排序方式： 共有41条查询结果，搜索用时 296 毫秒
31.
Monoclonal antibody (MAb) against Mycoplasma gallisepticum strain PG31 was produced in BALB/c mice. The MAb (designated M9) was of IgG3 isotype and reacted with an epitope in M gallisepticum antigens with molecular weights of 35, 90, 95, and 98 kilodaltons (kDa). The M9 reacted with M gallisepticum antigens in the dot-blot ELISA and in western blot assays. It agglutinated M gallisepticum strains PG31, F, R, S6, A5969, and 9 field isolates from various sources. A coagglutination assay, using Staphylococcus aureus (Cowan strain 1), was developed to enhance the agglutination of some weakly agglutinating M gallisepticum isolates. The M9 did not react with M synoviae, M iowae, M meleagridis, M gallinarum, or M gallinaceum in any of the aforementioned assays. This MAb may be useful in facilitating laboratory diagnosis of M gallisepticum infections. 相似文献
32.
An indirect enzyme-linked immunosorbent assay (ELISA) was developed to measure humoral antibody responses of chickens against Pasteurella multocida. A standard indirect hemagglutination (IHA) test was used to compare serologic results with those of ELISA. The ELISA was also used following challenge with P. multocida to compare the efficacy of three commercial fowl cholera vaccination regimens. Although antibody titers measured by ELISA and IHA were highly correlated, ELISA was at least twice as sensitive as IHA. Antibody measured by ELISA and IHA also correlated significantly with protection against P. multocida challenge. No mortality occurred in any of the three vaccinated challenged groups. However, control unvaccinated chickens experimentally infected with P. multocida developed signs of acute pasteurellosis and died by the 10th day post-challenge. Impression smears made of hepatic tissue from all chickens were stained (Wright's stain), and typical bipolar rods characteristic of Pasteurella were identified in smears from unvaccinated challenged controls only. 相似文献
33.
BS Gallardo VK Gupta FD Eagerton LI Jong VS Craig RR Shah NL Abbott 《Science (New York, N.Y.)》1999,283(5398):57-60
Electrochemical methods were combined with redox-active surfactants to actively control the motions and positions of aqueous and organic liquids on millimeter and smaller scales. Surfactant species generated at one electrode and consumed at another were used to manipulate the magnitude and direction of spatial gradients in surface tension and guide droplets of organic liquids through simple fluidic networks. Solid microparticles could be transported across unconfined surfaces. Electrochemical control of the position of surface-active species within aqueous films of liquid supported on homogeneous surfaces was used to direct these films into periodic arrays of droplets with deterministic shapes and sizes. 相似文献
34.
A computer-assisted single-serum-dilution indirect kinetic-based enzyme-linked immunosorbent assay (KELISA) was used for quantitating the natural decay rate of infectious bursal disease virus (IBDV) maternal antibody in progeny obtained from white leghorn breeders. The KELISA results were compared with those of a standard virus-neutralization (VN) test. Pullets were subjected to two IBDV immunization regimens. Group 1 was vaccinated at weeks 0, 2, and 10 with two live vaccines in drinking water and at week 20 with an oil-emulsified (SC) IBDV vaccine, group 2 received only the first and last immunizations, and group 3 served as the unvaccinated control. Pullets were artificially inseminated at 28 weeks of age. Progeny chicks from each group were bled every other day for 47 days. Both KELISA and VN test detected linear relationship in the decay of maternal antibodies. The VN test detected no significant differences (P greater than 0.05) in the IBDV maternal antibody titers at day 1 or in the rate of decay between the progeny from groups 1 and 2. The VN maternal antibody titers decreased at a rate of 0.16 log2 titer per day. In contrast, KELISA revealed higher IBDV maternal antibody titers in day-old progeny from pullets vaccinated 4 times (log2 = 14.3). However, KELISA titers of progeny from this group decreased at a faster rate than titers of progeny from pullets vaccinated twice (0.20 vs. 0.13 log2 titer per day). 相似文献
35.
Pasnik DJ Evans JJ Panangala VS Klesius PH Shelby RA Shoemaker CA 《Journal of fish diseases》2005,28(4):205-212
Streptococcus agalactiae is a major bacterial pathogen that is the cause of serious economic losses in many species of freshwater, marine and estuarine fish worldwide. A highly efficacious S. agalactiae vaccine was developed using extracellular products (ECP) and formalin-killed whole cells of S. agalactiae. The vaccine efficacy following storage of S. agalactiae ECP and formalin-killed S. agalactiae cells at 4 degrees C for 1 year was determined. The stored ECP containing S. agalactiae formalin-killed cells failed to prevent morbidity and mortality among the vaccinated fish, and the relative percentage survival was 29. Serum antibody responses of the stored ECP and freshly prepared ECP against soluble whole cell extract of S. agalactiae indicated that significantly less antibody was produced in fish immunized with stored ECP and S. agalactiae cells than in those fish immunized with freshly prepared ECP and S. agalactiae cells at day 31 post-vaccination. Silver staining of sodium dodecyl sulphate-polyacrylamide gels and immunostaining of Western blots with tilapia antiserum to S. agalactiae revealed that predominant 54 and 55 kDa bands were present in the freshly prepared ECP fraction. The 55 kDa band was absent from the stored ECP and new bands below 54 kDa appeared on the Western blot. The results of this study on S. agalactiae ECP provide evidence for a correlation between protection and antibody production to ECP and for the importance of the 55 kDa ECP antigen for vaccine efficacy. 相似文献
36.
