Development of a new lateral flow immunochromatographic for the diagnosis of bovine Tuberculosis

ALONSO N, GRIFFA N, MOYANO D, MON ML, TRAVERIA G, BARANDARIAN S, MARTÍNEZ VIVOT M, CANAL AM, SANTANGELO MP, SINGH M, ROMANO MI; ROMANO MARIA ISABEL

VETERINARY MICROBIOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017

0378-1135

Bovine tuberculosis (bTB) is one of the most important zoonotic diseases in the world. In particular, it produces important economic losses in the Argentine agricultural production. Current diagnosis of bovine tuberculosis in live animals is difficult. A large part of the problem is due to the diagnostic tests being imperfect, and the skin test for diagnosing bTB in cattle is no exception. Detection of specific antibodies would be a useful alternative tool to complement the single skin test, the reference technique currently used in Argentina. Moreover, serum samples are easy to collect and serology is faster, less expensive and complex, and more suitable for live animals than culture or other techniques. For this reason, the aim of the present work is to develop a diagnostic tool based on a lateral flow immunochromatography (LFIC) using Mycobacterium bovis (MB) specific antigens that allows a fast diagnosis of bTB. For this purpose, nitrocellulose strips printed with different concentrations of the specific antigens of MB, ESAT-6, CFP-10, MPB83,were delivered with sera obtained from experimentally infected and healthy animals. MPB83 was found to be more sensitive and specific at the 1µg/µl concentration and it was used as the test line. In order to validate the developed test 809 sera from animals of herds with bTB were tested with in house ELISA and with LFIC, 82 sera were positive by ELISA and 40 of them by the developed LFIC. It is interesting to note that of these 40 animals positive by LFIC, 38 were negative to the skin test. Subsequently, three animals, skin test (-), ELISA (+) and LFIC (+) were euthanized and we found the typical lesions of tuberculosis confirming the presence of the disease. On the other hand, one animal skin test (+) , ELISA (+) and LFIC (+) was necropsy and no lesion was observed. However, in all cases amplification of the IS6110 insertion sequence by PCR from tissue extraction was detected. In this work we have developed a technique that can detect infected animals that were not detected by the skin test and it will be useful to improve the control of bovine tuberculosis.