FOOD CONTROL
·
2021
·
IF 5.548
Shan Shan,Yanmei Huang,Zhaohong Huang,Zhonger Long,Chengwei Liu,Xuelong Zhao,Keyu Xing,Xiaoyue Xiao,Jintao Liu,Yunhong Huang,Weihua Lai,Daofeng Liu
Shiga toxin-producing Escherichia coli (STEC) is known as a kind of foodborne pathogens that can produce Shiga toxin type1, type 2, or both, encoded by stx1 and stx2 genes, respectively. Rapid and accurate detection of STEC and stx1 / stx2 subtyping assay in food and environment is essential for foodborne outbreak investigation. In this study, a method for the accurate and rapid subtyping of STEC single colony using asymmetric polymerase chain reaction (asPCR) combined with lateral flow immunoassay (LFIA) was established. AsPCR was conducted using biotinylated stx1 and digoxin-labeled stx2 primers to obtain several single stranded DNA amplicons labeled with biotin or/and digoxin. Subsequently, these amplicons were tagged with specific probes labeled with carboxylate-modified red polystyrene microspheres using sequential hybridization. Finally, STEC with different Shiga toxin gene types could be distinguished depending on the appearance of different test lines on an LFIA strip. Thus, the STEC single colony could be identified and subtyped accurately and conveniently using this method. This method showed high specificity. Twenty-four strains of STEC in milk were detected and subtyped using our method, which combines asPCR with LFIA.
研究领域:
微生物学
·
分子生物学
·
食品安全
·
病原体检测
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2026
·
IF 10.4
Mengxia Duan,Minghui Lu,Man Ding,Zhouping Wang,Shijia Wu,Nuo Duan
Colorimetric/fluorescent sensor for Stx2 based on UIO-66@PdIr was established. • Aptamer as a specific capture element enhanced the accuracy of the detection. • PdIr bimetallic nanoparticles exhibited excellent peroxidase-like activity. • UIO-66 as carrier enhanced PdIr loading and offered inherent fluorescence. • The sensor showed low LOD of 0.039 (colorimetric) and 0.0097 ng/mL (fluorescent). Shiga toxin II (Stx2) has attracted extensive attention due to its toxicity and pathogenicity, making the development of sensitive detection methods urgent. This study constructed a dual-mode sensing platform for the sensitive detection of Stx2 in food. Composite material UIO-66@PdIr with peroxidase-like activity and fluorescent properties was synthesized and combined with cDNA as the signal probe, while aptamer-modified magnetic beads served as the capture probe. Specific binding of Stx2 to the aptamer triggered the release of the signal probe, enabling colorimetric and fluorescence signal readout. The colorimetric mode showed a linear range of 0.05–100 ng/mL with an LOD of 0.039 ng/mL, and the fluorescence mode exhibited 0.01–1000 ng/mL with an LOD of 0.0097 ng/mL. Additionally, this method was successfully applied to the detection of Stx2 in food, and the recovery rates were 94.33% ∼ 102.20%. It indicated that the constructed sensor holds great practical potential for Stx2 detection. Download: Download high-res image (137KB) Download: Download full-size image
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED BIOCHEMISTRY AND MICROBIOLOGY
·
2024
·
IF 1
Hu J.,Wu Y.,Kang L.,Liu Y.,Wu Y.,Han D.,Wang J.
Abstract Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that seriously threats the public and animal health. The major virulence of STEC is Shiga toxin (Stx) which is encoded by Stx prophage. Stx prophage induction leads to the production of Stx. Our recent research has shown that dietary functional sugars can differently regulate Shiga toxin type 2 (Stx2) prophage induction. However, high-throughput assays are required to find more dietary inhibitors for Stx prophage induction. This study aims to establish the recA dual-luciferase reporter system for rapidly screening the functional sugars that can inhibit Stx prophage induction. Results showed that the recA dual-luciferase reporter plasmid was successfully constructed as confirmed by DNA sequencing. Established recA dual-luciferase reporter system showed similar screening results when compared with traditional temperate phage determination method (i.e., qPCR) and suggested that L-arabinose is a dietary functional Stx prophage induction inhibitor. Supplementation with L-arabinose in culture medium reduces Stx production in STEC isolated from fecal samples of diarrhea piglets. Collectively, the recA dual-luciferase reporter system is a promising tool for convenient and rapid screening of dietary Stx prophage induction inhibitor, especially suitable for large-scale screening experiments.
研究领域:
微生物学
·
分子生物学
·
食品安全
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
Gut Microbes
·
2023
·
IF 12.2
Jie Hu,Yifan Wu,Xingjian Zhou,Luyuan Kang,Shiyi Zhang,Yisi Liu,Yu Pi,Xilong Li,Junjun Wang,Dandan Han
The pathogenicity of Escherichia coli (E. coli) O157:H7 is predominantly associated with Shiga toxin 2 (Stx2) that poses a huge threat to human and animal intestinal health. Production of Stx2 requires expression of stx2 gene, which is located in the genome of lambdoid Stx2 prophage. Growing evidence has implicated that many commonly consumed foods participate in the regulation of prophage induction. In this study, we aimed to explore whether specific dietary functional sugars could inhibit Stx2 prophage induction in E. coli O157:H7, thereby preventing Stx2 production and promoting intestinal health. We demonstrated that Stx2 prophage induction in E. coli O157:H7 was strongly inhibited by L-arabinose both in vitro and in a mouse model. Mechanistically, L-arabinose at doses of 9, 12, or 15 mM diminished RecA protein levels, a master mediator of the SOS response, contributing to reduced Stx2-converting phage induction. L-Arabinose inhibited quorum sensing and oxidative stress response, which are known as positive regulators of the SOS response and subsequent Stx2 phage production. Furthermore, L-arabinose impaired E. coli O157:H7 arginine transport and metabolism that were involved in producing Stx2 phage. Collectively, our results suggest that L-arabinose may be exploited as a novel Stx2 prophage induction inhibitor against E. coli O157:H7 infection.
研究领域:
微生物学
·
食品科学
·
分子生物学
·
病理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）