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1.
P C Hannan R M Banks B S Bhogal S E Blanchflower A C Donald J P Fish D Smith 《Research in veterinary science》1984,36(2):153-163
The virulence of a laboratory adapted culture of Mycoplasma hyopneumoniae strain NB12 was determined in three- to five-day-old gnotobiotic piglets. Intranasal inoculation or exposure to an aerosol of the culture caused low incidences of pneumonia in the piglets. Passage of M hyopneumoniae strain NB12 in gnotobiotic piglets resulted in a rapid increase in virulence. After only three in vivo passages, severe pneumonia involving most lobes of the lung developed in all inoculated piglets within three and a half weeks. All 49 piglets inoculated with the piglet-passaged NB12 strain in nine subsequent experiments developed pneumonia but the extent of the pneumonic lesions varied considerably from piglet to piglet. The histopathology of the lung lesions was similar to that reported as being induced by other strains of M hyopneumoniae in gnotobiotic piglets and resembled that seen previously in conventionally reared neonatal piglets inoculated with homogenised lung from pigs with enzootic pneumonia. Aspiration pneumonia caused by milk inhalation occurred in some piglets. The pneumonia induced with the piglet-passaged NB12 strain was judged to be suitable for the study of porcine enzootic pneumonia or for the evaluation of chemotherapeutic agents. 相似文献
2.
猪瘟和猪支原体肺炎是两种较为常见的猪传染病,首免日龄接近,本试验通过对24头30—40日龄仔猪分别或同时免疫猪支原体肺炎活疫苗（RM48株）和猪瘟活疫苗（传代细胞源）,研究其相互之间是否存在免疫干扰。试验结果显示,两种疫苗同时免疫对其各自的近期免疫效力均无明显影响。 相似文献
3.
N. F. Friis 《Acta veterinaria Scandinavica》1976,17(3):343
In an examination of conjunctival samples from 40 piglets for mycoplasmas, 17 isolates were obtained. Eight could be identified as Mycoplasma hyorhinis, three as Mycoplasma flocculare, and one as Acholenlasma sp. Five strains were not readily identifiable, but together with two previously recovered strains they were found to represent a distinct serogroup. All seven strains were glucose and phosphatase positive. Incubation in a CO2-enriched atmosphere led to enhancement of the growth on solid medium. The serogroup was serologically related to M. hyorhinis, but not to a number of other glucose fermenting species of mycoplasma, and it may therefore be regarded as a new subspecies of M. hyorhinis. 相似文献
4.
猪支原体肺炎活疫苗（168株）肺内免疫机制研究 总被引：1，自引：0，他引：1
为研究猪支原体肺炎活疫苗(168株)的免疫机制,通过肺内接种免疫5 ～ 10日龄仔猪,并于免疫后不同时间点检测血清中IgG抗体效价、全血中淋巴细胞转化效率、呼吸道局部的IFN-γ浓度和特异性SIgA滴度,于免疫后28 d剖杀采集呼吸道上皮组织,通过扫描电镜法与原位杂交检测法观察疫苗株在呼吸道的存留以及对纤毛的影响情况.结果发现,免疫后猪血液中淋巴细胞转化增强1.52～2.01倍,支气管表面IFN-γ浓度和特异性SIgA滴度持续增加,但血清抗体一直未检测到.扫描电镜与原位杂交检测结果发现疫苗株能有效地黏附在支气管纤毛上皮细胞上,但对纤毛的影响较小.由此表明,猪支原体肺炎活疫苗(168株)通过肺内免疫可有效激活全身细胞免疫及呼吸道局部的黏膜免疫与细胞免疫反应,而且还可以通过黏附支气管纤毛上皮细胞产生占位效应而对上皮组织不产生损伤. 相似文献
5.
