الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
This study was conducted on Agricultural Research Station Cattle Farms and Slaughter houses at Kefir El Sheikh Governorate for sample collection, The Microbiology Laboratory at the High Institute of Public Health (HIPH), Alexandria University, The Microbiology Laboratory at the Animal Health Research Institute in Cairo (AHRI), Ministry of Agriculture and Land Reclamation for staining acid-fast bacilli (AFB), culture, biochemical and PCR tests.
The aim of this cross sectional study was to determine the distribution of Mycobacterium bovis infection in the field.
A total of 946 cows (milking and non milking ) reared in Agricultural Research Station Cattle Farms were taken . Samples were 70 milk samples were collected from 50 tankes of milk and 20 individual milk collected from milking adult cows (5-9 years) (ten cows per tanke ) , and Twenty three lymph nodes were collected from 23 tuberculin positive animals after slaughtering in the abbatoir from Slaughter houses in Kefir El Sheikh Governorate . All samples were transferred to the laboratory in an ice box within 24h.
Tuberculin test was be performed for all animals above 6 months old (946) according to General Organization of Veterinary Services (GOVS).
All samples were subjected to the following procedures:
- Direct microscopic examination .
- Preparation and culture onto Lowenstein-Jensen medium .
- Biochemical identification (Niacin test,Nitrate reduction test and Pyrazinamidase test).
- Molecular diagnosis of Mycobacterium using Real-time PCR:( Tissue samples, milk samples and isolated strains of Mycobacterium ).
The results of this study can be summarized as follows:
- Out of 946 cows were examined for bovine tuberculosis , 23 cases were positive by using single intradermal tuberculin test with percentage reached 2.4 % .
- Out of 23 The lymph nodes of all positive cases , 17 isolates of mycobacterium spp. (73.9%) ,while the microscopical examination showed 15 ( 65.2 %) and 21 cases were positive by using REAL TIME PCR WITH (91.3 %) .
- Out of 50 tanks milk, 2 positive samples by microscopical examination (4%), (2) isolates were recovered by cultural method (4%) , 2 tanks milk samples proved by The real time PCR(4%).
- Out of 20 individual Milk samples , 4 posotive isolates of mycobacterium spp (20%). and 6 milk samples were positive for bovine tuberculosis ( one positive sample from first tank and 5 positive samples from the second tank) (25%). and 2positive samples by microscopic examination (10%).
from this results the following can be concluded:
- Tuberculin test has low sensitivity, low specificity, not accurate and time consuming in the detection of M. bovis.
- Culture is time consuming and less sensitive than PCR.
- RT-PCR technique has a high sensitivity and specificity in the detection of M. bovis.
- PCR technique is more accurate and faster than conventional techniques in the diagnosis of bovine tuberculosis.
- RT-PCR had the highest results for lymph nodes and individual milk.
- Individual milk is the better than bulk milk for detection of M.bovis.
According to the results of this study it is recommended that:
1- The tuberculin test should not be used alone for screening the disease.
2- PCR technique can be used as a complementary to the tuberculin skin test to determine the disease status of animal or as a rapid screening test for herd testing program.
3- Milk pasteurization should be achieved .
4- Good meat inspection should be applied.
5- Samples should be taken from lymph nodes with or without visible lesions.
6- Further large scale studies are needed to determine M. bovis infection in all cattle farms of Egypt.