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1.
Using an indirect fluorescent antibody test, immunofluorescence of large spirochetes was observed with serum from swine that had recovered from swine dysentery. The spirochetes were obtained from scrapings of the colonic mucosa on the first day of diarrhea which was the time when the spirochete population was observed to be the highest. Of 29 exposed nonmedicated swine which developed and recovered from a diarrhea characteristic of swine dysentery 27 had antispirochete serum titers which ranged from 1:2 to 1:16. None of the 50 nonexposes swine developed a titer. Of 19 swine with a serum titer and reexposed with infective swine dysentery inoculum, 18 did not develop a diarrhea and were presumed to be immune. Considering these findings it is possible that this test could be used to detect antispirochete antibody in unknown swine serum.  相似文献   

2.
The diarrhea of swine dysentery receded in swine treated with 60 or 45 mg of tiamulin/L of drinking water (60 or 45 ppm). However, within 2 to 10 days (average 4.1 days) after drug withdrawal, diarrhea recurred. Tiamulin (22.5 mg/L in drinking water) did not markedly reduce the diarrhea during medication, and tylosin (66 mg/L in the drinking water) was not effective. In swine treated with 120 mg of dimetridazole/L of drinking water, there was no recurrence of diarrhea. After the recurrence of diarrhea in swine, repeated medication with tiamulin in drinking water reduced the severity of diarrhea and prevented deaths. After 1 to 3 retreatments, swine were immune to exposure with swine dysentery inoculum, and there was a significant (P less than 0.05) increase in their serum anti-Treponema hyodysenteriae antibodies. Seemingly, drug withdrawal permitted the occurrence and recurrence of diarrhea that was necessary to stimulate immunity.  相似文献   

3.
Swine dysentery was induced in 18 swine exposed by intravenous injection of a filtrate which contained Treponema hyodysenteriae and was obtained from macerated colonic scrapings of swine dysentery. However, swine dysentery did not develop in swine injected intravenously with a pure culture of T. hyodysenteriae or when combined with a colonic filtrate from normal swine. Diarrheal feces from the swine injected intravenously with the filtered T. hyodysenteriae contained more mucus, and fecal smears contained more T. hyodysenteriae and fewer other bacteria than did swine exposed orally to colon infected with swine dysentery or filtered T. hyodysenteriae. In the colons of the 12 swine injected intravenously with filtered T. hyodysenteriae that died, there was a minimum amount of croupous membrane and, microscopically, the T. hyodysenteriae were located deep in the colonic crypts. Five of the six surviving swine injected intravenously with filtered T. hyodysenteriae developed serum anti-T. hyodysenteriae antibodies using the indirect fluorescent antibody test and four of these swine developed diarrhea when reexposed with swine dysentery infected colon six weeks after initial exposure. None of the swine injected intravenously with cultured T. hyodysenteriae developed serum anti-T. hyodysenteriae antibodies and all were highly susceptible to swine dysentery.  相似文献   

4.
Serums from 119 swine exposed to swine dysentery inoculum, and medicated with various drugs, were tested for antibodies to the large spirochete, using the indirect fluorescent antibody test, and were compared in tests with known positive serums from 18 nonmedicated swine which had recovered naturally. An inverse relationship existed between the efficacy of the drug and the serum antibody titer (highest dilution of the serum producing immunofluorescence of large spirochetes). The more efficacious drugs or doses resulted in lesser development of serum antibody. Diarrhea usually seemed necessary for the development of serum antibody. With the less efficacious drugs, there were more days of diarrhea. Some swine had diarrhea but did not develop an antibody titer, and a few swine had a titer but did not develop diarrhea. Swine which developed a titer were more immune against reexposure with infective inoculum. The medicaments, especially those given at higher concentrations, seemed to resolve the diarrhea or prevent the development of diarrhea, occurrences which were necessary for the development of immunity.  相似文献   

5.
The addition of a combination of lincomycin and spectinomycin to feed at the total concentrations of 44 and 77 mg/kg, beginning at the time of exposure and continuing for 8 weeks, prevented experimentally induced swine dysentery in swine. The disease did not develop after the medication was withdrawn. In contrast, swine dysentery, similar to that seen in the nonmedicated swine, did develop in simultaneously exposed swine treated with feed containing either 44 mg of tylosin or 99 mg sodium arsanilate/kg. The swine fed sodium arsanilate and which developed hemorrhagic diarrhea had a more severe form of this type of diarrhea than did the nonmedicated swine. After reexposure to inefective inoculum of swine dysentery 86 days after initial exposure, all remaining swine previously medicated with either tylosin or sodium arsanilate and all nonmedicated swine were immune; whereas 17 of the 24 swine fed the combination of lincomycin and spectinomycin were susceptible to swine dysentery and developed diarrhea.  相似文献   

