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1.
Therapeutic effect of Berenil and Samorin in mice infected with four trypanosome populations isolated from Zambian cattle 总被引：2，自引：0，他引：2
Four populations of Trypanosoma congolense and Trypanosoma brucei brucei were isolated from cattle under different management practices and environments in Zambia. All four isolates had varied responses to both diminazene aceturate (Berenil) and isometamidium chloride (Samorin) as curative drugs in infected mice. Trypanosomes from a traditionally managed herd in a high-tsetse-challenge area had the strains most resistant to Berenil, with maximum curative dose of 45 mg kg-1 body weight. Another isolate from a high-tsetse-challenge area was evidently resistant both to Berenil at 40 mg kg-1 and to Samorin at 4 mg kg-1. The strains most susceptible to both Berenil and Samorin were from a commercially managed herd of cattle under medium tsetse challenge. They responded to recommended cattle standard doses of 3.5 mg kg-1 or 7 mg kg-1 Berenil and to as little as 0.25 mg kg-1 Samorin. It is evident that trypanosome strains resistant to Berenil and/or partially resistant to Samorin exist, and that both T. congolense and T. b. brucei are implicated. 相似文献
2.
R A Joshua 《Veterinary parasitology》1989,31(2):107-113
An assessment of the role of dogs, goats and sheep as reservoir hosts of African trypanosomes infective for humans (sleeping sickness) was carried out in Nigeria during a 2-year study period. Twelve stocks of Trypanosoma (Trypanozoon) brucei, 10 stocks of Trypanosoma congolense and 11 stocks of Trypanosoma vivax were isolated from a total of 699 animals, comprising 286 sheep, 221 goats and 192 dogs. The potential infectivity of the isolates for man was tested in vitro using the blood incubation infectivity test. None of the T. brucei group was resistant to the trypanocidal action of human serum; three of the T. congolense group were resistant to human serum. A parallel study of the trypanocidal action of test serum on authenticated T. brucei brucei and T. brucei gambiense showed that the human serum behaved as expected. The possibility is discussed that T. congolense might produce infections in man and should, therefore, be handled carefully both in the laboratory and by veterinarians in the field. 相似文献
3.
Limited studies have been undertaken on the treatment of infections with trypanosomes of the subgenus Herpetosoma, either in comparative studies on the effects of trypanocidal drugs or as potential non-pathogenic models for evaluating trypanocidal activities. The development of an in vitro cell culture system is described which enabled testing of trypanocides against 5 different species of Herpetosoma. The trypanocides used were Samorin, Novidium, Trypacide and Berenil. Variations were observed in the trypanocidal activity of the drugs on the different Herpetosoma parasites, e.g. T. lewisi and Samorin and T. microti and Novidium, compared with other parasites. Minimum effective concentration of Trypacide and Berenil against 5 Herpetosoma trypanosomes were of the order 10 mg ml-1. The results indicate that these parasites are much less sensitive to the drugs used than pathogenic, salivarian trypanosomes. 相似文献
4.
Isometamidium chloride (Samorin, RMB, England) is a widely used and highly effective trypanocide for the treatment of bovine trypanosomiases. However, the appearance of isometamidium-resistant populations of T. congolense in Africa makes it necessary to develop methods for the rapid and reliable detection of drug resistance in the laboratory. Currently available tests are time-consuming and/or expensive. In the present study, the short-term in vitro incubation of trypanosomes in a range of isometamidium concentrations and the infectivity of the parasites in mice has been assessed. A series of T. congolense isolates were used which were known to differ in their in vivo sensitivity to the drug. The results showed a close correlation between the known level of resistance and the capability of trypanosomes to remain infective after incubation in isometamidium. Thus isolates displaying a high level of resistance in vivo remained infective following incubation in higher concentrations of drug. This assay may provide a simple and reliable method for detecting drug resistance in T. congolense. 相似文献
5.
