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1.
Ten strains of Yersinia enterocolitica belonging to ten various serogroups isolated from raw milk were inoculated into groups of five guinea pigs and five calves. Y. enterocolitica serotype 0:16 was the only serotype tested that induced an antibody response to Brucella abortus in calves. No anti-Brucella response could be demonstrated serologically in guinea pigs. Activity of the anti-Y. enterocolitica 0:16 calf sera against B. abortus antigen was shown by the tube agglutination test, and by the complement fixation test. The early agglutinating antibody response was partly sensitive to reduction by 2-mercaptoethanol. This sensitivity decreased later in the response. This is the first report of anti-Brucella responses induced by a serotype of Y. enterocolitica other than 0:9; sera from a group of five calves inoculated with 0:9 were tested by the same serological techniques for comparison.  相似文献   

2.
Infection of normal adult cattle and sporadic serological Brucella abortus reactors, which no longer had diagnostic titers to B. abortus, with a culture of Escherichia coli isolated from a cow (or its environment) resulted in the production of a primary IgM serum antibody response to both B. abortus and E. coli. Cattle injected with heat killed E. coli and guinea pigs or young calves lacking natural agglutinins to B. abortus injected with live E. coli, produced serum antibody only to E. coli. The subsequent reinjections of live E. coli into the former two groups of cattle resulted in all but one animal in each group producing IgM ‘secondary’ responses to B. abortus of decreasing magnitude, while the anti-E. coli responses increased and eventually switched to synthesis of IgG class antibody. The remaining two animals produced a series of ‘secondary’ responses of IgM antibody to B. abortus similar in amplitude and duration to the primary immune response. The anti-E. coli agglutinins of these two animals increased in titer and IgG class antibody to E. coli was evident after several injections of E. coli. These results indicate that infection of cattle by E. coli can cause a problem in the serological fiagnosis of B. abortus infection. Speculations on the cause of this cross-reaction and ways of minimizing misdiagnosis are discussed.  相似文献   

3.
SUMMARY Groups of female calves were vaccinated subcutaneously with the standard dose of Brucella abortus strain 19 (S19) or with B. abortus 45/20 (S45/20). These calves and non-vaccinated control calves were mated at 15 months of age and challenged by way of the conjunctival sac with B. abortus strain 544 (S544). The incidence of abortion, stillbirths, weakling calves and healthy calves was observed after challenge and specimens were collected for culture at parturition and slaughter. Fifteen healthy calves were born to 18 animals vaccinated with S19, 12 were born to 18 animals vaccinated with S45/20 and 2 were born to 8 animals that were not vaccinated. B. abortus was isolated from 5 of the animals vaccinated with S19, 13 of the animals vaccinated with S45/20 and 9 of the 12 animals that were not vaccinated. Only one of the 5 infected animals vaccinated with S19 was vaccinated as an adult.  相似文献   

4.
New and currently used serological procedures were evaluated using sera from cattle that were challenged with B. abortus S544 (S544) after vaccination with either B. abortus S19 (S19) or B. abortus 45/20 (S45/20) as calves or adults. In animals vaccinated with S19, titres to the indirect haemolysis test (IHLT) rose more slowly, declined more rapidly and involved fewer animals than did titres to the complement fixation test (CFT). In animals vaccinated with S45/20 the rough antigen complement fixation test (RCFT) showed persistent titres. At slaughter the IHLT and CFT were found to be more specific and more sensitive than the Rose Bengal Plate Test (RBPT) and Serum Agglutination Test (SAT) in the detection of cattle infected with B. abortus.  相似文献   

5.
A whole blood lymphyocyte transformation (WBLT) assay was used to detect anti-brucella lymphocyte reactivity in guinea pigs. Brucella antigens stimulated an antigen-specific lymphoproliferative response in WBLT assays from Brucella abortus infected guinea pigs. The response was best detected from 6 to 16 weeks after challenge inoculation with viable B. abortus 2308. Lymphocytes were not stimulated by unrelated bacterial antigens and control animals did not respond to the Brucella antigens. The responding cell population was characterized as mostly T lymphocytes. The WBLT assay was found to be specific for the detection of anti-brucella lymphocyte reactivity. However, a negative response was not definitive, which indicated a need for repeated testing to establish that a guinea pig did not have anti-brucella lymphocyte sensitization.  相似文献   

