Low Occurrence of Listeria monocytogenes on Bovine Hides and Carcasses in Minas Gerais State, Brazil: Molecular Characterization and Antimicrobial Resistance

Listeria monocytogenes occurrence was assessed in three slaughterhouses located in Minas Gerais state, Brazil, by analysis of 209 bovine carcasses. Four sponge samples were obtained from each carcass in different steps (A, from hide, before bleeding; B, after hide removal; C, after evisceration; and D, after end washing), resulting in a total of 836 samples. The samples were tested for the presence of L. monocytogenes according to the International Organization for Standardization 11290-1, and positive results were recorded in steps A (1 of 209) and D (1 of 209) from slaughterhouse 03. L. monocytogenes isolates (n = 5) were identified by multiplex PCR as belonging to serogroup IIc (representing serotypes 1/2c or 3c) and presented identical pulsed-field gel electrophoresis profiles; in addition, the isolates harbored the virulence genes inlA, inlB, inlC, inlJ, plcA, hlyA, actA, and iap and were sensitive to ampicillin, vancomycin, gentamicin, erythromycin, tetracycline, rifampin, chloramphenicol, trimethoprim, and sulfamethoxazole. The obtained data indicated a low occurrence of L. monocyto genes on bovine hides and carcasses from slaughterhouses located in Minas Gerais state, Brazil, and the presence of distinct virulence makers and susceptibility to a variety of antimicrobials by the obtained isolates.,