scholarly journals Brucella melitensis B115-BASED ELISA TO UNRAVEL FALSE POSITIVE SEROLOGIC REACTIONS IN BOVINE BRUCELLOSIS: A FIELD STUDY

2019 ◽  
Author(s):  
adriana trotta ◽  
Mariarosaria Marinaro ◽  
Margie Cirilli ◽  
Alessio Sposato ◽  
Rosanna Adone ◽  
...  

Abstract Background: Brucellosis is a zoonosis whose incidence is not declining worldwide despite the global effort to control the disease. Accurate and precise diagnosis is a crucial step in any prophylaxis program but single tests to unequivocally detect animals infected with Brucella spp. are currently unavailable. In Italy, serological diagnosis of bovine brucellosis is performed with two official tests: a rapid agglutination test (i.e., Rose Bengal Plate test, RBPT) and a complement fixation test (CFT) that detect antibodies directed mainly to the smooth lipopolysaccharide (S-LPS). Neither of the two tests is able to avoid the detection of false positive serological reactions (FPSRs) caused by bacteria sharing S-LPS components with Brucella spp. and responsible for the single reactors (SR) phenomenon. A B. melitensis R strain-based ELISA showed a good diagnostic performance in unravelling FP animals; however, since a limited number of animals were analyzed in that study, a large field study was conducted here to discriminate between Brucella-infected from FP animals, with the final aim of reducing the unnecessary slaughter of the latter. Methods: An ELISA based on a R strain of Brucella, i.e., Brucella melitensis B115, was employed to measure specific IgG responses in a collection of bovine sera (n=648). Sera were obtained from 180 farms (either officially brucellosis-free or not brucellosis-free) recruited during an extended period of time (2014-2018) and were preliminarily assayed with the official tests by the Italian Reference Centers and then subjected to the ELISA. Results: Negative sera, when subjected to the ELISA, gave O.D. values below the cutoff; SR sera, i.e. RBPT positive and CFT negative, as well as double positive (DP) sera, i.e. RBPT and CFT positive, gave O.D. values that were below the cutoff. All positive sera, i.e. from Brucella-infected animals, were RBPT positive and CFT positive (ICFTU ranging from 20 to 1280) and gave ELISA O.D. values above the cutoff. Conclusions: The B. melitensis B115-based ELISA systematically unravelled all false positive (FP) sera while confirming the diagnosis in Brucella-infected animals. Thus, the test employed in the present study may complement the official assays to avoid the costly slaughter of FP animals.

2020 ◽  
Author(s):  
adriana trotta ◽  
Mariarosaria Marinaro ◽  
Margie Cirilli ◽  
Alessio Sposato ◽  
Rosanna Adone ◽  
...  

Abstract Background: Brucellosis is a zoonosis whose incidence is not declining worldwide despite the global effort to control the disease. Accurate and precise diagnosis is a crucial step in any prophylaxis program but single tests to unequivocally detect animals infected with Brucella spp. are currently unavailable. In Italy, serological diagnosis of bovine brucellosis is performed with two official tests: a rapid agglutination test (i.e., Rose Bengal Plate test, RBPT) and a complement fixation test (CFT) that detect antibodies directed mainly to the smooth lipopolysaccharide (S-LPS). Neither of the two tests is able to avoid the detection of false positive serological reactions (FPSRs) caused by bacteria sharing S-LPS components with Brucella spp. and responsible for the single reactors (SR) phenomenon. A B. melitensis R strain-based ELISA showed a good diagnostic performance in unravelling FP animals; however, since a limited number of animals were analyzed in that study, a large field study was conducted here to discriminate between Brucella-infected from FP animals, with the final aim of reducing the unnecessary slaughter of the latter. An ELISA based on a R strain of Brucella, i.e., Brucella melitensis B115, was employed to measure specific IgG responses in a collection of bovine sera (n=648). Sera were obtained from 180 farms (either officially brucellosis-free or not brucellosis-free) recruited during an extended period of time (2014-2018) and were preliminarily assayed with the official tests by the Italian Reference Centers and then subjected to the ELISA.Results: Negative sera, when subjected to the ELISA, gave O.D. values below the cutoff; SR sera, i.e. RBPT positive and CFT negative, as well as double positive (DP) sera, i.e. RBPT and CFT positive, gave O.D. values that were below the cutoff. All positive sera, i.e. from Brucella-infected animals, were RBPT positive and CFT positive (ICFTU ranging from 20 to 1280) and gave ELISA O.D. values above the cutoff. Conclusions: The B. melitensis B115-based ELISA systematically unravelled all false positive (FP) sera while confirming the diagnosis in Brucella-infected animals. Thus, the test employed in the present study may complement the official assays to avoid the costly slaughter of FP animals.


