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1.
The synergistic hemolysis-inhibition (SHI) test, a serologic test for the detection of infection with Corynebacterium pseudotuberculosis, was applied to serum samples from 196 goats and 76 sheep, including animals both with and without C pseudotuberculosis abscesses. Fifty-one of 52 (98%) goats and 27 of 28 (96%) sheep with abscesses caused by C pseudotuberculosis had seropositive titers. Seropositivity continued on subsequent samplings, even after superficial lesions were completely healed. The SHI test may detect subclinically infected animals, as well as animals with clinically recognizable lesions. Of the animals without abscesses, 53 of 186 (28%) goats and 4 of 41 (10%) sheep were seropositive. Either the SHI test is lacking in specificity or these titers are a reflection of a past or a current infection without any grossly visible abscesses.  相似文献   

2.
Fifteen goat kids were experimentally inoculated with Corynebacterium pseudotuberculosis. Five were given a strain of caprine origin (nitrate-negative biotype) intradermally, 5 were given a strain of equine origin (nitrate-positive biotype) intradermally, and 5 were inoculated intranasally with the caprine-origin strain. Animals were monitored for 127 days. The goats given the inocula intradermally developed abscesses; those given caprine-origin strain had multiple lesions both peripherally and in visceral locations (primarily endothoracic abscesses), whereas those given the equine-origin strain had abscesses only at injection sites and draining nodes. The difference in extent of lesions could be due to biotypic bacterial differences or to the individual strains used. Intranasally inoculated goats did not develop abscesses and were essentially no different from controls. The cranial part of the respiratory tract may not be an important portal of entry for C pseudotuberculosis. Serum samples obtained monthly from all animals were subjected to the synergistic hemolysis-inhibition test, which measures antibodies to the exotoxin of C pseudotuberculosis. Animals with abscesses developed titers within 1 month of inoculation. Animals without abscesses remained seronegative. The synergistic hemolysis-inhibition test may be a reliable diagnostic assay for caseous lymphadenitis in goats.  相似文献   

3.
Two goat flocks comprising 326 animals and four sheep flocks comprising 343 animals, all with a previously recognized problem of abscesses due to Corynebacterium pseudotuberculosis, were examined for the presence of abscesses and antibody titers to C. pseudotuberculosis as detected by direct microagglutination assay. In sheep there was a strong positive relationship between age and titer (p less than 0.0001). However, the relationship in goats between age and titer could not be determined due to a strong interaction between flock and age. When the relationship between abscesses and titer was examined, it was found that goats with abscesses had higher titers than those that did not (p less than 0.05), whereas there was no difference in titer between sheep with abscesses and those without (p = 0.5753). The sensitivity of the microagglutination test was poor to good for both species (52.3% for goats and 89.7% for sheep). The specificity of the test was fair to poor (64.9% for goats and 21.7% for sheep). Given a disease prevalence of 13.5% for goats and 8.5% for sheep the predictive value of the positive test was very poor (18.9% for goats and 9.6% for sheep) but the predictive value of the negative test was good to excellent (89.7% for goats and 95.8% for sheep). The poor specificity of the test and therefore the positive predictive value may be due in part to the criterion of classification of presence of disease, i.e. presence of an abscess at the time of sampling.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

4.
Corynebacterium pseudotuberculosis is a widespread facultative intracellular pathogen that causes caseous lymphadenitis disease in sheep and goats, and generates cutaneous abscesses and granulomas in horses and cattle. Although some genes have been studied for diagnostic and phylogenetic analysis within the genus Corynebacterium, at subspecies level the pathogen has been poorly analyzed. The aim of this study was to characterize C. pseudotuberculosis strains isolated from domestic animals, through the sequencing of a hypervariable rpoB gene segment. As result, there were identified host associated rpoB polymorphisms in strains infecting sheep, goats and horses from Chile. These differences suggest the existence of bacterial genotypes, in which the nucleotide similarity values were ranging from 98.8 to 99.8%. In conclusion, the analysis of polymorphisms in the partial rpoB sequence can be used as a diagnostic tool that differentiates C. pseudotuberculosis strains at subspecies level.  相似文献   

