A comparison of the enzyme linked immunosorbent assay and the indirect haemagglutination technique applied to sera from cattle experimentally infected with Taenia saginata (Goeze, 1782)

The serological response of 6 calves to experimental oral infection with between 60,000 and 100,000 Taenia saginata eggs at 3–12 months of age was monitored by the enzyme-linked immunosorbent assay (ELISA) and the tanned cell indirect haemagglutination technique (IDH). A serum antibody response was detected by both techniques by 2–3 weeks post infection, rising to a plateau about 4–6 weeks post infection. The serum antibody levels began to decline by about 30 weeks post infection. Two uninfected control cattle gave negative reactions.In addition, the serological response of 5 calves which had received a dose of 10,000 T. saginata eggs at 2–3 days of age and then weekly serial doses of 500 eggs for 12 months thereafter, was compared with a similar group of 5 calves, which had received the single infection of 10,000 eggs at 2–3 days of age only. Calves in both groups developed an antibody response detectable by the ELISA technique whereas those in a group of 5 control calves did not show such a response. When studied individually however there was marked variation in the serum antibody levels of these young cattle, as although some calves gave a relatively strong serological response, others hardly varied from the controls.     

Attempted infection of calves with Taenia crocutae cysticerci and their subsequent serological response

The susceptibility of naive cattle to infection with cysticerci of Taenia crocutae was tested using three six- to nine-month-old Ayrshire bull calves, previously unexposed to infection with taeniid eggs. One calf was given 10,000 T crocutae eggs orally, another 5000 hatched unactivated oncospheres orally and the third 5000 hatched and activated oncospheres by intravenous injection. None of the calves contained viable cysticerci at post mortem examination 15 to 17 weeks later. All three calves contained small numbers of lesions in the liver and lesions were also present in the lungs of the calf which received oncospheres intravenously. All the calves developed an antibody response which was most pronounced in the calf given hatched unactivated oncospheres orally.     

Resistance to Taenia pisiformis larvea in rabbits: Immunisation using live organism followed by chemotherapy therapy

Viable eggs or activated oncospheres of Taenia pisiformis were inoculated subcutaneously into rabbits. At various intervals the developing larvae were killed by treatment with Mebendazole. Most rabbits receiving oncospheres were protected against challenge infection if they were treated with Mebendazole 1 day after injection and absolute immunity was established in all rabbits if larvae were allowed to develop for 14 days before being killed. In rabbits receiving eggs, 21 days from injection to Mebendazole treatment was required before absolute immunity developed. Eggs appear to require a period of 1–2 weeks for hatching and oncosphere activation in a subcutaneous site. The data also indicate that production of functionally protective antigens occurs early during larval developement.     

Attempted immunisation of calves against infection with the cysticercus stage ofTaenia saginata

Summary Calves were inoculated with activated oncospheres ofTaenia hydatigena orT. ovis, dosed orally with eggs ofT. hydatigena or inoculated with living or lyophilised cysticerci ofT. crassiceps. There was no visible survival or development of any of these species in calves and none of these procedures stimulated an effective immunity against challenge withT. saginata eggs. Nevertheless, infections ofT. hydatigena andT. ovis developed in control lambs demonstrating the viability of the eggs used.

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Ensayos De Inmunizacion De Terneros Contra Infecciones Con El Cisticerco De LaTaenia Saginata

Resumen Se inocularon terneros con oncosferas activadas deTaenia hydatigena oTaenia ovis, se dosificaron oralmente con huevos deT. hydatigena o se inoculanon con cisticercos vivos o liofilizados deT. crassiceps. No se observó desarrollo alguno de estas especies en terneros inoculados y ninguno de los procedimientos estimuló una inmunidad efectiva contra la descarga con huevos deT. saginata. Sinembargo, los animales controles (ovejas) desarrollaron infecciones conT. hydatigena y T. ovis, demostrando así la viabilidad de los huevos usados en el experimento.

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Essai D'Immunisation De Veaux Contre L'Infection ATaenia Saginata Au Stade De Cysticerque

Résumé Des veaux ont été inoculés avec des oncosphères activées deTaenia hydatigena ouT. ovis. Ils ont reçu des doses orales d'oeufs deT. hydatigena, ou bien ont été inoculés avec des cysticerques vivants ou lyophilisés deT. crassiceps. Il n'y a pas eu de survie visible ou de developpement d'aucune de ces espèces chez les veaux et aucune de ces inoculations n'a a stimulé une immunité effective contre l'infection d'épreuve avec des oeufs deT. saginata, alors que des infections deT. hydatigena etT. ovis se sont développées chez des agneaux témoins démontrant la viabilité des oeufs utilisés.

