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Indirect Enzyme-linked Immunosorbent (indirect + enzyme-linked_immunosorbent)
Selected AbstractsOpportunities and constraints in the adaptation of technology for the diagnosis of bacterial plant diseases , experience from Tanzania,EPPO BULLETIN, Issue 3-4 2000R. Black In order to improve diagnostic services and plant quarantine capabilities in Tanzania, the techniques of semi-selective media, the BACTID system, metabolic profiling (Biolog), indirect enzyme-linked immunosorbent assays (ELISA) and polymerase chain reaction (PCR) were assessed for suitability with the existing facilities for the diagnosis and detection of plant-pathogenic bacteria of vegetables. Field-collected samples as well as farmers' own and commercial germplasm were used in studies involving Ralstonia solanacearum, Clavibacter michiganensis subsp. michiganensis and Xanthomonas campestris pv. vesicatoria in Solanaceae and X. c. pv. campestris in Brassicaceae. Each of the techniques was used successfully with one or more of the target pathogens; each had advantages depending on the speed, sensitivity and specificity required, as well as the costs of carrying out the diagnosis. However, constraints emerged relating to the use and disposal of materials such as plastic Petri dishes and toxic substances. The more familiar underlying constraints of high cost and poor availability of consumables and erratic water and electricity supply continued to present problems. These problems will be discussed in relation to the development of an integrated and sustainable approach to the provision of routine diagnostic services. [source] Serological detection and immunogold localization of cross-reactive antigens shared by Camellia sinensis and Exobasidium vexansJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2007B.N. Chakraborty Abstract Aims:, Pathogenicity of Exobasidium vexans, causal agent of blister blight of tea, was studied in 30 commercially cultivated tea varieties by analysing the antigenic patterns of host and pathogen using immunological techniques. Methods and Results:, Whole plant inoculation of tea varieties with E. vexans showed that T-78 and T-17/1/54 were most susceptible and most resistant respectively. Antigen preparations from tea varieties, pathogen, nonpathogen (Fusarium oxysporum) and of nonhosts (Glycine max, Leucaena leucocephala and Oryza sativa) were compared by indirect enzyme-linked immunosorbent assay and dot-immunobinding assay using polyclonal antibodies raised against the pathogen, nonpathogen, susceptible and resistant tea varieties. Cross-reactive antigens (CRA) were found among susceptible varieties and E. vexans isolates but not in resistant varieties, nonhosts or nonpathogen. Indirect staining of antibodies using fluorescein isothiocyanate indicated CRA were concentrated mainly around epidermal and mesophyll cells in compatible host (T-78). This was substantiated by ultrastructural studies using gold-labelled antibodies through transmission electron microscopy which showed specific localization in the chloroplasts and host cytoplasm. Conclusion:, Pathogenicity of E. vexans to different tea varieties is therefore related to the level of antigenic similarity between host and pathogen. Significance and Impact of the Study:, Immunological methods proved to be valuable in screening commercially cultivated tea varieties against E. vexans. [source] Chagas' disease: IgG isotypes against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens of Trypanosoma cruzi in chronic Chagasic patientsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 5 2007A.F.A. Verçosa Abstract The wide range of clinical Chagas' disease manifestations, of which heart involvement is the most significant, because of its characteristics, frequency and consequences, and lack of treatment and cure, justify research in this area. Specific immunoglobulin G (IgG) antibody subclasses have been associated with human Chagas' disease. Thus, in this study, the profile of IgG subclasses against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive T. cruzi,specific antigens was correlated with cardiac (CARD, n=33), cardiodigestive (CD, n=7), and indeterminate (IND, n=20) forms of Chagas' disease by indirect enzyme-linked immunosorbent assay (ELISA). IgG subclasses were detected in almost all Chagas patients studied. Nevertheless, only specific IgG2 isotype FRA was found with a significant statistical difference in CARD patients when compared to IND patients. This result suggests the potential use of this isotype for prognostic purposes, for