6.
Immunizing animals in the wild against Brucella (B.) abortus is essential to control bovine brucellosis because cattle can get the disease through close contact with infected wildlife. The aim of this experiment was to evaluate the effectiveness of the B. abortus strain RB51 vaccine in protecting infection as well as vertical transmission in Sprague-Dawley (SD) rats against B. abortus biotype 1. Virgin female SD rats (n = 48) two months of age were divided into two groups: one group (n = 24) received RB51 vaccine intraperitoneally with 3 × 1010 colony forming units (CFU) and the other group (n = 24) was used as non-vaccinated control. Non-vaccinated and RB51-vaccinated rats were challenged with 1.5 × 109 CFU of virulent B. abortus biotype 1 six weeks after vaccination. Three weeks after challenge, all rats were bred. Verification of RB51-vaccine induced protection in SD rats was determined by bacteriological, serological and molecular screening of maternal and fetal tissues at necropsy. The RB51 vaccine elicited 81.25% protection in SD rats against infection with B. abortus biotype 1. Offspring from rats vaccinated with RB51 had a decreased (p < 0.05) prevalence of vertical transmission of B. abortus biotype 1 compared to the offspring from non-vaccinated rats (20.23% and 87.50%, respectively). This is the first report of RB51 vaccination efficacy against the vertical transmission of B. abortus in the SD rat model.  相似文献   

7.
A cross-sectional study was carried out to determine seroprevalence and to identify risk factors associated with Chlamydophila abortus infection in 62 nonvaccinated dairy herds (671 cows) in Jordan between January and June 2007. Information regarding herd management was recorded through a personal interview with farmers. Antibodies against C. abortus were detected using an ELISA test kit. Chi-square analysis and multivariable logistic regression model were used to identify risk factors associated with C. abortus seropositivity. The true prevalence of antibodies against C. abortus in individual cows and cattle herds were 19.9?% and 66.3?%, respectively. Univariable Chi-square analysis revealed three variables with P????0.25 that were further offered to multivariable logistic regression analysis. Small-sized herds were identified as a risk factor for seropositivity to C. abortus, while sweeping followed by water hosing and using disinfectants were identified as protective factors. Cows in the age groups of >8 and ??10?years old and >2 and ??6?years old had the highest and lowest significant seroprevalence to C. abortus, respectively. Results of this study indicated that C. abortus is highly prevalent in Jordan's dairy herds and Chlamydophila infection could be controlled by applying strict biosecurity measures in the dairy farms.  相似文献   

8.
The effects of applied stimuli on the initiation of experimental infection were studied on lemmings, rabbits, hamsters, and guinea pigs. Stress was simulated by injection of cortisone acetate, or by trauma, heat, or cold. L. monocytogenes was the organism used for experimental infection. The results showed that the course of the infection was influenced in favour of the invading microorganism by the stress agents used. Hyperglycemia was present in the animals that developed the infection to overt disease. This suggests that hyperglycemia may be the trigger mechanism.  相似文献   

9.
Extract

The present owner of the farm on which this case occurred took it over in May, 1957. He bought in 12 heifers in May, 1958. which had not been vaccinated against Brucella abortus. During May to July, 1958, three of his cows (presumably vaccinated as calves) and one of these heifers aborted. In two of these cases (one cow and one of the heifers), the cause was determined to be B. abortus. Five maiden Large White sows were bought during April and May. Although pigs and cows were run in separate paddocks, the cows occasionally passed along a race to which the sows had access. One of these, the sow “Bess”, was clue to farrow on 20 August, but was observed to be aborting on 6 August.  相似文献   