5.
The relationship between the visceral form of caseous lymphadenitis and a chronic debilitating condition of mature sheep designated as the thin ewe syndrome was investigated. Internal abscesses were found during necropsy in 81% of animals with thin ewe syndrome and Corynebacterium pseudotuberculosis (C ovis) was recovered from 86% of the animals with internal abscesses. Other pyogenic bacteria, including C pyogenes, C equi, Staphylococcus epidermis, S aureus, and Pseudomonas aeruginosa were often recovered in association with C pseudotuberculosis. Moraxella sp was recovered in 41% of the animals with internal abscesses. In some abscesses, Moraxella sp was the dominant microorganism isolated and in others, they were outnumbered only by C pseudotuberculosis. Species isolated included M bovis, M osloensis, and M nonliquefaciens. The potential importance of Moraxella sp to the cause and pathogenesis of the thin ewe syndrome is not known. The results of the present study indicate that visceral caseous lymphadenitis is either an important contributing factor to the development of thin ewe syndrome or that the presence of thin ewe syndrome may predispose affected sheep to the development of visceral caseous lymphadenitis. A skin test reagent prepared by sonicating C pseudotuberculosis was of limited value in detecting animals with visceral caseous lymphadenitis. Only 56% of the animals with abscesses caused by C pseudotuberculosis gave positive delayed-type hypersensitivity skin test responses.  相似文献   

6.
A total of 86 abscesses (45 and 41) abscesses of sheep and goats, respectively) were examined for their causal agents; 44 of these abscesses were located subcutaneously, and the remaining 42 were in lungs, livers, intestines, and udders. A total of 23 different types of microorganisms were isolated from 78 abscesses; bacteria were not detected in the remaining eight abscesses. Microorganisms isolated were: species of the genera Corynebacterium, Staphylococcus, and Streptococcus and Pasteurella, Escherichia coli, and other gram-negative rods. Peptostreptococcus anaerobius and Eubacterium tortuosum were isolated in pure culture from one abscess each in goats. Two to four different microorganisms were associated with 25 of the 86 abscesses. It was determined that 11 isolates of Corynebacterium pyogenes, 2 isolates of Pasteurella haemolytica, 1 of P multocida, and 1 of C pseudotuberculosis were lethal to mice. Two of the C pyogenes isolates from subcutaneous spreading abscesses of goats were pathogenic for rabbits; these two isolates produced similar suppurative inflammation in goats experimentally, but did not cause death. As determined by experimental inoculation, goats were more susceptible than sheep to the two isolates. In nature, subcutaneous abscesses of goats associated with C pyogenes were of a more diffusive type which resulted in generalization of the infection and death of the animals. Postmortem examination of ten goats dying of field infection showed the presence of larvae of the warble-fly Przhevalskiana silenus at the site of infection.  相似文献   

7.
The optimal method of control of caseous lymphadenitis of goats caused by Corynebacterium pseudotuberculosis is eradication of infection by identification and removal of infected carrier animals. The objective of this study was to compare detection of C. pseudotuberculosis experimentally infected goats using a commercially available bovine interferon-gamma (IFN-gamma) whole blood enzyme-linked immunosorbent assay (ELISA) to serological response to a recombinant phospholipase D (PLD) ELISA. The tests were assessed repeatedly over 1 year in three infected and three non-infected goats. Using a IFN-gamma optical density cut-off at 0.10 as positive under the conditions used, the test accurately detected C. pseudotuberculosis experimentally infected goats over a 363 day period with a reliability of 89.2% and non-infected goats with a reliability of 97.1%. Using a cut-off value of the mean for negative samples plus two standard deviations, the PLD ELISA detected C. pseudotuberculosis experimentally infected goats over this period with a reliability of 81.0% and non-infected goats with a reliability of 97.0%. The PLD ELISA was however more predictive than the IFN-gamma ELISA of the presence of lesions observed at postmortem examination of infected goats.  相似文献   