Comparison of diagnostic techniques during subclinical single infections of trypanosomiasis in goats
Parasitological diagnostic techniques were compared in caprine hosts in which single subclinical infection with Trypanosoma vivax, Trypanosoma congolense or Trypanosoma brucei brucei had been established. The haematocrit centrifuge technique (HCT) was the most sensitive for the diagnosis of T. vivax and T. b. brucei while the buffy coat method (BCM) proved superior to all other techniques for T. congolense. Except with the miniature anion-exchange/centrifugation technique (mAEC), each of the concentration methods proved as sensitive as a combination of the Standard Trypanosome Detection Methods (STDM) and could detect trypanosomes at concentrations which were five times lower than those required by the STDM. The HCT diagnosed 60.8-90%, with a mean of 78.8%. Corresponding figures for other methods were: wet film, 33.3-50.8 (39.8); mouse inoculation, 0.0-82.5 (47.8); thin film, 43.3-73.3 (52.6); mAEC, 42.4-60.0 (53.2); thick film, 52.9-60.0 (56.2); silicone centrifugation 60.8-77.7 (67.3), and BCM, 60.0-78.4 (71.6). A combination of the HCT and BCM is suggested for routine diagnosis of caprine trypanosome infections. 相似文献
6.
Arunsi Ukairo Kalu 《Veterinary parasitology》1983,13(4):299-309
The effects of various trypanocides on parasitaemia was investigated in sheep experimentally-infected with Trypanosoma congolense strain 58/98. Intravenous injection of Berenil at the height of the first parasitaemic wave increased jugular parasite concentration by 12 and 16 times at the 9th and 20th minute post-treatment, respectively. With Pentamidine, maximum counts were 5.0–8.6 times zero-time concentration during the same periods. Peak effects of Samorin, Novidium and Ethidium were observed between the 60th and 90th minutes after drug administration and were 9.5, 6.3 and 3.5 times initial values, respectively. Injection of trypanocides resulted in double peaks of parasitaemia in which the second was usually higher than the first, except with Antrypol and Germani which had no significant effect on parasitaemia. The amplitude, but not the onset of the increase in parasitaemia in sheep, was found to be related to the therapeutic efficacy of the trypanocides in the treatment of Trypanosoma congolense infection in rats.Animals treated with the diamidines (Berenil and Pentamidine) exhibited apparent parasitologic cure of infection in sheep two to four days after treatment. However, administration of any of the drugs one week after the first treatment resulted in flushing of cryptic trypanosomes into the jugular vein and counts as high as 7.63 × 103 μl?1 were observed within ten minutes with Berenil. It is suggested that besides their therapeutic use, the diamidines may be of value in the parasitologic diagnosis of sub-patent trypanosomiasis due to Trypanosoma congolense. 相似文献
7.
C. C. Chukwu B. M. Anene K. O. Onuekwusi S. M. Anika 《The Journal of small animal practice》1990,31(3):141-144
Studies on relapsing Trypanosoma brucei brucei infections in dogs after Berenil treatment revealed that the first relapse occurred 13 to 64 days after chemotherapy and 36 to 79 days after inoculation. A second relapse infection was observed in two dogs 43 and 60 days after a second Berenil treatment. During the aparasitaemic period following chemotherapy in four dogs, successful transmission (as evidenced by subsequent parasitaemia) following the intraperitoneal inoculation of homogenate of brain from two of the dogs into recipient rats was obtained. Transmission with blood collected just before the animals were sacrificed was, however, negative. Hornogenates of other organs (liver, spleen, eyes, testes, kidneys, heart and lymph node) were also non-infective. One dog inoculated with relapsed trypanosomes and treated with Berenil soon after showing parasitaemia was completely cured of the infection. It was considered that the brain is the source of relapse in T b brucei infection after Berenil therapy and that the relapse was not due to drug resistance. 相似文献
8.
P A Onyeyili G O Egwu L T Zaria B A Orjiude 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1991,44(4):443-445
The therapeutic and prophylactic activity of difluoromethylornithine (DFMO) (2% in drinking water for 4 days) and Berenil (7 mg/kg live weight intraperitoneally) combination was investigated in mice infected with Trypanosoma brucei brucei. Using a previously described mouse model of the African trypanosomosis of the central nervous system, it was demonstrated that the combination was curative and acted synergistically. However, if used prophylactically it had no advantage over Berenil alone. 相似文献
9.
