|LIEBANA ,, ERNESTO|
Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2001
Publication Date: 2/2/2002
Interpretive Summary: Salmonella enterica serovar Enteritidis (SE) is the only Salmonella that routinely causes human illness by contaminating the internal contents of eggs obtained from otherwise healthy appearing hens. It has been an important public health problem for the past twenty years. It has been difficult to tell the difference between strains of SE that appear in different geographical locations, because all SE are genetically related and probably descended from only one or two lineages. The authors describe how SE from different regions can be distinguished from each other by applying improved methods for analysis that look for very small changes in genetic sequence (single nucleotide polymorphisms). An important finding was that there are different genetic types of phage type 4 SE, which has historically been associated with increased human illness when it appears in a region.
Technical Abstract: A total of 234 isolates of Salmonella enterica serovar Enteritidis from England (n=170), Northern Ireland (n=16), Spain (n=2), Hong Kong (n=1), and the USA (Georgia, n=26; Iowa, n=9; Pennsylvania, n=6; Hawaii, n=2; Maryland, n=1) belonging to phage-types (PT) 4 (n=89), PT7 (n=12), PT6 (n=72), PT8 (n=14), PT13a (n=29), PT29 (n=14), and PT34 (n=4) were selected dfrom different geographical locations within each country/state and were characterised by ribotyping with a combination of PstI and SphI enzymes, and pulsed field gel electrophoresis after digestion of DNA with XbaI.