scholarly journals Detection by Two Enzyme-Linked Immunosorbent Assays of Antibodies to Ehrlichia ruminantium in Field Sera Collected from Sheep and Cattle in Ghana

2003 ◽  
Vol 10 (5) ◽  
pp. 917-925 ◽  
Author(s):  
Lesley Bell-Sakyi ◽  
Enoch B. M. Koney ◽  
Otilia Dogbey ◽  
Keith J. Sumption ◽  
Alan R. Walker ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Amblyomma Variegatum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
Ehrlichia Ruminantium ◽  
Ruminant Species ◽  
Cutoff Values ◽  
Highly Sensitive ◽  
Percent Positivity ◽  
Cutoff Levels

ABSTRACT Two serological tests for detection of antibodies to Ehrlichia (previously Cowdria) ruminantium, the causative agent of heartwater, were compared by using field sera collected from sheep and cattle as part of serosurveys in Ghana. Sera selected as either negative or positive by a new polyclonal competitive enzyme-linked immunosorbent assay (PC-ELISA) were tested by the indirect MAP1-B ELISA. Cutoff values of 14 percent positivity (14 PP) for both ruminant species were obtained for the MAP1-B ELISA by using preseroconversion Ghanaian sera and were compared with previously recommended cutoff values of 29 PP for sheep and 38 PP for cattle. With the 14-PP cutoff, of 151 sheep sera which tested negative by PC-ELISA, 89% were also negative by MAP1-B ELISA, while of 419 sheep sera positive by PC-ELISA, 98% were also positive by MAP1-B ELISA. Of 261 bovine sera negative by PC-ELISA, 82% were also negative by MAP1-B ELISA. Of 511 bovine sera positive by PC-ELISA, only 47% were positive by MAP1-B ELISA; these included 168 sera collected from cattle following first seroconversion as detected by both tests, with 125 of these sera positive by PC-ELISA but only 59 and 5 positive by MAP1-B ELISA with the 14- and 38-PP cutoff levels, respectively. These results indicate that both assays are highly sensitive and specific for detection of E. ruminantium exposure in sheep but that the MAP1-B ELISA lacks sensitivity for postseroconversion bovine sera in comparison to the PC-ELISA. Both tests confirm E. ruminantium seroprevalence of at least 70% in Ghanaian sheep; levels of exposure among Amblyomma variegatum-infested Ghanaian cattle are likely to be higher than the seroprevalence value of 66% obtained with the PC-ELISA.

scholarly journals Rapid Detection of Campylobacter coli, C. jejuni, and Salmonella enterica on Poultry Carcasses by Using PCR-Enzyme-Linked Immunosorbent Assay

2003 ◽  
Vol 69 (6) ◽  
pp. 3492-3499 ◽  
Author(s):  
Yang Hong ◽  
Mark E. Berrang ◽  
Tongrui Liu ◽  
Charles L. Hofacre ◽  
Susan Sanchez ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Salmonella Enterica ◽  
Rapid Detection ◽  
Diarrheal Disease ◽  
False Negative ◽  
Enzyme Linked Immunosorbent Assay ◽  
Campylobacter Coli ◽  
Culture Methods ◽  
Isolation And Identification ◽  
Serological Tests

ABSTRACT Contamination of retail poultry by Campylobacter spp. and Salmonella enterica is a significant source of human diarrheal disease. Isolation and identification of these microorganisms require a series of biochemical and serological tests. In this study, Campylobacter ceuE and Salmonella invA genes were used to design probes in PCR-enzyme-linked immunosorbent assay (ELISA), as an alternative to conventional bacteriological methodology, for the rapid detection of Campylobacter jejuni, Campylobacter coli, and S. enterica from poultry samples. With PCR-ELISA (40 cycles), the detection limits for Salmonella and Campylobacter were 2 � 102 and 4 � 101 CFU/ml, respectively. ELISA increased the sensitivity of the conventional PCR method by 100- to 1,000-fold. DNA was extracted from carcass rinses and tetrathionate enrichments and used in PCR-ELISA for the detection of Campylobacter and S. enterica, respectively. With PCR-ELISA, Salmonella was detected in 20 of 120 (17%) chicken carcass rinses examined, without the inclusion of an enrichment step. Significant correlation was observed between PCR-ELISA and cultural methods (kappa = 0.83; chi-square test, P < 0.001) with only one false negative (1.67%) and four false positives (6.67%) when PCR-ELISA was used to screen 60 tetrathionate enrichment cultures for Salmonella. With PCR-ELISA, we observed a positive correlation between the ELISA absorbance (optical density at 405 nm) and the campylobacter cell number in carcass rinse, as determined by standard culture methods. Overall, PCR-ELISA is a rapid and cost-effective approach for the detection and enumeration of Salmonella and Campylobacter bacteria on poultry.

Development of a Highly Sensitive Enzyme-Linked Immunosorbent Assay Based on Polyclonal Antibodies for the Detection of Polychlorinated Dibenzo-p-dioxins

1998 ◽  
Vol 70 (6) ◽  
pp. 1092-1099 ◽  
Author(s):  
Yukio Sugawara ◽  
Shirley J. Gee ◽  
James R. Sanborn ◽  
S. Douglass Gilman ◽  
Bruce D. Hammock
Keyword(s):  
Immunosorbent Assay ◽  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Highly Sensitive

A highly sensitive and direct competitive enzyme-linked immunosorbent assay for the detection of di-(2-ethylhexyl) phthalate (DEHP) in infant supplies

2015 ◽  
Vol 7 (13) ◽  
pp. 5441-5446 ◽  
Author(s):  
Mingcui Zhang ◽  
Wentong Hong ◽  
Xiayu Wu ◽  
Yue Zhang ◽  
Fengzhu Li ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Highly Sensitive ◽  
Ethylhexyl Phthalate

A sensitive and specific direct competitive enzyme-linked immunosorbent assay (dc-ELISA) was studied in this paper for the detection of di-(2-ethylhexyl) phthalate (DEHP) based on an antigen-coating format.

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