6.
A direct fluorescent antibody test was developed for the identification of large spirochetes which are considered to be the cause of swine dysentery. Sera from swine which had recovered from swine dysentery and had been hyperimmunized by the intravenous and intraperitoneal injection of filtered spirochetes were used for conjugation with fluorescein isothiocyanate. A bright greenish fluorescence of large spirochetes was observed with the conjugated serum from hyperimmunized pig No. 1 when diluted 1:8 and hyperimmunized pig No. 2 when diluted 1:2. Pig No. 1 had developed a serum titer of 1:64 using the indirect fluorescent antibody test for large spirochetes. The conjugated serum from the three swine which had recovered from swine dysentery fluoresced spirochetes only when undiluted. The conjugated serum from the two swine treated while having a hemorrhagic diarrhea did not fluoresce spirochetes. No immunofluorescence of Vibrio spp. was observed.  相似文献   

7.
Sodium arsanilate was fed to nondiarrhetic swine, previously exposed to and treated for swine dysentery, for the purpose of inducing them into developing a swine dysentery diarrhea. From 40 to 100% of these swine in each pen had previously had a swine dysentery diarrhea. The isolate of Treponema hyodysenteriae in the diced colon which was used to expose the swine was resistant to sodium arsanilate. After an interim of no treatment for swine dysentery, sodium arsanilate was fed at a level of 220 parts per million for 21 days. Of the 14 pens containing swine fed sodium arsanilate, ten pens had one or more swine that developed a swine dysentery diarrhea while being fed sodium arsanilate. This was significantly (P less than 0.05) greater than the three pens that each had one pig that developed a swine dysentery diarrhea of 13 pens containing similar swine not fed sodium arsanilate during a comparable period. In the 14 pens containing swine fed sodium arsanilate, 14 swine were the first to develop a swine dysentery diarrhea since in four pens, two swine in each pen developed diarrhea within 24 hours of each other. This also was significantly (P less than 0.01) greater than the three swine in the ten pens not fed sodium arsanilate. From these results, it was theorized that sodium arsanilate excited the nondiarrhetic carrier into developing a swine dysentery diarrhea and that this phenomenon may have potential in identifying the carrier state.  相似文献   

8.
牛病毒性腹泻病毒感染对猪瘟免疫的影响   总被引：2，自引：0，他引：2  
张慧英 《四川畜牧兽医》2010,37(10):21-22,25
猪瘟病毒（CSFV）与同属的牛病毒性腹泻病病毒（BVDV）同源性较高,抗原性上有交叉。本次调查对368份猪瘟免疫猪血清样本进行BVDV抗原检测,其中7份呈阳性,阳性率1.90%。对7份BVDV阳性血清采用ELISA和IHA两种方法检测猪瘟（CSFV）抗体水平,抗体合格率偏低,两者的结果符合率为71%。研究表明：BVDV在一定程度上干扰了猪瘟疫苗的免疫效果,影响抗体水平。  相似文献   

9.
Swine dysentery did not recur during a nine week period after withdrawal of medication in swine fed ronidazole at a level of 60 parts per million of feed for ten weeks or fed either carbadox at 55 ppm or lincomycin at 110 ppm of feed for six weeks. During this period swine dysentery was neither transmitted to accompanying sentinels after the withdrawal of the above medication or was Treponema hyodysenteriae isolated and cultured or observed in stained smears from rectal swabs and feces or from colonic scrapings at necropsy. Beginning three weeks after the withdrawal of medication, all swine were fed sodium arsanilate at a concentration of 220 ppm of feed for three weeks in an attempt to excite the carrier of swine dysentery into developing a swine dysentery diarrhea. A swine dysentery diarrhea did recur during the feeding of sodium arsanilate in swine previously fed ronidazole at a level of 60 ppm of feed for only six weeks. It was concluded: that swine dysentery was probably eliminated with the feeding of ronidazole for the longer duration and with the feeding of carbadox and lincomycin and that sodium arsanilate was of value in identifying the carrier state.  相似文献   

