Aly Mohamed A, Domig Konrad J, Kneifel Wolfgang, Reimhult Erik
Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
Department of Food Science, Faculty of Agriculture, Ain Shams University, Cairo, Egypt.
Front Microbiol. 2019 Jul 2;10:1464. doi: 10.3389/fmicb.2019.01464. eCollection 2019.
is an emerging foodborne pathogen, which is linked to life-threatening infections causing septicemia, meningitis, and necrotizing enterocolitis. These infections have been epidemiologically connected to ingestion of contaminated reconstituted powder infant formula. Even at low water activity can survive for a long time; it is capable of protective biofilm formation and occasionally shows high virulence and pathogenicity even following stressful environmental conditions. Hence it is a challenging task for the food industry to control contamination of food ingredients and products through the entire production chain, since an increasing number of severe food-related outbreaks of infections has been observed. The seemingly great capability of to survive even strict countermeasures combined with its prevalence in many food ingredients requires a greater in depth understanding of its virulence factors to master the food safety issues related to this organism. In this context, we present the whole genome sequence (WGS) of two different isolated from skimmed milk powder (C7) and ready-to-eat salad mix (C8), respectively. These are compared to other, already sequenced, genomes. Sequencing of the allele revealed that both isolates were . We investigated the molecular characteristics of both isolates relevant for genes associated with pathogenesis and virulence factors, resistance to stressful environmental conditions (e.g., osmotic and heat), survival in desiccation as well as conducted a comparative genomic analysis. By using multi-locus sequence typing (MLST), the genetic type of both isolates is assessed and the number of unique genes is determined. DNA of C8 is shown to hold a novel and unique sequence type; the number of unique genes identified in the genomic sequence of C7 and C8 were 109 and 188, respectively. Some of the determined unique genes such as the and genes are linked to the Type VI Secretion System cluster, which is associated with pathogenicity and virulence factors. Moreover, seven genes encoding for multi-drug resistance were found in both isolates. The finding of a number of genes linked to producing capsules and biofilm are likely related to the observed resistance to desiccation.
是一种新兴的食源性病原体，与导致败血症、脑膜炎和坏死性小肠结肠炎的危及生命的感染有关。这些感染在流行病学上与摄入受污染的复原粉状婴儿配方奶粉有关。即使在低水分活度下也能长时间存活；它能够形成保护性生物膜，甚至在压力环境条件下偶尔也会表现出高毒力和致病性。因此，对于食品行业来说，在整个生产链中控制食品成分和产品的污染是一项具有挑战性的任务，因为已经观察到越来越多与食品相关的严重感染爆发。即使采取严格的应对措施，其仍具有很强的生存能力，再加上它在许多食品成分中普遍存在，这就需要更深入地了解其毒力因子，以掌握与这种生物体相关的食品安全问题。在此背景下，我们分别展示了从脱脂奶粉（C7）和即食沙拉混合物（C8）中分离出的两种不同的全基因组序列（WGS）。将这些序列与其他已测序的基因组进行比较。该等位基因的测序表明，这两种分离株均为 。我们研究了这两种分离株与发病机制、毒力因子、对压力环境条件（如渗透压和热）的抗性、干燥环境中的存活能力相关的分子特征，并进行了比较基因组分析。通过多位点序列分型（MLST），评估了这两种分离株的遗传类型并确定了独特基因的数量。C8的DNA显示具有一种新颖且独特的序列类型；在C7和C8的基因组序列中鉴定出的独特基因数量分别为109个和188个。一些已确定的独特基因，如 和 基因，与VI型分泌系统簇相关，该簇与致病性和毒力因子有关。此外，在这两种分离株中均发现了七个编码多重耐药性的基因。发现许多与产生荚膜和生物膜相关的基因可能与观察到的对干燥的抗性有关。
