Molecular epidemiology of Mycobacterium bovis isolates from South America

One hundred seventy-eight isolates of Mycobacterium bovis were subjected to DNA restriction fragment length polymorphism (RFLP) analysis, using the direct repeat element (DR) and the polymorphic GC-rich repeat sequence (PGRS) as probes. By combining the patterns generated by the two repeat DNA elements, 93 different patterns were observed. One hundred-one isolates were grouped in clusters, which include 25 different clusters. One pattern was the most frequently observed, clustering 18.5% of isolates. It was only found in the Center and northeast regions of Argentina and in one isolate from Paraguay. The isolates from Brazil analyzed here presented exclusive patterns (only found in a particular region). The number of exclusive patterns was high in all argentine regions: northeast 78%, center 81%, and Buenos Aires 81%.