首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Increasingly large numbers of poultry are held in production systems with access to outdoor areas. In these systems intestinal helminths are found with flock prevalences of up to 100%. Helminth infections influence chicken health negatively, which is why the following investigation has been performed.In the present experiment, 20 chickens of two inbred chicken lines containing the major histocompatibility complex (MHC) haplotypes, B14 and R5, were inoculated with 500 embryonated Ascaridia galli eggs. The A. galli-specific IgG titres of serum samples and the excretion of A. galli eggs in chicken faeces were measured for a period of 81 weeks.The level of excreted A. galli eggs measured as eggs per gram chicken faeces (EPG) varied greatly between chickens in each line. Significant differences were found between the two lines and with the R5 chickens reaching the highest levels. Likewise, the A. galli-specific IgG titres in serum differed significantly between the two lines, and an inverse relationship between infection level (EPG) and antibody titres was found. Although this inverse relationship suggests that humoral immunity may be involved in protection against A. galli infection, the high antibody titres did not prevent continued infection.  相似文献   

2.
The results of vaccination trials carried out on pups with maternally derived antibodies (MDA) to canine parvovirus (CPV), using a modified-live CPV-2b variant vaccine (29-97/40 strain), are reported. The vaccine was able to overcome the obstacle of MDA, and to elicit protective immunity in 100% of the pups whose antibody titres were 1:10-1:40, 83% of the pups with titres of 1:80, 57% of the pups with titres of 1:160, and even in 60% of the pups with antibody titres of 1:320.  相似文献   

3.
The results of vaccination trials carried out on pups with maternally derived antibodies (MDA) to canine parvovirus (CPV), using a modified‐live CPV‐2b variant vaccine (29‐97/40 strain), are reported. The vaccine was able to overcome the obstacle of MDA, and to elicit protective immunity in 100% of the pups whose antibody titres were 1:10–1:40, 83% of the pups with titres of 1:80, 57% of the pups with titres of 1:160, and even in 60% of the pups with antibody titres of 1:320.  相似文献   

4.
The adjuvant vaccine against infectious bovine rhinotracheitis (IBR) was tested as to its innocuousness and immunogenicity. The immunity response induced by a single or double application of different vaccine doses was evaluated according to the content of neutralization antibodies (NP) in the blood serum. A direct dependence was revealed between the size of the inoculum and NP content in the blood serum, with NP titres of 1 : 9.3; 1 : 26.6, 1 : 80 and 1 : 149 after doubled application of 1, 2, 5, and 10 ml of the vaccine. The calves inoculated at an age of one week produced antibodies in the same titres as one- to five-month-old calves. Singly inoculated animals mostly showed zero-level or low antibody titres, but revaccination induced general serum-positivity with NP titres 1 : 4 to 1 : 128. The animals which had been in contact with the IBR virus and were serologically negative during inoculation or had an NP content in the blood serum at a titre of 1 : 4 or less, gave an anamnestic response to inoculation, but revaccination did not lead to a significant rise in antibody content. Double administration of 2 ml of vaccine in four production charges induced the production of antibodies with average titres of 1 : 36, 1 : 25; 1 : 31 and 1 : 24. Inoculation of susceptible animals in non-infected herds and of clinically healthy animals in infected herds did not cause any health disorders. IBR; inactivated adjuvant vaccine; different age; different doses; immunity response; neutralization antibodies.  相似文献   

5.
The effect of the inoculation dose on the development of antibodies as measured by the indirect fluorescent antibody (IFA) test against E. maxima and E. acervulina was studied in two experiments in each of which six groups of six chickens each were inoculated with varying numbers of oocysts.The IFA titres reached their maximum 2 weeks after inoculation. The response was dose related for both species. This response was more pronounced in the infections with E. acervulina than in those with E. maxima, reflecting a difference in immunogenicity.Reinoculation with E. maxima indicated that the birds were immune and resulted in a rise of the titres. The maximum IFA titres obtained during the primary infection were never reached by reinfection. The titres decreased gradually during the 7 weeks following reinoculation. Reinoculation with E. acervulnia resulted in higher titres than those obtained during the first infection.  相似文献   

