Seropositividad de Brucella abortus en ganado bovino de Aguazul- Casanare / Seropositivity of Brucella abortus in cattle from Aguazul- Casanare

Resumen Introducción. La Brucelosis bovina, es una enfermedad bacteriana e infecto contagiosa, causada por Brucella abortus. Se transmite a través de la ingestión de forrajes y aguas contaminadas con descargas vaginales infectadas, que conlleva a una patología del sistema reproductor en bovinos, que impactan la sanidad pecuaria y la economía de la agroindustria. Objetivo. Evaluar el comportamiento de la brucelosis bovina en el municipio de Aguazul, Casanare (Colombia) y los factores asociados al desarrollo de esta enfermedad. Metodología. Estudio descritptivo de 26.187 muestras de suero sanguíneo de ganado bovino evaluadas, que corresponden a 260 predios del municipio de Aguazul. Se empleó técnicas serológicascomo rosa de bengala, fluorescencia polarizada y ELISA competitiva para la evaluación de positividad a Brucella abortus y se evaluaron las pérdidas económicas asociadas a positividad en los ensayos de laboratorio. Resultados y conclusiones. La positividad a brucelosis bovina correspondió al 1%, que corresponde a hembras menores de 24 meses de edad y entre 37 a 48 meses y, machos entre los 57 a 68 meses de edad. Se sugiere consolidar esfuerzos en investigación para evaluar los factores que contribuyen a la seropositividad en el ganado y el riesgo para la propagación y mantenimiento de la enfermedad.

Abstract Introduction. Bovine brucellosis is a contagious bacterial and infectious disease caused by Brucella abortus. It is transmitted through the ingestion of forage and water contaminatedwith infected vaginal discharges, which leads to a pathology of the reproductive system inbovines, which impacts livestock health and the economy of agribusiness. Aim. To evaluatethe behavior of bovine brucellosis in the municipality of Aguazul, Casanare (Colombia) and the factors associated with the development of this disease. Methodology. Descriptive study of 26,187 bovine blood serum samples evaluated, corresponding to 260 farms in the municipality of Aguazul. Serological techniques such as rose bengal, polarized fluorescence, and competitive ELISA were used to evaluate positivity to Brucella abortus and the economic losses associated with positivity in laboratory tests were evaluated. Results and conclusions. The positivity to bovine brucellosis corresponded to 1%, which corresponds to females under 24 months of age and between 37 to 48 months and males between 57 to 68 months of age. It is suggested to consolidate research efforts to evaluate the factors that contribute to seropositivity in cattle and the risk for the spread and maintenance of the disease

Establishment of two competitive ELISAs for specific detection of bluetongue virus serotype 4 / 生物工程学报

To develop a clinical diagnosis technique for bluetongue virus infection, we established serotype-specific methods to detect serotype 4 of bluetongue virus (BTV-4). Two monoclonal antibodies (mAbs) against VP2 protein of BTV-4, named 4A-1G7 and 4B-1B6, were used as competitive antibodies in the competitive enzyme-linked immunosorbent assays (C-ELISA). We detected 50 negative serum samples from sheep, goats and cattle by C-ELISA. The cut-off values of 4A-1G7 and 4B-1B6 mAbs were 49% and 40%, respectively. The results of the sensitivity, specificity and repeatability by detecting standard positive serum, were consistent with the general standard of Office International Des Epizooties. Furthermore, serum samples of BTV-4, BTV-18 and BTV-20 infection could be screened out through the combined C-ELISAs by 4A-1G7 and 4B-1B6 mAbs. Thus, this technique may diagnose BTV-4, BTV-18 and BTV-20 infections.

Preparation of a monoclonal antibody against hyaluronic acid and its application in immunoassay / 中国药科大学学报

@#This study was to develop a quantitative immunoassay for hyaluronic acid(HA). We firstly prepared a monoclonal antibody(MAb)against it. HA, activated by 1-cyano-4-dimethyl-aminopyridinium tetrafluoroborate(CDAP), was coupled to bovine serum albumin(BSA). BALB/c mice were immunized with purified complete antigen BSA-HA and the monoclonal antibody was prepared by hybridoma technique. To characterize the specificity of the antibody, inhibition enzyme-linked immunosorbent assay(ELISA)was conducted and the cross reactivity along with affinity constant was determined. The results showed that the substitution degree of BSA-HA(mBSA/wHA)was about 9. Also, a hybridoma cell line named 8B6 was obtained by hybridoma technology. The indirect ELISA titer of the ascetic fluid was 1 ∶256 000; the isotype of MAb 8B6 was IgG1 and the affinity constant was Ka=6. 71×109 mol-1. To establish the indirect competitive ELISA method, polystyrene microwell plates were coated with 10. 0 ng/mL HA and blocked with 1. 0% BSA. The linear range of indirect competitive ELISA was between 10. 0 ng/mL to 10. 0 μg/mL which confirmed that the method was specific and sensitive.

