purnell, R.E.; Kimber, C.D.; Payne, R.C.; Immunological Research on Tick-borne Cattle Diseases and Tick Control Project; East African Veterinary Research OrganizationAdult Rhipicephalus appendiculatus ticks, infected as nymphs by feeding them on an African buffalo harbouring Theileria lawrencei, were applied to the ears of rabbits. Equal numbers of the feeding ticks were removed daily from rabbits and either dissected and processed so that parasites in their salivary glands could be examined morphologically and classified, or ground in Eagle's Minimal Essential Medium, to harvest parasites from the ticks in the resultant supernatant fluid. The infectivity of the supernatant fluid was tested by inoculation of aliquots into groups of susceptible cattle. It was found that supernatant fluids produced from day 0 to day 2 fed ticks were uninfected to cattle but those produced from 3 to 9 days were infective. The most infective supernatant fluid was produced from 6 day fed ticks. The reactions resulting in cattle were correlated with the number and morphology of parasites in sections of salivary glands and it was found that mature parasites coincided with infectivity of the supernatant fluid to cattle. From the reactions in cattle inoculated with supernatant fluids from 5- and 6-day fed ticks it was concluded that this method of harvesting parasites was efficient. Examination of the salivary glands of a representative sample of a T. lawrencei infected tick batch is a potential means of screening material for T. lawrencei 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: 3. Chemoprophylactic Immunization of Cattle using Oxytetracycline and a Combination of Theilerial Strains(1975) Radley, D.E.; Brown, C.G.D.; Cunningham, M.P.; Kimber, C.D.; Musisi, F.L.; Payne, R.C.; Purnell, R.E.; Stagg, S.M.; Young, A.S.; East African Veterinary Research Organization, Kikuyu Kenya,In the first of two experiments performed, 29 animals were immunized by chemoprophylaxis against either a combination of three theilerial strains, Theileria parva (Muguga), T. parva (Kiambu 5) and T. lawrencei (Serengeti transformed), or against one or two elements of the combination separately, and then challenged with either T. parva (Kiambu 1) or T. lawrencei (Solio KB1), both of which were known to be heterologous to T. parva (Muguga). The animals immunized against the combination had mild or inapparent reactions to challenge, whilst the susceptible control cattle and many of those immunized against one or two strains either had severe reactions of died. In the second experiment, 17 cattle immunized by chemoprophylaxis against the combination were challenged with lethal doses of three theilerial strains, T. parva (Entebbe 1), T. parva (Entebbe 2) and T. parva (Ukunda), recently isolated from two widely separated areas of East Africa. They had mild or inapparent reactions whilst 13 of 15 susceptible control cattle died. Chemoprophylaxis using a combination of theilerial strains and a limited oxytetracycline regimen was shown to be an effective means of immunizing cattle against East African theilerioses. The use of this technique as a method of immunizing cattle before exposure in the field is proposed.Item East Coast Fever: Challenge if Immunised Cattle by Prolonged Exposure to Infected Ticks(1975) Radley, D.E.; Brown, C.G.D.; Cunnigham, M.P.; Kimber, C.D.; Musisi, F.L.; Purnell, R.E.; Stagg, S.M.; East African Veterinary Research Organization, Muguga, PO Box 32, Kikuyu, KenyaBos taurus steers, previously treated with acaricide but washed before the trial commenced, were introduced sequentially to a paddock with a high level of T. parva infected ticks. The 12 animals exhibited macroschizonts in lymph nodes at 7-12 days, a febrile response at 9-13 days, and died at 14-21 days. Tick counts were highest on ears (the maximum level was 330), and the build-up of tick attachment correlated with time to death. Four steers immunized three months previously with tick-derived T. parva stabilate material plus Terramycin ECF were kept in the paddock throughout the experiment (60 days). Prepatent period was 10-15 days, but despite high levels of tick attachment (peaks of 500 on ears), there were minimal symptoms and only a slight transient rise in antibody titre on day 40. A few macroschizonts were detected in lymph nodes during the first week of infection and they reappeared from days 34-38. A few piroplasms were seen intermittently in blood smears.Item East Coast Fever: Further Laboratory Investigations on the Use of Rabbits as Vehicles for Infecting Ticks with Theilerial