6.
Passive transfer experiments were performed to serve as a basis for analyzing the immune response of adult mice to FMDV infection. Animals were irradiated (750 rad: 1 lethal dose 50%) and reconstituted with allogeneic mononuclear cells from blood, spleen, thymus and peritoneal cavity from donors 2 and 8 days post-inoculation (p.i.). Donors were primed with 10 000 suckling mouse 50% lethal doses of FMDV strain O1 Campos. The following parameters were studied in recipient mice challenged with 10 000 suckling mouse 50% lethal doses of the same virus: (1) viremia; (b) FMDV neutralizing antibody titres; (c) sheep red blood cell (SRBC) hemagglutinating antibody titres. Viremia was substantially prolonged in irradiated control mice, which did not produce detectable antibodies to FMDV or SRBC. In contrast, the span of viremia was markedly shorter in animals reconstituted with cells obtained 8 days p.i. and its eclipse coincided with the onset of neutralizing antibody production. An equally efficient antibody response to the inoculation of SRBC was observed in these animals. No effect was detected after the transfer of cells obtained 2 days p.i. It is concluded that the humoral immune response plays a predominant role in the recovery from FMDV experimental infection in adult mice.  相似文献   

7.
Levamisole administered by oral, subcutaneous or transdermal routes following vaccination against Pasteurella multocida enhanced the humoral response in cross-bred calves. The group that received levamisole subcutaneously elicited highly significant (P less than 0.01) antibody titres during the primary humoral response in comparison with groups that received levamisole orally or transdermally. During the secondary response in the same experiment, levamisole administered subcutaneously and transdermally showed highly significant (P less than 0.01) haemagglutination titres relative to oral administration of the drug. In a second experiment, the group that received levamisole subcutaneously showed highly significant (P less than 0.01) antibody titres during the anamnestic humoral response over other treated groups.  相似文献   

8.
This study was conducted to determine the antibody response for porcine parvovirus (PPV) of 39 gilts in field conditions after vaccination. Gilts from four herds endemically infected with PPV were injected twice with a commercial vaccine of inactivated PPV and Erysipelothrix rhusiopathiae. The PPV antibodies were analysed both with haemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) in order to study the agreement between these methods. The possible association between high-antibody titres and reproductive failure (repeat breeding, culling for infertility, < or = 6 piglets born alive) was also investigated. In these study herds, endemically infected by PPV, most gilts (84.6%) had not seroconverted by the age of 6 months. On-field vaccination resulted in a consistent increase of humoral immunity not exceeding the antibody level of 1 : 512 in the majority of gilts in all herds examined. The agreement between ELISA and HI tests was moderate (Spearman's rho = 0.87, kappa = 0.63). The seroconversion over the level >1:512 by mid-pregnancy was not associated with reproductive failure.  相似文献   

9.
Listeriosis in sheep. Listeria monocytogenes excretion and immunological state in healthy sheep. Acta vet. scand. 1979, 20, 168–179. — The excretion of Listeria monocytogenes (Lm) in the faeces and milk, and humoral and cell mediated immunity against Lm, were examined in a sheep flock where no cases of listeriosis had occurred during the last 3 years. The investigation was carried out during the indoor season. During the first part of the season 2 of the 10 pregnant, 8 months old lambs excreted Lm in the faeces, but none of the 106 ewes, 2–10 years old. At lambing the organism was isolated from the faeces of 6 of the 10 1 year old lambs and from 64% of the ewes, and from the milk of 1 of the lambs and 41% of the ewes. Nearly all the isolates (98.5%) belonged to serotype 1.Antibody titres against Lm were found in sera and whey by an indirect haemagglutination method. The titres were higher for the ewes than for the hoggs and seemed to be influenced by the number of foetuses the animals carried.Cell mediated immunity was determined by a skin test where delayed hypersensitivity against an antigen prepared from Lm, was measured. Animals fed grass silage had a stronger reaction than animals fed hay, and a stronger reaction was found in animals with ≥ 3 foetuses than in the remainder.The investigation indicates that even in a healthy sheep flock all the animals may be exposed to Lm, and the majority may be latent carriers and excrete this organism in the faeces and milk during periods of stress.  相似文献   

