Distribution of Salmonella types at each time point when 250 pigs passed the slaughter line in slaughterhouse A2. (A) Positive samples from feces and/or mesenteric lymph nodes of pigs; (B) positive carcasses. Numbers in bars represent serotypes and genotypes as follows: 1, serotype Brandenburg; 2, serotype Typhimurium T11/T11; 2′, serotype Typhimurium T11/T11a; 3, serotype Derby D1; 4, serotype Derby D2a; 5, serotype Derby D2b; 6, serotype Derby D3; 7, serotype Derby D4; 8, serotype Infantis; 9, serotype Typhimurium T9; 10, serotype Virchow; 11, serotype Livingstone; 12, serotype Typhimurium T8/T8; 12′, serotype Typhimurium T8/T12; 13, serotype Typhimurium T4/T4; 13′, serotype Typhimurium T4/T4a; 14, serotype Typhimurium T5; 15, serotype Ohio O1; 16, serotype London; 17, serotype Typhimurium T3; 18, serotype Typhimurium T6; 19, serotype Rissen; 20, serotype Typhimurium T1; 21, serotype Goldcoast.