الفهرس 
Introduction and aim of the workيوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
Bovine tuberculosis is a chronic debilitating disease of bovines which cause severe economic losses and characterized by progressive development of nodular granulomas known as tubercles in any body tissue, but lesions are most frequently observed in the respiratory tract and associated lymph nodes. The disease represents a major trade barrier for animal related products and livestock production; and is ranked among the top seven zoonotic threats to human by WHO.
Diagnosis of tuberculosis in animals in Egypt uptill now is still undertaken by the single intradermal cervical tuberculin test (SICTT) by using human PPD (prepared from Mycobacterium tuberculosis) and the eradication program depend on (test and slaughter) slaughtering of animals which give positive tuberculin result, but this tuberculin test has many disadvantages as it give false positive and false negative results.
This study was carried out to compare between different diagnostic methods of tuberculosis to reach the faster and the more sensitive and specific diagnostic method.
-So the following trials were carried out:
1) 180 animals from El-Menofya Governate were tested by single intradermal cervical tuberculin test (SICTT) by using human PPD (prepared from Mycobacterium tuberculosis), 20 animals (11%) gave positive results. The positive reactors were slaughtered and collect tissues and lymph nodes which have lesions (20 lymph nodes, 15 lung, 11 liver and 6 spleen samples).
2) Blood samples without anticoagulants and blood samples with anticoagulants (heparin) were collected from 180 animals which were tested by SICTT previously.
3) The microscopic examination of tissues which collected from 20 positive tuberculin reactors (20 lymph nodes, 15 lung, 11 liver and 6 spleen samples) revealed that the lymph nodes had significantly higher number of positive results for M. bovis13/20(65%), followed by the lung 9/15(60%) then the liver 6/11(54.5%) finally the spleen had the least number of positives for BTB 3/6(50%).
4) The bacteriological examination of different tissues collected from tuberculin positive animals revealed that the lymph nodes had significantly higher number of positive results for Mycobacterium bovis 15/20(75%), followed by the lung 10/15(66.6%) then the liver 8/11(72.7%) finally the spleen had the least number of positives for BTB 4/6(66.6%).
5) Real time PCR was carried out on 52 tissues samples which collected from 20 positive tuberculin reactors (20 lymph nodes, 15 lung, 11 liver and 6 spleen samples) the results revealed that 47(90.3%) samples were positive.
6) Real time PCR was carried out on 37 isolates from positive cultures, the results revealed that 37(100%) isolates were positive.
7) ELISA was carried out on serum samples collected from 180 animals which were tested by SICTT previously, the results revealed that 21(11.6%) animals were positive by using bovine PPD antigen ELISA and 23(12.7%) animals were positive by using commercial mixture antigen ELISA.
8) Gamma interferon assay was carried out on whole blood samples collected from 180 animals which were tested by SICTT previously, the results revealed that 24(13.3%) animals were positive.
It is clear from the preliminary results that:
1) Using of commercial mixture antigen ELISA has appreciable value in diagnosis of bovine tuberculosis than PPD antigen ELISA.
2) Using of Gamma Interferon Assay (IFN-Ɣ assay) was able to detect more positive animals indicating that it is more sensitive than the SICTT and ELISA tests (PPD antigen ELISA and commercial mixture antigen ELISA).
3) Using of Real time PCR is much faster than culture, reducing the time for diagnosis to 2 days and providing the ability to detect the presence of Mycobacterium bovis in samples even when organisms have become nonviable for culture or when there is an overgrowth by other mycobacteria or low number of mycobacteria present in the sample, as well as they are more sensitive and specific.