Ma Angela, Neumann Norman, Chui Linda
Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB T6G 2R3, Canada.
School of Public Health, University of Alberta, Edmonton, AB T6G 2R3, Canada.
Microorganisms. 2021 Feb 15;9(2):403. doi: 10.3390/microorganisms9020403.
Despite the effectiveness of thermal inactivation processes, biofilms continue to be a persistent source of contamination in food processing environments. strains possessing the locus of heat resistance are a novel food safety threat and raises the question of whether these strains can also form biofilms. The objectives of this study were to determine biofilm formation in heat resistant isolates from clinical and environmental origins using an in-house, two-component apparatus and to characterize biofilm formation-associated genes in the isolates using whole genome sequencing. Optimal conditions for biofilm formation in each of the heat resistant isolates were determined by manipulating inoculum size, nutrient concentration, and temperature conditions. Biofilm formation in the heat resistant isolates was detected at temperatures of 24 °C and 37 °C but not at 4 °C. Furthermore, biofilm formation was observed in all environmental isolates but only one clinical isolate despite shared profiles in biofilm formation-associated genes encoded by the isolates from both sources. The circulation of heat resistant isolates with multi-stress tolerance capabilities in environments related to food processing signify that such strains may be a serious food safety and public health risk.
尽管热灭活工艺有效，但生物膜仍是食品加工环境中持续存在的污染源。具有耐热位点的菌株是一种新的食品安全威胁，并引发了这些菌株是否也能形成生物膜的问题。本研究的目的是使用内部的双组分装置确定来自临床和环境来源的耐热分离株中的生物膜形成情况，并使用全基因组测序对分离株中与生物膜形成相关的基因进行表征。通过控制接种量、营养浓度和温度条件，确定了每种耐热分离株中生物膜形成的最佳条件。在24℃和37℃的温度下检测到耐热分离株中的生物膜形成，但在4℃时未检测到。此外，尽管来自这两种来源的分离株编码的与生物膜形成相关的基因具有共同特征，但在所有环境分离株中都观察到了生物膜形成，而在临床分离株中仅观察到一株。具有多重应激耐受能力的耐热分离株在与食品加工相关的环境中的传播表明，此类菌株可能对食品安全和公共健康构成严重风险。
