The indirect enzyme-linked immunosorbent assay (ELISA) for the detection of anti-trypanosomal antibodies in bovine serum was adapted for use with dried blood spots on filter paper.
Absorbance (450 nm) results for samples were expressed as percent positivity, i.e. percentage of the median absorbance result of four replicates of the strong positive control serum.
The antibody-ELISA was evaluated in Zambia for use in epidemiological surveys of the prevalence of tsetse-transmitted bovine trypanosomosis. Known negative samples (sera, n=209; blood spots, n=466) were obtained from cattle from closed herds in tsetse-free areas close to Lusaka. Known positive samples (sera, n=367; blood spots, n=278) were obtained from cattle in Zambia's Central, Lusaka and Eastern Provinces, diagnosed as being infected with Trypanosoma brucei, T. congolense, or T. vivax using the phase-contrast buffy-coat technique or Giemsa-stained thick and thin blood smears. For sera (at a cut-off value of 23.0% positivity) sensitivity and specificity were 86.1 and 95.2%, respectively. For bloodspots (at a cut-off value of 18.8% positivity) sensitivity and specificity were 96.8 and 95.7%, respectively. The implications of persistence of antibodies following treatment or self-cure are discussed. 相似文献
Summary Five diagnostic tests for infection withTrypanosoma evansi have been compared in groups of camels experimentally infected or exposed to natural infection in the Sudan. The correlation of positive results obtained by assays of IgM levels, the mercuric chloride test and the formol gel test with the presence of active infection was unsatisfactory, but there was a good correlation between results obtained using IFAT and ELISA and proven infection. Sera from a high proportion of apparently uninfected camels from endemic areas gave positive reactions with all 5 tests, possibly indicating inadequate parasitological diagnosis or persistence of antibody after unsatisfactory chemotherapy. It was concluded that serological tests using trypanosomal antigens to detect antibodies were more sensitive for diagnosis than indirect tests based on raised euglobulin levels. Serodiagnostic tests may therefore have a place in future programmes for surveillance and control ofT. evansi infections in camels.
Serodiagnostico De La Infeccion PorTrypanosoma Evansi En Camellos En Sudan
Resumen Se compararon cinco pruebas diagnósticas para infecciones porTrypanosoma evansi en grupos de camellos infectados experimentalmente o expuestos a la infección natural. La correlación de los resultados positivos utilizando pruebas de difusión radial aisladas, le niveles de IgM, la prueba de cloruro de mercúrio, y la prueba de agar formol con la presencia de infección activa, fue insatisfactória. Hubo buena correlación entre los resultados obtenidos con IFAT y ELISA con infección comprobada. El suero de una proporción alta de camellos aparentemente sanos, provenientes de áreas endémicas, presentaron reacciones positivas con las cinco pruebas, indicando posiblemente un diagnóstico parasitológico inadecuado, o la persistencia de anticuerpos despues de una quimioterápia inadecuada. Se concluyó, que las pruebas serológicas usando antígenos preparados de tripanosomas para detectar anticuerpos, fueron más sensitovos que las pruebas indirectas basadas en el aumento de euglobulinas. Las pruebas serodiagnósticas posiblemente tendran un lugar en programas futuros de reconocimiento y control deT. evansi en camellos.
Serodiagnostic De La Trypanosomose AT. Evansi Chez Le Chameau Du Soudan
Résumé Cinq méthodes de diagnostic de la trypanosomose àT. evansi chez le chameau ont été comparées en utilisant des chameaux expérimentalement et naturellement infectés, au Soudan. La corrélation des résultats positifs obtenus par utilisation de la diffusion radiale des Igm, par le test au chlorure mercurique et par le test de la formol gélification à l'occasion des infections en évolution, n'a pas été satisfaisante alors qu'il y a eu bonne corrélation entre les résultats obtenus par IFAT et ELISA et des infections véritables.Les sérums d'une importante proportion de chameaux apparemment non infectés, en provenance de régions à maladie endémique, ont donné des réactions positives aux cinq tests, ce qui peut indiquer soit une insuffisance dans le diagnostic parasitologique soit la persistance d'anticorps résultant d'une chimiothérapie insuffisánte.Les auteurs concluent que les tests sérologiques utilisant des trypanosomes comme antigènes pour mettre les anticorps en évidence sont plus sensibles, en matière de diagnostic, que les tests indirects basés sur la détection des niveaux des IgM. C'est pourquoi les tests faisant appel aux méthodes de sérodiagnostic doivent avoir leur place dans les programmes à venir concernant tant la surveillance que la lutte contre les infections du chameau àT. evansi.
