Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) for Genotyping of Egyptian Brucella Isolates

In this comparative study, three Brucella vaccinal strains namely S19, RB51 and Rev-1 along with three Brucella reference strains designated as ETHER (Brucella melitensis biovar 3), 16M (Brucella melitensis biovar 1) and REO198 (Brucella ovis), in addition to 6 local isolates recovered from different animal species that proved to be Brucella melitensis biovar 3 biochemically and serologically. Multiplex PCR and MLVA were used to differentiate between the aforementioned Brucella strains. Multiplex PCR and MLVA using only three primer pairs to amplify three minisatellites loci in panel 1 were very successful and accurate in terms of characterization and typing of Brucella vaccines, reference and wild Brucella strains. Multiplex PCR and MLVA data were closely identical to those obtained by the traditional methods of identification. However, the molecular typing of the Brucella strains by multiplex PCR and MLVA had several advantages over the use of the conventional methods being very fast, precise, easier, more sensitive and economic and could be applied on minimal sample preparation. So, PCR and MLVA is a reliable tool in testing of the seed culture during the preparation of Brucella vaccines as well as in evaluating them in quality control laboratories, also powerful epidemiological tools for detection and diagnosis of brucellosis and helping in determining the situation of the disease.