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.
The migration of fluorescein isothiocyanate labelled lymphocytes through the tracheobronchial mucosa has been studied in cattle. Following intratracheal inoculation of labelled non-infected autologous lymphocytes and bovine leukosis virus (BLV) infected heterologous (presumed allogeneic) lymphocytes, the labelled lymphocytes appeared in the blood circulation between 4 and 7 days post inoculation. Following intravenous inoculation of labelled autologous lymphocytes, the cells could be detected in the circulation for 10 days post inoculation whereas BLV infected and non-infected heterologous lymphocytes could be detected for only 2 days. The migration of BLV-infected heterologous lymphocytes through the tracheobronchial mucosa caused a delay in the appearance of labelled lymphocytes in the circulation and a corresponding delay in the appearance of BLV antibodies. Comparison was made of the effect of two different routes of inoculation, subcutaneous and intratracheal on the incubation period as indicated by the detection of antibody. Subcutaneous inoculation of 1 X 10(4), 5 X 10(3), 1 X 10(3) of lymphocytes from a BLV infected cow caused seroconversion whereas 5 X 10(2) cells did not. Intratracheal inoculation of 5 X 10(3) cells caused sero-conversion. One animal did not develop BLV antibody until 30 weeks after inoculation although BLV could be isolated from the blood at 24 and 26 weeks post inoculation.  相似文献   

2.
The purpose of this investigation was to determine if culture supernatants of Pasteurella haemolytica containing crude leukotoxin and lipopolysaccharide (CLCL) causes disseminated intravascular coagulopathy (DIC) when injected into calves. The effect of intraduodenal (ID) exposure followed by a subsequent subcutaneous (SC) inoculation of either heat-treated or untreated CLCL was evaluated. The relative contribution of the crude leukotoxin and lipopolysaccharide (LPS) to the virulence of P. haemolytica was evaluated. One group of calves received an ID inoculation of CLCL followed two weeks later by a SC inoculation of CLCL; one group received an ID inoculation of tissue culture medium followed two weeks later by a SC inoculation of CLCL; and a third group received an ID inoculation of CLCL followed two weeks later by a SC inoculation of heat-treated CLCL. Hematological parameters used to evaluate DIC included white cell count, platelet count, neutrophil number, fibrinogen, fibrin degradation products, one stage prothrombin time (OSPT), activated partial thromboplastin time, body temperature and clinical signs. Each parameter was measured in calves at 0, 2, 4, 6, 12 and 24 h following the SC inoculation of CLCL. Each group had significant changes over time in all parameters except body temperature. Calves that received a SC inoculation of heat-treated CLCL had smaller changes in all parameters except OSPT compared to the other groups. Results suggest that the LPS and leukotoxin of P. haemolytica exert additive effects on the coagulation cascade and number of peripheral leukocytes, and that the ID inoculation of CLCL does not affect the response of calves to a SC inoculation of toxin.  相似文献   

3.
Sixty calves, 3 to 6 months old, were vaccinated once against Babesia bovis in groups of 10, by the following methods: (a) tick infestation; (b) inoculation of virulent parasites obtained from the tick-infested animals immediately after infection; (c) inoculation of the parasites used in (b) attenuated by passage through splenectomised calves; (d) inoculation of commercially-available, living, attenuated vaccine; (e) inoculation of virulent parasites obtained from the tick-infested animals in (a) one year after infection; (f) inoculation of the parasites used in (e) attenuated by passage. All vaccinated animals were maintained tick-free and were strongly immune to challenge with a heterologous strain of B. bovis approximately 4 years after vaccination. There was no difference in immunogenicity between any of the B. bovis populations.  相似文献   

