University of Campinas (UNICAMP), Department of Food Technology, Brazil.
University of Campinas (UNICAMP), Department of Food Science, Brazil.
Int J Food Microbiol. 2015 May 4;200:5-12. doi: 10.1016/j.ijfoodmicro.2015.01.003. Epub 2015 Jan 22.
The formation of mono-species biofilm (Listeria monocytogenes) and multi-species biofilms (Enterococcus faecium, Enterococcus faecalis, and L. monocytogenes) was evaluated. In addition, the effectiveness of sanitation procedures for the control of the multi-species biofilm also was evaluated. The biofilms were grown on stainless steel coupons at various incubation temperatures (7, 25 and 39°C) and contact times (0, 1, 2, 4, 6 and 8 days). In all tests, at 7°C, the microbial counts were below 0.4 log CFU/cm(2) and not characteristic of biofilms. In mono-species biofilm, the counts of L. monocytogenes after 8 days of contact were 4.1 and 2.8 log CFU/cm(2) at 25 and 39°C, respectively. In the multi-species biofilms, Enterococcus spp. were present at counts of 8 log CFU/cm(2) at 25 and 39°C after 8 days of contact. However, the L. monocytogenes in multi-species biofilms was significantly affected by the presence of Enterococcus spp. and by temperature. At 25°C, the growth of L. monocytogenes biofilms was favored in multi-species cultures, with counts above 6 log CFU/cm(2) after 8 days of contact. In contrast, at 39°C, a negative effect was observed for L. monocytogenes biofilm growth in mixed cultures, with a significant reduction in counts over time and values below 0.4 log CFU/cm(2) starting at day 4. Anionic tensioactive cleaning complemented with another procedure (acid cleaning, disinfection or acid cleaning+disinfection) eliminated the multi-species biofilms under all conditions tested (counts of all micro-organisms<0.4 log CFU/cm(2)). Peracetic acid was the most effective disinfectant, eliminating the multi-species biofilms under all tested conditions (counts of the all microorganisms <0.4 log CFU/cm(2)). In contrast, biguanide was the least effective disinfectant, failing to eliminate biofilms under all the test conditions.
评估了单物种生物膜（单核细胞增生李斯特菌）和多物种生物膜（屎肠球菌、粪肠球菌和单核细胞增生李斯特菌）的形成。此外，还评估了卫生程序对多物种生物膜控制的有效性。生物膜在不同的孵育温度（7、25 和 39°C）和接触时间（0、1、2、4、6 和 8 天）下在不锈钢试片上生长。在所有测试中，在 7°C 时，微生物计数低于 0.4 log CFU/cm(2)，不具有生物膜特征。在单物种生物膜中，在 25 和 39°C 下接触 8 天后，单核细胞增生李斯特菌的计数分别为 4.1 和 2.8 log CFU/cm(2)。在多物种生物膜中，屎肠球菌在 25 和 39°C 下接触 8 天后的计数分别为 8 log CFU/cm(2)。然而，多物种生物膜中的单核细胞增生李斯特菌受到肠球菌属的存在和温度的显著影响。在 25°C 下，单核细胞增生李斯特菌生物膜在多物种培养物中的生长得到促进，在接触 8 天后计数超过 6 log CFU/cm(2)。相比之下，在 39°C 下，混合培养物中单核细胞增生李斯特菌生物膜的生长受到负面影响，随着时间的推移计数显著减少，从第 4 天开始计数低于 0.4 log CFU/cm(2)。阴离子表面活性剂清洁与另一种方法（酸清洁、消毒或酸清洁+消毒）配合使用，在所有测试条件下消除了多物种生物膜（所有微生物计数<0.4 log CFU/cm(2)）。过氧乙酸是最有效的消毒剂，在所有测试条件下消除了多物种生物膜（所有微生物计数<0.4 log CFU/cm(2)）。相比之下，双胍类是最无效的消毒剂，在所有测试条件下都不能消除生物膜。
