Diversity of Strains of Salmonella enterica Serotype Enteritidis from English Poultry Farms Assessed by Multiple Genetic Fingerprinting

Abstract

Reliable and sufficiently discriminative methods are needed for differentiating individual strains of Salmonella enterica serotype Enteritidis beyond the phenotypic level; however, a consensus has not been reached as to which molecular method is best suited for this purpose. In addition, data are lacking on the molecular fingerprinting of serotype Enteritidis from poultry environments in the United Kingdom. This study evaluated the combined use of classical methods (phage typing) with three well-established molecular methods (ribotyping, macrorestriction analysis of genomic DNA, and plasmid profiling) in the assessment of diversity within 104 isolates of serotype Enteritidis from eight unaffiliated poultry farms in England. The most sensitive technique for identifying polymorphism was PstI-SphI ribotyping, distinguishing a total of 22 patterns, 10 of which were found among phage type 4 isolates. Pulsed-field gel electrophoresis of XbaI-digested genomic DNA segregated the isolates into only six types with minor differences between them. In addition, 14 plasmid profiles were found among this population. When all of the typing methods were combined, 54 types of strains were differentiated, and most of the poultry farms presented a variety of strains, which suggests that serotype Enteritidis organisms representing different genomic groups are circulating in England. In conclusion, geographical and animal origins of Salmonella serotype Enteritidis isolates may have a considerable influence on selecting the best typing strategy for individual programs, and a single method cannot be relied on for discriminating between strains.

A longitudinal study of environmental salmonella contamination in caged and free-range layer flocks

“…While PT4, which has been strongly associated with infection of layers in the UK and Europe (Cogan & Humphrey, 2003), was detected on six of the eight farms, it was present in combination with other persistent S. Enteritidis phage types on five of these. This is consistent with previous findings (Liebana et al ., 2001), whereby a variety of often closely related phage types was seen in samples from poultry farms in geographically varied UK Abbreviations : e, Salmonella Enteritidis ; a, Salmonella Agona ; bi, Salmonella Binza ; br, Salmonella Braenderup ; co, Salmonella Corvallis ; cu, Salmonella Cubana ; i, S . Infantis ; k, Salmonella Kedougou ; l, S .…”

ERIC-PCR genotyping of field isolates ofSalmonella entericasubsp.entericaserovar Gallinarum biovars Gallinarum and Pullorum

“…DNA fingerprinting techniques are powerful tools by providing genetic information about the isolates related to an ongoing outbreak and may thus be used for this purpose (Liebana et al, 2001).…”

Characteristics of Persistent Salmonella Enteritidis Strains in Two Integrated Broiler Chicken Operations of Korea

“…In recent years, many DNA-based genotyping techniques have been utilized to delineate epidemiological relationships between various isolates [23,32]. But, the combination of several methods including phage typing, serotyping, antibiogram and genetic typing may provide a powerful discriminatory tool for the epidemiological analysis of unrelated and related Salmonella strains [14,16].…”