4.
李春玥  马飞  杨高文  刘楠  张英俊 《草地学报》2022,30(10):2541-2548
退化草地土壤肥力和有益微生物的降低是补播植物建植的主要限制因子。为探究植物共生菌与施肥对补播豆科的退化草地群落结构和生产力的影响,本研究选取黄花苜蓿(Medicago falcate)、羊草(Leymus chinensis)和冷蒿(Artemisia frigida)进行盆栽试验。结果表明:(1)与不接种相比,接种丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)使黄花苜蓿的地上生物量显著提高259.54%;不接种加施磷肥比不施肥下黄花苜蓿地上生物量显著提高465.93%,而双接种加施磷肥比不施肥下黄花苜蓿的地上生物量仅显著提高46.58%;(2)与不接种相比,接种AMF使羊草的地上生物量显著降低60.66%;不接种加施磷肥比不施肥时羊草地上生物量显著提高34.49%;(3)不接种加施磷肥比不施肥下冷蒿地上生物量显著提高149.32%;接种AMF时,冷蒿地上生物量在氮磷同施处理下较其它施肥处理平均显著提高129.39%。因此,在退化草地中补播黄花苜蓿时,为减少肥料用量及节约成本,可通过接种AMF替代施用磷肥。  相似文献   

5.
Eimeria (E.) tenella (local isolate) sporozoites were adapted on the chorioallantoic membrane (CAM) of 10-12 days chicken embryos and completed its life cycle in 6~7 days at 39℃ and 70 per cent humidity. Only 23 embryos (4.6%) were found dead from 1~4 day post inoculation of sporozoites with mild lesions on CAM with no gametocytes but few sporozoites in chorioallantoic fluid (CAF). On 5~7 day post inoculation, 432 embryos (86.4%) were found dead with severe haemorrhages on CAM and CAF contained uncountable number of gametocytes. After seven days post inoculation, 45 embryos (9%) were found to be alive. Some oocysts were also detected in the CAF on 6~7 days post inoculation. In the histological sections of the CAM, there were abundant small dark colored rounded bodies of gametes; distributed extensively in tissues of CAM on 5~7 days post inoculation of sporozoites. In some cases, cluster of small mature and immature relatively large bodies were seen in increasing numbers on 5~6 days post inoculation.  相似文献   

6.
The fermentation cultivation process of Avibacterium paragallinarum C-Apg-8(serovar A) had been improved in terms of inoculation method, culture time, the initial inoculation quantity of microorganism and so on.The results showed that the single-batch production capacity of Avibacterium paragallinarum fermentation could increase almost five times by changing the present two-step inoculation method(the primary seed→the secondary seed(7500 mL) →300 L) to the four-step inoculation method(4 mL→160 mL→1600 mL→30000 mL→300 L), and adjusting the inoculation proportion from 2.5% to 2.5%-10%.The improved cultivation way had been changed from spinner cultivation to fermenter cultivation without changing the volume of fermentation, and without adding the staff and the cost of raw material.  相似文献   

7.
本试验从接种方式、培养时间、初始接种量等方面对副鸡禽杆菌C-Apg-8(A型)的发酵培养条件进行了工艺改进。结果显示,通过将现有副鸡禽杆菌生产的二步接种法(一级种子→二级种子(7500mL)→300L)改为四步接种法(4mL→160mL→1600mL→30000mL→300L),接种比例由之前的2.5%变为2.5%~10%,培养方式由大瓶培养变为发酵罐培养,同时在不改变单批次发酵总体积、不增加人员和原材料成本的情况下,最终可以使副鸡禽杆菌发酵单批产量增加约5倍。  相似文献   

8.
Five trials were conducted to compare four in vitro methods of isolating avian infectious bronchitis virus (IBV)-direct organ culture of infected tracheal rings (DOC), inoculation of tracheal organ culture (OC), inoculation of chicken embryo, and inoculation of cultured cells. DOC was prepared from tracheas of chickens experimentally inoculated with field samples. In the other methods, pooled tracheal and kidney suspensions were used to inoculate OC, chicken embryos, and cultured cells. IBV was consistently isolated at the initial passage by the DOC and OC inoculation systems, but it was not always isolated by embryo inoculation and never isolated by cultured-cell inoculation. When combined with immunofluorescent staining, DOC was much more efficient than the OC inoculation system for isolation and identification of the five strains of IBV tested because of its simplicity and speed.  相似文献   

