Multiply Resistant (MR) Salmonella enterica serotype Typhimurium DT 12 and DT 120: A case of MR DT 104 in disguise?

Abstract

Multiresistant Salmonella enterica serotype Typhimurium definitive phage type (DT) 12 and DT 120 are more closely related to DT 104 than to non-multiresistant strains of their respective phage types. Multiresistant DT 12 and DT 120 appear to have arisen due to changes in phage susceptibility of DT 104 rather than horizontal transfer of resistance genes.