10.
Q fever is a zoonosis caused by the intracellular bacterium Coxiella burnetii. Both humoral and cellular immunity are important in the host defence against intracellular bacteria. Little is known about the immune response to C. burnetii infections in domestic ruminants even though these species are the major source of Q fever in humans. To investigate the goat’s immune response we inoculated groups of pregnant goats via inhalation with a Dutch outbreak isolate of C. burnetii. All animals were successfully infected. Phase 1 and Phase 2 IgM- and IgG-specific antibodies were measured. Cellular immune responses were investigated by interferon-gamma, enzyme-linked immunosorbent spot test (IFN-γ Elispot), lymphocyte proliferation test (LPT) and systemic cytokines. After two weeks post inoculation (wpi), a strong anti-C. burnetii Phase 2 IgM and IgG antibody response was observed while the increase in IgM anti-Phase 1 antibodies was less pronounced. IgG anti-Phase 1 antibodies started to rise at 6 wpi. Cellular immune responses were observed after parturition. Our results demonstrated humoral and cellular immune responses to C. burnetii infection in pregnant goats. Cell-mediated immune responses did not differ enough to distinguish between Coxiella-infected and non-infected pregnant animals, whereas a strong-phase specific antibody response is detected after 2 wpi. This humoral immune response may be useful in the early detection of C. burnetii-infected pregnant goats.  相似文献   

11.
On a property in the Nelson District, blood and urine samples were taken from red deer (Cervus elaphus) from which low (<1:100) antibody titres to serovar copenhageni and suspected leptospiral abortions had previously been reported. A total of 27 hinds were sampled. Microscopic agglutination test (MAT) titres in sera ranging from 1:32 to 1:128 were found in six animals. Thirteen leptospiral isolations were made from nine of the 27 urine samples. Four of these were typed as copenhageni and nine as hardjo. Two cultures were prepared from each urine sample and hardjo and copenhageni were both isolated from single urine samples from two animals. None of the 27 deer had serum MAT titres at 1:32 or above to copenhageni.  相似文献   

12.
To investigate effective new rabies vaccines, a fusion protein consisting of the rabies virus (RV) glycoprotein and the heat-labile enterotoxin B subunit of Escherichia coli (LTB) was successfully constructed and delivered in a live attenuated Salmonella strain LH430. Mice were immunised with LH430 carrying pVAX1-G, pVAX1-G-LTB or pVAX1-ori-G-LTB. The antibody titres of mice immunised with oral LH430 carrying pVAX1-G-LTB or pVAX1-ori-G-LTB were significantly higher than those of pVAX1-G-immunised mice. The results of the challenge with the rabies virus standard strain (CVS-11) showed that the LH430 strain carrying the G-LTB gene induced immunity and elevated IL-2 levels in immunised mice (7P < 0.01), whereas LH430 carrying pVAX1-G did not contribute to protection. These results show that LH430 carrying recombinant G-LTB could provide overall immunity against challenge with CVS-11 and should be considered to be a potential rabies vaccine.  相似文献   

13.
Equine babesiosis, a tick transmitted haemoprotozoan disease caused by Theileria equi is globally distributed and responsible for heavy economic losses to the equine husbandry. Equids reared in endemic areas usually pick up infection at an early age and become immune tolerant throughout their life span. We studied the level of passively transferred antibodies in neonate foals born from pre-immuned mares. Latently T. equi infected pre-immuned pony and donkey mares (three each) were selected and T. equi antibody titres in neonates was monitored till 90 days post foaling (DPF) by applying Dot-ELISA on sequentially collected serum samples from foals and their dams. A very high antibody titre was observed in pre-immuned pony and donkey mares. The maximum antibody of 1:60 to 1:80 was observed in pony's and donkey's foal on 2–16 and 2–10 DPF, respectively and thereafter it declined to less than 1:20 on 63–77 and 56–63 DPF. Simultaneously parasite carrying status in neonate foals and their dam was also monitored by applying PCR on blood samples. We could demonstrate PCR amplification in dam's blood samples while no amplification was recorded in neonate's blood samples. This study indicated that new-born foals were born naïve and passively transferred immunity was transitory which wanes after 63–77 DPF.  相似文献   