Summary Drug resistance by pathogenic trypanosomes in Somali livestock has been suspected for some time but there have been few attempts
to examine this problem in detail. Field isolations from two areas in the Lower Shabelle Region were obtained by injecting
blood from trypanosome infected cattle into a recipient calf. Once the calf became parasitaemic it was treated with a standard
dose of isometamidium chloride (Samorin, RMB) at 0·5 mg/kg. When a subsequent relapse infection developed, indicative of drug
resistance, blood was taken and injected into groups of cattle and mice and these were treated with a range of doses of isometamidium
chloride and diminazene aceturate (Berenil, Hoechst AC) to determine the dagree of drug resistance. Both isolates showed remarkably
high levels of drug resistance to both isometamidium chloride and diminazene aceturate, with minimum curative doses in cattle
of >2·0 mg/kg and 7·5 mg/kg for the two drugs respectively. Minimum curative doses in mice were approximately ten-fold those
in cattle. Fortunately there have been a very few reports from Africa of such high levels of resistance ofTrypanosoma congolense to this normal “sanative pair” of drugs. The results indicate that drug resistance could be an important constrain on the
use of trypanocidal drugs to control trypanosomosis in Somalia.
Resumen La resistencia de triponosomas patógenos a quimioterapéuticos, ya se sospechaba en Somalia, pero no se habian hecho intentos para estudiar el problema en detalle en ganado bovino. Se hicieron dos aislamientos en dos áreas de la Región Baja de Shabelle, inyectando sangre de ganado infectado en un ternero recipiente. Una vez que el ternero desarrolló parasitémia, se trató con una dosis estándar de cloruro de isometamideo (Samorin, RMB) 0·5 mg/kg. Cuando se presentó una recaida, indicativa de resistencia a la droga utilizada, se tomó sangre del ternero enfermo inoculandose seguidamente en grupos de ganado y ratones, los que se trataron con un rango de dosis de cloruro de isometamideo y aceturato de diminazene (Berenil, Hoechst AC), con el fin de determinar el grado y nivel de resistencia quimioterapéutica. Ambas cepas aisladas mostraron altos niveles de resistencia quimioterapéutica a Samorin y Berenil, con las dosis curativas mínimas y máximas utilizadas para ganado bovino, 2·0 mg/kg y 7·5 mg/kg, para ambas drogas respectivamente. Las dosis curativas mínimas en ratones fueron diez veces superiores a las usadas en ganado. Afortunadamente existen pocos informes en Africa de niveles tan altos de resistencia delTrypanosoma congolense a estas dos drogas curativas, Samorin y Berenil. Los resultados indican que la resistencia a drogas podria ser un obstaculo importante en el uso de drogas trypanocidas en el control de tripanosomiasis en Somalia.
Résumé Depuis un certain temps, on soup?onnait que les trypanosomes pathogènes du bétail Somali présentaient une résistance aux médicaments, mais peu d'essais approfondis avaient été effectués à ce sujet. Dans deux zones du bas-Shebelli, des isolements sur le terrain ont été obtenus par injection du sang de bovin infecté par le trypanosome à un veau récepteur. Une fois le veau parasité, une dose standard de 0,5 mg/kg de chlorure d'isométamidium (Samorin, RMB) lui a été administrée. Ensuite, lors d'une rechute indiquant une résistance au médicament, du sang a été prélevé et injecté à des groupes de bovins et de souris. Ces derniers ont été traités avec une série de doses d'isométamidium et d'acéturate de diminazene (Berenil, Hoechst MC) pour déterminer le degré de résistance au médicament. Ces deux groupes isolés ont montré des seuils de résistance élevés pour les deux médicaments avec, pour les bovins, des doses curatives minimales supérieues à 2,0 mg/kg pour l'isométamidium et supérieures à 7,5 mg/kg pour l'acéturate. Chez les souris, ces doses représentaient environ 10 fois celles des bovins. Heureusement, très peu de compterendus provenant d'Afrique ont mentionné de tels niveaux de résistace àTrypanosoma congolense avec ces deux médicaments. Les résultats indiquent que cette résistance pourrait etre une importante contrainte dans l'utilisation de ces trypanocides pour lutter contre la trypanosomose en Somalie.相似文献
10.