9.
The pathogenesis of bluetongue (BT) could vary with route of inoculation. Using laboratory-passaged moderately virulent bluetongue virus serotype 23 (BTV-23), one of the most prevalent Indian serotype, we investigated the pathogenesis of BT in intradermally (ID) and intravenously (IV) inoculated native sheep. The ID inoculation resulted in relatively increased clinical signs and lesions in many organs as compared to IV inoculation. BTV-23 detection by real-time RT-PCR and isolation studies revealed that ID inoculation can be more efficient than IV ones in disseminating and spreading virus to systemic organs, including pre-scapular draining lymph node, spleen, lungs and pulmonary artery. Furthermore, the ID inoculation resulted in early onset and increased humoral response with significant increase (P<0.01) in antibody titre at various intervals. Taken together, these data suggest that ID inoculation can be more potent in reproducing many aspects of natural infection, including clinical disease, viral and immune responses, and may be useful route in setting up experimental infections for challenge or pathogenesis studies using laboratory passaged BTVs.  相似文献   

10.
布氏艾美耳球虫感染后鸡血清生化指标变化的研究   总被引:6,自引:0,他引:6  
以15日龄公雏作为试验对象,利用TECHNICONRA-100SYSTEM血液生化分析仪,研究了鸡在人工感染E.brunetti(41500个孢子化卵囊/只)后3、5、 7、9和11d时其血清中葡萄糖、谷丙转氨酶、谷草转氨酶碱性磷酸酶、乳酸脱氨酶、淀粉酶、尿酸、总蛋白、白蛋白、钙和镁的变化。结果表明:E.brunetti感染鸡后其血清谷丙转氨酶活性显著升高(P〈0.01);血清白蛋白含量和碱性磷酸酶活性均明显降低(  相似文献   

11.
Twenty-seven six-week-old cesarean-derived, colostrum-deprived pigs were inoculated intratracheally with an isolate of Haemophilus pleuropneumoniae serotype 5 (principles) of high virulence (I-200) or low virulence (B-8) or phosphate buffered saline (controls). Pigs given I-200 had severe serofibrinous pleuropneumonia at three hours after inoculation; two of three pigs were dead by 24 hours after inoculation. Interalveolar septa in the caudal lung lobes were 41% thicker than septa from control pigs at three hours after inoculation and 79% thicker by 24 hours after inoculation. Interalveolar septal capillaries in caudal lung lobes were 10.2% larger than control capillaries at three hours after inoculation and 25.6% larger by 24 hours after inoculation. Interalveolar septal capillary platelet volume was greater than the platelet volume of controls; 70% of these platelets were aggregated. There was severe diffuse alveolar, interalveolar septal, and interlobular septal edema at three hours after inoculation with fibrin, neutrophils, and macrophages present in later samples. Thirty-three percent of the lung parenchyma was necrotic at 24 hours after inoculation. Endothelial cell degeneration was generally mild, but necrotic in regions of pulmonary infarction. Pigs inoculated with the B-8 isolate did not develop marked macroscopic lesions at any sampling time. Interalveolar septa were 18% thicker than controls nine hours after inoculation and 5% thicker at six and 24 hours after inoculation. Capillary platelet volume was greatest at nine hours after inoculation with 50% of these platelets aggregated; 30% of the platelet volume was aggregated at the 24-hour sample period. Moderate diffuse pulmonary and interlobular septal edema was present at three, six, and nine hours after inoculation, but absent 24 hours after inoculation. Intravascular macrophages were present in the six, nine, and 24-hour lung samples in both B-8 and I-200 inoculated pigs. These cells were adherent to interalveolar septal capillary endothelial cells and contained phagocytized cellular debris and fibrin. These results indicate the early effects of H. pleuropneumoniae infection involve macrophage and platelet activation, and a marked increase in interalveolar septal capillary permeability.  相似文献   