monitoring the progression of chronic Chagas' disease, and for predicting the risk of CARD damage. This is important information, as it could help physicians to evaluate and manage the treatment of their patients. However, a follow-up study is necessary to confirm our result. J. Clin. Lab. Anal. 21:271,276, 2007. © 2007 Wiley-Liss, Inc. [source] Prevalence of high antibody titers of pertussis in Turkey: reflection of circulating microorganism and a threat to infantsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 3 2007Berrin Esen Abstract Acute pertussis infection among adults can cause its transmission to the larger population, especially to infants and young children, who can develop severe disease. In order to determine an age-dependent pertussis immune response, anti-pertussis toxin (PT) antibody was detected by the indirect enzyme-linked immunosorbent assay (ELISA) method in serum samples from 2,085 healthy subjects ranging in age from 6 months to ,60 years. Also included in the evaluation were responses to a questionnaire including sociodemographic characteristics, vaccination, and infection history. Titers of 50,99 ELISA units (EU)/mL and of ,100,EU/mL were accepted as indicative for recent exposure or infection. In addition, 30,EU/mL was estimated to be a sufficient titer in women of childbearing age to protect their newborns until administration of their first dose of pertussis vaccine. After the age of 4,5 years, presence of high-titered antibodies that increase with age might be a reflection of circulating infection and indicate the magnitude of the threat to infants. According to the questionnaires, in the groups younger than 15 years old, three to four doses of diphtheria toxoid-whole cell pertussis-tetanus toxoid (DwPT) were administered in 47.2 to 77.4%, 91.2 to 100.0%, and 83.5 to 100.0% of participants in Diyarbakir, Samsun, and Antalya, respectively. In addition, up to half of the expectant mothers we studied lacked a sufficient level of estimated antibody titers. To protect infants from life-threatening pertussis infection, improving vaccination coverage to ensure herd immunity and uniformly establishing coverage throughout the country are essential. Furthermore, revaccination with acellular vaccine for schoolchildren as well as for the households of pregnant women is recommended. J. Clin. Lab. Anal. 21:154,161, 2007. © 2007 Wiley-Liss, Inc. [source] Hepatitis E antibody profiles in serum and urineJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 3 2002M.S. Joshi Abstract The aim of this study was to evaluate anti-HEV antibody profiles in urine specimens in comparison to corresponding serum samples to assess the utility of urine as a clinical specimen. Paired serum and urine specimens from 71 hepatitis E patients, 33 non-E hepatitis patients, 63 patients with nonhepatic diseases, and 26 healthy individuals were tested by recombinant HEV protein (55 kD)-based indirect enzyme-linked immunosorbent assay (ELISA). Uronegativity for anti-HEV IgM was noted in 71 (100%) serologically confirmed patients with hepatitis E. Hepatitis E patients (10/10) showed urinary absence or very low levels of total IgM by capture ELISA, suggesting absence or low levels of filtration, and/or local synthesis, and/or transudation of IgM in urine during infection. When these patients were tested for total IgG and IgA, microquantities of immunoglobulins were noted in all urine samples (10/10 for each). However, the proportions of uropositivity for anti-HEV IgG and IgA in hepatitis E patients were low and indicated only 21.42% and 49.33% concordance with seropositivity, respectively. Control groups also showed low and variable uropositivity for anti-HEV IgG and IgA. Overall, HEV-specific antibodies exhibited by serum in recent and past infections were not found in urine. The study demonstrated the inadequacy of urine specimens for detection of hepatitis E antibodies. J. Clin. Lab. Anal. 16:137,142, 2002. © 2002 Wiley-Liss, Inc. [source] Detection of nodavirus in barramundi, Lates calcarifer (Bloch), using recombinant coat protein-based ELISA and RT,PCRJOURNAL OF FISH DISEASES, Issue 3 2001Huang The coat protein encoded by the nodavirus RNA2 gene originally isolated from greasy grouper, Epinephelus tauvina, was cloned, expressed as a recombinant polyhistidine-tailed fusion protein and characterized by immunoblot analysis. The purified recombinant protein was used to develop an indirect enzyme-linked immunosorbent assay (ELISA) to detect body exudate and plasma antibodies against the coat protein in both experimentally infected and commercial barramundi. In