The present study examined the development of anaemia in Small East African goats experimentally infected with Trypanosoma congolense or Trypanosoma brucei. Experimental goats received a primary trypanosome challenge on day 0, treated with diminazene aceturate on day 49 and received a secondary trypanosome challenge on day 77 of the 136-day experiment. Both primary and secondary challenges were characterised by reduced peripheral erythrocyte counts, fall in packed cell volume (PCV), hypohaemoglobinaemia and reductions in the myeloid:erythroid ratios (M:E) compared with the uninfected goats. The progressive reduction in the M:E ratios denoted increased erythrogenesis in response to increased destruction of erythrocytes in blood by infecting trypanosomes or their products. The more rapid fall in M:E ratio in T. congolense infections shows that this parasite causes more severe clinical pathological effects in goats than T. brucei. 相似文献
11.
Summary This paper describes the investigation of a disease outbreak among 10 adult pigs in Nsukka, Anambra State, Nigeria. Prior
to the investigation one sow died of the disease. Trypanosomes were later detected in the blood of two of the nine pigs subsequently
investigated. All the pigs were then treated with deep intramuscular injection of 8 mg/kg diminazene aceturate (Berenil).
Thirty six days after treatment a boar and a sow relapsed with signs similar to the ones shown previously. Further examination
of their blood and faeces revealed nothing of parasitological significance. Following deteriorating condition and development
of nervous signs the boar was salvaged while the sow died of the infection. Brain impression smears taken from both animals
during postmortem examination revealed numerous trypanosome parasites identified by morphology and blood incubation infectivity
test (BIIT) asTrypanosoma brucei brucei. The clinical and economic significance of the outbreak are discussed.
Resumen Se describe un brote de tripanosomiasis porcina en cerdos en Nsukka, Estado de Anambra, Nigeria. Antes de la investigación, una cerda murió de la enfermedad. Se detectaron tripanosomas en dos de los nueve cerdos investigados. Todos los cerdos fueron tratados con inyecciones intramusculares de 8 mg/kg de aceturato de diminazene (Berenil). Treinta y seis días después del tratamiento, un macho y una henbra desarrollaron una sintomatología similar a la vista previamente. Exámenes subsecuentes de sangre y heces no revelaron nada de significancia parasitológica. Después del deterioro de las condiciones físcias y metabólicas y el desarrollo de síntomas nerviosos, el macho se sacrificó mientras que la hembra murió. Las impresiones de cerebro revelaron numerosos tripanosomas, los cuales fueron identificados por morfología y mediante la prueba de incubación de infectividad, comoTrypanosoma brucei brucei. Se discute la importancia económica del brote.
Résumé Cet article décrit l'enquête menée sur un foyer pathologique concernant dix porcs adultes à Nsukka, Etat d'Anambra au Nigéria. Prélablement à l'enquête proprement dite, une truie était morte de trypanosomose. Ultérieurement des trypanosomes furent trouvés dans le sang de deux des neuf porcs traités par une injection intramusculaire profonde d'acéturate de diminazéne (Bérénil) à la dose de 8 mg/kg. Trente six jours après le traitement, un verrat et une truie firent une rechute avec des signes identiques à ceux déjà constatés. Des examens ultérieurs du sang et des fèces ne revélèrent aucun parasite. A la suite d'une aggravation de leur état général et de l'apparition de signes nerveux, le verrat guérit mais la truie succomba de l'infection naturelle. Les frottis par décalque du cerveau prélevés sur les 2 animaux lors d'une autopsie, ont révélé de nombreux trypanosomes. Par leur morphologie et par le test d'infectivité du sang, après incubation, ceux-ci furent identifiés comme étantTrypanosoma brucei brucei. La signification clinique et économique de ce foyer fait l'objet d'une discussion.相似文献
12.
