Comparison between the Resistance of Benzalkonium Chloride–Adapted and –Nonadapted Biofilms of Listeria monocytogenes to Modified Atmosphere Packaging and Nisin Once Transferred to Mussels

Abstract

Benzalkonium chloride-adapted and -nonadapted Listeria monocytogenes biofilm cells were transferred by contact to cooked or live mussels and packed in rich CO(2) and O(2), respectively. The viabilities of transferred cells during storage of these packed samples at 2.5 °C were compared. In addition, in cooked mussels the combined effect of CO(2) and nisin against the survival of L. monocytogenes was also studied by using a first-order factorial design. The results obtained demonstrated that biofilms formed by benzalkonium chloride-adapted L. monocytogenes cells could be more resistant to the application of modified atmospheres rich in CO(2) and nisin once they have been transferred to cooked mussels by contact (simulating cross-contamination). This implies an increase in the risk associated with the presence of these cells in food processing plants. Significant empirical equations obtained after 7, 11, and 20 days showed an inhibitory effect of CO(2) and nisin against L. monocytogenes. However, a significant positive interaction between both variables highlights an incompatibility between CO(2) and nisin at high concentrations. Results also demonstrated that L. monocytogenes could persist after cross-contamination during the processing of live mussels, so L. monocytogenes is of concern as a contaminant in live mussels packaged in high-O(2) atmospheres.

A new and efficient method to obtain benzalkonium chloride adapted cells of Listeria monocytogenes

“…In fact, in previous studies BAC-adapted cells were obtained after days or even weeks of culture (Aase et al, 2000;To et al, 2002;Romanova et al, 2006) as it can be observed in the Table 4. Moreover, adapted cells obtained with the proposed method in 2008 had been used during years in subsequent studies (Saá Ibusquiza et al, 2011a, 2011b, 2012 and no reversion in the adaptation to BAC was observed.…”

Stochastic Dynamic Mass Spectrometric Quantitative and Structural Analyses of Pharmaceutics and Biocides in Biota and Sewage Sludge

“…The determination of pharmaceutics and biocides in biota, including the analysis of invertebrates, plankton, fish, human tissues and fluids, birds, and marine mammals, is importance for assessing the risk for human health and environmental damage [ 38 , 39 ], as well as determining the potential ecological risk index [ 38 , 39 , 40 ]. The biomonitoring includes saltwater and freshwater mussels [ 1 , 41 , 42 , 43 ]. These biological species filter large quantities of water, thus accumulating both organic and inorganic pollutants from water or suspended matter at elevated levels.…”