Serological monitoring on brucellosis in livestock of Korea / 대한수의학회지

In Korea, brucellosis has been reported periodically in cattle and rarely in dogs; however, it has not previously been screened in domestic animals such as elk, pigs and goats. To investigate the serological prevalence, serum samples were taken from the aforementioned animals annually during 2007-2013 and screened by the rose-bengal test (RBT) or modified RBT, after which positive sera were evaluated by the standard tube agglutination test (STAT). Finally, RBT and STAT-positive sera were confirmed by competitive-ELISA. Brucella abortus biovar 1 was isolated from three elk that were shown to be positive serologically in 2008. There was no evidence of brucellosis in pigs. Based on serological monitoring and investigation of etiological agents, there is no evidence of outbreak of brucellosis in elk, pigs or goats of Korea since 2008. However, the possibility for brucellosis from cattle to affect these other livestock exists; therefore, extensive and continuous serological monitoring is required to maintain their brucellosis-free status.

Production and Characterization of Monoclonal Antibodies to Bluetongue Virus / 中国病毒学·英文版

In the present study, a total of 24 Mabs were produced against bluetongue virus (BTV) by polyethyleneglycol (PEG) mediated fusion method using sensitized lymphocytes and myeloma cells. All these clones were characterized for their reactivity to whole virus and recombinant BTV-VP7 protein, titres, isotypes and their reactivity with 24 BTV-serotype specific sera in cELISA. Out of 24 clones, a majority of them (n = 18)belong to various IgG subclasses and the remaining (n = 6) to the IgM class. A panel of eight clones reactive to both whole BTV and purified rVP7 protein were identified based on their reactivity in iELISA. For competitive ELISA, the clone designated as 4A10 showed better inhibition to hyperimmune serum of BTV serotype 23. However, this clone showed a variable percent of inhibition ranging from 16.6% with BTV 12 serotype to 78.9% with BTV16 serotype using 24 serotype specific sera of BTV originating from guinea pig at their lowest dilutions. From the available panel of clones, only 4A 10 was found to have a possible diagnostic application.

Evaluation of a competitive ELISA for antibody detection against avian influenza virus

Active serologic surveillance is necessary to control the spread of the avian influenza virus (AIV). In this study, we evaluated a commercially-available cELISA in terms of its ability to detect AIV antibodies in the sera of 3,358 animals from twelve species. cELISA detected antibodies against reference H1- through H15-subtype AIV strains without cross reactivity. Furthermore, the cELISA was able to detect antibodies produced following a challenge of the AIV H9N2 subtype in chickens, or following vaccination of the AIV H9 or H5 subtypes in chickens, ducks and geese. Next, we tested the sensitivity and specificity of the cELISA with sera from twelve different animal species, and compared these results with those obtained by the hemagglutination-inhibition (HI) test, the "gold standard" in AIV sera surveillance, a second commercially-available cELISA (IZS ELISA), or the agar gel precipitation (AGP) test. Compared with the HI test, the sensitivities and specificities of cELISA were 95% and 96% in chicken, 86% and 88% in duck, 97% and 100% in turkey, 100% and 87% in goose, and 91% and 97% in swine, respectively. The sensitivities and specificities of the cELISA in this study were higher than those of IZS ELISA for the duck, turkey, goose, and grey partridge sera samples. The results of AGP test against duck and turkey sera also showed significant correlation with the results of cELISA (R-value >0.9). In terms of flock sensitivity, the cELISA correlated better with the HI test than with commercially-available indirect ELISAs, with 100% flock sensitivity.