A direct card agglutination test for Trypanosoma evansi, CATT/T. evansi based on the predominant variable antigen-type (pVAT) RoTat 1.2 was evaluated previously in the field in Isiolo District, Kenya. Sixteen out of 51 (31.4%) parasitologically positive camels were negative by the antibody detection test. In the present study, trypanosomes isolated from the camels were analysed in an attempt to determine the cause of the false negative results of CATT/T. evansi. A total of 20 field isolates comprised 16 stocks from camels that were negative by CATT/T. evansi, and 4 from CATT/T. evansi-positive camels. In addition, 15 known T. evansi and four T. brucei were used as reference. Purified DNA samples were tested using an established RoTat 1.2-based polymerase chain reaction (PCR) that yields a 488 bp product for the specific detection of T. evansi. Antibodies to RoTat 1.2 variant surface glycoprotein (VSG) were used in Western blotting to detect RoTat 1.2 VSG linear epitopes. Results of PCR and Western blot showed that the 16 stocks isolated from CATT/T. evansi-negative camels fell into three groups. In Group 1, both the RoTat 1.2 VSG gene and the VSG were absent in three stocks. In five trypanosome stocks in Group 2, the RoTat 1.2 VSG gene was detected, but Western blot was negative indicating absence of the expressed VSG. Five other stocks containing the RoTat 1.2 VSG gene were also in this group. The RoTat 1.2 VSG gene was detected and Western blot was positive in all four trypanosome stocks in Group 3. All four stocks from CATT/T. evansi-positive camels contained the RoTat 1.2 VSG gene and the expressed VSG. The reference T. evansi KETRI 2479 lacked the RoTat 1.2 VSG gene and there was no immune reactivity detected by Western blot. The rest of the reference T. evansi stocks examined contained the RoTat 1.2 VSG gene. All the four T. brucei samples examined were negative by PCR and Western blot. In conclusion, this study showed that the RoTat 1.2 VSG gene was absent from some T. evansi trypanosomes in Kenya. 相似文献
13.
The role played by domestic animals in the transmission of gambiense Human African Trypanosomosis remains uncertain. Northwest Uganda is endemic for Trypanosoma brucei gambiense. Of the 3267 blood samples from domestic animals in four counties examined by hematocrit centrifugation technique (HCT), 210 (6.4%) were positive for trypanosomes. The prevalence of animal trypanosomosis was estimated at 13.8% in Terego County, 4.2% in East Moyo County, 3.1% in Koboko County, and zero in West Moyo County. The trypanosome infection rates varied from 0.2% in goats, 3.5% in dogs, 5.0% in sheep, 7.5% in cattle, to 15.5% in pigs. DNA was extracted from the blood samples by Chelex method, Sigma and Qiagen DNA extraction Kits. A total of 417(12.8%) DNA samples tested positive by polymerase chain reaction (PCR) using T. brucei species specific primers (TBR) indicating that the DNA was of Trypanozoon trypanosomes while 2850 (87.2%) samples were TBR-PCR negative. The T. brucei infection rates based on TBR-PCR were highest in pigs with 21.7%, followed by cattle (14.5%), dogs (12.4%), sheep (10.8%), and lowest in goats with 3.2%, which indicated that pigs were most bitten by infected tsetse than other domestic animals. TBR-PCR detected 6.3% more infected domestic animals that had been missed, and confirmed the 6.4% cases detected by HCT in the field. Statistical analysis done using one-way ANOVA Kruskal-Wallis test (Prism version 5.0) showed no significant difference in trypanosome infections among domestic animals using both HCT and TBR-PCR techniques in the different counties (Confidence Interval of 95%, p-values >0.05). All the 417 trypanosome DNA samples were negative by PCR using two sets of primers specific for the T. b. gambiense specific glycoprotein gene and serum resistance associated gene of T. b. rhodesiense, indicating that they were probably not from the two human infective trypanosomes. Polymerase chain reaction using primers based on ribosomal internal transcribed spacer-1 region (ITS-PCR) resolved the 417 DNA of trypanosome samples into 323 (77.5%) as single trypanosome infections due to T. brucei and 39 (9.4%) mixed infections but missed detecting 55 (13.1%) samples, possibly because of the low sensitivity of ITS-PCR as compared to TBR-PCR. The 31 mixed infections were due to T. brucei (T.b) and T. vivax (T.v); while 8 mixed infections were of T. congolense (T.c) and T. brucei but no mixed trypanosome infections with T. congolense, T. brucei, and T. vivax were detected. Statistical analysis done using one way ANOVA Kruskal-Wallis test (Prism version 5.0) to compare single and mixed trypanosome infections showed no significant difference in trypanosome infections due to single (T.v, T.b, T.c) and mixed (T.v+T.b; T.v+T.c; T.b+T.c; T.v+T.b+T.c) trypanosome species among domestic animals in the different counties using ITS-PCR technique (Confidence Interval of 95%, p-values >0.05). It was concluded that domestic animals in northwest Uganda were probably not reservoirs of T. b. gambiense and there was no infection, as yet, with T. b. rhodesiense parasites. 相似文献
14.