12.
通过L9(34)正交试验,研究不同根瘤菌梯度、接种方式和氮肥梯度对岷山红三叶异黄酮含量和产量的影响。结果表明,接种根瘤菌对岷山红三叶异黄酮含量和产量都有显著影响(P<0.05),以每千克岷山红三叶种子接种16g根瘤菌效果较好。接种根瘤菌的方式、氮肥梯度对岷山红三叶异黄酮含量和产量不存在显著影响,但以拌种和不施氮肥效果较好。综合根瘤菌梯度、接种方式和氮肥梯度对岷山红三叶异黄酮含量和产量的影响以A2B2C1效果最优。  相似文献   

13.
A study was conducted to determine the immune (increased antibody) and protective (reduced colony-forming units) responses induced in mice by a: (i) single vaccinal inoculation, using various concentrations of Brucella cell surface protein (BCSP) or lipopolysaccharide (LPS); (ii) primary inoculation, using various concentrations of BCSP, followed by a secondary inoculation, using a standard concentration of BCSP; and (iii) primary inoculation, using 1 concentration of BCSP or LPS, followed by a secondary inoculation, using various concentrations of BCSP or LPS. Four weeks after the primary inoculation, mice were challenge exposed with approximately 1 x 10(4) colony-forming units of Brucella abortus strain 2308 and all mice were euthanatized at 6 weeks. Reduced splenic weights and reduced colony-forming units in the spleens of vaccinated mice, compared with nonvaccinated mice, were the criteria of protection. Increase in serum IgM and IgG was defined as immunity. Both BCSP and LPS induced protective and immune responses that were proportional to the dose given up to an optimal limit. However, concentrations higher than optimal decreased the protective and immune responses. This was true for mice given either 1 or 2 vaccinal inoculations. Enhanced secondary protective responses were seen only when suboptimal doses were used in the primary inoculation. Excessive or optimal doses in the secondary inoculations prevented or obscured the protectiveness and immunity by primary inoculations. The protective effects appeared to be additive when suboptimal doses were used in the primary and secondary inoculations.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
低温是影响植物生长的主要限制因子。采用沙培法研究了接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)对2份不同海拔梯度下的购买自北京正道公司(ZD)和采集自西藏康马县(KM)垂穗披碱草(Elymus nutans)生长与生理特性的影响。结果表明:接种AMF的植株根系均受到不同程度的侵染,且侵染率随时间的变化呈先增加后减少的趋势。低温胁迫下,2种垂穗披碱草的生长均受到一定程度的抑制。然而,接种活性AMF能显著提高低温胁迫下ZD和KM的地上和地下生物量、根系形态结构指标、光合色素含量和抗氧化物酶类活性,且显著降低低温胁迫下植株相对电解质渗透率(REL)、丙二醛(MDA)含量、超氧阴离子(O2·-)含量和过氧化氢(H2O2)含量(P<0.05)。综上所述,接种活性AMF能够明显提高45 d垂穗披碱草ZD和KM幼苗对低温胁迫的耐受性。  相似文献   

15.
Mice and swine vaccinated (subcutaneous inoculation) with live acriflavine-fast attenuated Erysipelothrix rhusiopathiae, strain Koganei 65-0.15 (serovar 2), were challenge exposed with 10 strains of E rhusiopathiae pathogenic for swine; the latter strains comprised serovars 9 and 10 and other previously undetermined. Vaccinated mice did not die after they were challenge exposed (subcutaneous inoculation) with serovars 4, 6, 7, 8, 9, 10, 15, 16, or N, but vaccinated mice challenge exposed with strain 2553 (serovar 20) had 30% mortality. Nonvaccinated control mice died after they were challenge exposed with all serovars tested. One of 2 vaccinated swine challenge exposed (intradermal inoculation) with each of strains 911 (serovar 8), 2179 (serovar 10), or 2553 developed localized urticarial lesion at the site of intradermal inoculation. Vaccinated swine challenge exposed with serovars 4, 6, 7, 9, 15, 16, or N did not have clinical signs of acute swine erysipelas. Nonvaccinated control swine developed localized lesions at the site of intradermal challenge inoculation.  相似文献   

