Low occurrence of Salmonella in the beef processing chain from Minas Gerais state, Brazil: From bovine hides to end cuts

The present study aimed to track possible contamination sources of Salmonella spp. during bovine slaughtering. Three slaughterhouses located in Minas Gerais state, Brazil were selected and 836 samples were obtained by surface swabbing of 209 bovine carcasses at four steps of slaughtering: I) after bleeding (from the hide), II) after skinning, III) after evisceration, and IV) after end washing (performed with cold water). Samples were subjected to Salmonella spp. detection according to ISO 6975, and the suspected isolates were identified by PCR as Salmonella by targeting the ompC gene and performing serotyping. Twenty isolates were confirmed as Salmonella and subjected to XbaI macrorestriction and pulsed-field gel electrophoresis (PFGE). Salmonella spp. was detected in the hides of six animals, during slaughtering after skinning (one carcass), after evisceration (two carcasses), and after end washing (three carcasses). Isolates were serotyped as S. Dublin (n = 7), S. Derby (n = 8), S. Infantis (n = 1), S. Give (n = 1), and S. salamae subsp. salamae (n = 3). PFGE demonstrated identical Salmonella pulse-types from hides and slaughtering steps of skinning and evisceration, as well as from animal hides obtained from distinct slaughterhouses. The obtained data indicate a low prevalence of Salmonella spp. during bovine slaughtering in selected industries from Minas Gerais state, Brazil, but identified possible routes of contamination of pathogenic serotypes.