RAPISARDA Viviana Andrea
congresos y reuniones científicas
ELIMINATION OF FOODBORNE BACTERIA BY AN OXIDATIVE TREATMENT
OLMEDO, G. M.; KOLLING, Y.; CERIONI, L.; RAPISARDA, V. A.; RODRÍGUEZ-MONTELONGO, L.; VOLENTINI, S. I.
Congreso; VII CONGRESO DE LA SOCIEDAD ARGENTINA DE MICROBIOLOGÍA GENERAL (SAMIGE) Bicentenario; 2011
Most food consumed daily is exposed to both gram-positive and gram-negative pathogen bacteria. Contamination can occur during growing, harvesting, processing, storing, and shipping of fresh or minimally processed products. For those reasons, it is important to study disinfectants that are able to eliminate a wide range of undesirable microorganisms. Oxidizing biocides such as hypochlorite and peroxides are widely used in food sanitization because of their antimicrobial effects, availability and low cost. In our laboratory, we have previously standardized a sequential oxidative treatment (SOT) for the elimination of fungal phytopathogens and Xanthomonas axonodopodis pv citri, consisting in two sequential incubations, first with NaOCl, and then with H2O2 in presence of Cu2SO4. The combination of these compounds in the SOT generated a synergistic effect. Here, we tested in vitro the biocidal capacity of the oxidizing compounds over several microorganisms. The bacteria used were Escherichia coli MC4100, Listeria innocua, Salmonella typhymurium, and Klebsiella pneumoniae, as pathogenic and surrogate foodborne bacteria. We determined the MIC for each compound in individual form and then we established the optimal combination of them for each microorganism. The most sensitive foodborne bacterium was K. pneumoniae and the most resistant was L. innocua. We could eliminate all tested bacteria when applied an oxidative treatment consisting on a brief incubation (2 min) with 50 ppm NaClO, 0.1 mM CuSO4 and 200 mM H2O2. This effective treatment is easy to apply and involves short times of contact between the oxidative compounds and bacteria. Thus, it may be applied in the disinfection of food contact surfaces and materials used in the manufacturing of food products.