Plasmid characterisation in the investigation of an epidemic caused by multiply resistant Shigella dysenteriae type 1 in Central Africa.

A strain of Shigella dysenteriae type 1 resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides, and tetracyclines has caused an epidemic of shiga dysentery in northeast Zaire. Since November 1979, it has caused many deaths in an extensive area which now includes neighbouring Rwanda. The strain carries a resistance plasmid of compatibility group X, indistinguishable from the plasmid previously found in strains from Somalia. This contrasts with multiply resistant strains of Sh. dystenteriae type 1 from Central America and South-East Asia in which resistance is determined by plasmids of compatibility group B.