Genotypic Characterization of Salmonella enterica Serotype Enteritidis Isolated from Food-Poisoning Cases and Chickens by Pulsed Field Gel Electrophoresis

A total of 22 Salmonella enterica serotype Enteritidis (S. Enteritidis) isolates from human and chicken sources were analyzed by pulsed field gel electrophoresis (PFGE) using XbaI restriction enzyme to assess the genetic relationships between strains from different sources. PFGE permitted the resolution of XbaI restriction fragments of the 22 S. Enteritidis into 6 distinct PFGE types (PFT), designated PFT1 to PFT6, and 2 subtypes within PFT2, and allowed to detect between 9 and 10 bands with fragments sizes in the range of $25\~635\;kb$. Four of twelve isolates from human showed an identical PFGE patterns with 2 isolates from chickens. Also, another one isolate from human showed an identical PFGE patterns with other 5 isolates from chickens. Only one isolate from chicken, however, showed a different pattern compared to other PFTs. These results suggested that sporadic human food-poisoning cases infections caused by S. Enteritidis in this study were due to the consumption of contaminated chicken meats and that a clonally highly similar strains exist and spread between human and chicken sources.