ABSTRACTPasserine salmonellosis is a well-recognized disease of birds in the order Passeriformes, which includes common songbirds such as finches and sparrows, caused by infection withSalmonella entericaserovar Typhimurium. Previous research has suggested that some subtypes ofS. Typhimurium—definitive phage types (DTs) 40, 56 variant, and 160—are host adapted to passerines and that these birds may represent a reservoir of infection for humans and other animals. Here, we have used the whole-genome sequences of 11 isolates from British passerines, five isolates of similar DTs from humans and a domestic cat, and previously publishedS. Typhimurium genomes that include similar DTs from other hosts to investigate the phylogenetic relatedness of passerine salmonellae to otherS. Typhimurium isolates and investigate possible genetic features of the distinct disease pathogenesis ofS. Typhimurium in passerines. Our results demonstrate that the 11 passerine isolates and 13 other isolates, including those from nonpasserine hosts, were genetically closely related, with a median pairwise single nucleotide polymorphism (SNP) difference of 130 SNPs. These 24 isolates did not carry antimicrobial resistance genetic determinants or theS. Typhimurium virulence plasmid. Although our study does not provide evidence ofSalmonellatransmission from passerines to other hosts, our results are consistent with the hypothesis that wild birds represent a potential reservoir of theseSalmonellasubtypes, and thus, sensible personal hygiene precautions should be taken when feeding or handling garden birds.IMPORTANCEPasserine salmonellosis, caused by certain definitive phage types (DTs) ofSalmonellaTyphimurium, has been documented as a cause of wild passerine mortality since the 1950s in many countries, often in the vicinity of garden bird feeding stations. To gain better insight into its epidemiology and host-pathogen interactions, we sequenced the genomes of a collection of 11 isolates from wild passerine salmonellosis in England and Wales. Phylogenetic analysis showed these passerine isolates to be closely related to each other and to form a clade that is distinct from other strains ofS. Typhimurium, which included a multidrug-resistant isolate from invasive nontyphoidalSalmonelladisease that shares the same phage type as several of the passerine isolates. Closely related to wild passerine isolates and within the same clade were fourS. Typhimurium isolates from humans as well as isolates from horses, poultry, cattle, an unspecified wild bird, and a domestic cat and dog with similar DTs and/or multilocus sequence types. This suggests the potential for cross-species transmission, and the genome sequences provide a valuable resource to investigate passerine salmonellosis further.
Genome Sequences of 13 Isolates of Salmonella enterica Serovar Typhimurium var. Copenhagen Obtained from Wild Pigeons in Canada