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1.
The aim of this study was to examine the immunomodulatory effect of high levels of dietary vitamin C in healthy and immunocompromised rohu (Labeo rohita) treated with aflatoxin B1 (AFB1). Four groups of rohu were fed experimental diets containing either no vitamin C or supplemented with vitamin C at 500 ppm for 60 days. On the first day of feeding, one group fed the high vitamin C diet and one fed the vitamin C deficient diet, were injected intraperitoneally with a single doses of AFB1 at 1.25 mg kg(-1) body weight. The effect of AFB1 and high dietary vitamin C on specific and non-specific immunity, and disease resistance against Aeromonas hydrophila were examined in the rohu. The ability of vitamin C to counteract immunosuppression induced by AFB1 was also examined. Specific immunity indicated by haemagglutination and haemolysin titres against sheep red blood cells (SRBC), and bacterial agglutination appeared to be unaffected by either the AFB1 treatment or the vitamin C enriched diet. A significant reduction was observed in the non-specific immunity of AFB1-treated fish, however, indicated by lowered bactericidal and lysozyme activities. High dietary vitamin C, on the other hand, enhanced the non-specific immunity of fish, including an enhanced phagocytic ratio and increased serum lysozyme activity. Feeding a high level of dietary vitamin C to AFB1-treated fish increased these parameters to levels similar to those found in control fish. High dietary vitamin C significantly (p < 0.05) enhanced protection against Aeromonas hydrophila infection in both healthy and immunocompromised fish. Results from this study help to establish the beneficial effect of dietary vitamin C on AFB1-induced immunosuppression, as well as confirming the immunostimulatory effect of vitamin C in rohu.  相似文献   

2.
Tropical theileriosis, caused by Theileria annulata, is an important tick-borne disease of cattle. A cell culture attenuated vaccine has been developed in our laboratory by long-term in vitro propagation of the schizont stage of the parasite. A longitudinal study was conducted at selected farms housing indigenous, cross-bred and exotic animals to investigate the effect of vaccination on the epidemiology of the disease. A total of 120 animals in 4 age groups were vaccinated with the vaccine before the onset of disease season. An equal number of age-matched animals were kept as controls at the same sites. Animals were monitored for 14 months at monthly intervals. The 97.5% vaccinated animals showed a rise in antibody titres 1 month post-vaccination, as determined by single dilution ELISA. The 78.3% of non-vaccinated animals became sero-positive over the period of observation. Mean antibody titres were significantly higher in vaccinated than non-vaccinated animals. Cross-bred animals showed higher antibody titres followed by exotic and indigenous animals in both the vaccinated and non-vaccinated groups. However, the antibody titres in animals of different ages were similar. The 36.7% vaccinated and 64.2% non-vaccinated animals became carriers (<0.5% piroplasms in erythrocytes) during the observation period. Clinical cases of theileriosis were recorded only in the non-vaccinated group suggesting that vaccinated animals were sufficiently immune to withstand field tick challenge for at least 14 months.  相似文献   

3.
Zhou Z  He S  Liu Y  Cao Y  Meng K  Yao B  Ringø E  Yoon I 《Veterinary microbiology》2011,149(3-4):399-405
The purpose of the present study was to investigate whether dietary antibiotic-induced changes in the fish intestinal microbiota altered host physiological responses to the infection with Aeromonas hydrophila in hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂). After an 8-week induction period with an antibiotic-supplemented or antibiotic-non-supplemented diet, 160 hybrid tilapias in 16 tanks were each injected with phosphate buffered saline (PBS) or A. hydrophila at a dose of one-half of the LD(50). Then, all of the diets were changed to a prebiotic-supplemented one for the sequential 8-week response period. Parameters including production, gut microbial diversity and count, and non-specific immunity were determined at the end of the response period. Our results showed that A. hydrophila infection had no effects on the growth and diet conversion of tilapia, but it caused the decrease of the gut bacterial count, the number of visual bands, and the Shannon diversity and equitability indexes of gut bacteria in antibiotic-non-supplemented fish based on PCR-DGGE fingerprints. Infection with A. hydrophila reduced the gut bacterial evenness (lower Shannon equitability index), and slightly improved the gut bacterial richness (more visual bands) in antibiotic-supplemented tilapia. In addition, A. hydrophila infection affected non-specific immunity such as serum lysozyme activity and serum alternative complement pathway (C3 and C4) activities regardless of hybrid tilapia fed antibiotic-supplemented diets. These changes varied based on the intestinal microbial status of the fish before infection with A. hydrophila.  相似文献   

