Genome sequence analysis of 91 Salmonella Enteritidis isolates from mice caught on poultry farms in the mid 1990s.

A total of 91 draft genome sequences were used to analyze isolates of Salmonella enterica serovar Enteritidis obtained from feral mice caught on poultry farms in Pennsylvania. One objective was to find mutations disrupting open reading frames (ORFs) and another was to determine if ORF-disruptive mutations were present in isolates obtained from other sources. A total of 83 mice were obtained between 1995-1998. Isolates separated into two genomic clades and 12 subgroups due to 742 mutations. Nineteen ORF-disruptive mutations were found, and in addition, bigA had exceptional heterogeneity requiring additional evaluation. The TRAMS algorithm detected only 6 ORF disruptions. The sefD mutation was the most frequently encountered mutation and it was prevalent in human, poultry, environmental and mouse isolates. These results confirm previous assessments of the mouse as a rich source of Salmonella enterica serovar Enteritidis that varies in genotype and phenotype. Published by Elsevier Inc.