The use of a single restriction fragment length polymorphism (RFLP)-PCR assay which is able to characterise all important bovine trypanosome species was evaluated for the detection of mixed infections with Trypanosoma brucei brucei, Trypanosoma theileri, Trypanosoma congolense and Trypanosoma vivax. Results showed that mixed infections are detectable at a minimum ratio of 2%/98% of standardised DNA solutions with a concentration of 10 ng ml(-1). All mixed infections gave clear profiles that could be easily differentiated except with T. theileri and T. congolense where the T. theileri band was concealed by the T. congolense profile. 相似文献
15.
Teneral tsetse flies infected with either Trypanosoma brucei or T. vivax were fed on healthy cattle. Blood samples collected daily from the cattle were examined by microscopy for the presence of trypanosomes, in thick smear, thin smear and in the buffy coat (BC). All the cattle fed upon by infected tsetse developed a fluctuating parasitaemia. DNA was extracted from the blood of these cattle and subjected to polymerase chain reaction (PCR) using oligonucleotide primers specific for T. brucei or T. vivax. The PCR products unique to either T. brucei or T. vivax were identified following amplification of DNA from the blood samples of infected cattle, whereas none was detectable in the DNA from the blood of the cattle exposed to non-infected teneral tsetse. In a concurrent set of experiments, one of the oligonucleotide primers in each pair was biotinylated for use in PCR-ELISA to examine all the blood samples with this assay. Both the PCR and the PCR-ELISA revealed trypanosome DNA in 85% of blood samples serially collected from the cattle experimentally infected with T. brucei. In contrast, the parasitological assays showed trypanosomes in only 21% of the samples. In the blood samples from cattle experimentally infected with T. vivax, PCR and PCR-ELISA revealed trypanosome DNA in 93 and 94%, respectively. Microscopy revealed parasites in only 63% of the BCs prepared from these cattle. Neither PCR nor PCR-ELISA detected any trypanosome DNA in blood samples collected from the animals in the trypanosome-free areas. However, both assays revealed the presence of trypanosome DNA in a number of blood samples from cattle in trypanosomosis-endemic areas. 相似文献
16.
Karimuribo ED Morrison LJ Black A Turner CM Kambarage DM Ballingall KT 《Veterinary parasitology》2011,179(1-3):35-42
Trypanosomosis caused by infection with protozoan parasites of the genus Trypanosoma is a major health constraint to cattle production in many African countries. One hundred and seventy one Bos indicus cattle from traditional pastoral Maasai (87) and more intensively managed Boran (84) animals in Tanzania were screened by PCR for the presence of African animal trypanosomes (Trypanosoma congolense, Trypanosoma vivax and Trypanosoma brucei), using blood samples archived on FTA cards. All cattle screened for trypanosomes were also genotyped at the highly polymorphic major histocompatibility complex (MHC) class II DRB3 locus to investigate possible associations between host MHC and trypanosome infection. Overall, 23.4% of the 171 cattle tested positive for at least one of the three trypanosome species. The prevalence of individual trypanosome species was 8.8% (T. congolense), 4.7% (T. vivax) and 15.8% (T. brucei). The high prevalence of T. brucei compared with T. congolense and T. vivax was unexpected as this species has previously been considered to be of lesser importance in terms of African bovine trypanosomosis. Significantly higher numbers of Maasai cattle were infected with T. brucei (23.0%, p=0.009) and T. congolense (13.8%, p=0.019) compared with Boran cattle (8.3% and 3.6%, respectively). Analysis of BoLA-DRB3 diversity in this cohort identified extensive allelic diversity. Thirty-three BoLA-DRB3 PCR-RFLP defined alleles were identified. One allele (DRB3*15) was significantly associated with an increased risk (odds ratio, OR=2.71, p=0.034) of T. brucei infection and three alleles (DRB3*35, *16 and *23) were associated with increased risk of T. congolense infection. While further work is required to dissect the role of these alleles in susceptibility to T. brucei and T. congolense infections, this study demonstrates the utility of FTA archived blood samples in combined molecular analyses of both host and pathogen. 相似文献
17.
