R Ferreira1, L S Fonseca, W Lilenbaum. 1. Department of Medical Microbiology, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. ferreirarachel@hotmail.com
Abstract
AIMS: The aim of this study is to evaluate the AGID serological test for detection of antibodies anti-Mycobacterium paratuberculosis and its possible adoption as diagnostic method in our field conditions. METHODS: Bovine serum samples from dairy herds in Rio de Janeiro State, Brazil, were screened for the presence of antibodies against Myco. paratuberculosis using three different ELISA tests. A panel of 48 randomly selected sera were evaluated by an Agarose Gel Immunodiffusion (AGID) test using Protoplasmatic Paratuberculosis Antigen (PPA). AGID results were compared to the standards--the results of the three ELISA tests, and the specificity and sensitivity were calculated. RESULTS: From 48 sera tested for AGID, 14 (29.17%) were positive and 34 (70.83%) were negative. AGID sensitivity was 57% with two false-positive reactions, and specificity was 92.5% with nine false-negative results. The positive predictive value was calculated in 85.7% for a confidence interval of 95%. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to its low sensitivity and specificity rates, AGID test has shown to be unsatisfactory as a screening diagnostic method for subclinical herd infection, but it can be useful as a confirmatory test for clinical suspect animals.
AIMS: The aim of this study is to evaluate the AGID serological test for detection of antibodies anti-Mycobacterium paratuberculosis and its possible adoption as diagnostic method in our field conditions. METHODS:Bovine serum samples from dairy herds in Rio de Janeiro State, Brazil, were screened for the presence of antibodies against Myco. paratuberculosis using three different ELISA tests. A panel of 48 randomly selected sera were evaluated by an Agarose Gel Immunodiffusion (AGID) test using Protoplasmatic Paratuberculosis Antigen (PPA). AGID results were compared to the standards--the results of the three ELISA tests, and the specificity and sensitivity were calculated. RESULTS: From 48 sera tested for AGID, 14 (29.17%) were positive and 34 (70.83%) were negative. AGID sensitivity was 57% with two false-positive reactions, and specificity was 92.5% with nine false-negative results. The positive predictive value was calculated in 85.7% for a confidence interval of 95%. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to its low sensitivity and specificity rates, AGID test has shown to be unsatisfactory as a screening diagnostic method for subclinical herd infection, but it can be useful as a confirmatory test for clinical suspect animals.
Authors: Alifiya S Motiwala; Megan Strother; Natalie E Theus; Roger W Stich; Beverly Byrum; William P Shulaw; Vivek Kapur; Srinand Sreevatsan Journal: J Clin Microbiol Date: 2005-05 Impact factor: 5.948
Authors: Alifiya S Motiwala; Megan Strother; Alongkorn Amonsin; Beverly Byrum; Saleh A Naser; Judith R Stabel; William P Shulaw; John P Bannantine; Vivek Kapur; Srinand Sreevatsan Journal: J Clin Microbiol Date: 2003-05 Impact factor: 5.948
Authors: I F Espeschit; D G G Schwarz; A C S Faria; M C C Souza; F A Paolicchi; R A Juste; I A Carvalho; M A S Moreira Journal: Trop Anim Health Prod Date: 2017-09-07 Impact factor: 1.559