4.
A double blind field trial was carried out with a live attenuated bovine respiratory syncytial virus vaccine. The trial involved 530 calves, two to 10 months old, on 27 dairy farms, where respiratory problems due to bovine respiratory syncytial virus infections had been observed during the preceding year. In 17 herds either all calves were vaccinated (nine groups) or all calves received a placebo (eight groups). In 10 herds half the number of calves were vaccinated and the other half kept as non-vaccinated controls. Calves were vaccinated intramuscularly twice with an interval of four to five weeks. These groups were under regular clinical observation and animals were tested periodically for antibodies to bovine respiratory syncytial virus and parainfluenza type 3 virus. Serological examination indicated that no bovine respiratory syncytial virus infection had occurred prior to the first vaccination in August. Vaccination did not cause adverse reactions. Low concentrations of neutralising and complement fixing antibodies were induced by vaccination and a sharp increase of antibody titres was observed after natural infection of vaccinated animals. Infections with bovine respiratory syncytial virus occurred in six out of eight non-vaccinated groups, in nine out of 10 partly vaccinated groups and in only two out of nine completely vaccinated groups. Virus infection in completely vaccinated groups was significantly reduced compared with partly vaccinated and non-vaccinated groups. The incidence of bovine respiratory syncytial virus lower respiratory disease was significantly reduced in completely vaccinated groups compared to non-vaccinated groups. Generally only mild signs of upper respiratory disease were present in completely vaccinated groups after bovine respiratory syncytial virus infection.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
The responses were monitored of young crossbred calves vaccinated against tropical theileriosis during the winter against a field tick challenge in the disease season. Thirty-eight calves below 2 months of age, born after the end of the disease season, were selected at an organized farm. Twenty-five animals were vaccinated with Theileria annulata (Hisar) cell culture vaccine (developed at CCS HAU Hisar laboratory) after the end of the disease season and 13 calves were kept as non-vaccinated controls. These calves were observed for their susceptibility to theileriosis in the new disease season. There was an increase in antibody titre in 18 of the 25 vaccinated animals one month after vaccination. The antibody titre then declined gradually, but remained higher than those of the non-vaccinated animals at month 0. No fever or other clinical signs of tropical theileriosis were observed in any of the vaccinated animals. Nine out of 25 (36%) vaccinated calves showed occasional piroplasms (<;0.5%) in blood smears. All the vaccinated animals withstood the field tick challenge. On the other hand, 9 of the 13 (69%) unvaccinated calves exhibited occasional piroplasms, and included three clinical cases of tropical theileriosis. These observations suggest that young crossbred calves vaccinated with the T. annulata (Hisar) cell culture vaccine at the end of the disease season were relatively resistant during the next disease season.  相似文献   

6.
本试验旨在研究蛋氨酸对幼建鲤疾病抵抗能力及免疫应答的影响.选择体重为(12.34±0.02)g健康建鲤864尾,平均分成6组,每组144尾(每组设3个重复,每个重复48尾),分别饲喂蛋氨酸水平为0.39%、0.70%、1.00%、1.30%、1.60%和1.90%的饲料,饲养60 d后用嗜水气单胞菌攻毒17 d,考察蛋氨酸对幼建鲤免疫功能的影响.结果表明:适宜蛋氨酸水平极显著提高了攻毒前头肾体指数、后肾体指数、脾体指数、血液红、白细胞数量和攻毒后红细胞数量(P<0.01);显著提高了攻毒前白细胞吞噬率和攻毒后成活率、白细胞数量、白细胞吞噬率、血清酸性磷酸酶活力、溶菌酶含量、补体C3含量、凝集素水平和抗嗜水气单胞菌抗体效价(P<0.05).由此得出,蛋氨酸通过增强白细胞吞噬能力和提高特异性抗体效价从而提高幼建鲤的非特异性和特异性免疫力,增强疾病抵抗力.  相似文献   

