[Molecular subtyping of Salmonella enterica serotype Enteritidis in a post epidemic period]

Abstract

Background: In the last two decades, Salmonella enterica serotype Enteritidis has become one of the main agents causing food borne diseases worldwide. This agent is transmitted mainly by contaminated meat and poultry.

Aim: To determine the genetic subtypes of Salmonella enterica serotype Enteritidis, circulating in Chile between 2001 and 2003, a post epidemic period.

Material and methods: One hundred ninety three isolates coming from human samples, prepared foods and animal products for human consumption, were analyzed by pulsed field electrophoresis, using PulseNet standardized protocol.

Results: Thirteen subtypes of Salmonella enterica serotype Enteritidis were identified, that had between 0 and 13 bands. A predominant subtype was identified in 172 strains (88%) that came from human isolates, prepared foods and animal products for human consumption. Other four subtypes, found in prepared foods and animal products for human consumption, were also found in human isolates. Most subtypes were tightly interrelated Subtypes II, VIII and XI were also found in the 1994 epidemic.

Conclusions: Subtyping of bacterial strains by pulsed field electrophoresis is useful for the surveillance of food borne diseases.