8.
Groups of sheep were dosed with vaccines containing Corynebacterium pseudotuberculosis toxoid combined in varying amounts with 5 clostridial antigens. Resistance of the sheep to infection with C pseudotuberculosis was tested at 1, 6 and 12 months after vaccination by infection with pus from ovine lymph glands actively infected with C pseudotuberculosis. The outcome was assessed 3 months after challenge by slaughter and inspection of the sheep for caseous lymphadenitis lesions. Protection was demonstrated by a significant reduction in the proportion of immunised sheep exhibiting lesions compared with control sheep, and by fewer abscesses in affected immunised sheep than in affected control sheep. A positive correlation was found between amount of C pseudotuberculosis toxoid administered and degree of protection obtained. Chromatographically-purified toxoid induced essentially the same protection, suggesting that anti-toxic immunity is the major factor in protection.  相似文献   

9.
Post-mortem examination of 658 goats showed that 17 (2.5%) exhibited hepatic abscesses. The following bacteria were isolated: Corynebacterium pseudotuberculosis (58.9%), Escherichia coli (11.8%), Corynebacterium sp. (11.8%), Pasteurella haemolytica (5.9%), Proteus sp. (5.9%) and Staphylococcus aureus (5.9%). Hepatic abscesses occurred more frequently in adult animals. Eleven of the 17 goats (64.7%) were older than 12 months of age. Four goats (23.5%) were 12 months of age and only two (11.8%) were less than 1 year of age. All of the goats with hepatic abscesses were in poor nutritional condition and the abscesses were invariably associated with accompanying pathological disorders at other body sites.  相似文献   

10.
A serologic technique useful for detecting antibodies formed in horses in response to infection with Corynebacterium pseudotuberculosis is described. The test relies on the ability of C. pseudotuberculosis toxin to produce a wide zone of hemolysis when applied to erythrocytes previously treated with a sterile filtrate of Corynebacterium equi broth culture. The synergistic hemolytic activity can be neutralized by anti-C. pseudotuberculosis serum. This test was used to analyze sera from 616 horses for the presence of C. pseudotuberculosis antitoxin. Of 177 animals (see Table 2) found positive, there were 34 horses with bacteriologically confirmed, active infections and 18 with active but unconfirmed infections. In addition, 13 animals had a history of having had the disease and 112 had no history or evidence of having had the infection. The other 439 horses had negative titers. Statistical treatments confirmed the value of the test as an epidemiological tool but precluded using only titers for the diagnosis of active clinical disease.  相似文献   

11.
The features of naturally occurring Yersinia pseudotuberculosis serotype III infections in 16 sheep, one goat and 3 pigs, and Y. pseudotuberculosis serotype I infections in 3 goats, are described. Affected animals usually had diarrhoea and were in poor condition or emaciated. A number were moribund or dead when submitted for necropsy. Thickening of the caecal and colonic mucosa was the only gross lesion attributable to Y. pseudotuberculosis infection, with liver or other visceral abscesses not being seen. Characteristic microabscesses were demonstrated in the intestinal mucosa of 10 sheep, one goat and one pig infected with Y. pseudotuberculosis serotype III and one goat infected with Y. pseudotuberculosis serotype I. Sheep, goats and pigs dosed orally with Y. pseudotuberculosis serotype III, the serotype isolated most commonly from these species, developed intestinal infection. In sheep and pigs, infection was accompanied by diarrhoea. Haematological changes and specific antibodies were elicited in all 3 species in response to infection. Microabscesses were seen in the intestinal mucosa of all experimentally exposed animals. The occurrence of field cases and the results of experimental exposure confirm that Y. pseudotuberculosis serotype III is an enteropathogen of sheep, goats and pigs. The association of Y. pseudotuberculosis serotype I with lesions in a goat, indicates that this bacterium may also be a pathogen of this species. It is concluded that Y. pseudotuberculosis serotype III is an enteric pathogen of a wide range of ungulate species including cattle, buffalo, deer, antelopes, sheep, goats and pigs. Serotypes I and II, while having a more restricted host range, are probably also pathogens of ungulates and, in particular, deer, antelopes and goats.  相似文献   