     

A preliminary report onMeriones unguiculatus as an experimental host forTaenia saginata metacestodes

Jirds (Meriones unguiculatus) were treated with dexamethasone and inoculated subcutaneously with 100–300 oncospheres ofTaenia saginata. Ten of the jirds received 0.5 mg of the drug per animal twice weekly during the first month after inoculation and then once a week until necropsy and four of these became infected. Up to 20 viable metacestodes were recovered in the subcutaneous tissue at the site of inoculation three months after infection.     

Serum IgG Concentrations after Intravenous Serum Transfusion in a Randomized Clinical Trial in Dairy Calves with Inadequate Transfer of Colostral Immunoglobulins

Background: Plasma transfusions have been used clinically in the management of neonates with failure of passive transfer. No studies have evaluated the effect of IV serum transfusions on serum IgG concentrations in dairy calves with inadequate transfer of passive immunity.
Hypothesis: A commercially available serum product will increase serum immunoglobulin concentration in calves with inadequate transfer of colostral immunoglobulins.
Animals: Thirty-two Jersey and Jersey-Holstein cross calves with inadequate colostral transfer of immunoglobulins (serum total protein <5.0 g/L).
Methods: Thirty-two calves were randomly assigned to either control (n = 15) or treated (n = 17) groups. Treated calves received 0.5 L of a pooled serum product IV. Serum IgG concentrations before and after serum transfusion were determined by radial immunodiffusion.
Results: Serum protein concentrations increased from time 0 to 72 hours in both control and transfused calves and the difference was significant between the control and treatment groups ( P < .001). Mean pre- and posttreatment serum IgG concentrations in control and transfused calves did not differ significantly. Median serum IgG concentrations decreased from 0 to 72 hours by 70 mg/dL in control calves and increased over the same time interval in transfused calves by 210 mg/dL. The difference was significant between groups ( P < .001). The percentage of calves that had failure of immunoglobulin transfer 72 hours after serum transfusion was 82.4%.
Conclusions and Clinical Importance: Serum administration at the dosage reported did not provide adequate serum IgG concentrations in neonatal calves with inadequate transfer of colostral immunoglobulins.     

Vaccination of calves against Taenia saginata infection using a “parasite-free” vaccine

Calves were vaccinated with antigens collected during in vitro cultivation of the larval stages of Taenia ovis, T. hydatigena or T. saginata, and challenged 4 weeks later with 4 000 T. saginata eggs. Calves vaccinated with T. saginata antigen were highly resistant to the challenge infection and those groups vaccinated with T. ovis and T. hydatigena were also significantly resistant.     

Influence of colostral quality on serum proteins in dairy calves raised in smallholder farms in Thailand

The objective of this study was to analyze the influence of colostral quality on serum proteins in calves. Samples were collected from visited farms in Kasetsart University Veterinary Teaching Hospital at Kamphaeng Saen and Nong Pho Animal Hospital. In total, 35 dairy farms contributed 80 dams and calves’ samples. Colostrum samples from 80 dairy cows and blood samples from their calves were taken to evaluate colostral immunoglobulins (Ig) and immunoglobulin G (IgG), and calf serum protein and IgG. Total colostral Ig, colostral and serum IgG, and serum protein were measured by a colostrometer, single radial immunodiffusion, and refractrometer, respectively. Immunoglobulin G and serum protein concentrations increased in the 1st day after birth, and maximum concentrations were seen in the 2nd day and then decreased in the 7th and 14th days. Average?±?SD total colostral IgG concentrations at calving date and at 1 and 2 days after calving were 93.85?±?33.89, 37.11?±?23.51, and 17.23?±?9.4 mg/mL, respectively. The profile of total Ig and IgG concentrations in colostrum had a similar pattern, with the maximum concentrations obtained in calving date and rapidly decreased thereafter. Low IgG concentrations were seen in the 7th and 14th day after calving. The calves that were fed with high quality colostrum had higher serum protein at 1 day of age, 7.49?±?1.01 g/dL, than calves fed with low quality colostrum, 6.40?±?0.86 g/dL (P?<?0.01). The increase in serum protein after first colostrum feeding of high and low quality colostrum was 1.55?±?1.07 and 0.81?±?0.69 g/dL, respectively (P?=?0.02).     