7.
Outbreaks of infectious bovine rhinotracheitis (IBR) have recently been observed in vaccinated feedlot calves in Alberta a few months post-arrival. To investigate the cause of these outbreaks, lung and tracheal tissues were collected from calves that died of IBR during a post-arrival outbreak of disease. Bovine herpesvirus-1 (BHV-1), the causative agent of IBR, was isolated from 6 out of 15 tissues. Of these 6 isolates, 5 failed to react with a monoclonal antibody specific for one of the epitopes on glycoprotein D, one of the most important antigens of BHV-1. The ability of one of these mutant BHV-1 isolates to cause disease in calves vaccinated with a modified-live IBR vaccine was assessed in an experimental challenge study. After one vaccination, the majority of the calves developed humoral and cellular immune responses. Secondary vaccination resulted in a substantially enhanced level of immunity in all animals. Three months after the second vaccination, calves were either challenged with one of the mutant isolates or with a conventional challenge strain of BHV-1. Regardless of the type of virus used for challenge, vaccinated calves experienced significantly (P < 0.05) less weight loss and temperature rises, had lower nasal scores, and shed less virus than non-vaccinated animals. The only statistically significant (P < 0.05) difference between the 2 challenge viruses was the amount of virus shed, which was higher in non-vaccinated calves challenged with the mutant virus than in those challenged with the conventional virus. These data show that calves vaccinated with a modified-live IBR vaccine are protected from challenge with either the mutant or the conventional virus.  相似文献   

8.
Vaccination as a possible means of preventing lantana poisoning   总被引：4，自引：0，他引：4  
The toxic triterpene acids lantadene A and lantadene B were isolated from Lantana camara and conjugated to bovine serum albumen or haemocyanin. The conjugates were emulsified with complete Freund's adjuvant and injected into sheep and cattle. Vaccinated animals produced antibodies against the toxic compounds. Cholestasis was less severe in vaccinated than in non-vaccinated sheep challenged with a toxic dose of lantana. The results indicated a mild protective effect of vaccination against the hepatotoxic effects of lantana toxins.  相似文献   

9.
The use of the rapid quantitative plate agglutination test (QPAT) utilizing triphenyltetrazolium chloride (TTC) stained antigen for the differentiation of bovine brucellosis and yersiniosis is described. It was found with experimental laboratory animals and cattle, that titres against homologous antigen tended to exceed titres against heterologous antigen and that this reaction together with measurement of the Yersinia OH agglutinin titre could be used for purposes of differentiation. It was, however, not possible to differentiate these infections in serum from cattle with naturally-occurring antibodies. It was also shown that Brucella 0 agglutination in the QPAT was very weak in some sera with high titred anti-Brucella antibodies by serum agglutination, while Yersinia 0 agglutination was not. The QPAT, using Yersinia 0 antigen, therefore correlated well with the results obtained using Brucella 0 antigen in serum agglutination tests. It is suggested that Yersinia 0 antigen may be a suitable antigen for use in rapid agglutination tests because of this relative insusceptibility to false negative results.  相似文献   

10.
Data from 42,224 cattle from 694 herds collected during the brucellosis eradication campaign were used to examine the effects of calfhood strain 19 vaccination. The prevalence of infection in vaccinated herds was 1.8% compared with 9.1% in non-vaccinated herds (p< 0.005). The mean titre in the former group was lower (p< 0.001). Vaccinated herds required 3.3 herd tests to achieve a provisionally free status compared with 4.8 in non-vaccinated herds (0.001 < p < 0.005). Vaccination did not significantly reduce the number of herd tests in herds with less than 100 breeding females. In tests after the initial herd test only 0.5% reactors were found in vaccinated herds compared with 6.9% in non-vaccinated herds (p< 0.005). There were 0.9% false positive to the Rose Bengal plate test in non-vaccinated and 2.1% in vaccinated animals (p< 0.005) in non-infected herds. In infected herds this percentage was 3.0% and 4.2% respectively by (p< 0.05). In the non-infected herds there were 0.04% false positives to the complement fixation test out of 10,506 non-vaccinated cattle tested and 0.2% out of 24,734 vaccinated cattle.  相似文献   