12.
A field trial to evaluate a whole cell vaccine for the prevention of caseous lymphadenitis (CLA) in sheep and goats was performed in one goat herd and one sheep flock over a period of three years. In goats, there was a nonstatistically significant trend for fewer cases of CLA in the vaccinated animals compared to the controls. In sheep, from six months to 36 months postinitial vaccination, the proportion of vaccinated sheep that developed CLA was significantly less (p less than 0.05) than in the control sheep. The antibody titers to Corynebacterium pseudotuberculosis as detected by microagglutination assay were significantly different (p less than 0.0001) at all times except at the initial vaccination. Swellings occurred at the vaccination site at an incidence level of 29.6% in goats and 34.1% in sheep. The vaccine appeared to be efficacious in reducing the proportion of sheep that developed CLA when challenged naturally in a field situation.  相似文献   

13.
The optimal method of control of caseous lymphadenitis of sheep caused by Corynebacterium pseudotuberculosis is eradication of infection by identification and removal of infected carrier animals. Current serological approaches to identification of infected sheep are generally hampered by low sensitivity and specificity of available tests. The objective of this study was to develop a whole blood assay for detection of C. pseudotuberculosis-infected sheep, based on detection of IFN-gamma response to whole cell C. pseudotuberculosis antigens, and to determine the reliability of the assay. A commercially available bovine interferon-gamma assay enzyme-linked immunosorbent assay was used and the test optimised using experimentally infected sheep. The assay was also tested on known CLA-negative sheep. Setting a IFN-gamma optical density cut-off at 0.100 as positive under the conditions used, the test detected C. pseudotuberculosis experimentally infected sheep over a 450-day period with a reliability of 95.7%. It identified known non-infected sheep with a reliability of 95.5%. Repeated vaccination of three uninfected sheep with a commercially available bacterin-toxoid vaccine did not interfere with the assay. The IFN-gamma response of sheep whole blood to C. pseudotuberculosis antigens offers promise for use in a test-and-removal approach to eradication of CLA in sheep.  相似文献   

14.
A double-antibody sandwich ELISA for detection of antibodies directed against the exotoxin of Corynebacterium pseudotuberculosis, the cause of caseous lymphadenitis (CL) in small ruminants, was developed. A concentrated exotoxin was used. For interpretation of ELISA results, these sera were tested: sequentially obtained sera of C pseudotuberculosis-inoculated goats and sheep that were monitored for 68 weeks; sequentially obtained sera from 80 goats of 3 flocks with CL; sera from 652 goats of 7 flocks without CL; sera from 160 sheep of 4 flocks without CL; and 2,265 caprine and 208 ovine sera submitted for diagnostic testing. Data regarding the infection status and history of 10,454 of the 23,302 animals were collected after testing; most of these were goats that had been part of a CL control program. Specificity and sensitivity of the ELISA were nearly 100%. Subsequently, 31,978 animals from which no data on infection status of flocks had been collected were then tested. It was concluded that the ELISA is a useful diagnostic test for CL eradication programs. Sera with doubtful or inconclusive ELISA results were examined by use of immunoblot analysis. Proteins from C pseudotuberculosis culture supernatant were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto nitrocellulose. Six proteins with molecular mass of 68, 65, 39, 38, 31, and 29 kDa reacted with sera from goats and sheep with experimentally induced or naturally acquired infection. Immunoblot analysis was valuable in classifying sera with doubtful or inconclusive results by ELISA.  相似文献   

