Cronobacter是一种重要的食源性病原体,可引起严重的新生儿脑膜炎,坏死性小肠结肠炎,和菌血症.目前,Cronobacter中生物膜形成的知识有限。在本研究中,对谷物相关样品中Cronobacter的生物膜形成能力和相关基因表达变化进行了系统的研究。我们从307个Cronobacter分离物分析48小时的结果显示14个菌株(4.6%)具有很强的生物膜形成能力,在47株(15.3%)中,142株弱(46.2%),其余104株菌株没有这种能力(33.9%)。对5株具有强生物膜形成能力的菌株的进一步研究表明,在培养24小时后,Cronobacter的生物膜形成最大。在48h-72h左右达到峰值,此后逐渐减少。京都基因和基因组百科全书(KEGG)分析显示,差异表达基因(DEG)参与鞭毛组装,氧化磷酸化,核糖体,光合作用,O-抗原核苷酸糖生物合成,柠檬酸盐循环(三羧酸循环,TCA)和细菌趋化性在生物膜形成细胞中富集。与浮游细胞相比,涉及这些富集途径的基因大多下调。几种转录调节基因,如csrA和bolA,细胞表面组成调节基因glgS显著上调。通过定量实时PCR分析,发现13个(92.3%)选择的基因中的12个与浮游和生物膜细胞的RNA-Seq一致,从而增加对我们数据的信心。本研究为进一步研究生物被膜形成的调控机制奠定了良好的理论基础,为制定新的食品安全措施奠定了基础。临床疾病预防和控制。
Cronobacter is an important foodborne pathogen that can cause severe neonatal meningitis, necrotizing enterocolitis, and bacteremia. Currently, there is limited knowledge of biofilm formation in Cronobacter. In the present study, biofilm formation ability and associated gene expression changes in Cronobacter from cereal related samples was carried out systematically. Our results from 307 Cronobacter isolates analyzed for 48 h showed strong biofilm-forming ability in 14 strains (4.6%), moderate in 47 strains (15.3%), weak in 142 strains (46.2%), and no such ability in the remaining 104 strains (33.9%). Further studies on five strains with strong biofilm-forming ability showed that maximum biofilm formation in Cronobacter occurred after 24 h of cultivation, reaching a peak around 48 h-72 h, reducing gradually thereafter. Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed that differentially expressed genes (DEGs) involved in flagellar assembly, oxidative phosphorylation, ribosome, photosynthesis, O-Antigen nucleotide sugar biosynthesis, citrate cycle (tricarboxylic acid cycle, TCA) and bacterial chemotaxis were enriched in biofilm forming cells. The genes involved these enrichment pathways were mostly downregulated when compared to planktonic cells. Several transcriptional regulator genes such as csrA and bolA, and the cell surface composition regulator gene glgS were significantly upregulated. 12 of 13 (92.3%) selected genes was found to be in agreement with the RNA-Seq of planktonic and biofilm cells by Quantitative real-time PCR analysis, thus increasing confidence in our data. Our research lays a sound theoretical basis for further studies on mechanisms regulating biofilm formation and provides a foundation for development of new food safety measures, clinical disease prevention and control.