A Doko B Guedegbe R Baelmans F Demey A N'Diaye V S Pandey A Verhulst 《Veterinary parasitology》1991,40(1-2):1-7
Blood of different breeds of cattle, namely Lagune from the Atlantic province, Borgou and Borgou x Zebu from the Borgou province, and Somba and Zebu from the Atacora province of Benin, were examined for trypanosome infection. Thick and thin blood smears for trypanosomes, the card agglutination test (CATT), indirect immunofluorescent antibody test (IFAT) and trypanolytic test for antibodies to trypanosomes were used. Trypanosomes were detected in 19.3% (range 9.8-31.4%) of animals by examination of blood smears; antibodies to trypanosomes were found in 89.8% (range 88.4-100%) of samples by IFAT, 50.6% (range 34-87.5%) by CATT and 3.4% (range 1.1-7.1%) by trypanolytic test. Trypanosoma vivax and Trypanosoma congolense were the main species in Benin with a low number of Trypanosoma brucei. Zebu had lower infection rates than trypanotolerant breeds of Benin. The infection rates of various trypanotolerant breeds were not significantly different. 相似文献
18.
F W Jennings 《Research in veterinary science》1987,43(2):173-176
The simultaneous administration, to Trypanosoma brucei infected mice, of rolitetracycline or oxytetracycline and diminazene aceturate appeared to have no effect on the initial trypanocidal action of the diminazene aceturate in that trypanosomes were cleared from the circulation. It also had no effect on the duration of the aparasitaemic period which follows diminazene aceturate treatment and the mice remained free of circulating trypanosomes for some time. However, if used prophylactically, relatively large amounts of tetracyclines (4 x 10 mg kg-1) administered with 40 mg kg-1 diminazene aceturate caused a reduction of the prophylactic period compared with those mice given only diminazene aceturate. This reduction in the prophylactic period is unlikely to have any practical significance in the combination diminazene aceturate/tetracycline treatment of domestic animals as diminazene aceturate is used therapeutically and not prophylactically in the control of trypanosomiasis. 相似文献
19.
J E Moulton 《Veterinary pathology》1986,23(1):21-28
Fourteen goats were experimentally infected with Trypanosoma brucei with the following results: Four animals became terminally ill 24 to 47 days after inoculation of trypanosomes and were killed for necropsy. A second group of four goats became sick, had signs of systemic trypanosomiasis, were treated with diminazine aceturate (Berenil) and recovered showing no signs of disease over observation periods of 151 to 163 days. A third group of six goats, were treated with Berenil and temporarily recovered and in 60 to 79 days after therapy; four of these goats underwent relapse infection characterized by severe central nervous system (CNS) disease. Two of these goats were necropsied 45 days after chemotherapy, before clinical signs were evident, to show early neurological lesions. In group 3 (the relapse group), the microscopic changes became more severe as relapse infection progressed. Microscopically, the central nervous system lesions were edema, hyperemia, and infiltration of plasma cells, small lymphocytes, and some macrophages in the leptomeninges, choroid plexus, and brain parenchyma. Relapse infection is discussed from the standpoint of an occult phase of the disease where parasites are protected from the effects of trypanocidal drugs by the blood-brain barrier. 相似文献
20.
Faye D Pereira de Almeida PJ Goossens B Osaer S Ndao M Berkvens D Speybroeck N Nieberding F Geerts S 《Veterinary parasitology》2001,101(2):101-114
In a study of the prevalence and incidence of trypanosomosis in horses and donkeys in two regions of the Gambia, surveys were carried out at Niamina east and Bansang south with a high and low to moderate tsetse challenge, respectively. Eleven horses and 67 donkeys were sampled monthly from August 1997 to September 1998. Blood samples were examined for trypanosomes using the buffy-coat (BC) method and polymerase chain reaction (PCR). Three primer sets were used, specific for either Trypanosoma vivax (TVW), Trypanosoma congolense (GOL) or Trypanosoma brucei (ORPHON5J).The BC results showed that the prevalence (August 1997) and the average monthly incidence (September 1997-1998) of trypanosome infections in horses (45.5 and 16%, respectively) were significantly higher than in donkeys (6.2 and 9%, respectively). Using PCR, the number of detected cases was seven times higher than using the BC. T. congolense was the most frequently observed species, followed by T. vivax and T. brucei. This study confirms earlier observations by other authors that donkeys, which are exposed to a similar tsetse challenge as horses, are significantly less infected with trypanosomes than the latter. 相似文献