Análise genética de Salmonella typhimurium ferment adoras de lactose isoladas no Rio de Janeiro

Abstract

Lactose fermenting Salmonella typhimurium are endemic in São Paulo, but not in Rio de Janeiro Two isolations are described from the latter city. These Rio de Janeiro strains have a plasmid of 7.4 megadaltons. These plasmids were not auto-transferable, were thermostable and were not eliminated by acridine orange. One of these strains arose from a plasmid that had the lactose operon repressed, leading us to speculate about the evolution of the lactose fermenting character in Brazilian Salmonella.