APPLICATION OF MICROAGGLUTINATION TEST FOR DETECTION OF ANTIBODIES TO SALMONELLA GALLINARUM IN COMMERCIAL LAYER CHICKENS

摘要

In this study a microagglutination test (MAT) was developed, evaluated and compared with a rapid whole-blood agglutination test (RWBAT) for detection of Salmonella gallinarum antibodies in commercial layer chickens in Morogoro, Tanzania. The results showed that at Kigurunyembe farm, 16 (32%) of chicken tested were RWBAT positive while 30 (60%) were MAT positive among the 50 sera tested. Results from Kilakala farm revealed 10 (20%) sera that were RWBAT positive whereas 5 (10%) were positive for MAT among the 50 sera tested. On both farms, S. gallinarum was isolated from 21 chickens. The sensitivities, specificities, positive and negative predictive values for MAT were 57, 71, 34 and 86%, respectively, and 67, 85, 54 and 82 %, respectively for RWBAT.Although MAT was slightly less sensitive and less specific than RWBAT, it revealed a higher true seroprevalence (35%) of fowl typhoid than RWBAT (26%). When the test is optimized it may be preferred because it uses less time, space and antigen while permitting more objective evaluation of antibody liters. Higher growth and seroprevalence of S. gallinarum was observed in Rhode Island Red than Black Australop chickens.