P Dom F Haesebrouck 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(4):303-306
The virulence of a NAD-independent Actinobacillus pleuropneumoniae serotype 2 strain and NAD-dependent serotype 2, 3 and 9 strains was compared under experimental conditions. Hysterectomy-derived piglets were inoculated endobronchially with 50-500 cfu of these strains. All 23 piglets inoculated with the NAD-dependent strains developed acute disease within 12 hours post inoculation. Twenty-two of these piglets died within 24 hours after the first clinical signs. Three of nine piglets inoculated with the NAD-independent strain did not develop clinical disease. In the other six piglets, disease signs were similar as in the piglets inoculated with the NAD-dependent strains. No differences in clinical disease were observed between colostrum deprived piglets and piglets that obtained colostrum from a SPF sow. 相似文献
6.
Tests for presence of mycoplasmas were conducted on 20 insemination bulls known as mycoplasma spreaders, with 5 sperm pellet batches of 20 pellets each being investigated for each animal. Mycoplasma contamination was positively recorded from 83 of the above 100 batches. Mycoplasma (M.) bovigenitalium, M. californicum. M. arginini, M. bovirhinis, and Acholeplasma laidlawii were typed by means of indirect immunofluorescent technique, which confirmed the presence also in the GDR of mycoplasma species described in the literature and detected in sperm samples. The solid culturing media used in the above tests, medium-B agar and cattle blood agar with staphylococcal nutrix, proved to be equally suitable for isolation of mycoplasma from sperm samples. Mycoplasma was positively identified in about one third of all pellets/batches tested. 3 pellets to one batch should be sufficient a random sample size from which to obtain information at least very close to real contamination. 相似文献
7.
Vicca J Stakenborg T Maes D Butaye P Peeters J de Kruif A Haesebrouck F 《Veterinary microbiology》2003,97(3-4):177-190
The course of enzootic pneumonia, caused by Mycoplasma hyopneumoniae, is strongly influenced by management and housing conditions. Other factors, including differences in virulence between M. hyopneumoniae strains, may also be involved. The aim of this study was to evaluate the virulence of six M. hyopneumoniae field isolates and link it to genetic differences as determined by randomly amplified polymorphic DNA (RAPD) analysis. Ninety, conventional M. hyopneumoniae-free piglets were inoculated intratracheally with the field isolates, a virulent reference strain or sterile culture medium. Animals were examined daily for the presence of disease signs and a respiratory disease score (RDS) was assessed per pig. Twenty-eight days post infection, pigs were euthanized, blood sampled and a lung lesion score was given. Lung samples were processed for histopathology, immunofluorescence testing for M. hyopneumoniae and isolation of M. hyopneumoniae. RAPD analysis was performed on all M. hyopneumoniae strains. Significant differences between isolates were found for the RDS, lung lesion score, histopathology, immunofluorescence and serology. Based on the results of the different parameters, isolates were divided into three "virulence" groups: low, moderately and highly virulent strains. Typically, a 5000 bp RAPD fragment was associated with the highly and moderately virulent strains whereas it was absent in low virulent strains. It was concluded that high variation in virulence exists between M. hyopneumoniae strains isolated from different swine herds. Further studies are required to determine whether the 5000 bp fragment obtained in the RAPD analysis can be used as a virulence marker. 相似文献
8.
Mycoplasma gallisepticum infection results in numerous clinical signs including a reduction in egg production in laying chickens. Attempts to prevent mycoplasmosis have included vaccination with both killed and attenuated live M. gallisepticum strains. Live vaccines provide reduction in clinical signs and have been shown to replace indigenous strains when used in a consistent program for several placements. Antibiotic therapy is another option for controlling losses associated with mycoplasmosis. Therapeutic antibiotics with activity against mycoplasma approved for use in poultry include tetracyclines and tylosin. These drugs also are approved for feed efficiency when administered in the feed at levels below the therapeutic index for mycoplasma. The data presented here suggest that birds vaccinated with the live 6/85 strain of M. gallisepticum and then fed tylosin, at the approved level for feed efficiency, exhibit a serologic vaccine response similar to that of unmedicated birds but show improved feed efficiency. 相似文献
9.
