Further Evaluation of an Indirect Enzyme‐Linked Immunosorbent Assay for the Diagnosis of Bovine Tuberculosis

Abstract

Summary The sensitivity and specificity of an ELISA for the detection of bovine IgG anti‐Mycobacterium bovis antibodies were 73.6% and 94.1%, respectively, as determined in 53 bacteriologically confirmed tuberculous cattle and 101 healthy cattle from a tuberculosis‐free area. In addition, the results of ELISA and tuberculin tests in 149 cattle were compared with those of subsequent necropsy studies. Both tests failed to detect 2 animals with tuberculous lesions and positive culture; 3/12 cattle with M. bovis isolation and no lesions, and 2/7 with atypical mycobacterial infection reacted to tuberculin, but none had antibodies; in 128 cattle with neither lesions nor mycobacterial isolation, 6 were tuberculin reactors and 7 others had antibodies. Negative results were obtained by ELISA in 21/22 paratuberculous cattle. Antibodies were not detected in 88.9 % to 96.4 % of 697 cattle from two tuberculin negative herds of an endemic area. In a herd with proved M. bovis infection, distribution of seropositive animals in tuberculin and non‐tuberculin reactors was similar. Antibody responses to cutaneous tuberculin stimuli were observed in 4 experimentally infected cattle, but only in 2/10 healthy controls after repeated PPD stimuli. Nine controls which had either received a single tuberculin dose or none showed no increase in antibody levels. The low sensitivity of this ELISA limits its usefulness as a diagnostic tool for bovine tuberculosis eradication campaigns. However, it could be helpful in epidemiological surveillance if its efficiency to identify infected herds is demonstrated. Zusammenfassung Weitere Erkenntnisse über einen indirekten ELISA zur Diagnose der bovinen Tuberkulose Zur Prüfung der Sensitivität und Spezifität eines ELISA zur Diagnose boviner Tuberkulose wurden Seren von Rindern mit bakteriologisch gesicherter Tuberkulose (n: 53), sowie von Tieren aus einem tuberkulosefreien Gebiet (n: 101) untersucht; die Resultate stimmten in 73,6 % bzw. 94,1 % der Fälle überein. Des weiteren wurden die ELISA‐ und Tuberkulintest‐Ergebnisse von 149 Rindern mit denen einer nachfolgenden pathologisch‐anatomischen Untersuchung verglichen. Beide Testsysteme waren nicht in der Lage, zwei Tiere mit pathologisch/anatomisch und bakteriologisch gesicherter Tuberkulose zu erkennen; drei von 12 Tieren, aus denen M. bovis isoliert wurde und die keine morphologischen Veränderungen aufwiesen, sowie 2 von 7 Tieren, die mit atypischen Mykobakterien infiziert waren, zeigten zwar eine positive Tuberkulinprobe, aber es konnten keine Antikörper nachgewiesen werden; von 128 Rindern, bei denen weder pathologisch‐anatomische Veränderungen beobachtet werden konnten noch Mycobakterien isoliert wurden, zeigten 6 eine positive Tuberkulinreaktion und 7 weitere Tiere wiesen Antikörper auf. Bei 21 von 22 an Paratuberkulose erkrankten Rindern verliefen die ELISA‐Untersuchungen negativ. Bei Rindern aus zwei Tuberkulin‐negativen Herden (n: 697) konnten ebenfalls in 88,9% und 96,4% der Fälle keine Antikörper festgestellt werden. In einer Rinderherde mit ...

Seroprevalence and Risk Factors Associated to Mycobacterium bovis in Wild Artiodactyl Species from Southern Spain, 2006–2010

“…The lower Se of the bPPD-ELISA or the early detection of antibodies using the MPB83-ELISA, could explain the differences between tests [16], [17]. Similar results of accuracy were previously reported using a bPPD-ELISA in wild boar [14], [15] and cattle [18]. However, a close comparison among studies is difficult to interpret because of the different cut-off values, antigens used, type of samples, infection status or species analyzed.…”

Evaluation of ELISA in the serodiagnosis of bovine farcy

“…The sensitivity (92.7%) and specificity (97%) obtained in the present study using the cut-off value ≥1.8 OD were excellent. This is comparable to a previous work by Ritacco et al (1990) for the serodiagnosis of bovine tuberculosis in Argentina with 73.6% sensitivity and 94.1 specificity, and to figures obtained by Larsen et al (2000).…”

A polymerase chain reaction and enzyme linked immunosorbent assay based approach for diagnosis and differentiation between vaccinated and infected cattle with Mycobacterium bovis

“…Several serological tests are being developed and there is also the possibility that they can be adapted to detect mycobacterial antibody in bulk milk tank samples for herd testing. [6] The low sensitivity of enzyme-linked immunosorbent assay (ELISA) limits its usefulness as a diagnostic tool for bovine tuberculosis (BTB) eradication campaigns[7] but utilization of combinations of strain-specific mycobacterial antigens like MTB40, ESAT6, CFP10, MBP70, Rv3870 and Rv1580c could resolve both specificity and sensitivity. [8] Due to dysgonic and very slow growth, the identification of M. bovis by conventional biochemical methods is cumbersome and time-consuming.…”