10.
Lymphadenopathy is a commonly found condition in guinea pigs that suffer diseases caused by bacterial organisms as Streptococcus zooepidemicus, Yersinia pseudotuberculosis, Bordetella, and Salmonellae (S. linate) which access cervical lymph nodes via an abraded oral mucosa. In this study, we investigate all possible alterations present in cytological smears obtained from cervical lymph nodes of guinea pigs with lymphadenopathy. Thirty-one clinical cases of guinea pigs with different grades of lymphadenomegaly and 10 clinically healthy guinea pigs were considered. The fine-needle nonaspiration cytology (FNNAC) provided an adequate quantity and quality of samples for cytological analysis. Air-dried FNNAC smears yielded excellent results with Wright stain. From 31 evaluated clinical cases, 64.5% were compatible with pseudoeosinophilic lymphadenitis, 22.6% compatible with reactive lymphatic node, 6.45% compatible with lymphoma, and 6.45% with Hodgkin's-like lymphoma. The findings revealed the usefulness of the FNNAC technique and Romanowsky stains as fast and easy methods for lymph node sampling and analysis, and also, the importance of recognizing various causes of lymphadenopathies associated with morbidity and mortality in guinea pigs which would influence treatment protocols and prognosis for patients.  相似文献   

11.
Chlamydia abortus is one of the most common abortive agents worldwide in sheep. Few studies have been reported C. abortus infection among sheep in Egypt but the available data is scarce. The objective of the present study was to determine the seroprevalence of C. abortus among sheep, the associated risk factors and its molecular characterization. The present study was conducted on 675 sheep in six Governorates at Northern Egypt. Data analysis confirmed the presence of antibodies against C. abortus in 93 out of 675 sheep. The logistic regression model was fitted to identify the associated risk factors with C. abortus infection. The results revealed that C. abortus increased significantly in ewes (OR = 4.04, 95 %CI: 1.44−11.28) during autumn season (OR = 3.6, 95 %CI: 1.64–8.28), in ewes with a history of abortion (OR = 1.4, 95 %CI: 0.87–2.50) and in farm where no lambing pen (OR = 2.2, 95 %CI: 1.30–3.94) or abscence of post abortion measures (OR = 1.96, 95%CI: 1.23-3.12). In addition, age, flock size and exchange of breeding ram had no significant effect on prevalence of chlamydiosis. Also, PCR assay was confirmed presence of C. abortus as accusative pathogen in aborted ewe and the genetic characterization of Egyptian C. abortus strain revealed 100 % identity with another strain from Iraq. A control program should be applied to reduce economic losses and risk of human infection.  相似文献   

12.
The preliminary study was conducted to assess the virulence of a strain of Brucella abortus (1969D) and to compare the susceptibility of water buffalo and cattle calves to infection by the intraconjunctival route. Seven of each cattle and water buffalo (Bubalus bubalis) calves aged 3–6 months were inoculated intraconjunctivally with counts ranging from 1.5 × 107 to 1.7 × 1010 colony forming units of B. abortus. Animals were monitored over an 8-week period for clinical manifestations and serological and hematological evidence of infection. At slaughter, eight lymph nodes from each animal were sampled for bacteriological and histopathological assessments. Lymph nodes from three water buffalo (43%) and five cattle (71%) yielded B. abortus (P = 0.048). Parotid/prescapular lymph nodes were most sensitive in detecting B. abortus. Our data suggest that B. abortus strain 1969D may be used as challenge strain, and water buffalo appeared to have a lower susceptibility to B. abortus infection than cattle.  相似文献   

13.
Background: Medical treatment of clinical otitis media and interna in guinea pigs is often unsatisfactory. Total ear canal ablation and lateral bulla osteotomy are used successfully in dogs, cats, and rabbits to treat chronic, medically nonresponsive ear disease. However, in guinea pigs this surgery can cause death. This study aimed to evaluate and describe a standardized myringotomy technique to treat guinea pigs with otitis media and interna. Methods: Ear dissections and endoscopically assisted myringotomy were evaluated on guinea pig carcasses to choose the most suitable endoscope and optics. Three client-owned guinea pigs with chronic otitis media and interna had a myringotomy with bacteriological sampling and therapeutic irrigation of the tympanic cavity performed. Anesthesia for the procedures was 25 minutes, the patients were recovered and eating within 2–6 hours, and discharged on targeted antibiotic therapy within 24 hours. Videotoscopy was performed at 7- and 14-days follow-up to assess the ear canal, healing of the tympanic membrane, and to evaluate the tympanic cavity. Repeat lavaging of the tympanic cavity was performed until the tympanic membrane incision was healed. Further follow-up occurred at 21- and 154-days postmyringotomy. Results: Two out of three guinea pigs had complete resolution of clinical signs, and the other showed clinical improvement from a 90° head tilt to a 30° head tilt. Conclusions and case series relevance: Videotoscopy assisted myringotomy under general anesthesia was a quick and straightforward endosurgical technique in three guinea pigs with chronic otitis media and interna. It allowed the collection of fluid for bacteriological culture and provided symptomatic relief.  相似文献   