H J Ball 《Veterinary microbiology》1990,22(4):383-388
Twelve strains of M. bovigenitalium and two of three strains of M. canadense caused an infection resulting in a pathogenic effect when experimentally inoculated into the ovine mammary gland. Differences in the pathogenesis were quantified by the duration of continuous mycoplasma excretion and the duration of high milk cell levels, but variation in the susceptability of the experimental animals prevented the establishment of firm conclusions on the relative virulence of the strains. Seven M. bovigenitalium and two M. canadense strains were eventually eliminated naturally from the infected glands, but four M. bovigenitalium strain infections ultimately became sub-clinical with intermittent mycoplasma excretion and low milk cell levels. 相似文献
10.
Effect of growth in cell cultures and strain on virulence of Mycoplasma hyopneumoniae for swine 总被引：2，自引：0，他引：2
In an attempt to develop better methods for consistent induction of pneumonia in naturally born swine, using cultures of Mycoplasma hyopneumoniae, fifty 6-week-old, naturally born pigs from a respiratory disease-free herd were used in 3 trials. Pigs inoculated with Mycoplasma hyopneumoniae strain 232 (passage 21) grown for 1 passage or 5 passages in Eagle minimal essential medium plus 20% porcine serum, with or without human lung fibroblasts, had a mean (+/- SD) value range between 5.4 +/- 3.6 and 9.2 +/- 2.1% of consolidated lung area. In the second trial, pigs inoculated 1, 2, or 3 days in succession with strain 232 grown in Eagle medium or Friis mycoplasmal medium with 20% porcine serum had between 5.1 +/- 7 and 8.7 +/- 4.3% of consolidated lung area. In the third trial, virulence of Mycoplasma hyopneumoniae strains 144L (p27), 11 (p26), J (p60), and 232 (p27) grown in Friis mycoplasmal medium was compared. Pigs inoculated with those strains had 5.1 +/- 4.1, 2.6 +/- 3.1, 0, and 4.3 +/- 4% of consolidated lung area, respectively. Significant differences were not found in consolidated lung area among groups in trials 1 and 2, and among groups of pigs inoculated with M hyopneumoniae strains 144L, 11, and 232 in trial 3. Pneumonia was not detected in pigs inoculated with strain J in trial 3. 相似文献
11.
Immunological and pathological reactions in piglets experimentally infected with Mycoplasma hyopneumoniae and/or Mycoplasma flocculare. 总被引：2，自引：0，他引：2
M Strasser P Abiven M Kobisch J Nicolet 《Veterinary immunology and immunopathology》1992,31(1-2):141-153
The aim of this work was to examine in vivo whether infection with Mycoplasma hyopneumoniae (M. hyop) and/or Mycoplasma flocculare (M. floc) would interact and influence the severity of enzootic pneumonia in piglets. Specific pathogen-free, hysterectomy-derived piglets were allocated to six groups and experimentally inoculated with M. hyop. and/or M. floc at the age of 2 or 8 weeks. Clinical symptoms, frequency of coughing and temperature measurement were noted daily. Lung lesions were recorded by post-mortem examination and histological observations. The cross-inoculation with both mycoplasmas did not influence the clinical or the pathological picture of the disease. Evolution of specific and crossreacting antibodies was analyzed by ELISA and immunoblotting. Animals inoculated with M. floc did not develop any lesions but showed a weak antibody response 6-8 weeks post-infection (p.i.). No cross-reacting antibodies against M. hyop proteins were detected. In animals inoculated with M. hyop, the first antibody response was detectable 4-5 weeks p.i. and was stronger in piglets infected at the age of 2 weeks than at the age of 8 weeks. Three cross-reacting antibodies against M. floc proteins with molecular weights of 110, 47 and 33 kDa were detected by antibodies to M. hyop. Experimental infections with both mycoplasmas did not show differences in the pattern of species-specific proteins. 相似文献
12.