15.
Two groups of male, 9-week-old goats (5 goats/group) were vaccinated subcutaneously with formalized exotoxin of Corynebacterium pseudotuberculosis, with Freund's incomplete adjuvant. Each goat was given 2 vaccinations, 2 weeks apart. At each vaccination, each group 1 goat was given 0.5 ml of toxoid, and each group 2 goat was given 1 ml of toxoid. Twenty days after the 2nd vaccination, vaccinated goats and 5 nonvaccinated 12-week-old goats (controls) were inoculated intradermally (challenge exposed) with live C pseudotuberculosis, monitored for 13 weeks, and euthanatized. At necropsy, 5 of the 10 vaccinated goats did not have C pseudotuberculosis lesions, 3 had abscesses limited to the inoculation site and draining lymph node, and 2 had disseminated bacterial lesions. Of the 5 nonvaccinated controls, 4 had disseminated abscesses and 1 had a single abscess in an internal node. Serologically, 9 of the 10 vaccinated goats developed positive (greater than or equal to 1:8) antibody titers against the exotoxin within 1 week after inoculation; the 10th goat seroconverted 2 weeks after inoculation, whereas control goats required 3 weeks to develop a positive antibody response. Therefore, early during an infection with C pseudotuberculosis, antibodies against the exotoxin may protect a goat against spread of the organism. All goats were injected intradermally before challenge exposure, 10 days after challenge exposure, and at 4, 8, and 12 weeks after challenge exposure with a skin-test reagent composed of fragmented bacterial cells.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
Caseous lymphadenitis (CLA), a chronic bacterial disease of sheep and goats caused by Corynebacterium pseudotuberculosis, could be controlled by eradication of infected carriers. This study aimed at validation of a whole blood interferon-gamma (IFN-gamma) enzyme immunoassay (EIA) (Bovigam, Pfizer) in naturally infected sheep for use in eradication of infection from a flock. This assay used formalin-inactivated whole bacterial cells as antigen. The sensitivity of the whole cell assay was improved by increasing both the volume of blood and the number of bacterial cells. The assay was validated in experimentally infected sheep and in a flock of known-negative sheep, as well as in a naturally infected flock, a proportion of which was vaccinated with a commercial CLA vaccine. An optical density (540nm) (OD) cut-off of 0.09 was effective in classifying animals as test positive or negative in the naturally infected flock, although there was variation in OD between visits, notably with weakly reacting animals. The test had a sensitivity of 91% and a specificity of 98%. Postmortem data supported the results in test-negative animals. Visit-to-visit variation in IFN-gamma EIA OD in the naturally infected flock as well as CLA disease status was used to develop an algorithm for the eradication of CLA from a known infected flock. The whole blood IFN-gamma assay shows promise for eradication of caseous lymphadenitis from sheep flocks.  相似文献   

17.
Caseous lymphadenitis is an infectious sheep and goats disease caused by Corynebacterium pseudotuberculosis and characterized by abscesses in superficial and visceral lymph nodes. C. pseudotuberculosis strains isolated from these hosts have been shown to be very difficult to type by the existing methods. The aim of this study is evaluating the potential of the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis strains isolated in sheep. One hundred and twenty seven isolates of C. pseudotuberculosis were isolated from lesions suspected to have had caseous lymphadenitis collected from sheep at the slaughterhouse. Animals were from 24 flocks in 13 municipalities of the Minas Gerais State, Brazil. Species identification of the isolates was performed by routine biochemical tests and mPCR. Fingerprint was performed by RAPD using ERIC-1R, ERIC-2 and ERIC-1R+ERIC-2 primers. Seventeen different genotypes were generated by ERIC 1-PCR, 21 genotypes by ERIC 2-PCR and 21 genotypes by ERIC 1+2-PCR. Hunter-Gaston Discrimination Index (HGDI) found for ERIC 1, ERIC 2, ERIC 1+2 PCR were 0.69, 0.87, and 0.84, respectively. For most herds evaluated observed at most three different genotypes among isolates from animals of these property, in all ERIC-PCR assays. However a few flocks observed between four and nine genotypes per flock. The W Kendall value found for correlation among the three techniques of ERIC-PCR was 0.91 (P<5.0 x 10(-6)). The results show that ERIC-PCR has good discriminatory power and advantages over other DNA-based typing methods, making it a useful tool to discriminate C. pseudotuberculosis isolates.  相似文献   