14.
One dose of inactivated, adjuvanted rabies vaccine of cell culture origin (Rabisin) induced good but short-duration immunity in close to 100% of the 50 semi-domesticated reindeer (Rangifer tarandus tarandus L.) vaccinated. Most of the animals (44) had rabies virus antibody titre ≥1.5 IU/ml at 38 days after vaccination. Five animals had titre 0.5 IU. Antibody titres were not, however, present 1 year after primary vaccination in most animals. About 1 year (360-413 days) after primary vaccination, 22 of the 39 reindeer that could be sampled had rabies virus antibody titre <0.5 IU/ml.  相似文献   

15.
ABSTRACT

1. The survivability, innate and adaptive immunity, growth and production traits up to 72 weeks of age were determined in Ghagus, Nicobari (unimproved indigenous) and White Leghorn (WLH) breeds and the study investigated links between innate and adaptive immunity and survivability and production traits.

2. At 20 and 40 weeks of age, there was a significant effect of breed on innate immunity assessed by measuring titres of natural antibody (NAb) binding to rabbit red blood cells (RRBC) and adaptive immunity assessed by measuring specific antibody titre (SpAb) to Newcastle disease virus.

3. Highest survivability was in WLH (91.6%) followed by Nicobari (87.1%) and Ghagus (82.9%) breeds. Growth traits at different ages were higher (P< 0.001) in Ghagus followed by WLH and Nicobari breeds. Egg production up to 72 weeks was higher (P < 0.001) in WLH followed by Nicobari and Ghagus breeds, whereas egg weight at different ages was higher (P < 0.001) in WLH than Ghagus and Nicobari breeds.

4. NAb titres measured at 20 weeks were significantly (P = 0.002) associated with the survivability of hens during 20 to 72 weeks of age. Breed-wise analysis showed a significant (P = 0.019) association between NAb titres at 20 weeks and survivability in the Ghagus breed. Furthermore, NAb titres at 20 weeks were higher in hens which survived to 72 weeks compared with those that died (P = 0.002).

5. Measuring NAb titres to RRBC is quick, economical and simple. This method has potential to be used in a breeding programme to increase survivability of laying hens.  相似文献   

16.
In the present study, we have followed up Leishmania infantum infection in dogs: (1) naturally infected; (2) experimentally infected with amastigotes; and (3) experimentally infected with culture promastigotes. The main objective was to evaluate the differences of the humoral and cellular immune responses of each group. Sera from 12 beagle dogs were analysed for total anti-leishmanial antibodies and IgG1 and IgG2 subclasses by enzyme-linked immunosorbent assay (ELISA). Lymphoproliferation to L. infantum antigen was also performed. All naturally infected animals were symptomatic with a marked humoral response. Dogs inoculated with amastigotes were asymptomotic and presented lower antibody titres than naturally infected. Dogs inoculated with culture promastigotes were asymptomotic with no significant humoral response. Strong proliferative responses to Leishmania antigen was observed in dogs inoculated with promastigotes. In our experimental model, IgG1 antibody levels presented a similar pattern in all infected animals, and IgG2 reactivity was high in naturally infected dogs.  相似文献   