11.
Abstract

The specificity of channel catfish Ictalurus punctatus serum antibody to Edwardsiella ictaluri was characterized by microtiter agglutination assay. There was no correlation between antibody titer to Aeromonas hydrophila and antibody titer to E. ictaluri in wild or feral channel catfish. Anti-E. ictaluri antibodies in naturally infected channel catfish were not removed by adsorption by nine other species of bacteria found in the channel catfish intestine and fish ponds. Channel catfish immunized with nine other species of bacteria did not develop substantial antibody titer to E. ictaluri. The antibody response of channel catfish to E. ictaluri is highly specific, and the microtiter agglutination test is a specific indicator of previous exposure to E. ictaluri  相似文献   

12.
An adjuvanted Moraxella bovis bacterin containing attachment antigens and cornea-degrading enzyme antigens protected cattle from infectious bovine keratoconjunctivitis (IBK) when experimentally challenged with homologous and heterologous challenge cultures of M. bovis. This bacterin also protected cattle against field exposure to M. bovis. Transmission electron microscopy and fluorescein labeled anti-M. bovis pili antiserum showed pili on the M. bovis bacterin strain. Scanning electron microscopy demonstrated a fibrillar glycocalyx. The bacterin strain of M. bovis, but not all strains of M. bovis, destroyed bovine corneal cell monolayers in vitro. Bovine corneal cells began to separate from each other within 5 min after M. bovis organisms were added and adhered to the cell monolayers. Moraxella bovis organisms remained attached to the disintegrating cells as the cell membrane separated and was digested. Vaccination stimulated bacterial agglutination antibodies. However, protection against experimental challenge was more closely related to the cornea-degrading enzyme content of the experimental bacterins. Twenty-two of 29 cattle (76%) vaccinated with bacterins containing a relative enzyme activity (REA) greater than 0.4 were protected in a rigorous challenge of immunity test. Only 1 of 21 non-vaccinated calves (5%) was free of IBK. Ninety-two percent (24/26) of calves vaccinated with a bacterin containing a REA greater than 0.29 remained free of IBK following field exposure, whereas 47% (8/17) non-vaccinated calves developed IBK. Only 8 of 12 calves (67%) vaccinated with a bacterin containing a REA of 0.09 remained free of IBK. In a larger field efficacy test consisting of 32 herds in six states, the incidence of IBK in individual herds ranged from 0% to 55%. The overall rate of infection was 11.2%. Vaccination of calves with an M. bovis bacterin that contained a REA of 0.63 reduced the incidence of IBK from 11.2% (217/1931) in the non-vaccinated controls to 4.3% (66/1520) in cattle vaccinated once and to 3.1% (48/1536) in cattle vaccinated twice.  相似文献   

13.
Only few data are available on the effect of fumonisins on the immune response. The aim of the present study was to examine whether dietary fumonisin B1 (FB1) has any effect on the humoral and cellular immune response in weaned pigs, depending on the dose and the time of toxin exposure. Fusarium moniliforme fungal culture was added to the experimental animals' diet to ensure an FB1 intake of 1, 5 and 10 ppm (first experiment) or 100 mg per animal per day (second experiment). The control animals were fed a toxin-free diet. In order to determine the immune response, the animals were vaccinated against Aujeszky's disease with inactivated vaccine (Aujesping K, Phylaxia-Sanofi, Budapest, Hungary). Specific and nonspecific in vitro cellular immune response was measured by the lymphocyte stimulation test (LST) induced by PHA-P, Con A, LPS and inactivated suspension of the Aujeszky's disease virus. Humoral immune response, e.g. specific antibody titre, was measured by the virus neutralisation (VN) test. None of the immunological parameters examined showed significant differences between groups. It could be concluded that fumonisin B1 had no significant effect on the humoral and cellular specific and nonspecific immune response when fed in a high dose (100 mg/animal/day for 8 days) or in a low concentration even for a longer period (1, 5 and 10 ppm for 3-4 months).  相似文献   