Simultaneous detection of amphetamine, methamphetamine and ephedrine by heterology competitive enzyme-linked immunosorbent assay

Background: Simultaneous screening of ephedrine with amphetamine or methamphetamine in drug abusers is useful in countries, such as Thailand, that prohibit the use of ephedrine. The lack of an adequate screening test kit suitable for this purpose is a significant obstacle in the detection of ephedrine abusers. A reliable analytical method for the simultaneous detection of amphetamine, methamphetamine and ephedrine is needed. Objective: To develop a process for the detection of amphetamine, methamphetamine and ephedrine by enzyme-linked immunosorbent assay (ELISA), based on the polyclonal antibody and heterology principle. Methods: The 3-aminopropyl (3AP) and 4-aminobutyl (4AB) derivatives of amphetamine (A), methamphetamine (M) and ephedrine (E) were chemically synthesized. They were used for the preparations of immunogens and hapten tracers. Direct competitive ELISA of matrix combinations of antisera and hapten tracers were performed using amphetamine, methamphetamine and ephedrine as the analytes. Only the competitive reactions with specified sensitivity and specificity are selected. Results: The study discovered three assay combinations that demonstrated concentration-dependent competition of analyte (single or multiple). They passed the confirmation test for the cut-off concentration and had no cross-reactivity with other amines or structured related compounds. The assay combinations of 4ABA-Ab with 3APA-PO and 4ABE-Ab with 3APM-PO were specific for the detection of amphetamine with ephedrine and methamphetamine with ephedrine, respectively. The third assay combination of 4ABE-Ab with 3APE-PO was highly specific to ephedrine with negligible cross-reactivity from other structure-related compounds. Direct competitive ELISA of 4ABE-Ab with 3APM-PO has been proven useful in field tests for the detection of methamphetamine in urine samples from Thai truck drivers suspected of drug abuse. Conclusion: By using heterology, these three assay combinations could be used separately or simultaneously for drug abuse screening.

Comparative efficacy of standard AGID, CCIE and competitive ELISA for detecting bluetongue virus antibodies in indigenous breeds of sheep and goats in Rajasthan, India

The sero-prevalence of antibodies against blue tongue virus (BTV) in 408 local breeds of sheep in Rajasthan state in India was investigated using standard agar gel immunodiffusion (AGID) test. Maximum seropositivities of 11.3% (13/115), 10.7% (13/121), 7.1% (11/155) and 5.9% (1/17) were recorded in the Chokla, Magra, Nali and Pugal breeds, respectively. Out of 107 goat serum samples, 6 (5.6%) were AGID positive. The performance of the standard AGID, counter current immuno-electrophoresis (CCIE) and the competitive enzyme-linked immunosorbent assay (cELISA) for the detection of serum antibody against BTV in indigenous breeds of sheep were compared. Out of 178 sheep serum samples tested, 17 (9.5%), 22 (12.3%) and 54 (30.3%) were positive for group-specific bluetongue antibodies by AGID, CCIE and cELISA, respectively. There was appreciable difference in the seroprevalence detected by AGID, CCIE and cELISA in clinically healthy and diseased sheep with regard to relative sensitivities and specificities of the tests with cELISA being highly sensitive and specific followed by CCIE and AGID test. It was concluded that these indigenous breeds of sheep may be a potential reservoir of BTV infection and cELISA should be routinely used for the detection of antibodies against BTV in these local breeds of sheep.

Development of the Enzyme Immunoassay for the Detection of Anti-HSV-2 Antibody with HSV-2 Specific Monoclonal Antibody / 감염

BACKGROUND: The serological diagnosis of herpes simplex virus type 2 (HSV-2) infection has pitfalls, in that most of the antibodies against HSV-2 cross-react with HSV-1 and the prevalence of HSV-1 infection is high, especially in Korea. In this study, we tried to establish the serological diagnostic method, which could detect and measure the specific antibodies against HSV- 2 by competitive immunofluorescent staining method as well as competitive ELISA based on the specific monoclonal antibody, MH2-7. METHODS: Immunofluorescent staining and western blot analysis were used to characterize the antigens recognized by MH2-7. Competitive immunofluorescent staining (IF), competitive enzyme immunoassay (ELISA), and western blot analysis were used to detect specific antibodies against HSV-2 in patients' sera. RESULTS: In western blot analysis, the sera from two of six patients clinically diagnosed as genital herpes showed characteristic band patterns, which have been known to be compatible with HSV-2 infection. In competitive immunofluorescent staining, only the sera from the two patients clinically diagnosed as genital herpes and with characteristic band pattern showed competition with MH2-7 monoclonal antibody. The dilution range of the serum showing specific competition was between 1:10 and 1:80. Competitive ELISA was also performed and evaluated as the diagnostic efficacy as ELISA has been known to be advantageous over IF staining in mass screening. The result showed linear dose-response relationship for the patient's sera in inhibition of the reactivity of MH2-7. CONCLUSION: We suggest that the competitive immunofluorescent staining method and competitive ELISA based on the specific monoclonal antibody MH2-7 is a simple, accurate, and precise method, which can be used in serological diagnosis of HSV-2 infection.