Piroplasms(1974) Purnell, R.E.; Irvin, A.D.; Kimber, C.D.; Omwoyo, P.L.; Payne, R.C.; East African Veterinary Research Organisation, Muguga, KenyaA series of experiments was carried out in which attempts were made to achieve maximum survival of Theileria parva-infected bovine erythrocytes in inoculated rabbits. By varying the treatment of the rabbits and of the erythrocytes and by altering the route of inoculation, it was finally shown that the best and most consistent results could be obtained by the intravenous inoculation of 20 ml of infected bovine blood into splenectomised rabbits. When nymphal Rhipicephalus appendiculatus ticks were fed on such rabbits, the resultant adult ticks showed high Theileria parva infection rates in their salivary glands.Item Immunochemical Studies on East Coast Fever: I. Partial Segregation and Characterization of the Theileria Parva Schizont Antigen(1974) Wagner, G.G.; Brown, C.G.D.; Duffus, W.P.H.; Kimber, C.D.; Crowford, J.G.; Lule, M.; United States Department of Agriculture Co-operative Research Project: UNDP /FAO Immunological Research on Tick-borne Cattle Diseases: Tick Control Project, at the East African Veterinary Research Organization: Tick Control Project, at the Veterinary Research LaboratorySerologically specific antigens of Theileria parva were extracted from schizonts in infected bovine lymphoblast. The antigens were readily detected by complement fixation and immunodiffusion tests. Partial characterization of the antigens was achieved by Sephadex G200 chromatography, density gradient centrifugation, and precipitation in ammonium sulphate solution. The results indicate that the major antigen has a molecular weight in the region of 200,000 to 400,000 with sedimentation coefficient of approximately 7S.Item The Indirect Fluorescent Antibody Technique Applied to Dried Blood, for use as a Screening Test in the Diagnosis of Human Trypanosomiasis in Africa(1967) Bailey, N.M.; Cunningham, M.P.; Kimber, C.D.; East African Trypanosomiasis Research Organization, Totoro, Uganda; East African Trypanosomiasis Research Organization, Tororo UgandaFluorescent antibody tests based on the technique developed by COONS, CREECH and JONES (1941) are widely used for the detection in serum of specific antibodies to infectious micro-organisms. FIFE and MUSCHEL (1959) described an indirect fluorescent antibody technique (1FT) for the serodiagnosis of Chagas's disease. Trypanosoma cruzi cultured on a diphasic blood agar medium was used as the antigen and, as this had to be kept moist, the entire technique was carried out in test tubes. A modification of this technique has been shown by SADUN et al. (1963) to be of value in the serodiagnosis of human trypanosomiasis. Thin blood smears from rats infected with T. CTUzi, T. gambiense and T. rhodesiense were used as antigen, and this resulted in a test which could be rapidly carried out on glass slides with serum collected from suspected cases of disease. ANDERSON et al. (1961) described a technique for the diagnosis of schistosomiasis by immunofluorescence, making use of blood samples dried on filter paper, and SADUN et al. (1963) showed that dried blood samples could be also used in the diagnosis of human trypanosomiasis. Their technique involved the elution of serum from the dried blood samples contained in plastic tubes, and the subsequent extrusion of the eluate in a carpenter's vice. This technique was somewhat tedious and time-consuming and only a limited number of tests could be carried out at anyone time. A modified technique has now been developed for the diagnosis, by immunofluorescence, of human T. rhodesiense infection. The complete procedure is carried out on glass microscope slides at room temperature, and large numbers of blood samples can be examined in a short period of time.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 Isolation of a Theileria Species from Eland (Taurotragus Oryx) Infective for Cattle(1977) Young, A.S.; Grootenhuis, J.G.; Kimber, C.D.; Kanhai, G.K.; East African Veterinary Research Organisation, Muguga, Kikuyu, KenyaTheileria infections were induced in cattle by feeding ticks on them from 3 sources:(a) adult rhipicephalid ticks obtained from the vegetation in a paddock containing an eland EAO at the Animal Orphanage, Nairobi National Park, Kenya, (b) Rhipicephalus appendiculatus adults fed as nymphs on the same eland, (c) R. pulchellus adults fed as nymphs on an eland W 68 captured in the Machakos district of Kenya. Both eland were harbouring Theileria parasites at the time nymphal ticks were fed. Mild infections were produced when adult ticks from these 3 batches