14.
A case of a myxoma virus strain in vaccinated and non-vaccinated rabbits is described, and genetic identification of that strain was performed in this study. In two commercial farms being 150km apart, myxomatosis has been occurred after the import of animals from a common supplier. The disease was manifested firstly in the existing non-immune population of does and fatteners, and later in all vaccinated animals, being 2-3 months immune at the time of first symptoms. Morbidity was almost 100% with nasal discharge, listlessness, fever, eyelid swelling, eye and nasal purulent discharge, papules in the ears, facial oedema, and swelling of the anagenital region, with result always the death of the animals. Examination by PCR had shown the presence of a 492-bp specific product in all the symptomatic animals tested from both farms, having 100% nucleotide sequence identity with the homologous region of the myxoma virus Lausanne strain. The simultaneous occurrence of myxomatosis in the vaccinated and non-vaccinated rabbits of both farms, suggests that the supplier was possibly the source of a viral isolate with increased virulence.  相似文献   

15.
As immunosuppression in pigeons is common and results in reduced post-vaccination immunity and lower health status of the birds, studies have been taken up aimed at evaluation of the effect of three doses of methisoprinol on the percentage of CD4+ and CD8+ T lymphocyte subpopulation in peripheral blood and in the spleen and the titre of anti-NDV antibodies in the serum of pigeons in four groups (A, B, C, D), with 20 birds each. Pigeons in each group were immunised against paramyxovirosis at week 6 and 9 of life. Water for injection (group A - control) or methisoprinol at 100 mg/kg of body weight (group B), 200 mg/kg of body weight (group C) and 600 mg/kg of body weight (group D) was administered intramuscularly for 3 days before each vaccination. The immunological analyses were carried out by flow cytometry and the ELISA test. The findings indicate that methisoprinol administered intramuscularly at 100 and 200 mg/kg of body weight for 3 successive days before vaccination against paramyxovirosis mainly stimulates the mechanisms of non-specific humoral and cellular immunity, which is indicated by a higher percentage of the subpopulation of CD4+ T lymphocytes in peripheral blood and in the spleen and a higher titre of anti-NDV antibodies.  相似文献   

16.
A case of a myxoma virus strain in vaccinated and non-vaccinated rabbits is described, and genetic identification of that strain was performed in this study. In two commercial farms being 150 km apart, myxomatosis has been occurred after the import of animals from a common supplier. The disease was manifested firstly in the existing non-immune population of does and fatteners, and later in all vaccinated animals, being 2–3 months immune at the time of first symptoms. Morbidity was almost 100% with nasal discharge, listlessness, fever, eyelid swelling, eye and nasal purulent discharge, papules in the ears, facial oedema, and swelling of the anagenital region, with result always the death of the animals. Examination by PCR had shown the presence of a 492-bp specific product in all the symptomatic animals tested from both farms, having 100% nucleotide sequence identity with the homologous region of the myxoma virus Lausanne strain. The simultaneous occurrence of myxomatosis in the vaccinated and non-vaccinated rabbits of both farms, suggests that the supplier was possibly the source of a viral isolate with increased virulence.  相似文献   

17.
The purpose of the study was to determine the influence of the Bioimmuno preparation administered in feed and/or immunisation with the Respisure One vaccine on the development of selected indices of non-specific and specific humoral immune response against Mycoplasma hyopneumoniae (Mhp) infections in pigs. The study was performed on 28 piglets at the age of 4 weeks, divided into four equal groups. The biopreparations were administered according to the following pattern: group I--Bioimmuno (IFI Olsztyn, Poland) with feedstuff at amount of 1 kg/50 kg of feed for 48 h before vaccination with Respisure One (Pfizer) on day 28 of life; group II--Bioimmuno only (1 kg/50 kg feedstuff) for 48 h before vaccination with Respisure One of groups I and III; group III--Respisure One only on day 28 of life (2 ml/animal i.m.) and group C (control)--PBS (2 ml/animal i.m.) simultaneously with vaccination of groups I and III. On days 0, 3, 7, 14 and 21 after immunomodulation and/or immunisation, the serum level of gamma-globulins, the activity of lysozyme (LSM) as well as the serum levels of cytokines: interferon gamma (IFNgamma), interleukin 1 beta (IL-1beta) and interleukin 6 (IL-6) were determined, as indices of non-specific immune response against Mhp infections in pigs. The study has revealed that in piglets after weaning the application of the Bioimmuno and/or Respisure One biopreparations improves the non-specific immunity parameters stimulating an increase in serum levels of gamma-globulins, lysozyme and cytokines (IFNgamma, IL-1beta, IL-6), while late appearing seroconversion confirms a minor role of specific humoral immunity in the protection against Mhp infection.  相似文献   