Immunizing potential of various stages of Taenia ovis eggs injected subcutaneously into neonatal or sixteen-week-old lambs

When viable eggs of Taenia ovis were given orally to 1-week-old lambs, infection occurred only in those lambs that had been deprived of colostrum. When viable eggs were injected subcutaneously into 1-week-old lambs, no larvae developed at the injection site, and no resistance was stimulated against an oral challenge of T. ovis eggs given 11 weeks later. However, when eggs, oncospheres or developing cysticerci were subcutaneously injected into 16-week-old lambs, all grew at the injection site and stimulated a high degree of immunity to oral infection. Colostrum-derived antibodies against T. ovis apparently suppressed the immunizing potential of T. ovis eggs injected subcutaneously into neonatal lambs.     

Effect of intraperitoneal inoculation of mebendazole on Taenia saginata cysticercosis in calves

Mebendazole was injected intraperitoneally at a dose of 40 mg/kg into six calves that had been inoculated 6 weeks earlier with eggs of T. saginata. The lethal effect of the drug on cysticerci was not significant in the mebendazole treated animals in comparison with those treated with a placebo. This was evaluated by counting the total number of cysticerci in each calf and the relative numbers of viable and degenerated cysts, an in vitro test for viability of cysticerci, and histological examination of the infected muscle tissue.     

Maximising the absorption of colostral immunoglobulins in the newborn dairy calf

Various systems of early post natal management of the newborn calf were examined to determine which would consistently achieve high serum concentrations of maternally derived immunoglobulins, and to examine the factors which might influence this transfer. Early assisted sucking of colostrum to satiation produced consistently high serum concentrations of absorbed immunoglobulins with a mean of 27.17 +/- 8.92 zinc sulphate turbidity (ZST) units for 100 calves. No significant increase in the serum concentrations of absorbed immunoglobulins occurred when calves, which had been assisted to suck immediately after birth, were permitted to remain with their dams and encouraged to suck again at 12 hours (29.20 +/- 9.40 ZST units). Despite early assisted sucking, a small proportion of calves may remain hypogammaglobulinaemic because of the low concentration of immunoglobulins in their dams' colostrum; leakage of colostrum from the udder before calving was the major cause of these low immunoglobulin concentrations. A highly significant correlation was demonstrated between the colostral immunoglobulin concentrations and the passively acquired serum immunoglobulin concentrations of the calves. With this intensive system of early assisted sucking the breed of the calf did not significantly influence the absorption of colostral immunoglobulins.     

Effect of colostrum administration by use of oroesophageal intubation on serum IgG concentrations in Holstein bull calves

OBJECTIVE: To determine the amount of colostral IgG required for adequate passive transfer in calves administered colostrum by use of oroesophageal intubation and evaluate the impact of other factors on passive transfer of colostral immunoglobulins in calves. ANIMALS: 120 Holstein bull calves. PROCEDURES: Calves were randomly assigned to specific treatment groups on the basis of volume of colostrum administered and age of calf at administration of colostrum. Colostrum was administered once by oroesophageal intubation. Equal numbers of calves received 1, 2, 3, or 4 L of colostrum, and equal numbers of calves received colostrum at 2, 6, 10, 14, 18, or 22 hours after birth. Serum samples were obtained from calves 48 hours after birth for IgG determination by radial immunodiffusion assay. Effects of factors affecting transfer of colostral immunoglobulins were determined by use of a stepwise multiple regression model and logistic regression models. RESULTS: A minimum of 153 g of colostral IgG was required for optimum colostral transfer of immunoglobulins when calves were fed 3L of colostrum at 2 hours after birth. Substantially larger IgG intakes were required by calves fed colostrum > 2 hours after birth. CONCLUSIONS AND CLINICAL RELEVANCE: Feeding 100 g of colostral IgG by oroesophageal intubation was insufficient for adequate passive transfer of colostral immunoglobulins. At least 150 to 200 g of colostral IgG was required for adequate passive transfer of colostral immunoglobulins. Use of an oroesophageal tube for administration of 3 L of colostrum to calves within 2 hours after birth is recommended.     