10.
An indirect fluorescent antibody test was adapted for measuring serum anti-Treponema hyodysenteriae antibodies with a fluorometer. The immunofluorescence was recorded as fluorescent signal units. Cultures of T. hyodysenteriae and Treponema innocens were used as antigen. There was a significant (P less than 0.01) correlation between the immunofluorescence recorded with the fluorometer and that evaluated visually with a microscope. The swine exposed orally to swine dysentery infective inoculum and subsequently hyperimmunized by the intravenous inoculation of live cultures of T. hyodysenteriae had the highest average fluorescent signal unit, which was 104.5. There was a significant (P less than 0.01) correlation between the level of anti-T. hyodysenteriae antibody and the interval length between the last day of diarrhea and the day of bleeding. However, in measuring fluorescent signal units in serum from swine infected with nonpathogenic large spirochetes, (T. innocens), there was also a significant (P less than 0.01) correlation between T. hyodysenteriae and T. innocens as antigen. The coefficient of variation of the average fluorescent signal unit for a highly positive serum and a highly negative serum between 16 runs of assays were 5.7% and 19% respectively; the coefficient of variation of the average fluorescent signal unit for duplicate samples on 358 serum samples tested was 5.8%.  相似文献   

11.
李化东  陈昌林 《猪业科学》2021,38(1):102-104
自2018年第一例非洲猪瘟疫情报道至今已经两年多了。为了快速扩繁猪群,许多清空场及新建场不得不大量外购来源复杂后备猪进群。因此,猪场在对猪流行性腹泻的防控上面临着更大的挑战。文章介绍了病毒性腹泻暴发的原因、防控难点和综合防控措施,期望为养殖业同人在实际生产中,科学防控猪流行性腹泻提供一定的参考借鉴。  相似文献   

12.
本研究用猪瘟疫苗初次致敏豚鼠未引起异常反应,两周后进行第2次激发可见明显的异常反应,甚至死亡,这证明了猪瘟疫苗可能引起变态反应的发生。为了找到疫苗中的真正过敏原,本研究进行了疫苗中主要成分的分组试验,结果表明犊牛血清的致敏作用最强,其次为猪瘟病毒,牛睾丸细胞最弱。同时进行了4种致敏和激发途经的比较实验,并用ELISA法测定了致敏和激发后血清中的IgE水平。结果表明各种致敏途径均可致敏,但激发时,以静脉注射最为严重,且致敏后和激发后均未检测到血清中的IgE水平有显著提高。  相似文献   

13.
Study was made of the pharmacokinetics and toxicopathy of deoxynivalenol (DON, vomitoxin) given IV to swine. In the 24 hours after swine were given DON, clinical signs of vomiting, diarrhea, muscular weakness, tremors, and twilight coma were similar to those observed with other 12,13-epoxytrichothecenes. Hypoglycemia and pancreatic islet cell lesions were observed which indicated that DON-induced changes in intermediary metabolism may be an insidious aspect of DON intoxication. Histopathologic examination of all organ systems revealed pancreatic acinar and islet cell necrosis and mild lympholysis of the mesenteric lymph nodes. The renal excretion of DON was altered by IV infusion of saline solution. Pharmacokinetic findings may indicate that DON was both secreted and reabsorbed by the renal tubules. The half-life of DON ranged from 2.08 to 3.65 hours. Residues of DON were not found in skeletal muscle of swine at 24 hours after dosing.  相似文献   

14.
Megakaryocytic infection and thrombocytopenia in African swine fever   总被引：1，自引：0，他引：1  
Pigs infected with an African swine fever field isolate of modified virulence became acutely thrombocytopenic four to five days after the onset of fever and viremia. By eight days after inoculation, all pigs were thrombocytopenic. Immunofluorescence microscopy demonstrated that 2 to 10% of the megakaryocytes were infected. By 13 days after inoculation, platelet counts returned to within normal limits, and there was megakaryocytic hyperplasia despite a continued viremia. Secondary complications delayed the return of normal circulating platelet levels in some pigs. The clinical findings of African swine fever are discussed in light of the gross and histologic lesions.  相似文献   

