Genotypes of Brucella abortus field isolates from different geographical regions of Chile

Abstract

Bovine brucellosis is an endemic, zoonotic disease of high economic impact. The genetic identification of the prevalent Brucella abortus strains, the pathogen, is key to pursue further epidemiological strategies for disease control. The insertion sequence IS711 has been used as genetic marker to differentiate among Brucella species, members of the same specie and within the same biovar. We have analyzed the IS711-RFLP pattern for 46 B. abortus isolates, collected during the period of 1997-2005 from 16 different geographical areas of Chile. All isolates were previously identified by conventional techniques as B. abortusbiovar 1. Of these, 87% sharedthesame IS711 DNA profile, while an 8.7 % corresponded to the pattern of RB51 vaccine strain. We report the finding of two new strains, not differentiated by AMOS PCR, which showed unreported patterns of IS711-RFLP.