猪流行性腹泻病毒分离鉴定及其灭活疫苗免疫保护效果研究 总被引：5，自引：0，他引：5
为筛选能用于猪流行性腹泻病毒(PEDV)疫苗研发的流行毒株,收集PEDV阳性病料,以Vero细胞进行病毒分离试验,并对分离毒株进行外源病毒检测、病毒培养特性研究、仔猪毒力试验及免疫效力试验等。9份PEDV阳性病料共分离到3株病毒,分别命名为PEDV-SC12、PEDV-JS12、PEDV-JX12。其中PEDV-SC12株存在支原体污染;PEDV-JS12株与PEDV-JX12株均能被PEDV特异性阳性血清中和;PEDV-JS12株能在Vero细胞上增殖并产生细胞病变,但适应细胞45代以后病毒培养效价仍然偏低;PEDV-JX12滴度能维持在106.0 TCID50/mL以上。PEDV-JX12株毒力试验显示,该分离株能够通过人工感染复制出腹泻病例,并能从发病动物体内检测到感染的病毒。免疫攻毒保护试验显示,以PEDV-JX12株制备的灭活疫苗免疫母猪,对所产仔猪攻毒后免疫组6.25%(1/16)发病,对照组100%(8/8)发病。说明PEDV-JX12株能够适应细胞培养,免疫接种母猪能给仔猪提供有效保护,可以用于PEDV流行毒株的疫苗研发。 相似文献
13.
以ＥｃｏＲＩ、ＨｉｎｄＩＩ酶解四种禽源支原体基因组ＤＮＡ所获得的片段用琼脂糖凝胶进行电泳。结果表明,四种禽源支原体基因组ＤＮＡ经上述酶切后所获得的片段图谱有很大的差异性,表明它们之间的相关性很小;８个鸡毒支原体菌株ＤＮＡ经酶切、电泳后所获得的片段亦具有相对的差异性,说明酶切图谱分析不适用于禽类支原体种的鉴定。由于该技术有很高的分辨率,可以区分同种不同株之间的基因差异,因此,这种技术对禽类支原体病流行病学研究很有意义,并为今后禽源支原体分子生物学研究打下了基础。 相似文献
14.
Six cows were inoculated into the mammary gland with eight mycoplasma strains isolated from the genital tract of bulls and two type strains. The milk of cows infected with Mycoplasma bovigenitalium strains isolated from the genital tracts of bulls showed a change in the appearance and contained large quantities of mycoplasmas and specific antibodies. The mastitis was most intense in about 9 days and began to subside in 17 days infection. The type strain of M. bovigenitalium PG11 failed to produce mastitis. On the other hand, the type strain of M. bovis PG45 produced severe mastitis after a 14-day latency period, with the infection spreading to the uninoculated quarters, causing atrophy of the mammary gland, and persisting till slaughter. The sera of all cows that developed mastitis after experimental infection contained high titres of specific antibodies. The two infecting mycoplasma species were recovered from the inner organs and mammary glands of these cows after slaughter. 相似文献
15.
de la Fe C Assuncão P Ramírez AS Poveda JB 《Berliner und Münchener tier?rztliche Wochenschrift》2004,117(1-2):1-5
The suitability of 5 agents for the inactivation of different field strains of the four mycoplasma species associated with contagious agalactia syndrome in goats, i.e. Mycoplasma agalactiae, Mycoplasma mycoides subsp. mycoides LC, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens, was investigated. Immunoprophylaxis of this syndrome is still based on inactivated vaccines, which traditionally use formalin as the inactivating agent. Moreover, the limited information existing about this type of vaccine is only based on assays against Mycoplasma agalactiae. Our results showed that formalin (0.1%, 37 degrees C during 16 hours) and phenol (0.5%, 24 hours) were effective against all species tested. Surprisingly, binary ethileneimine (BEI), a classical virus-inactivating agent, also proved to be very effective when it was used in a 0.1 M concentration over 24 hours. With heat treatment, every species was inactivated at 60 degrees C. No satisfying results were obtained with purified saponin. To evaluate the harmful effects of each agent on mycoplasmal proteins, a representative strain was subjected to an effective inactivation protocol with each agent, which was monitored by Western immunoblotting. Immunoblotting was performed using sera of animals inoculated with the respective mycoplasma species, to compare the effect of all the agents on treated strains with untreated strains. The results confirmed that phenol, BEI and to a lesser extent also formalin inactivated all species without causing a significant damage while heat caused stronger damage on surface proteins. Future in vivo studies should be conducted because, as recently shown, the combined use of a suitable inactivant and adjuvant could give rise to the induction of certain cytokines and strong antibody production of a specific isotype pattern, thus opening ways to develop more efficacious inactivated vaccines against contagious agalactia. 相似文献
16.