17.
The excretion of Listeria monocytogenes (Lm) in the faeces and milk, and humoral immunity against Lm, were examined in a sheep flock with outbreaks of listeric encephalitis and in a flock with outbreaks of listeric abortion. The encephalitis flock consisted of 86 ewes and 20 hoggs, the abortion flock of 45 ewes and 3 hoggs, all of them pregnant. Faecal excretion rate in the encephalitis flock varied from about 25 % in the first part of the indoor season to nearly zero 1 month later, to about 30 % 1 month before lambing and about 15 % at lambing. About 15 % of the animals also excreted Lm in the milk. Lm 4 was the dominating serotype.In the abortion flock about 2/3 of the animals excreted Lm in the faeces and 1/3 in the milk at lambing. All the isolates belonged to serotype 1, which also was isolated from grass silage and strawbedding samples.In the encephalitis flock ewes with ≥ 3 foetuses had a higher excretion rate than the remainder, while no such differences were found in the abortion flock.Antibody titres against Lm in sera and whey in the encephalitis flock were of the same order as in the healthy flock described in an earlier publication (Grønstøl 1979), except that the highest titres were found in the hoggs. Serum titres from the abortion flock after lambing were significantly higher than in the encephalitis flock, while whey titres were of the same order.Treatment with 2-mercapto-ethanol reduced the titres substantially in sera from the abortion flock, indicating that the antibodies belonged to the IgM-fraction, while only a slight reduction was seen after similar treatment of the whey.  相似文献   

18.
(1) Two hundred and twenty-seven adult turkeys of both sexes, of two varieties (104 Black and 123 White) were used to evaluate their immunocompetence status and body weights. (2) Response to sheep red blood cells (SRBC) (humoral immunity) was measured by Haemagglutination (HA) test 5 days post immunisation (dpi) and expressed as log2 values. Mercaptoethanol resistant (MER) antibodies representing IgG were determined by Mercaptoethanol HA test and Mercaptoethanol sensitive (MES) antibodies, representing IgM as the difference in total HA titre and IgG. Serum lysozyme concentrations were estimated by 'Lysoplate assay' and expressed in log2 values. (3) Least squares analysis of variance revealed that the White variety had higher adult body weight (4.788 +/- 0.040 kg) than the Black (3.774 +/- 0.044 kg). Sexual dimorphism was apparent and meals were heavier than females in both varieties. The interaction effect of variety and sex on body weight was also significant. (4) Least squares means for immunological traits, namely, total anti-SRBC antibodies, MER, MES titres and serum lysozyme were 7.161 +/- 0.189, 0.801 +/- 0.071, 6.362 +/- 0.160 and 1.766 +/- 0.043 microg/ml, respectively. The Black variety had a higher MES antibody titre than the White. (5) Sex had an effect on all the immunological traits except on MER titres. Females generally had higher anti-SRBC, MER and MES titres and serum lysozyme. The variety x sex interaction effect was significant for MES titres and serum lysozyme. White males had the lowest MES titres.  相似文献   

19.
The humoral immune response to the novel antigen Brucella abortus (S19) was examined in nonpregnant ewes and in ewes at different stages of pregnancy. Both the primary and secondary responses were monitored, by measuring the levels of total antibody, Immunoglobulin G (IgG), and complement fixing antibody. Results showed that total antibody production was significantly (p<0.01) impaired in late pregnancy and that IgG titres persisted at significantly (p<0.05) higher levels in non-pregnant animals late in the primary response and following the booster inoculation. Complement fixing antibody levels were significantly higher in non-pregnant ewes and animals inoculated post-partum. These results suggest that active immunity can be altered during pregnancy, with qualitative changes in the class and biological activity of antibody.  相似文献   

20.
The effect of vaccinating pregnant cows with an inactivated vaccine against Mannheimia haemolytica, BRSV and PI3V infections on selected immune responses in their offspring was examined. Blood samples were collected weekly for 12 weeks from six newborn calves from each of vaccinated (experimental) and unvaccinated (control) dams. Specific antibodies to M. haemolytica, BRSV and PI3V and mean values of IgA, IgG concentrations were significantly higher in the experimental calves compared with the controls. However, specific antibody titres to adenovirus type 3, BHV1 and BVDV in the experimental calves had constant levels while the control group levels changed. The IgM, Hp and SAA concentrations generally increased until week 8 in the experimental group, but the control group titres became higher after week 9. This study demonstrates that specific immunisation of cows pre-partum significantly stimulated parameters associated with immunity and it also controlled the acute phase response intensity in their offspring. Therefore the vaccination of dams may provide additional antibody protection against infection to their offspring.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号