Salmonella Serotypes Present in Turkey Samples

Salmonella enterica is a well-known foodborne pathogen that is a major cause of foodborne illness across the globe. Poultry products pose particular risk for contamination at many points during slaughter, including the steps required to scald, defeather, eviscerate, and cool the carcass, as well as during processing, distribution, and preparation.¹ Recently, researchers in Turkey analyzed samples of ground turkey and turkey meat parts to determine the specific S. enterica serotypes present. Erol et al.² acquired samples from three retailers over the course of 19 months. They used standard cultivation techniques, including enrichment broths and agars, to isolate 169 colonies of S. enterica. Of these colonies, 112 derived from ground turkey samples and 54 from samples of turkey meat parts. To verify the colonies, the researchers used used polymerase chain reaction (PCR) to detect and amplify the oriC gene using S. enterica ser. Typhimurium ATCC 14028 as a positive control. Finally, Erol et al. performed serotyping using lam agglutination and serum neutralization to identify 15 strains of S. enterica, including S. enterica serovars Corvallis (46 colonies, 27%), Kentucky (22 colonies, 13%), Bredeney (20 colonies, 12%), Virchow (20 colonies, 12%), Saintpaul (18 colonies, 11%), and Agona (17 colonies, 10%). Less prevalent serovars were Heidelberg, Hadar, Munchen, Stanleyville, Montevideo, subspecies I, group C, Typhimurium, and Newport. In terms of distribution among sample types, ground turkey was the source for all colonies of S. enterica serovars Kentucky, Virchow, Heidelberg, Stanleyville, Montevideo, Subspecies I, Group C, and Newport. Ground turkey was also the source for 39 of 46 colonies of S. enterica ser. Corvallis. Turkey meat parts sourced 90% and 67% of the colonies of S. enterica serovars Bredeney and Saintpaul, respectively. Turkey meat parts were also the source for all colonies of the less prevalent S. enterica serovars Hadar, Munchen, and Typhimurium. Erol et al. analyzed the seasonal distribution of S. enterica serotypes sourced from turkey products: winter 39 colonies (23%), spring 26 colonies (15%), summer 53 colonies (31%), autumn 51 colonies (30%). Overall, a greater number of serotypes occurred in samples from warm months with 16 strains present in winter/spring and 19 present in summer/autumn. The most prevalent strain, S. enterica ser. Corvallis, predominated in samples from spring, summer, and autumn and was second in prevalence to S. enterica ser. Bredeney in winter. 86% of the colonies of the second most prevalent strain, S. enterica ser. Kentucky, appeared in samples collected in spring, summer, and autumn. The researchers did not report a correlation between producers and serotype profiles but did note a correlation between supermarkets and serotype distribution. They state that the two serotypes largely sourced from turkey meat parts, S. enterica serovars Bredeneyand Saintpaul, derived from samples purchased at one supermarket at 78% and 58%, respectively. References 1 Nde, C. et al. (2007) ‘Cross contamination of turkey carcasses by Salmonella species during defeathering.’ Poultry Science 86(1) 162-7. 2 Erol, I. et al. (2013) ‘Serotype distribution of Salmonella isolates from turkey ground meat and meat parts.’ Biomed Research International, 281591. doi: 10.1155/2013/281591