Biological Indices for Early Detection of Cadmium Poisoning: Significance of Urinary Metallothionein / 대한산업의학회지

Metallothionein(MT) is a low molecular weight protein that is induced as a defence mechanism for cadmium (Cd) toxicity. In present study, urinary MT was determined using a competitive ELISA in Cd-exposed rats. In addition, measures the urinary, blood and renal Cd concentration and the urinary excretion of total protein, beta 2-microglobulin (MG) and N-acetyl-beta-D-glucosaminidase(NAG) at 1, 3, 7, 14, 28 days after Cd injection in Cd-exposed rats with dosers of 0.8 and 1.6 mg Cd/kg body weight respectively. The urinary, blood and renal Cd were specific for Cd-exposure, that increased in proportional to dose of Cd. The urinary and blood Cd tended to slightly decrease, while renal Cd tended to increase by lapse of time after Cd exposure. this finding indicates that renal Cd is more specific than urinary and blood Cd for Cd exposure. The urinary excretion of MT showed a statistically significant increase in Cd exposed rats(0.8 and 1.6 no Cd/kg body weight). The increase of urinary excretion of MT was more evident at 7, 14, 28 lays after Cd exposure than the changes of urinary excretion of total protein, beta-MG and NAG. The Pearson's correlation coefficients between urinary Cd and urinary MT, beta-MG, NAG and total protein were 0.4344, 0.3727, 0.3307 and 0.2099, respectively. These findings indicate that the urinary MT is more sensitive and specific than total protein, beta-MG and NAG for Cd exposure. The present results suggest that the urinary MT, using a simple and rapid competitive ELISA, is a valuable index as screening test in epidemiologic study for Cd exposed group.

Biological Index for Cadmium Exposure: Assay of Metallothionein by Competitive ELISA / 대한산업의학회지

Metallothionein (MT) is a cadmium binding protein that played major' roles in protective mechanism for cadmium toxicity. In the present study, competitive ELISA was established to assay the MT expression utilizing monospecific antibody which was generated against MT-L A total of 10 Sprague-Dawley rats was injected with CdCl2 for two weeks to induce MT. The cytosolic fraction of rat liver was obtained by differential centrifugation. Two major MT isozymes (MT-I & MT-II) at ca. 10 kDa were purified by Sephadex G-75 gel filtration followed by DEAE-Trisacryl-M anion exchange column chromatogra-phy, respectively. Two rabbits were immunized 4 times consecutively with the conjugate of purified MT-L The sera were collected by heart puncture. When immunoblot was carried out, the immunized rabbit sera (anti-MT-I) exhibited specific immunoreactive band at MT-I while showed any cross reactions neither with MT-II nor with other cytosolic proteins.. By chequerboard titration using the monospecific antibody, the competitive ELISA was established. The dose-dependent relationship was observed between anti-MT-I antibody and the amount of MT in biological samples (r(2)=O.9980). These results suggested strongly that competitive ELISA is a simple, rapid and reproducible method for screening cadmium exposure.

Biological Index for Cadmium Exposure: Assay of Metallothionein by Competitive ELISA / 대한산업의학회지

Metallothionein (MT) is a cadmium binding protein that played major' roles in protective mechanism for cadmium toxicity. In the present study, competitive ELISA was established to assay the MT expression utilizing monospecific antibody which was generated against MT-L A total of 10 Sprague-Dawley rats was injected with CdCl2 for two weeks to induce MT. The cytosolic fraction of rat liver was obtained by differential centrifugation. Two major MT isozymes (MT-I & MT-II) at ca. 10 kDa were purified by Sephadex G-75 gel filtration followed by DEAE-Trisacryl-M anion exchange column chromatogra-phy, respectively. Two rabbits were immunized 4 times consecutively with the conjugate of purified MT-L The sera were collected by heart puncture. When immunoblot was carried out, the immunized rabbit sera (anti-MT-I) exhibited specific immunoreactive band at MT-I while showed any cross reactions neither with MT-II nor with other cytosolic proteins.. By chequerboard titration using the monospecific antibody, the competitive ELISA was established. The dose-dependent relationship was observed between anti-MT-I antibody and the amount of MT in biological samples (r(2)=O.9980). These results suggested strongly that competitive ELISA is a simple, rapid and reproducible method for screening cadmium exposure.