Application of multiple-locus variable-number tandem-repeat analysis in Brucellosis surveillance

Objective To establish the standard operating procedures on multiple locus variable number tandem repeat analysis and to evaluate the values in identification of Brucella(B.) melitensis and epidemiological trace-back.Methods Sixteen B.melitensis,22 B.abortus,21 B.suis and 10 B.cnais were investigated by Brucella MLVA-16 genotyping scheme.All data were analyzed using BioNumerics version 5.1 software (AppliedMaths,Belgium).Clustering analysis was based on the categorical coefficient and unweighted pair group method using arithmetic averages(UPGMA) method.Polymorphism at each locus was quantified using Nei's diversity index.Resultant genotypes were compared using the web-based Brucella 2010 MLVA database.Results MLVA methods were successfully established and some strains can be clustered.Bruce06,bruce08,bruce11,bruce12,bruce42,bruce43,bruce45 and bruce55 were useful for species identification of Brucella isolates.Bruce04,bruce07,bruce09,bruce16 and bruce 30 afforded a higher discriminatory power for investigation of strain relatedness in regions of endemicity.Conclusions The MLVA method has proved to be highly discriminatory and epidemiological concordance and is easy for Brucellosis surveillance in province-level lab. Key words: Brucella;  Gene;  Multiple-locus variable-number tandem-repeat analysis