Bacteriological and molecular detection of brucellosis with special reference to the effect of disinfectants on isolated strains

Lobna M. A. Salem

Abstract

A total of 127 specimens (13 aborted foeti, 46 milk samples, 37 lymph nodes, 14 livers, 14 spleen and 6 vaginal discharges) were collected and examined for isolation and typing of Brucella microorganism. The results detected 15 strains (5 aborted foeti, 4 milk, 5 lymph nodes and 1 spleen) were detected and typed as Br. melitensis biovar 3. Application of PCR test for rapid identification of Brucella strains which isolated from lymph nodes five of naturally infected animals (two cattle, one buffaloes, one sheep and one goat) revealed that all samples were reacted positively with Br. melitensis specific DNA products with a molecular size of 731 pb. On sequencing, the Nucleotide sequence alignment of obtained sequences with other Brucella strain indicated that the obtained isolate have high identity with Br. melitensis biovar 3. The bacteriocidal activity of tested disinfectants against isolated Br. melitensis strain at variables concentration revealed that halogen showed highest bactericidal activity followed by QACs and phenolic while alkaline wasthe lowest effect.

Key words