15.
Sera from African swine fever-resistant pigs with infection-inhibitory activity decreased virus replication in infected porcine buffy coat cultures. This same effect was observed even after virus was adsorbed. The infection-inhibition was not reversed by removing the immune serum from the assay cultures. Reduction of African swine fever virus replication by immune sera was demonstrated by fluorescent focus assay on MS cell line cultures. Virus-neutralization tests showed a persistent fraction of non-neutralized virus, which was not demonstrable by infection-inhibition tests. One hypothesis for explaining this difference is proposed.  相似文献   

16.
2019年猪病流行情况与2020年流行趋势及防控对策   总被引：1，自引：1，他引：0  
文章结合实验室的监测数据,概述了2019年我国非洲猪瘟、猪繁殖与呼吸综合征、猪瘟、猪伪狂犬病、猪流行性腹泻等重要猪病的流行状况,着重总结了非洲猪瘟疫情发生情况。分析了2020年非洲猪瘟等疫病的流行趋势,同时提出了坚持生物安全、严格处置非洲猪瘟疫情等防控策略。  相似文献   

17.
Antibodies to bovine serum albumin were detected in swine sera by use of an immunoblotting technique. Such sera had false-positive reactions, as determined by results of African swine fever virus serodiagnostic techniques when bovine serum albumin was a contaminant in the soluble cytoplasmic antigen obtained from infected cells cultured in the presence of bovine serum. The soluble cytoplasmic antigen obtained from cell cultures infected with African swine fever virus in the presence of porcine serum did not react with the false-positive sera and, therefore, was used for African swine fever virus serodiagnostic methods, with 0% false-positive results.  相似文献   

18.
文章着重概述了2020年我国非洲猪瘟的流行和发生情况,提及了猪繁殖与呼吸综合征、猪瘟、猪伪狂犬病、猪流行性腹泻等重要猪病。分析了2021年非洲猪瘟的流行趋势,并提出了相应的防控策略。  相似文献   

19.
A heterologous radioimmunoassay system was developed for the determination of circulating IGF-II concentrations in swine. The assay utilized a monoclonal antibody against human IGF-II (Amano Intl. Ez, VA) and bovine IGF-II (Monsanto Co., MO) as the cold standard and iodinated ligand. Serial dilutions of acid-ethanol extracted normal swine sera resulted in a curve which was parallel to the bovine IGF-II standard curve. Recovery of unlabeled standard added to extracted swine sera was 101%. Neither IGF-I nor insulin were capable of cross-reacting in this assay at levels up to 100-fold excess.

Using this assay, serum IGF-II levels were determined to be significantly lower when subnormal growth hormone (GH) levels existed such as in hypophysectomized swine. However, in contrast to serum IGF-I concentrations, supranormal levels of porcine GH (pGH) did not elevate serum IGF-II concentrations after 13 wk of treatment in 25 kg hogs (initial body wt). In addition, serum IGF-II levels were reduced in fasted swine, despite a significant increase in circulating GH concentrations. Thus, although normal concentrations of GH are required for maintenance of physiological levels of IGF-II in swine, the mechanism for stimulation of IGF-II secretion is less GH-dependent than IGF-I.  相似文献   


20.
Pituitary-ovarian function was analyzed in a strain of miniature swine previously shown to produce a low ovulation rate resulting in the formation of only 8.6 corpora lutea (CL)/animal. Five multiparous (M) and four nulliparous (N) miniature pigs with a mean inbreeding coefficient of .39 were monitored for estrous behavior through four consecutive estrous cycles. Daily blood samples were collected from 5 d before to 5 d after the onset of the second, third and fourth estrus and at 48-h intervals during the remainder of the second and third estrous cycle. Laparoscopy was used to examine the ovaries 1 and 5 d after onset of the third estrus and 2 d after the beginning of the fourth estrus. For the entire group, temporal fluctuations among serum estradiol-17 beta, luteinizing hormone (LH) and progesterone concentrations and sexual behavior were similar to previously published data in standard swine breeds. Although the mean lengths of the estrous cycle were not different (P greater than .05) between parity subgroups (M, 23 +/- 1.3 vs N, 22 +/- .7 d), multiparous pigs were in estrus longer (P less than .05) than nulliparous females (M, 3.7 +/- .2 vs N, 2.2 +/- .4 d). Parity subgroups were similar with respect to the mean number of follicles forming CL (M, 8.8 +/- .7 vs N, 9.2 +/- .2). Although an average of 6.2 +/- 2.1 CL had formed by 24-h after onset of estrus in the nulliparous subgroup, no CL were detected in the multiparous subgroup at this time.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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