2020 ◽  
Author(s):  
Adriana Trotta ◽  
Mariarosaria Marinaro ◽  
Margie Cirilli ◽  
Alessio Sposato ◽  
Rosanna Adone ◽  
...  

Abstract Background: Brucellosis is a zoonosis whose incidence is not declining worldwide despite the global effort to control the disease. Accurate and precise diagnosis is a crucial step in any prophylaxis program but single tests to unequivocally detect animals infected with Brucella spp. are currently unavailable. In Italy, serological diagnosis of bovine brucellosis is performed with two official tests: a rapid agglutination test (i.e., Rose Bengal Plate test, RBPT) and a complement fixation test (CFT) that detect antibodies directed mainly to the smooth lipopolysaccharide (S-LPS). Neither of the two tests is able to avoid the detection of false positive serological reactions (FPSRs) caused by bacteria sharing S-LPS components with Brucella spp. and responsible for the single reactors (SR) phenomenon. A B. melitensis R strain-based ELISA showed a good diagnostic performance in unravelling FP animals; however, since a limited number of animals were analyzed in that study, a large field study was conducted here to discriminate between Brucella-infected from FP animals, with the final aim of reducing the unnecessary slaughter of the latter. An ELISA based on a R strain of Brucella, i.e., Brucella melitensis B115, was employed to measure specific IgG responses in a collection of bovine sera (n=648). Sera were obtained from 180 farms (either officially brucellosis-free or not brucellosis-free) recruited during an extended period of time (2014-2018) and were preliminarily assayed with the official tests by the Italian Reference Centers and then subjected to the ELISA. Results: Negative sera, when subjected to the ELISA, gave O.D. values below the cutoff; SR sera, i.e. RBPT positive and CFT negative, as well as double positive (DP) sera, i.e. RBPT and CFT positive, gave O.D. values that were below the cutoff. All positive sera, i.e. from Brucella-infected animals, were RBPT positive and CFT positive (ICFTU ranging from 20 to 1280) and gave ELISA O.D. values above the cutoff. Conclusions: The B. melitensis B115-based ELISA systematically unravelled all false positive (FP) sera while confirming the diagnosis in Brucella-infected animals. Thus, the test employed in the present study may complement the official assays to avoid the costly slaughter of FP animals.


2019 ◽  
Author(s):  
Adriana Trotta ◽  
Mariarosaria Marinaro ◽  
Margie Cirilli ◽  
Alessio Sposato ◽  
Rosanna Adone ◽  
...  

Abstract Background: Brucellosis is a zoonosis whose incidence is not declining worldwide despite the global effort to control the disease. Accurate and precise diagnosis is a crucial step in any prophylaxis program but single tests to unequivocally detect animals infected with Brucella spp. are currently unavailable. In Italy, serological diagnosis of bovine brucellosis is performed with two official tests: a rapid agglutination test (i.e., Rose Bengal Plate test, RBPT) and a complement fixation test (CFT) that detect antibodies directed mainly to the smooth lipopolysaccharide (S-LPS). Neither of the two tests is able to avoid the detection of false positive serological reactions (FPSRs) caused by bacteria sharing S-LPS components with Brucella spp. and responsible for the single reactors (SR) phenomenon. An ELISA based on a R strain of Brucella, i.e., Brucella melitensis B115, was employed to measure specific IgG responses in a collection of bovine sera (n=648). Sera were obtained from 180 farms (either officially brucellosis-free or not brucellosis-free) recruited during an extended period of time (2014-2018) and were preliminarily assayed with the official tests by the Italian Reference Centers and then subjected to the ELISA. Results: Negative sera, when subjected to the ELISA, gave an O.D. value below the cutoff (i.e., 0.143); SR sera, i.e. RBPT positive and CFT negative, as well as double positive sera, i.e. RBPT and CFT positive, gave O.D. values that were below the cutoff. All positive sera, i.e. from Brucella-infected animals, were RBPT positive and CFT positive (ICFTU ranging from 20 to 1280) and gave ELISA O.D. values above the cutoff. Conclusions: Neither of the two official tests is able to avoid the detection of FPSRs caused by bacteria sharing S-LPS components with Brucella spp. The B. melitensis B115-based ELISA systematically unravelled all false positive (FP) sera while confirming the diagnosis, so the test employed in the present study may complement official tests to avoid the costly slaughter of FP animals and consequently the economic losses.


