Analysis of Salmonella enteritidis strains isolated from food-poisoning cases in Taiwan by pulsed field gel electrophoresis, plasmid profile and phage typing

Aims: To establish the molecular typing data for Salmonella enteritidis due to its increasing role in Salmonella infections in Taiwan. Methods and Results: Sixty-three Salm. enteritidis strains isolated fi om r elated and unrelated patients suffering from food-borne poisoning during 19 91-97 were collected and subjected to pulsed field gel electrophoresis (PFG E), plasmid analysis and phage typing. For PFGE, XbaI, SpeI and NotI restri ction enzymes were used for chromosomal DNA digestion. The results showed t hat, for these 63 Salmonella strains, 10 PFGE pattern combinations were fou nd. Of these, pattern X3 S3 N3 was the major subtype, since 46 strains isol ated from different locations at different times during 1991-97 showed this PFGE pattern. Plasmid anal sis showed only three plasmid profiles and phag e typing show-ed that most of the Salmonella strains were of the phage type PT4. Conclusions: Most of the Salm. enteritidis strains circulating in Taiwan ar e of ver similar genetic types or are highly related and that strains of PF GE pattern X3 S3 N3 are the prevalent and recirculating strains of Salm. en teritidis which caused food-poisoning cases in Taiwan in 1991-97. Significance and Impact of the Study: This study provides information that ill Salmonella infection, certain subtypes of Salm. enteritidis should be s crutinized.