Specific and shared antigenic components of Taenia saginata oncospheres

Taenia saginata oncosphere components were analysed by double diffusion. Antigenic components in saline or detergent (Triton x-100) extracts of T saginata oncospheres were identified using a rabbit polyclonal serum directed against the oncosphere and compared with extracts prepared from the metacestodes and proglottids of T saginata and six other helminths commonly found in cattle. There were seven antigenic components found in the saline extract of the oncospheres, of which six were shared with the metacestodes and proglottids. None of these components was consistently different from those of the other six helminths. However, one of the four components in the detergent extract of the oncospheres was present in neither of the extracts of other stages of T saginata nor in extracts of other helminths. This may be of diagnostic significance.     

Bovine cysticercosis—Development of a real-time PCR to enhance classification of suspect cysts identified at meat inspection

Laboratory confirmation methods are important in bovine cysticerosis diagnosis as other pathologies can result in morphologically similar lesions resulting in false identifications. We developed a probe-based real-time PCR assay to identify Taenia saginata in suspect cysts encountered at meat inspection and compared its use with the traditional method of identification, histology, as well as a published nested PCR. The assay simultaneously detects T. saginata DNA and a bovine internal control using the cytochrome c oxidase subunit 1 gene of each species and shows specificity against parasites causing lesions morphologically similar to those of T. saginata. The assay was sufficiently sensitive to detect 1 fg (Ct 35.09 ± 0.95) of target DNA using serially-diluted plasmid DNA in reactions spiked with bovine DNA as well as in all viable and caseated positive control cysts. A loss in PCR sensitivity was observed with increasing cyst degeneration as seen in other molecular methods. In comparison to histology, the assay offered greater sensitivity and accuracy with 10/19 (53%) T. saginata positives detected by real-time PCR and none by histology. When the results were compared with the reference PCR, the assay was less sensitive but offered advantages of faster turnaround times and reduced contamination risk. Estimates of the assay's repeatability and reproducibility showed the assay is highly reliable with reliability coefficients greater than 0.94.     

Effect of different systems of colostral nutrition on the level of immunoglobulins in the blood of calves]

New-born calves, artificially fed colostrum or native colostral whey, either dried or preserved by another method, had good health and good weight gains (between 0.05 and 0.60 kg). No greater differences were observed between the groups of calves given three times the colostrum of their mothers, calves given mixed colostrum, and calves fed colostral whey powder. In all groups only individual differences in IgG content in the blood serum were observed after 48 hours from birth. Hypogammaglobulinaemia occurred in individual cases both in calves given small amounts of colostrum or colostral whey and in calves given sufficient quantities. The time that had elapsed from birth to the first drinking did not exert any greater influence upon the IgG level in the blood; the decisive factor was the amount of colostrum taken in by the calf in the first dose. The rate of the absorption of IgG1, IgG2, IgA, and IgM from colostrum and the concentration of the immunoglobulins in the serum depended on the quantity of colostrum in the first dose and were not influenced to any greater degree by the amount of colostrum given to the calves in further doses. The amount of IgG in the blood serum of calves corresponded approximately to the level of colostral antibodies to the virus PI-3. The antibodies to the virus PI-3 and small quantities of IgG were observed also in the serum to new-born calves before drinking colostrum.     

In vitro hatching and activation ofTaenia taeniaeformis oncospheres

Previously described techniques for hatching eggs ofTaenia taeniaeformis were found to give inconsistent and generally ineffective results, even the degree of disaggregation of the embryophore varying with the strain of parasite. Furthermore, the hatched and activated oncospheres did not survive in the hatching fluid.Following a series of studies on the composition of the hatching fluids, a more reliable procedure was developed.Pretreatment with hypochlorite, at 0.67% w/w available chlorine, caused disaggregation of the embryophoral blocks of virtually all the eggs. When this was followed by exposure to a solution containing 10 mg.ml^–1 trypsin, 10% ox bile and 10% heat-inactivated foetal calf serum in modified RPMI with HEPES buffer and L-glutamine, about 50% of the viable oncospheres were activated and escaped from the oncospheral membrane. Most of the activated oncospheres survived in this hatching fluid for at least three hours.     