2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Adriana Trotta ◽  
Mariarosaria Marinaro ◽  
Margie Cirilli ◽  
Alessio Sposato ◽  
Rosanna Adone ◽  
...  

2011 ◽  
Author(s):  
Utpal Bhattacharya ◽  
Andreas Hackethal ◽  
Simon Kaesler ◽  
Benjamin Loos ◽  
Steffen Meyer

2020 ◽  
Vol 28 ◽  
Author(s):  
Jingjing Ren ◽  
Qisheng Peng

: Brucellosis caused by bacteria of the genus of Brucella remains a major zoonosis in the widely world, which is an infectious disease with a severe economic impact on animal husbandry and public health. The genus of Brucella includes ten species and the most prevalent is Brucella melitensis. The diagnosis of Brucella melitensis ruminant brucellosis is based on bacteriological and immunological tests. The use of vaccines and the false-positive serological reactions (FPSR) caused by other cross-reacting bacteria represent the immunological contexts. This complex context results in the development of the large number of diagnosis of Brucella melitensis brucellosis. The aim of this article is to briefly review the detection methods and compare the superiorities of different tests.


2016 ◽  
Vol 37 (5Supl2) ◽  
pp. 3413
Author(s):  
Erivânia Camelo de Almeida ◽  
Aderaldo Alexandrino Freitas ◽  
Késia Alcântara Queiroz Pontual ◽  
Marcília Maria Alves Souza ◽  
Marcos Amaku ◽  
...  

This study was conducted to characterize the epidemiology of bovine brucellosis in the state of Pernambuco, Brazil. The state was divided into three regions, and in each region, approximately 300 properties were randomly sampled. From these selected properties, a pre-established number of animals were randomly selected and blood serum samples were obtained. A total of 3,901 animals were selected from 900 properties. For each selected property, an epidemiological questionnaire was administered to assess the type of farming, the animal husbandry practices and the sanitary practices that could be associated with the presence of brucellosis infection. The testing protocol consisted of screening the samples with a buffered acidified plate antigen test and retesting the positive samples with a complement fixation test (CF). One positive animal was enough to define an infected herd. The prevalence rates of infected herds and animals in the state were 4.5% [3.2; 6.4%] and 1.4% [0.7; 2.7%], respectively. By region, the prevalence rates of infected herds and animals, respectively, were as follows: Zona da Mata, 3.3% [1.8; 6.1%] and 1.7% [0.5; 3.0%]; Agreste, 7.4% [4.9; 10.9%] and 1.9% [0.8; 3.0%]; and Sertão, 1.3% [0.5; 3.5%] and 0.7% [0.0; 1.6%]. Flooded pastures (OR = 2.86 [1.37; 6.42]) and the presence of 13 or more females in the herd (3rd quartile) (OR = 2.65 [1.19; 5.89]) were identified as risk factors. The existence of veterinary care emerged as a protective factor against bovine brucellosis in the state of Pernambuco (OR = 0.24 [0.10; 0.58]).


1976 ◽  
Vol 76 (2) ◽  
pp. 287-298 ◽  
Author(s):  
G. S. Allan ◽  
R. J. Chappel ◽  
P. Williamson ◽  
D. J. McNaught

SUMMARYBrucella-specific antibodies of different immunoglobulin classes were quantitatively evaluated with respect to their efficiency in serological tests for bovine brucellosis.IgM reacted more efficiently than IgG1and IgG2in both the Rose Bengal plate test and serum agglutination test. The complement fixation test was found to be slightly more sensitive to IgM than to IgG1and did not react to IgG2.IgM was, however, partly inactivated when heated at 60°C. in the presence of serum.


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