High hydrostatic pressure effects on Listeria monocytogenes and L. innocua: Evidence for variability in inactivation behaviour and in resistance to pediocin bacHA-6111-2

• Carolina Bruschi ^[1] ; Norton Komora ^[1] ; Sónia Marília Castro ^[1] ; Jorge Saraiva ^[2] ; Vânia Borges Ferreira ^[1] ; Paula Teixeira ^[1]
  1. [1] Universidade Católica Portuguesa

     Universidade Católica Portuguesa

     Socorro, Portugal

     
  2. [2] Universidade de Aveiro

     Universidade de Aveiro

     Vera Cruz, Portugal

     
• Localización: Food microbiology, ISSN 0740-0020, Vol. 64 (June), 2017, págs. 226-231
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The effect of high hydrostatic pressure (HHP) on the survival of 14 strains of Listeria monocytogenes from food or clinical origins, selected to represent different pheno and genotypes, was evaluated. Stationary phase cells were submitted to 300, 400 and 500 MPa at 10 °C, for 5 min. A high variability in the resistance of L. monocytogenes to pressure was observed, and particularly two strains isolated from food were significantly more baroresistant than the rest. Strains of L. monocytogenes resistant to one or more antibiotics exhibited significantly higher levels of survival after the high pressure treatment at 400 MPa. No correlation was found between strains' origin or thermal tolerance and resistance to HHP. The suitability of two strains of L. innocua as surrogates of L. monocytogenes, was also investigated. These exhibited significantly higher sensitivities to HHP than observed for some L. monocytogenes. The antimicrobial effect of the antilisterial bacteriocin (bacHA-6111-2) increased after L. monocytogenes cells had been exposed to pressure. The data obtained underlines the importance of strain selection for studies aiming to evaluate HHP efficacy to ensure safety of HHP-treated foods.