16.
Acquisition of immunity to Hammondia hammondi, a newly recognized coccidian of cats, was studied in 18 specific-pathogen-free cats. One cat was given a single oral inoculation, 11 cats were given 2 oral inoculations, and 1 cat was given 3 oral inoculations of homogenized mouse carcasses containing H hammondi. In all cats, oocyst shedding began 6 to 9 days after the 1st inoculation. Oocyst shedding peaked at 1 to 2 days after the onset of shedding and lasted for 1 to 2 weeks. None of the cats became sick. Of the 11 cats inoculated twice (between 2-51 days after the 1st inoculation), 5 shed oocysts 7 to 14 days after the repeat inoculation; however, fewer oocysts were shed at this time. One cat that was inoculated thrice (14 and 51 days after the 1st inoculation) shed oocysts 14 to 17 days after the 3rd inoculation but not after the 2nd inoculation. Spontaneous oocyst shedding was studied in 9 of these 13 H hammondi-infected cats for 5 months. Two cats spontaneously shed oocysts: One cat (inoculated only once) spontaneously re-shed oocysts 21 to 24, 31 to 33, 49 to 50, and 118 to 120 days after inoculation; The other cat (inoculated twice-the 2nd time, 6 days after the 1st inoculation) re-shed oocysts 38 to 48, 85 to 89, and 133 to 136 days after the 1st inoculation. The course of H hammondi infection was studied in 5 cats given weekly injections of 6-methyl prednisolone acetate for at least 7 weeks, starting 18 days before inoculation in 2 cats, and starting 14, 34, and 45 day after inoculation in 3 cats. The induced hyperadrenocorticism did not affect the prepatent period or induce parasitism of extraintestinal organs. The 3 cats infected for 14, 34, and 45 days, re-shed oocysts after hyperadrenocorticism was induced. It was concluded that immunity to H hammondi infection in cats is less stable than immunity to the related coccidian, Toxoplasma gondii.  相似文献   

17.
Wheat straw, sugarcane bagasse medium and konara oak logs used to cultivate edible basidiomycetes were treated with ammonium hydroxide to investigate the relationship between the degree of rotting and the effect of ammonium hydroxide treatment on digestibility. Wheat straw was sampled before inoculation and on days 67 and 97 after inoculation with Pleurotus salmoneostramineus. Similarly, bagasse media were sampled before inoculation and on days 47 and 96 after inoculation with Pleurotus abalonus. Konara oak logs were sampled before inoculation and at 2 and 4 years after inoculation with Lentinula edodes. Aliquots of the samples were treated with ammonium hydroxide (NH4‐N, 3% dry matter) at 45°C for 10 days. Ammonium hydroxide treatment increased the in vitro dry matter digestibility (IVDMD) and gas production (IVGP) of all the samples, except the konara oak samples collected before inoculation. The degree of increased digestibility was largest for the samples collected after short cultivation periods, followed by those collected after long cultivation periods and those collected before inoculation. However, the IVDMD and IVGP values after short cultivation periods were lower than those after long cultivation periods. Ammonium hydroxide treatment is effective at improving the digestibility of white‐rotted materials, although the effect is lessened as rotting proceeds.  相似文献   

