Publicação
Biofilms of Listeria monocytogenes produced at 12ºC either in pure culture or in co-culture with Pseudomonas aeruginosa showed reduced susceptibility to sanitizers
| Resumo: | The biofilm-forming ability of 21 Listeria monocytogenes isolates, previously pulsotyped and corresponding to 16 strains, from different origins was evaluated using the Calgary Biofilm DeviceR , at 37 ◦C. Biofilms of 4 selected strains were also produced either on pure cultures or on co-cultures with Pseudomonas aeruginosa (PAO1), at 12 ◦C and at 37 ◦C. For these biofilms, the minimum biofilm eradication concentrations (MBECs) of 4 commercial dairy sanitizers (1 alkyl amine acetate based—T99, 2 chlorine based—T66 and DD, and 1 phosphoric acid based—BP) were determined. Listeria monocytogenes biofilms grown, either at 37 ◦C or 12 ◦C, were able to achieve similar cell densities by using different incubation periods (24 h and 7 d, respectively). In co-culture biofilms, P. aeruginosa was the dominant species, either at 37 ◦C or at 12 ◦C, representing 99% of a total biofilm population of 6 to 7 log CFU/peg. Co-culture biofilms were generally less susceptible than L. monocytogenes pure cultures. More interestingly, the biofilms produced at 12 ◦C were usually less susceptible to the sanitizers than when produced at 37 ◦C. Single or co-culture biofilms of L. monocytogenes and PAO1, particularly produced at 12 ◦C, retrieved MBEC values for agents T99 and BP that were, at times, above the maximum in-use recommended concentrations for these agents. The results presented here reinforce the importance of the temperature used for biofilm formation, when susceptibility to sanitizers is being assessed |
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| Autores principais: | Lourenço, António |
| Outros Autores: | Machado, Henrique; Brito, Luísa |
| Assunto: | biofilms Calgary biofilm device Listeria monocytogenes low temperature sanitizers |
| Ano: | 2011 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | The biofilm-forming ability of 21 Listeria monocytogenes isolates, previously pulsotyped and corresponding to 16 strains, from different origins was evaluated using the Calgary Biofilm DeviceR , at 37 ◦C. Biofilms of 4 selected strains were also produced either on pure cultures or on co-cultures with Pseudomonas aeruginosa (PAO1), at 12 ◦C and at 37 ◦C. For these biofilms, the minimum biofilm eradication concentrations (MBECs) of 4 commercial dairy sanitizers (1 alkyl amine acetate based—T99, 2 chlorine based—T66 and DD, and 1 phosphoric acid based—BP) were determined. Listeria monocytogenes biofilms grown, either at 37 ◦C or 12 ◦C, were able to achieve similar cell densities by using different incubation periods (24 h and 7 d, respectively). In co-culture biofilms, P. aeruginosa was the dominant species, either at 37 ◦C or at 12 ◦C, representing 99% of a total biofilm population of 6 to 7 log CFU/peg. Co-culture biofilms were generally less susceptible than L. monocytogenes pure cultures. More interestingly, the biofilms produced at 12 ◦C were usually less susceptible to the sanitizers than when produced at 37 ◦C. Single or co-culture biofilms of L. monocytogenes and PAO1, particularly produced at 12 ◦C, retrieved MBEC values for agents T99 and BP that were, at times, above the maximum in-use recommended concentrations for these agents. The results presented here reinforce the importance of the temperature used for biofilm formation, when susceptibility to sanitizers is being assessed |
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