Validation of a second generation competitive enzyme immunoassay (CELISA) for the diagnosis of brucellosis in various species of domestic animals

Seroprevalence and risk factors of Brucellosis in small ruminants slaughtered at Debre Ziet and Modjo export abattoirs, Ethiopia

“…This might be due to similar sources of small ruminants, since most small ruminants slaughtered in the export abattoirs came from pastoral and agro-pastoral areas of the country. Boukary et al [24] reported an overall true brucellosis prevalence of 3.6% in sheep in Nigeria; Negash et al [8] reported a prevalence of 9.39% in caprines and 8.77% in ovines in Dire-Dawa regions; similarly, Ashenafi et al [13] observed prevalence rates of 3.2% and 5.8% in ovines and caprines in the pastoral areas of the Afar region, respectively. All export abattoirs in Ethiopia slaughtered and exported only male animals who were relatively young and healthy.…”

Diagnostic performance of serological tests for swine brucellosis in the presence of false positive serological reactions

“…1). This criterion assumes that the practical relevance of false-positive and falsenegative results is the same (Nielsen et al, 1999(Nielsen et al, , 2008Minas et al, 2005) but this is not true under many circumstances. In slowspreading and low prevalence infections like swine brucellosis by B. suis biovar 2 in Europe (EFSA, 2009), the major problem is the lack of specificity caused by FPSR because of the trade restrictions and culling of healthy animals generated.…”

Evaluation of Indirect Enzyme-Linked Immunosorbent Assays and IgG Avidity Assays Using a Protein A-Peroxidase Conjugate for Serological Distinction between Brucella abortus S19-Vaccinated and -Infected Cows

“…In addition, it is possible that the residual percentages of the positivity rates found with animals from GIV may be due to cross-reactivity, due mainly to the fact that the antigen preparation used in the present work was constituted by B. abortus S-LPS. It was already demonstrated in the literature that a number of bacteria induce antibody responses that cause false-positive reactions in tests for brucellosis, mostly when using B. abortus S-LPS (28)(29)(30)32). As the serum samples of group IV came from animals with epidemiological characteristics well defined, i.e., unvaccinated animals from a brucellosis-free region, the possibility of infection or residual vaccination interference in the results obtained in the present work is low.…”

“…The use of monoclonal antibodies that do not react with PAG has been standardized in a second generation of the cELISA for detection of bovine antibody to B. abortus, thus eliminating reagent variables as the requirement for polyclonal anti-mouse enzyme conjugate for detection. In this new cELISA, a slightly lower exclusion of S19-vaccinated animals was found, with vaccinate specificity of 53.8% (28,29). In our study using the iELISA with protein A-HRPO, we found a high rate of exclusion of antibodies generated after vaccina- a GI, nonvaccinated seropositive cows originated from areas where Brucella is endemic or an outbreak is occurring (n ϭ 41); GII, S19-vaccinated heifers between 3 and 8 months of age, originated from areas where Brucella is endemic, and serum samples were analyzed at 3 months postvaccination (n ϭ 79); GIII, S19-vaccinated cows between 3 and 8 months of age, originated from areas where Brucella is endemic, and serum samples were analyzed after 24 months of age (n ϭ 105); GIV, nonvaccinated seronegative cows originated from areas where Brucella is nonendemic (n ϭ 278).…”

“…ELISAs have been evaluated as alternative techniques for this purpose, but the attempt to standardize primary binding assays has generally not been successful due to the wide variety of protocols used by individual laboratories and additional troubles in standardizing reagents, such as the anti-immunoglobulin conjugates required by the ELISA and the polyclonal anti-mouse antibodies required by the cELISA as detection reagents (28). In this context, ELISAs using affinity conjugates as protein A or G labeled with peroxidase have been shown to be useful in allowing a serological distinction of different IgG antibody isotypes, which can be important in characterizing the profile of Brucella infection (22,32).…”