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Evaluation of vaccination with Neospora caninum protein for prevention of fetal loss associated with experimentally induced neosporosis in sheep
2004
Jenkins, M.C. | Tuo, W. | Dubey, J.P.
Objective--To evaluate the immunologic response of a killed tachyzoite vaccine against Neospora caninum and its effectiveness in preventing fetal loss associated with experimentally induced neosporosis in sheep. Animals--30 Dorset ewes. Procedure--Ewes were randomly allocated to receive vaccination on days 1 and 60 of the study with a killed N caninum tachyzoite preparation in a commercially available adjuvant or a saline-adjuvant mixture. A ram was placed on pasture with the ewes from days 15 to 60. Blood was collected from ewes before primary and booster vaccinations and prior to experimental challenge with N caninum tachyzoite performed on day 90; sera were assessed via Neospora agglutination (NA) and immunofluorescence antibody (IFA) assays. Blood was collected from lambs before they suckled, and sera were tested for antibodies against N caninum. Results--Of the 14 vaccinated ewes that became pregnant, 12 gave birth to live-born lambs; in contrast, 5 of 11 pregnant control ewes gave birth to live-born lambs. Whereas vaccination improved fetal survival in pregnant ewes challenged with N caninum tachyzoites, it did not appear to have any appreciable effect on transmission of N caninum to offspring, as indicated by results of NA and IFA assays. Conclusions and Clinical Relevance--The N caninum tachyzoite vaccine used in this study appeared to provide protection against fetal loss associated with experimentally induced neosporosis in a high proportion of pregnant ewes.
Show more [+] Less [-]Increase of mannose residues, as Salmonella typhimurium-adhering factor, on the cecal mucosa of germ-free chickens infected with Eimeria tenella
1993
Baba, W. | Tsukamoto, Y. | Fukata, T. | Sasai, K. | Arakawa, A.
To study increase of the Salmonella population in the cecum of chickens infected with Eimeria tenella, quantitative changes in mannose residues on the cecal mucosa were investigated. Inhibition of S typhimurium adherence to the cecum by a 2% carbohydrate (D-mannose, D-galactose, L-fucose, alpha-methyl-D-glucoside) in phosphate-buffered saline solution was examined. Only D-mannose had inhibitory effects. Whereas, D-galactose had somewhat enhancing effects on adherence of S typhimurium to the cecal mucosa of uninfected germ-free chickens. In infected and uninfected chickens, D-mannose inhibited adherence of S typhimurium. D-mannose significantly (P < 0.05) increased adherence of Bacteroides sp. In infected and uninfected chickens, D-mannose did not have any effect on adherence of Clostridium perfringens and Bifidobacterium thermophilum. Under microscopic observation, only concanavalin A and Lens culinaris agglutinin, of 8 lectins examined, were recognized as lectin-positive staining lines or spots in the cecal mucosa, indicating presence of mannose residues on the cecal mucosa. In E tenella-infected chickens, lectin-positive staining was seen strongly on the coarse surface of damaged cells and at the bottom of the crypts. These results indicate that coccidial infection may induce increase of mannose residues on the intestinal surface and allow adhesion of more salmonellae to the intestine.
Show more [+] Less [-]Column chromatographic characterization of cytoplasmic proteins in Eimeria maxima oocysts from chickens
1989
Ainsworth, A.J. | Pote, L. | Haney, J. | Brown, J.
Cytoplasmic proteins from unsporulated and sporulated Eimeria maxima oocysts were analyzed by gel-filtration column chromatography. Unsporulated oocysts were characterized as having 3 major cytoplasmic proteins and sporulated oocysts as having 5 major cytoplasmic proteins. Molecular weights ranged from 5 X 10(3) to 1.4 X 10(6). Larger molecular weight proteins were detected in sporulated and unsporulated oocysts, but were associated more with sporocysts of sporulated oocysts.
Show more [+] Less [-]Bovine coccidiosis: Protective effects of low-level infection and coccidiostat treatments in calves
1984
Conlogue, G. | Foreyt, W.J. | Wescott, R.B.
Eimeria spp., calves (exper.) treated with lasalocid (Bovatec) or decoquinate (Deccox) and premunized did not develop diarrhea, calves premunized but not treated were no more resistant to challenge than nonpremunized calves, premunization alone cannot be expected to prevent coccidiosis when animals are exposed to large numbers of oocysts
Show more [+] Less [-]Efficacy of lasalocid sodium against coccidiosis (Eimeria zuernii and Eimeria bovis) in calves
1982
Stromberg, B.E. | Schlotthauer, J.C. | Armstrong, B.D. | Brandt, W.E. | Liss, C.
Eimeria zuernii, E. bovis, calves (exper.), lasalocid sodium in various doses evaluated
Show more [+] Less [-]Alpha-difluoromethylornithine: A promising lead for preventive chemotherapy for coccidiosis
1982
Hanson, W.L. | Bradford, M.M. | Chapman, W.L., jr | Waits, V.B. | McCann, P.P.