14.
Summary

Calves (n = 2) born to dams with experimentally induced brucellosis, and calves (n = 4) born to dams with naturally occurring infection were examined by the delayed‐type hypersensitivity (DTH) test for possible B. abortus infection. The results were compared with the serum agglutination test, complement fixation test, and Coombs test. Five calves were nursed by their dams for 8–10 weeks after birth. One calf was separated from its dam and fed artificial milk.

Three to five months after birth, four calves tested seropositive in the serologic tests. Antibodies were detected in one calf as early as 1 week after birth. The calf fed on artificial milk was seronegative 4–5 weeks after birth. All calves reacted to the DTH test antigen from week 12 until the end of the experiment, even though serologic tests were negative. We conclude that the DTH test is a valuable technique for diagnosing Brucella in calves born to infected dams.  相似文献   

15.
The aim of this study was to identify possible effects of different vaccination strategies (concomitantly or not) against brucellosis and clostridia on intake, performance, feeding behavior, blood parameters, and immune responses of dairy heifers calves. Fifty heifers calves were enrolled [38 Gyr (Zebu, Bos taurus indicus) and 12 5/8 Holstein Gyr]. At 120 d of age, animals were randomly distributed among 3 groups: B (n = 18), vaccinated against brucellosis; C (n = 14), vaccinated against clostridia and CB (n = 18), vaccinated concomitantly for both. Rectal and thermographic temperatures were evaluated on days 1, 0, 1, 2, 3, 5, 7,10, 14, and 28 relatives to the vaccination day. Feed and water intake, body weight (BW), and feeding behavior were monitored daily by an electronic feeding system. Blood was sampled on days 0, 3, 7, 14, and 28, relative to the vaccination day for determination of glucose and -hydroxybutyrate (BHBA) concentrations. Blood sampled on day 0 (prevaccination) and on days 28 and 42 were used to evaluate the immune response against Brucella abortus and clostridia. There was an increase in rectal temperature between the first and the third day postvaccination in the 3 groups. The thermography revealed an increase of local temperature for 7 d on groups B and CB. Group C had increased local temperature for a longer period, lasting for up to 14 d. Dry mater intake was reduced for groups B and CB, but no alteration was observed for group C. No alterations regarding initial BW, final BW, average daily weight gain, and feed efficiency were observed. No differences were observed for the 3 vaccination groups for blood parameters throughout the evaluation period. The concomitant vaccination against brucellosis and clostridia led to lower neutralizing antibody titers against epsilon toxin of Clostridium perfringens and botulinum toxin type C of C. botulinum (C > CB > B). When cellular proliferation assay and serological tests to B. abortus were evaluated, no differences were observed between groups B and CB. The present results indicate that the concomitant vaccination against brucellosis and clostridia has no relevant impact on the intake, performance, and feeding behavior of dairy calves. However, the concomitant vaccination of vaccines against these 2 pathogens impacts animal immunity against clostridial infections.  相似文献   

16.
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17.
This study was aimed to evaluate the effect of 0.0015% preservative-free tafluprost (Zioptan®) and 0.005% preservative containing latanoprost ophthalmic solutions (Lataprost®) on intraocular pressure (IOP) in healthy male guinea pigs (Cavia porcellus). A total of 16 male guinea pigs were randomly assigned to receive one drop of tafluprost or one drop of latanoprost in the right eye. The contralateral eye served as control. IOP was measured using a rebound tonometer at time 0(baseline), after 30 minutes and every 60 minutes for the next three hours and then every three hours for the next 21 hours. Administration of tafluprost and latanoprost was not associated with changes in IOP in the treated eyes. The maximum IOP-lowering effect of the ophthalmic solutions was observed 30 minutes post-instillation in the treated eyes (-1.25 ± 1.50 mmHg, P-value = 0.194 in group A and -1.50 ± 1.29 mmHg, P-value = 0.103 in group B) and returned to normal after 9 and 12 hours in group A and B, respectively. There was no significant difference between the IOP measurements of the right and left eyes in neither groups during the study (repeated measure test and Generalized Linear Mixed Model). The administration of one drop of tafluprost and latanoprost had no significant effect on the IOP of healthy guinea pigs. Further studies are needed in guinea pigs affected by glaucoma to explore the effectiveness of these drugs.  相似文献   