猪支原体肺炎灭活疫苗和弱毒活疫苗的临床应用均有很好的效果。简述了猪支原体肺炎灭活疫苗以体液免疫为主、弱毒活疫苗以细胞免疫和粘膜免疫为主的不同免疫学特性,分析认为占位效应可能是猪支原体肺炎弱毒活疫苗独特的免疫原理之一,提出了灭活疫苗可能的改良方向及保证弱毒疫苗高效免疫的三项措施,以期为猪支原体肺炎防控提供参考。 相似文献
17.
现有的布鲁菌减毒活疫苗存在一定毒力,且野强毒株和减毒活疫苗株间缺少可供鉴别的抗原,导致在血清学检测上自然感染与疫苗接种很难区分,限制了现有的减毒活疫苗的广泛应用.本文拟对布鲁菌的减毒活疫苗株S2进行遗传改造,克服上述缺陷.本研究利用同源重组的方法,得到了布鲁菌S2株omp10基因缺失株.分别用基因缺失株和疫苗株感染小鼠,比较基因缺失株小鼠体内的存活能力.结果成功构建了布鲁菌S2株omp10基因缺失株,动物试验结果表明,基因缺失株仍能在小鼠体内存活,具备作为减毒活疫苗的特性.与原始S2株比较,基因缺失株的感染力进一步减弱.表明omp10基因在布鲁菌的毒力及体内生存方面发挥了作用,为基因标记疫苗的研制奠定了基础. 相似文献
18.
Experimental infection of specific pathogen free piglets with French strains of Streptococcus suis capsular type 2. 总被引：3，自引：0，他引：3
F Berthelot-Hérault R Cariolet A Labbé M Gottschalk J Y Cardinal M Kobisch 《Canadian journal of veterinary research》2001,65(3):196-200
A standardized model of Streptococcus suis type 2 infection in specific-pathogen-free piglets, housed in high-security barns, was used to compare the virulence of 3 French field strains of S. suis serotype 2 isolated from tonsils of a healthy pig (strain 65) or from diseased pigs (meningitis, strain 166', or septicemia, strain 24). In one of the 2 trials, 7-week-old pigs, in 3 groups of 8, were inoculated intravenously with 2 x 10(8) colony-forming units of S. suis type 2. In each group, 1 uninfected animal was a sentinel. Eight animals were also used as negative control group. The experiment was repeated under similar conditions with strains 65 and 166'. Virulence differed markedly among these S. suis strains when clinical signs, zootechnical performances, lesions, and bacteriological data were analyzed. Strain 65 did not induce clinical signs in inoculated pigs. In contrast, pigs infected with the other 2 strains exhibited clinical signs and typical lesions of S. suis type 2 infections. Differences in virulence were also observed between the 2 virulent strains. Sentinel animals exhibited the same manifestations as those recorded in inoculated piglets. Results were similar in the second trial, indicating that under the present experimental conditions, results were reproducible. The standardized conditions described in this study could be a useful tool to further study about the S. suis infection. 相似文献
19.
用健康易感仔猪进行同群感染试验和连续五代返强试验对猪肺炎支原体活疫苗(168株)进行安全性试验,同时也进行了该活疫苗单剂量、单剂量重复和大剂量试验及5批次疫苗免疫商品猪的临床试验。结果发现,猪支原体肺炎活疫苗(168株)免疫猪后,免疫猪和同群感染猪均未观察到典型的临床症状和病理变化;连续五代返强试验,试验猪均未观察到典型的临床症状和病理变化,说明该疫苗株未出现返强。单剂量、单剂量重复和大剂量试验及5批次疫苗的临床试验也未观察到不良反应。这说明受试批次猪支原体肺炎活疫苗(168株)具有良好的安全性。 相似文献