An Outbreak of Multidrug-Resistant, Quinolone-ResistantSalmonella entericaSerotype Typhimurium DT104

Food-borne salmonella infections have become a major problem in industrialized countries. The strain of Salmonella enterica serotype typhimurium known as definitive phage type 104 (DT104) is usually resistant to five drugs: ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline. An increasing proportion of DT104 isolates also have reduced susceptibility to fluoroquinolones.The Danish salmonella surveillance program determines...