18.
In conformity with the findings of previous investigators, it was shown by density gradient ultracentrifugation that the antibodies in sera collected from calves shortly after vaccination with Brucella abortus, strain 19, were entirely or mainly rapidly-sedimenting. These macroglobulin (19S or IgM) antibodies showed complement-fixing as well as agglutinative activity with Br. abortus antigen. In later bleedings from the same vaccinated calves, antibodies with an intermediate sedimentation rate, (IgG), were present, as well as IgM. Sera from 15 of 22 non-vaccinated, relatively recent field cases of brucellosis appeared to contain only the IgG class of antibodies. In one herd, however, two cows with IgM only and five with both IgM and IgA were found; all seven of these cattle had been serologically negative before their introduction into this known infected herd a few months earlier. The agglutinative activity of sera from four cases of brucellosis of long standing and from eight cows, 4 to 13 years of age, that had been vaccinated as calves, was confined to the IgG fraction.  相似文献   

19.
The outer membrane proteins (OMPs) of Brucella (B.) abortus have been extensively studied, but their immunogenicity and protective ability against B. abortus infection are still unclear. In the present study, B. abortus Omp28, a group 3 antigen, was amplified by PCR and cloned into a maltose fusion protein expression system. Recombinant Omp28 (rOmp28) was expressed in Escherichia coli and was then purified. Immunogenicity of rOmp28 was confirmed by Western blot analysis with Brucella-positive mouse serum. Furthermore, humoral- or cell-mediated immune responses measured by the production of IgG1 or IgG2a in rOmp28-immunized mice and the ability of rOmp28 immunization to protect against B. abortus infection were evaluated in a mouse model. In the immunogenicity analysis, the mean titers of IgG1 and IgG2a produced by rOmp28-immunized mice were 20-fold higher than those of PBS-treated mice throughout the entire experimental period. Furthermore, spleen proliferation and bacterial burden in the spleen of rOmp28-immunized mice were approximately 1.5-fold lower than those of PBS-treated mice when challenged with virulent B. abortus. These findings suggest that rOmp28 from B. abortus is a good candidate for manufacturing an effective subunit vaccine against B. abortus infection in animals.  相似文献   

20.
Neonatally thymectomized and normal Holstein-Friesian calves were exposed to bovine viral diarrhea virus and challenged 22 days later. Baseline values in non-specific mitogen induced lymphocyte blastogenesis and serologic responses to tetanus toxoid and Brucella abortus strain 19 were established in neonatally thymectomized and normal calves.Neither viral recovery nor protective antibody production followed the very low level primary exposure to bovine viral diarrhea virus. The expected clinical response to an appropriate challenge inoculum did not occur, however, suggesting an immune response to bovine viral diarrhea virus had been initiated by the primary exposure. Five of eight calves developed protective serum levels of bovine viral diarrhea antibody. This may represent an example of immunologic priming. Exposure to low levels of bovine viral diarrhea virus also has potential implications in the pathogenesis of chronic bovine viral diarrhea wherein low level exposure may interfere with the development of protective levels of bovine viral diarrhea antibody as was observed in three calves.Circulating lymphocyte concentrations and results of non-specific mitogen stimulation of lymphocytes revealed a reduced phytohemagglutinin response in conjunction with a slightly increased response to bacterial lipopolysaccharide and pokeweed mitogen in the presence of moderate lymphopenia. The capacity of lymphocytes to respond to phytohemagglutinin was unchanged but an increased total response, as occurred in control thymectomized and intact calves, did not occur.The response to tetanus toxoid, a thymus-independent antigen, was increased following exposure to bovine viral diarrhea virus, perhaps reflecting an alteration in thymic-independent regulation. The lack of a differential response to Brucella abortus strain 19 implied competence in thymus-dependent helper cells.  相似文献   

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