18.
The occurrence of abscess disease, caseous lymphadenitis, and pulmonary adenomatosis in sheep in Denmark is reported for the first time. Subcutaneous abscesses were observed in imported 4- to 5-month-old lambs of the Lacaune breed 10 days after arrival in Denmark. Abscesses were mostly located in the head, neck and shoulder regions close to the regional lymph nodes. Bacteriological examinations revealed growth of Staphylococcus aureus ssp. anaerobius in all animals with subcutaneously located abscesses containing a viscous white-yellow odourless mass. In addition, Corynebacterium pseudotuberculosis was isolated from abscesses in one animal and lesions consistent with pulmonary adenomatosis were found in four animals.  相似文献   

19.
Corynebacterium pseudotuberculosis is a Gram positive bacterium that produces caseous lymphadenitis in sheep and goats, and a granulomatous lymphadenitis in llamas and alpacas. To evaluate the immune potential of different doses of cell wall and toxin components of C. pseudotuberculosis from alpaca origin, 12 adult alpacas were allotted at random to four groups, and SC inoculated in the left flank with vaccines composed of low and high doses of bacterial crude antigens, cell wall: 250 and 500 microg/ml and toxin: 133 and 265 microg/ml, respectively. The vaccines were supplemented with 20 microg/ml of muramyl dipeptide as adjuvant. Three alpacas were sham inoculated with adjuvant as a control. After 3 weeks, immunized and naive alpacas were challenged intradermally in the right flank with 1 x 10(6) colony forming units (CFU) of C. pseudotuberculosis. The alpacas were sacrificed at days 28, 58 and 112 after inoculation, and the degree of protection induced by vaccines was demonstrated by the absence of abscesses and/or bacteria. The alpacas vaccinated with high dose of toxin, did not show abscesses. In contrast, the alpacas vaccinated with a low dose of toxin showed abscesses at the inoculation site, regional, and renal lymph nodes. The cell wall vaccinated alpacas showed a lesser degree of protection than the other groups with superficial and internal abscesses. The control alpacas had persistent fever and abscesses at the inoculation site, regional, and internal lymph nodes. In addition, a robust and early humoral response was observed in all vaccinated alpacas after challenge, lasting at least 3 months. The results suggest that the toxin of C. pseudotuberculosis is a very important antigen, inducing a dose dependant protective immunity against this bacterium in alpacas.  相似文献   

20.
From 1973 through 1988, 518 external and internal abscesses were diagnosed in a large commercial goat herd. Of the 518 abscesses, 238 were primary and 280 were secondary abscesses in the same or other anatomic locations. During this period, the herd varied in size from 94 goats in 1973 to 431 goats in 1988. Abscesses in the jaw area were detected in 141 goats, 4 of which developed osteomyelitis of the mandible. Sternal abscesses were detected in 72 goats, with 2 also having osteomyelitis of the sternum diagnosed at necropsy. Most of the abscesses were in the jaw, sternal, facial, and cervical areas. Lung abscesses were diagnosed at necropsy in 20 goats that most recently had 1 or more superficial abscesses. Abscess incidence was 27.6% (112 of 406) in wethers and 22.9% (154 of 687) in does. Actinomyces pyogenes was isolated most frequently by bacteriologic culture of abscess specimens and about 3 times as often as was Corynebacterium pseudotuberculosis or Staphylococcus sp, usually coagulase-positive S aureus. Bacteriologic culture of blood samples, taken during abscess episodes, yielded A pyogenes (n = 3) or C pseudotuberculosis (n = 1) in 3 goats. Results of antibiotic treatment of abscesses were disappointing, with little evidence of altering the course of the disease or sterilizing the abscess, despite the fact that the bacteria were susceptible in vitro to the antibiotics used. Excision of intact abscesses was the preferred treatment for abscesses of the jaw and facial areas.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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