We determined the complete genomic RNA sequence of a new type of betanodavirus Korea shellfish nervous necrosis virus (KSNNV) isolated from shellfish. Compared with other isolates representing four genotypes of betanodaviruses, the identity of the whole nucleotide sequence of the virus was in the range of 76%–83% with the presence of specific genetic motifs and formed a separate new branch in the phylogenetic analysis. In pathogenic analysis by immersion method, KSNNV‐KOR1 shows 100% cumulative mortality like SFRG10/2012BGGa1 (RGNNV) in newly hatched sevenband grouper and mandarin fish, which is clearly different from those found in negative control groups. There were no significant differences in increasing rates of mortality and viral intra‐tissue concentration of larval fishes infected with KSNNV‐KOR1 at both 20 and 25°C water temperature. Histopathological examination of each fish species in the moribund stage revealed the presence of clear vacuoles in both brain and retinal tissues similar to typical histopathology features of RGNNV. In the present study, we first report a new betanodavirus from shellfish as the aetiological agent of viral nervous necrosis disease in fish with complete genomic nucleotide sequence and pathogenic analysis. 相似文献
ABSTRACT The attractiveness of various protein sources of 16 feed ingredients was determined in juvenile rockfish (Sebastes schlegeli) by using reinforced acrylic tank composed of three equally divided rectangular attracting chambers and an acclimatization chamber. Thirty fish were held in the acclimatization chamber at a time and tournament comparison of feed ingredients was applied to evaluate attractiveness. Jack mackerel (JM) (40.0%), sardine (SM) (33.3%), Pollack (PM) (40.0%), shrimp (SHM) (36.7%), mussel meal (40.0%) and oyster (43.3%) meals achieved the highest feeding attractiveness to rockfish in the 1st through 6th preliminary test, respectively. JM (40.0%), SHM (36.7%), squid meal (SQM) (33.3%), SM (40.3%), PM (40.0%) and PM (36.7%) achieved the highest feeding attractiveness to fish in the 7th through 12th preliminary test, respectively. Among the top five feed ingredients showing high attractiveness to rockfish, JM achieved higher attractiveness than PM and SHM in the 1st trial. In the 2nd trial, attractiveness of JM to rockfish was higher than SM and SQM. SM achieved higher attractiveness to rockfish than SQM, but not different from PM throughout the 30-min observation in the 3rd trial. The strongest feeding attractant response of rockfish was observed in JM, followed by SM, SQM, PM, and SHM, in order among various feed ingredients. 相似文献
Using current knowledge of bovine trichomoniasis, a computer spreadsheet simulation model was developed to contribute to the understanding of the disease dynamics and the disease's impact on calf crop, weaner calf production, and revenue returns. Two disease prevalence simulations were generated with the model. In each simulation, 200 susceptible cows were confined with 5 fertile bulls. In simulation 1, one bull was infected with Tritrichomonas foetus (prevalence, 20%); in simulation 2, 2 bulls were infected (prevalence, 40%). The remaining bulls in these groups were designated noninfected. The disease simulation outcomes for breeding and calving variables were compared with a similar but noninfected model group, simulation 0. The disease model predicted a reduction of 14 to 50% in annual calf crop, a prolonged breeding season, a reduction of 5 to 12% in the suckling/growing period, a reduction of 4 to 10% in pounds of marketable calf crop at weaning, a reduction of 4 to 10% in monetary return per calf born, and a substantial reduction of 5 to 35% in the return per cow confined with a fertile bull. 相似文献
Tritrichomonas foetus is a venereal disease of cattle that has a clear pattern of adverse reproductive sequela in the affected female, with a carrier state in the bull in which he shows no outward signs. Given sexual rest and symptomatic treatment, the female returns to reproductive viability. In contrast, the male remains infective and is a risk to other female contacts. Prevention of the disease relies on excluding infected males and females from the population of susceptible cattle. Control of this disease requires a plan to identify, isolate, and treat infected females, and eliminate or cull infected males. Improvements in culture technique and the application of newer methods, such as polymerase chain reaction, enhance the likelihood of detecting infected animals. 相似文献
The present study compared the efficiency of transgenic (TG) cloned embryo production by somatic cell nuclear transfer (SCNT) with fetal-derived fibroblast cells (FFCs) which were transfected with pEGFP-N1 to in vitro-fertilized (IVF), parthenogenetic and SCNT counterparts by evaluating the rates of cleavage and blastocyst formation, apoptosis rate at different developmental stages, cell number, ploidy and gene expression in blastocysts. In SCNT and TG embryos, the rates of cleavage and blastocyst formation were significantly lower (p < 0.05) than those of IVF controls, but it did not differ between SCNT and TG embryos. In IVF control, 86.7% embryos displayed diploid chromosomal complements and the rates were significantly (p < 0.05) higher than those of SCNT and TG embryos. Most TG embryos (79%) with FFCs expressed the gene by both PCR and under fluorescence microscopy. The expression of apoptosis by TUNEL was first detected at six to eight cell stages in all embryos of IVF, SCNT and TG groups, but the expression rate at each developmental stages was significantly higher (p < 0.05) in SCNT and TG embryos than in IVF counterparts. The expression rate in inner cell mass (ICM) of TG embryos was significantly higher (p < 0.05) than in SCNT and IVF embryos. These results indicate that the high occurrence of apoptosis observed in SCNT and TG embryos compared with IVF counterparts might influence the developmental competence. Moreover, the SCNT embryos derived using non-transfected donor cells exhibited a lower apoptosis expression in ICM cells than in TG embryos derived using pEGP-N1-transfected donor cells suggesting a possible role of negative gene effect in TG embryos. 相似文献
Strains of Mycoplasma ovipneumoniae and Pasteurella haemolytica isolated from sheep affected with chronic pneumonia were inoculated by endobronchial route to conventionally-reared and SPF (Specific Pathogen-Free) lambs. Changes resembling those of the naturally-occurring disease were produced in most lambs given the organisms in combination and in some given M. ovipneumoniae alone. Similar but less extensive changes were seen in SPF lambs and fewer animals were affected. Different strains of M. ovipneumoniae did not affect the extent of changes produced in SPF lambs. M. ovipneumoniae became established in the lungs of both types of sheep; P. haemolytica did so less readily.
It was concluded that chronic pneumonia may be reproduced in conventional animals by combined inoculation of M. ovipneumoniae and P. haemolytica. Age and status of immunity to mycoplasmas may account for the different responses of conventional and SPF lambs. 相似文献