addition, the nucleotide sequence was employed to develop a RT,PCR detection assay based on the T4 region. The results showed that the virus could be detected as early as 3 days post-infection by RT,PCR while antibodies against the recombinant coat protein were detectable on day 6 post-infection. Among 112 commercial barramundi samples collected from October 1999 to April 2000, 9% showed positive ELISA results which were further verified by Western blot. [source] Production of Polyclonal Antibodies to a Recombinant Coat Protein of Potato mop-top virusJOURNAL OF PHYTOPATHOLOGY, Issue 4 2003ovská Abstract The coat protein (CP) coding regions of two Czech Potato mop-top virus (PMTV) isolates were sequenced and shown to be identical. One, the Korneta isolate CP gene, was cloned in several expression vectors. The recombinant PMTV-CP was expressed in Escherichia coli and the purified recombinant protein was used to produce PMTV-specific polyclonal antibodies. The antiserum had a titre of 1 : 2000 in an indirect enzyme-linked immunosorbent assay (ELISA) and reacted specifically in immunoblotting and IPTA- ELISA (indirect plate-trapped antigen (PTA)-ELISA). [source] Rhizobacteria-mediated resistance against the blackeye cowpea mosaic strain of bean common mosaic virus in cowpea (Vigna unguiculata)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2009Arakere Chunchegowda Udaya Shankar Abstract BACKGROUND: The present study investigated the effect of seven Bacillus -species plant-growth-promoting rhizobacteria (PGPR) seed treatments on the induction of disease resistance in cowpea against mosaic disease caused by the blackeye cowpea mosaic strain of bean common mosaic virus (BCMV). RESULTS: Initially, although all PGPR strains recorded significant enhancement of seed germination and seedling vigour, GBO3 and T4 strains were very promising. In general, all strains gave reduced BCMV incidence compared with the non-bacterised control, both under screen-house and under field conditions. Cowpea seeds treated with Bacillus pumilus (T4) and Bacillus subtilis (GBO3) strains offered protection of 42 and 41% against BCMV under screen-house conditions. Under field conditions, strain GBO3 offered 34% protection against BCMV. The protection offered by PGPR strains against BCMV was evaluated by indirect enzyme-linked immunosorbent assay (ELISA), with lowest immunoreactive values recorded in cowpea seeds treated with strains GBO3 and T4 in comparison with the non-bacterised control. In addition, it was observed that strain combination worked better in inducing resistance than individual strains. Cowpea seeds treated with a combination of strains GBO3 + T4 registered the highest protection against BCMV. CONCLUSION: PGPR strains were effective in protecting cowpea plants against BCMV under both screen-house and field conditions by inducing resistance against the virus. Thus, it is proposed that PGPR strains, particularly GBO3, could be potential inducers against BCMV and growth enhancers in cowpea. Copyright © 2009 Society of Chemical Industry [source] Sensitive detection of Ralstonia solanacearum in soil: a comparison of different detection techniquesPLANT PATHOLOGY, Issue 4 2000P. M. Pradhanang The sensitivity and specificity of various methods were compared for routine detection of Ralstonia solanacearum in a sandy loam soil. Populations fewer than 102 CFU per g soil were detected by dilution plating on a modified semiselective medium (SMSA). In comparison, a tomato bioassay was shown consistently to detect populations at or greater than 7·5 × 105 CFU per g soil. An indirect enzyme-linked immunosorbent assay (ELISA) was as sensitive as the tomato bioassay, but detected as few as 104 CFU per g soil when the suspension was first incubated in SMSA broth prior to testing. Detection using a nested polymerase chain reaction (PCR) was equally as sensitive as that using culture on SMSA agar, but only when the infested soil sample was first enriched overnight in SMSA broth prior to the nested PCR. Longer incubation periods in SMSA broth also increased the sensitivity of pathogen detection using a conventional PCR method, permitting detection of as few as 102 CFU per g soil after 60 h enrichment in SMSA broth. When evaluated using naturally infected field soils in Nepal, isolation of R. solanacearum on SMSA was reliable only when pathogen populations were higher than those of saprophytic soilborne bacteria. As few as 5 × 102 CFU of R. solanacearum per g were recovered from naturally infested soil, whereas the sensitivity of indirect ELISA was 106 CFU g,1. [source] | ||||||||||