Eimeria tenella, chickens (exper.), alpha-difluoromethylornithine promising for preventive chemotherapy, perhaps prevents schizont formation, anticoccidial effect possibly due to inhibition of putrescine biosynthesis; immunity to reinfection after treatment
Show more [+] Less [-]Reduced intestinal absorption in broilers during Eimeria mitis infection
1982
Ruff, M.D. | Edgar, S.A.
Eimeria mitis, 2 strains, chickens, reduced intestinal absorption of glucose and L-methionine, reduced weight gain, depigmentation of plasma, gross lesions absent
Show more [+] Less [-]Abortions, fetal death, and stillbirths in pregnant pygmy goats inoculated with tachyzoites of Neospora caninum
1995
Lindsay, D.S. | Rippey, N.S. | Powe, T.A. | Sartin, E.A. | Dubey, J.P. | Blagburn, B.L.
Neospora caninum-induced abortion is a major production problem in the daily cattle industry in the United States and worldwide. Abortions attributable to naturally acquired N caninum infection also have been observed in pygmy goats. We studied experimentally induced infections with N caninum in pregnant pygmy does to determine whether abortions attributable to N caninum infection would occur after inoculation. Seven pregnant pygmy does (1 control doe and 6 inoculated with N caninum) were studied. The control doe remained clinically normal throughout the study and delivered 2 healthy kids. Abortion, fetal death, and stillbirths were observed in some pregnant does inoculated with N caninum. Two pregnant pygmy does inoculated with N caninum early in gestation (day 51) had fetuses that died and were aborted, or died and were reabsorbed. Neospora caninum tachyzoites and lesions were observed in the brain, spinal cord, and heart of aborted fetuses; parasites also were isolated from the placenta. Four additional pregnant pygmy does (2 inoculated at mid-gestation [day 85], and 2 at late gestation [day 127]) did not abort after inoculation. However, 1 doe inoculated during mid-gestation delivered a stillborn fetus that had died about 1 week prior to parturition. This kid was congenitally infected with N caninum. Neospora caninum was isolated from the placentas of all inoculated does examined. Neonatal neosporosis was not observed in live-born kids, nor were stages of N caninum isolated from any live-born kid. Does did not undergo abortion or have congenitally infected kids when they were rebred and evaluated for neosporosis.
Show more [+] Less [-]Immunohistologic examination of monoclonal antibodies generated against Eimeria bovis sporozoites for reactivity to meronts and sexual stages of E bovis and other eimerian parasites
1991
Lindsay, D.S. | Dubey, J.P. | Fayer, R.
Seven monoclonal antibodies (MAB) generated against sporozoites of Eimeria bovis were tested for reactivity against immature and mature first-generation meronts, sexual stages, and oocysts in tissues from experimentally infected calves by use of an avidin-biotin peroxidase complex (ABPC) immunohistologic test. Three of the 7 MAB reacted in the ABPC test. One of these, MAB-4FB4, reacted only with mature E bovis meronts. The other 2 MAB, MAB2AE7 and MAB4AD7, reacted with all the developmental stages of E bovis tested. Asexual stages and sexual stages of E tenella from chickens and E papillata from mice also were examined in the ABPC test. Monoclonal antibodies MAB-2AE7 and MAB-4AD7 reacted with all stages of these eimerian protozoa. None of the other 5 MAB reacted with these parasites. Results of this study suggested that antigens are shared among the asexual and sexual stages of several diverse Eimeria species.
Show more [+] Less [-]Effects of inoculations with Eimeria zuernii on young calves treated with decoquinate or narasin with or without dexamethasone
1989
Fitzgerald, P.R. | Mansfield, M.E.
Sixteen 7-week-old Holstein male calves were inoculated with sporulated oocysts of Eimeria zuernii. Four calves (controls) were euthanatized and necropsied at 14 and 20 days after inoculation (DAI). Two calves were treated with 20 mg of dexamethasone (IM) on 13, 14, and 15 DAI and euthanatized and necropsied 17 DAI and 2 calves were given similar treatments and necropsied 20 DAI. The 8 other calves were euthanatized and necropsied 20 DAI. Two were started on the anticoccidial drug decoquinate in feed 13 DAI; 2 others were given decoquinated on the same schedule plus dexamethasone on 13, 14, and 15 DAI. Two calves were given the antibiotic narasin in feed beginning 13 DAI and 2 calves were given parasin on the same schedule plus dexamethasone on 13, 14, and 15 DAI. All calves, except 2 controls necropsied 14 DAI and 4 calves given decoquinate, discharged moderate-to-large numbers of oocysts in feces and had moderate-to-severe changes in fecal consistency. Histologic examintions revealed large numbers of endogenous stages in tissues of calves treated or not treated with dexamethasone. Few endogenous stages were observed in tissues from calves that were given decoquinate or decoquinate plus dexamethasone. Calves given narasin or narasin plus dexamethasone had moderate-to-large numbers of endogenous stages in the tissues.
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