FC Varago VS Moutacas BC Carvalho RV Serapião F Vieira H Chiarini‐Garcia FZ Brandão LS Camargo M Henry MA Lagares 《Reproduction in domestic animals》2014,49(5):839-844
The aim of this work was to evaluate the efficiency of the cryoprotectants dimethylformamide and ethylene glycol for cryopreservation of ovine embryos using vitrification and conventional freezing. The recovered embryos were distributed randomly in three treatment groups: Gr. 1: conventional freezing (n = 44), Gr. 2: vitrification with ethylene glycol (n = 39) and Gr. 3: vitrification with dimethylformamide (n = 38). Quality of fresh embryos in control group as well as of frozen and vitrified embryos was examined by three methodologies: staining with propidium iodide and Hoechst 33258 and evaluation under fluorescent microscopy, evaluation of re‐expansion and hatching rates after culture, and determination of apoptotic index with TUNEL technique. It was established that re‐expansion rate in all treatment groups was similar. In the same time, hatching rates were higher in Gr. 1 (40.5%) and Gr. 2 (35.3%) in comparison with Gr. 3 (15.5%, p < 0.05). The number of dead cells in vitrified embryos of Gr. 2 and Gr. 3 was higher (42.6 ± 26.2 and 63.2 ± 34.65, respectively) in comparison with Gr. 1 (conventional freezing, 10.1 ± 8.5, p < 0.05). Embryos vitrified with dimethylformamide included the same quality of apoptotic cells that Gr. 1 (conventional freezing) and fresh embryos. In conclusion, the dimethylformamide and ethylene glycol used as cryoprotectant to vitrify ovine embryos, in the concentrations and exposition time tested in this work, were not as efficient as the conventional freezing for cryopreservation of ovine embryos Thus, the conventional freezing with ethylene glycol was the most efficient method to cryopreserve ovine embryos in comparison with vitrification. 相似文献
37.
Victor S. Panangala Craig A. Shoemaker & Phillip H. Klesius 《Aquaculture Research》2007,38(5):508-517
Flavobacterium columnare is a ubiquitous Gram-negative bacterium that causes columnaris disease in a wide variety of fish worldwide. Timely detection of this bacterium is important to prevent its spreading and to reduce the economic loss to fish farmers. We developed a TaqMan-based real-time polymerase chain reaction (PCR) targeting a 113 bp nucleotide region of the chondroitin AC lyase gene of F. columnare G4. Specificity of the assay evaluated with 20 isolates of F. columnare and 15 other taxonomically or ecologically related bacteria revealed that the primers and probe were 100% specific for detection of F. columnare. The sensitivity limit of detection of F. columnare in pure cultures, over a range of dilutions [3.1 × 100–3.1 × 106 colony-forming units (CFU) mL−1], was observed to be ∼3 bacterial cells. The lowest limit of detection in nucleic acids from pure culture of F. columnare was 5.4 fg and the assay was linear with the log of amount of nucleic acid (R2=0.994) over that range (5.4 ng–5.4 fg). In tissues (blood, gills and kidney) of F. columnare experimentally infected fish, the bacterial numbers measured by TaqMan real-time PCR ranged from 3.4 × 100 to 9.5 × 105 CFU mL−1. In both F. columnare experimentally infected and spiked samples, positive PCR results were confirmed by bacteriological culture with 100% agreement. The TaqMan real-time PCR developed in this study is specific, sensitive and reproducible for the detection and quantitation of F. columnare in infected fish. 相似文献
38.
Abstract Channel catfish, Ictalurus punctatus (Rafinesque), were immunized with Ichthyophthirius multifiliis (Ich) theronts and trophonts, and the immune response and host protection against both homologous and heterologous serotypes of Ich were evaluated. Immunizations were done with two immobilization serotypes (ARS4 and ARS6) of live theronts by bath immersion (trial I) and with sonicated trophonts by intraperitoneal (i.p.) injection (trial II). Cutaneous and serum antibody titres against Ich following immunization were measured and survival of catfish was determined after theront challenge. Theronts were immobilized by the antiserum from fish immunized with homologous theronts or trophonts, but not by the serum of fish immunized with the heterologous serotype. Serum from fish immunized by immersion with live theronts showed higher enzyme-linked immunosorbent assay titres against both homologous and heterologous serotypes than fish immunized by i.p. injection of trophonts. Channel catfish immunized by immersion with live theronts or by i.p. injection with sonicated trophonts developed an immune response against Ich and provided cross-protection against challenge from both serotypes (ARS4 and ARS6) of the parasite. Sonicated trophont antigens in aqueous solution by i.p. injection could stimulate an immune response in fish, but the immunity was of short duration. 相似文献
39.
40.