18.
The capacity of a TK-negative (TK-) and gI/gE-negative (gI/gE-) pseudorabies virus (PRV) mutant to protect pigs against Aujeszky's disease carried out by experimental infection with a virulent PRV strain, was tested. There were three groups, each of four susceptible pigs which were inoculated twice by two different schedules. Group 1 received the modified virus by the intradermal (first inoculation)-intramuscular (second inoculation) routes; group 2 was treated by the intranasal (first inoculation)-intramuscular (second inoculation) routes. The third group was left untreated as the control. All of the pigs were challenged intranasally with a virulent PRV strain and they were subsequently injected with dexamethasone. Two pigs in each group were necropsied on days 5 and 15 after dexamethasone inoculation. The challenge exposure resulted in mild clinical signs, increase in growth and a shorter period of virus shedding in vaccinated pigs, whereas the control group showed severe signs of Aujeszky's disease. No difference in the titre of the virulent virus which was excreted by pigs of all three groups, was observed and all animals seroconverted. Both the mutant strain and the wild-type virus established a latent infection although only the latter was reactivated and shed. Slight lesions were observed in target tissues of the vaccinated animals and no significant differences were detected between the two inoculation schedules.  相似文献   

19.
Viable Haemophilus somnus of reproductive tract origin (OSU-1167) was inoculated transcervically into the uterus of 6 virgin heifers. Five heifers were sham-inoculated (intrauterine) with sterile mycoplasmal medium and served as controls. After inoculation and observation, all heifers had nasal and vaginal vestibular swab specimens and serum obtained periodically for 44 days. Signs of systemic illness were not detected. On the day after inoculation, all inoculated heifers had signs of vulvovaginitis, whereas none of the control heifers had similar signs (P less than 0.002). Haemophilus somnus was not isolated from any nasal or vaginal vestibular swab specimens obtained before inoculation or from any nasal swab specimens obtained after inoculation. During the 44 days after inoculation, H somnus was isolated from 25 of 54 vestibular specimens obtained from inoculated heifers and from 3 of 45 specimens obtained from controls (P less than 0.02). Vulvovaginal lesions were associated with vestibular isolation of H somnus in 23 of 25 (92%) such isolations from inoculated heifers; lesions were never associated with concurrent isolation of H somnus in controls. All heifers had H somnus microagglutination test (MAT) titer less than or equal to 256 against a commercially prepared H somnus antigen at the beginning of the study. Considered as groups, neither inoculated nor control heifers achieved fourfold increases in MAT titer during the 44 days after inoculation. When compared by day of sample collection, inoculated heifers did have significantly (P less than 0.04) lower geometric mean titer at 7 days after inoculation than did control heifers when tested by use of a commercially prepared antigen.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
为了探究镉(cadimum, Cd)胁迫下生物炭和丛枝菌根(arbuscular mycorrhizal, AM)对植物生长的协同效应,采用盆栽试验,研究在3个Cd污染(0,3,6 mg Cd·kg-1)水平下,施用小麦秸秆生物炭和接种AM真菌(Glomus intraradices BEG 141)对玉米生长和生理生化特性的影响。结果表明,施用生物炭和接种AM真菌单独或复合处理均能提高玉米的株高、生物量、光合色素含量、光合特性和抗氧化酶活性,降低胞间CO2浓度(Ci)、MDA含量。接种AM真菌促进玉米生长效果优于生物炭,而生物炭对提高土壤pH效果较好,施用生物炭和接种AM真菌复合处理对Cd胁迫下玉米生长和改善玉米生理生化特性的促进效应最佳。其中,在6 mg Cd·kg-1水平下,施用生物炭和接种AM真菌复合处理使株高、生物量分别增加43.87%、79.10%;净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)分别提高33.09%,45.04%,31.27%;叶片的超氧化物歧化酶(superoxide dismutase,SOD)活性、过氧化物酶(peroxidase,POD)活性、过氧化氢酶(catalase,CAT)活性分别提高51.42%,82.91%,43.96%。综合来看,生物炭和AM真菌单独或复合处理均能够减轻Cd胁迫和促进植物生长,以生物炭和AM真菌复合处理效果最佳,AM真菌处理效果次之,生物炭处理效果较差。  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