Transfer of immunoglobulins and survival of newborn calves

The survival of 405 newborn calves in a large Central Florida dairy was monitored for a period of 20 weeks. Post-colostral serum samples were obtained from 234 newborn calves 2 to 7 days postpartum and assayed for total serum protein concentration using a refractometer. In the dams, the concentration of colostral immunoglobulins (Ig) at the first postpartum milking was determined by a colostrometer. Season of calving, sex, and breed of the newborn calves were recorded. The likelihood a calf would have satisfactory serum protein (greater than or equal to 5.5 g/dl) given its breed, season of calving, dam's colostral Ig, and dam's calving body condition score were determined using logistic regression analysis. Factors affecting the survival of these calves, up to 20 weeks of age, were studied using the Cox's proportional hazard model. Newborn calves' serum proteins ranged from 3.0 to 8.3 g/dl with a mean of 5.1 g/dl. Calves born to dams with satisfactory colostral Ig (greater than or equal to 50 mg/ml) were unlikely to have satisfactory serum proteins (odds ratio = 0.4) after adjustment for season of calving, parity, breed and dam's body condition score. Calves born from October to January were 3 times more likely to have satisfactory serum proteins compared to calves born during the period of February to July. However, there was no difference in serum proteins between calves born in August and September compared to the ones born in February to July. The survival rate of calves born to dams with satisfactory levels of colostral Ig was poor compared to ones born to dams with low colostral Ig.     

The influence of colostral leukocytes on the immune system of the neonatal calf. II. Effects on passive and active immunization

The influence of colostral leukocytes on the concentration of immunoglobulins and antibodies against an enterotoxigenic strain of E. coli in the sera of newborn calves was investigated for four weeks using four experimental groups. The calves received either complete colostrum (COL-, n = 16), cell-supplemented milk substitute (MS+, n = 7) or pure milk substitute (MS-, n = 6) during the first three days of life. The cows were not specifically immunized. The sera of the COL+ calves had significantly higher concentrations of antibodies against E. coli mainly of IgG1 specificity on the second day of life as compared to those of the COL-. The sera of the COL+ calves contained significantly more IgM on days 2 and 5 and slightly more IgA during the first week. Both COL groups had equal concentrations of serum IgG. It appears that colostral leukocytes which are an integral part of the colostrum enhance the passive immunity of the neonatal calf, especially in regard of antibodies and immunoglobulin classes which are essential for intestinal immunity. The concentration of IgM in the sera of the MS+ calves was reduced, that of IgG did not rise to appreciable amounts; the IgA synthesis started one week later as compared to the MS- group. The administration of isolated colostral cells led to an impairment of the natural active immunization.     

Strategic anthelmintic treatment of young cattle during summer in a Mediterranean-type climatic environment

A worm-control program utilising treatment of young grazing cattle with fenbendazole on two occasions during summer was tested in the Mediterranean-type climatic environment of south-west Western Australia. The grazing system aimed to produce steers by introducing three-month-old weaned calves to pasture in mid-winter until they were sold in early summer. Comparisons were made of the numbers of worm eggs passed on to plots by treated and untreated animals during autumn, the performances of treated and untreated cattle and the performances of calves introduced to the plots in mid-winter. The “tracer” calf technique was used to determine the availability of infective larvae on one untreated and one treated plot for each of the two years of the experiment.Treated animals deposited less Ostertagia spp. eggs on to pasture during autumn than did untreated animals in one of the two years. In both years they deposited less eggs of worm species other than Ostertagia spp. Less intestinal worms were acquired by “tracer” calves grazing treatment plots than those grazing no-treatment plots in both years, but there were no differences in the number of abomasal worms acquired.The reduction in availability of infective larvae of intestinal worms was insufficient to prevent the occurrence of parasitic gastroenteritis in calves introduced to the plots in mid-winter. The fenbendazole treatments did not confer any immediate body-weight advantage on treated animals.On both treatment and no-treatment plots, there were few infective larvae available to grazing cattle during early autumn, there was a rapid attainment of peak availability in winter and then a decline to low availability by mid-spring. In one year, infective larvae of intestinal worms (almost exclusively Cooperia spp.) increased in availability again in late spring and early summer. A high proportion of retarded worms was never a feature of the worm counts of “tracer” calves.It was concluded that the treatments may have been more effective had they been given during autumn.     

异源性抗原抗猪囊尾蚴感染的研究

本文报道了泡状带绦虫活化六钩蚴的超声裂解抗原可以诱导猪体产生抗猪带绦虫攻击感染的交叉保护作用。猪囊尾蚴匀浆抗原也使猪体产生了较强的抗猪带绦虫攻击感染的保护作用。泡状带绦虫六钩蚴超裂抗原免疫组与猪囊尾蚴匀浆抗原免疫组的保护情况是相似的,这表明异源免疫也可使猪体产生较好的抗猪囊尾蚴感染的免疫。由于制备异源性抗原的泡状带绦虫能够从狗的体内获得,因此在体外培养猪带绦虫未获成功之前可以解决从人体获取猪带绦虫的困难。