This study assessed the efficacy of Rosmarinus officinalis L. essential oil (ROEO) and 1,8-cineole (CIN) in inhibiting the survival of Pseudomonas aeruginosa ATCC 9027, and the capacity to induce direct protection and bacterial cross protection against lactic acid, NaCl and high temperature following exposure to different sublethal amounts of the compounds in a meat based broth. Overnight exposure of P. aeruginosa to sublethal concentrations of both compounds revealed no induction of direct protection and cross protection. Cells subjected to 24-hour cycles of adaptation in increasing amounts of the antimicrobials showed no increase in direct tolerance, as they were able to survive in growth medium containing up to 1/4 and 1/2 of the minimum inhibitory concentration of the ROEO and CIN, respectively. The results of this study revealed evidence for lack of induction of direct protection or cross protection in P. aeruginosa ATCC 9027 when exposed to sublethal amounts of ROEO or CIN in a meat-based broth, as determined by monitoring cell survival and growth behavior. © 2012 Elsevier Ltd.
Gomes Neto, N. J., da Silva Luz, I., Honório, V. G., da Conceição, M. L., & de Souza, E. L. (2012). Pseudomonas aeruginosa cells adapted to Rosmarinus officinalis L. essential oil and 1,8-cineole acquire no direct and cross protection in a meat-based broth. Food Research International, 49(1), 143–146. https://doi.org/10.1016/j.foodres.2012.07.049