were applied to cattle associated with low numbers of schizonts and piroplasms. The indirect fluorescent antibody test demonstrated that cattle recovered from infections resulting from the above 3 tick batches from eland W 68 and EAO produced antibodies which reacted with schizont antigen of the Theileria species (eland) and Theileria species (Githunguri) which had been isolated from cattle and not to antigens of other Theileria species used. The cattle recovered from the Theileria species (eland) were fully susceptible to a lethal challenge of a T. parva (Muguga) stabilate. It was concluded that the Theileria species (eland) and Theileria species (Githunguri) may be closely related and could represent a new species of Theileria infective to cattle.Item Response of Whole-body Irradiated Mice to Inoculation of Theileria Parva Infected Bovine Lymphoid Cells(1974) Irvin, A.D.; Brown, C.G.D.; Kanhai, G.K.; Kimber, C.D.; Crawford, J.G.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaTheileria parva-infected bovine lymphoid cells produced tumour-like masses at the site of subcutaneous inoculation in whole-body irradiated Swiss mice. The optimal dose range for irradiation was 800 to 900 rad. Intact parasitized cells were detected in these masses up to about d. 17 after inoculation and were then gradually rejected as the host's defence mechanisms recovered. The masses appeared to be produced by the continued growth of tissue culture in the immuno-suppressed host. There was no evidence that mouse cells became parasitized.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.Item Theileria Lawrencei Infection of Cattle and African Buffalo: Evaluation of a Buffalo Cell Culture Schizont Antigen for the Indirect Fluorescent Antibody Test.(1974) Burridge, M.J.; Young, A.S.; Stagg, D.A.; Kanhai, G.K.; Kimber, C.D.; East African Veterinary Research Organization, Muguga, PO Box 32, Kikuyu, KenyaA schizont antigen for the indirect fluorescent antibody test was prepared from culture suspension of African buffalo lymphoid cells infected with Theileria lawrencei (T.l.) macroschizonts. This antigen was compared with Theileria parva and T.l. cell culture schizont antigens prepared from infected bovine cells, using bovine antiserum to parva and T.l. and buffalo antiserum to T.l. Complete cross-identity of these three antigens was found with all antiserum. Five buffalo naturally infected with T.l. had significant antibody titres to all three schizont antigens, using an anti-bovine conjugate in the indirect fluorescent antibody test. The peak antibody titres of these buffalo were between 1:40 and 1:2560 to the three schizont antigens. These results suggest that this test could be usefully employed in epidemological surveys.Item The use of Fluorescent Antibody Techniques to Detect Theileria Parva in the Salivary Glands of the Tick Rhipicephalus Appendiculatus(1973) Kimber, C.D.; Purnell, R.E.; Sellwood, S.A.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaNymphal Rhipicephalus appendiculatus ticks were experimentally infected with Theileria parva. Developing stages of the parasite were subsequently detected in the salivary glands of the resultant adult ticks using direct and indirect fluorescent antibody techniques. It was found that the indirect method used was more sensitive than the direct methods, probably because of difficulties in preparing a direct conjugate of sufficient activity against the tick stages of the parasite.Item Use of the Indirect Fluorescent Antibody Technique in Serologic Studies of Theileria lawrencei Infections in Cattle(1972) Burridge, M.J.; Kimber, C.D.; Young, A.S.; East African Veterinary Research Organization, Muguga, KenyaThe serological response of cattle infected with either T. lawrencei or T. parva was determined by the indirect fluorescent antibody (IFA) test using T. lawrencei, T. parva, and T. mutans as antigens. Complete cross-identity between T. lawrencei and T. parva schizont antigens and between T. lawrencei and T. parva piroplasm antigens was found when the four antigens were tested against serum samples of cattle recovered from either T. lawrencei or T. parva infections. Antibody titres to the two schizont antigens increased in all cattle that recovered from experimentally induced T. lawrencei and T. parva infection. All but one animal that recovered from T. lawrencei infection had increased antibody titres to the two piroplasm antigens. None of the cattle that recovered from T. lawrencei infection responded to T. mutans piroplasm antigen. Results demonstrate the close antigenic relationship between T. lawrencei and T. parva.
