SOME BACTERIOLOGICAL AND SEROLOGICAL STUDIES ON BRUCELLOSIS IN RUMINANTS

Abstract

Brucellosis is an incapacitating zoonosis in humans and economically disastrous disease in farm animals caused by the genus Brucella. It causes reproductive losses in animals in the form of late stage abortion, retained placenta, weak or dead birth and infertility in females and orchitis and epididymitis in males with hygroma and arthritis. Additionally, brucellosis is notorious for its latent infection. In Egypt, brucellosis is reported in all farm animal species and in the environment. The bacteriological method include field and lab means has a limited sensitivity and has the added difficulty of being unpractical to apply at large scale in control campaigns. Therefore, the investigation was designed to evaluate the diagnostic performance characteristics of some serological tests used for brucellosis diagnosis of large and small ruminants in some governorates. In this study, a number of 11 Brucella isolates were isolated from five governorates (Beheira, Sharkia, Kafr El-Sheikh, Giza and Gharbia). Only four isolates were identified as B. abortus bv.1 and 7 isolates were identified as B. melltensis bv.3 according to their morphological, physiological, serological and genetic characteristics. Low diagnostic performance characteristics of Riv.T in small ruminants specially in ewes if compared to other serological tests, makes it unwise to replace the standard confirmatory CFT test recommended by the OIE, European Commissions, USDA for international trade by Riv.T even in large ruminants. Diagnostic performance characteristics of serological tests in large ruminants were better than the corresponding picture in small ruminants especially for MAT and Riv.T. Whereas the characteristics of EDTA-mMAT were better than MAT in both large and small ruminants. Keywords: Brucella, MAT, EDTA-mMAT, Riv.T, USDA, CFT, OIE