Salmonellosis in Ukraine: An analysis of food products contamination, Salmonella transmission, and serovar diversity during 2012–2023

A laboratory-based surveillance was conducted to study the transmission of Salmonella infection in Ukraine during the period 2012-2023. The study focused on the different categories of food products, feed, and animals as the main transmission factors and tried to analyze the relationship between them. The serological profile of Salmonella was predominantly observed in samples from objects of veterinary control, including biological/pathological material from animals and biomaterials from poultry within the National Poultry Salmonellosis Control Program. The study found that the most frequently isolated serovars were S. Enteritidis (20.03%), followed by S. Typhimurium (14.76%), S. Pullorum (without biovar identification;10.71%), S. Pullorum biovar Pullorum (10.50%), S. Pullorum var. Gallinarum (6.62%), S. Choleraesuis (5.79%), S. Livingstone (2.53%), and S. Infantis (1.70%). In 2021, an isolate of monophasic S. Typhimurium was identified for the first time in pathological material from pigs. The study also found that the most frequent Salmonella-positive categories of food products in Ukraine were meat and meat products (78.16%), eggs and egg products (11.75%); dairy products (3.319%), fish products (2.71%), ready-to-eat food products (1.96%). The largest specific share of Salmonella isolates from food products and feed was S. Enteritidis, followed by serotypes such as S. Infantis, S. Typhimurium, S. Livingstone, S. Virchow, and rare serotypes such as S. Nigeria and S. Thompson. The dominance of certain serovars such as S. Enteritidis, S. Typhimurium, S. Infantis, S. Livingstone, and S. Virchow in biomaterials from sick animals indicates their primary role in the infection of food products of animal origin. Hence, a stress to enhance diagnostic and monitoring frameworks at animal herd levels. The findings of this study can be used as a basis for evidence-based epidemiology, as well as for the implementation of joint steps to improve the effectiveness of control measures against salmonellosis in each region.