18.
Clostridium perfringens type D-producing epsilon toxin is a common cause of death in sheep and goats worldwide. Although anti-epsilon toxin serum antibodies have been detected in healthy non-vaccinated sheep, the information regarding naturally acquired antibodies in ruminants is scanty. The objective of the present report was to characterize the development of naturally acquired antibodies against C. perfringens epsilon toxin in goats. The levels of anti-epsilon toxin antibodies in blood serum of goat kids from two different herds were examined continuously for 14 months. Goats were not vaccinated against any clostridial disease and received heterologous colostrums from cows that were not vaccinated against any clostridial disease. During the survey one of these flocks suffered an unexpectedly severe C. perfringens type D enterotoxemia outbreak. The results showed that natural acquired antibodies against C. perfringens epsilon toxin can appear as early as 6 weeks in young goats and increase with the age without evidence of clinical disease. The enterotoxemia outbreak was coincident with a significant increase in the level of anti-epsilon toxin antibodies.  相似文献   

19.
An enzyme-linked immunosorbent assay (ELISA) was developed for detecting antibody to Tritrichomonas foetus using both whole cell antigen (WCA) and membrane protein antigen (MPA). The test was used to detect specific antibody in serum, preputial washings and seminal plasma samples from 7 adult bulls which were vaccinated subcutaneously on 3 occasions with a membrane protein vaccine against T. foetus var brisbane in an oil adjuvant, and from 4 unvaccinated control animals. One month after administration of the third dose of vaccine, vaccinated and control bulls were repeatedly challenged with the live vaccine strain of the T. foetus. A steady increase in serum antibody titre was detected after each inoculation of vaccine when both antigens were used in the ELISA. However, MPA was more sensitive. After challenge, vaccinated bulls developed an increased titre. No specific antibody was detected in control bulls, except in one bull after challenge in which seroconversion was detected. The serum antibody titres of both groups of animals were also measured with the microagglutination test which proved less sensitive than the ELISA. Antibody titres to both antigens, although lower than in serum, were detected in the seminal plasma of vaccinated animals. The control bulls remained non-responsive. No antibody was detected by ELISA in preputial washings from either control or vaccinated bulls prior to challenge. Post-challenge, some of the vaccinated bulls were responsive with both antigens whereas the control bulls remained negative.  相似文献   

20.
The aim of the present study was to determine the effect of dietary lysozyme levels on growth performance, gut health and non‐specific immunity of weanling piglets. A total of 150 weanling piglets were allocated to six treatments. The piglets were fed the same basel diet supplemented with 0, 30, 60, 90 and 120 mg/kg lysozyme as well as antibiotics for 28 days. From day 14 to day 28 of dietary treatment, piglets fed 90 mg/kg lysozyme had greater average daily gain than piglets fed control diet. During the whole experimental period, piglets fed 120 mg/kg lysozyme tended to have greater average daily gain than piglets fed control diet. Compared with piglets fed control diet, piglets fed diets containing antibiotics and 90 mg/kg lysozyme had greater villus height to crypt depth ratio in duodenum and jejunum. Additionally, dietary supplementation of 60 and 90 mg/kg lysozyme as well as antibiotics enhanced the phagocytic activity of peritoneal macrophages in piglets. In conclusion, dietary lysozyme can accelerate the growth of weanling piglets by improving gut health and non‐specific immunity and supplementing 90 mg/kg lysozyme is as effective as antibiotics (20 mg/kg colistin sulphate + 50 mg/kg kitasamycin) in improving the growth performance of weanling piglets.  相似文献   

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