Molecular epidemiology of Salmonella typhimurium isolates from human sporadic and outbreak cases.
The molecular epidemiology of a representative collection of sporadic foreign and domestically acquired Salmonella Typhimurium (S. Typhimurium) isolates from Norwegian patients in 1996-9 was studied by numerical analysis of pulsed-field gel electrophoresis (PFGE) profiles. Three subclusters (E5, F1 and G1) comprised 47% of the 102 sporadic isolates investigated and 45% of the domestically acquired isolates fell in subclusters E5 and F1. Distinct seasonal and geographic variations were evident for these strains which have been responsible for both local outbreaks (E5) and a national epidemic (F1) where salmonella-infected hedgehogs and birds constituted the suggested primary source of infection. Subcluster G1 was dominated by imported multi-resistant definitive type (DT) 104 isolates. All multi-resistant isolates contained integron-associated gene cassette-structures. This study presents valuable information on the relative significance, geographic distribution and antibiotic resistance features of distinct S. Typhimurium clones causing human salmonellosis among Norwegians.
Division of Infectious Disease Control, Norwegian Institute of Public Health, Oslo.
E
E
Heir
B A
BA
Lindstedt
I
I
Nygård
T
T
Vardund
V
V
Hasseltvedt
G
G
Kapperud
D000818:Animals; D001717:Birds; D004196:Disease Outbreaks; D018432:Drug Resistance, Multiple; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D005843:Geography; D006364:Hedgehogs; D006801:Humans; D012480:Salmonella Infections / Q000188:drug therapy / Q000453:epidemiology*; D012486:Salmonella typhimurium / Q000235:genetics* / Q000472:pathogenicity; D012621:Seasons