PT - JOURNAL ARTICLE AU - Lukinmaa, Susanna AU - Schildt, Raili AU - Rinttilä, Teemu AU - Siitonen, Anja TI - <em>Salmonella</em> Enteritidis Phage Types 1 and 4: Pheno- and Genotypic Epidemiology of Recent Outbreaks in Finland DP - 1999 Jul 01 TA - Journal of Clinical Microbiology PG - 2176--2182 VI - 37 IP - 7 4099 - http://jcm.asm.org/content/37/7/2176.short 4100 - http://jcm.asm.org/content/37/7/2176.full SO - J. Clin. Microbiol.1999 Jul 01; 37 AB - In the 1990s, Salmonella enterica subsp.enterica serovar Enteritidis has caused 15 outbreaks in Finland; 12 of them were caused by phage type 1 (PT1) and PT4. Thus far, there has been no clear evidence as to the source of theseSalmonella Enteritidis PT1 and PT4 strains, so it was necessary to try to characterize them further. SalmonellaEnteritidis PT1 (n = 57) and PT4 (n = 43) isolates from different sources were analyzed by genomic pulsed-field gel electrophoresis (PFGE), plasmid profiling, and antimicrobial resistance testing to investigate the distribution of their subtypes in Finland. It was also hoped that this investigation would help in identifying the sources of the infections, especially the sources of the outbreaks caused by PT1 and PT4 in the 1990s. The results showed that both PFGE and plasmid profiling, but not antimicrobial susceptibility testing, were capable of differentiating isolates of Salmonella Enteritidis PT1 and PT4. By genotypic methods, it was possible to divide both PT1 and PT4 isolates into 12 subtypes. It could also be shown that all PT1 outbreak isolates were identical and, at least with this collection of isolates, that the outbreaks did not originate from the Baltic countries or from Russia, where this phage type predominates. It was also established that the outbreaks caused by PT4 all had different origins. Valuable information for future investigations was gained on the distribution of molecular subtypes of strains that originated from the tourist resorts that are popular among Finns and of strains that were isolated from livestock.