Pathogens
·
2025
·Vol. 14
·期 5
·501
·
IF 3.3
Jia-Tong Han,Yu-Xuan Tang,Si-Yi Wu,Yi-Ran Chen,Zhan-Peng Zou,Hang Zeng,Zhongjia Yu
Escherichia colicontamination in poultry is a significant concern due to its potential to cause foodborne illness. The presence of extraintestinal pathogenicE. coli(ExPEC) strains in chicken carcasses can lead to severe human infections. This study investigates the prevalence, virulence, and antibiotic resistance ofE. coliisolates from chicken carcasses processed in both wet market and industrial environments, with a focus on the detection capabilities of MALDI-TOF MS. A total of 119E. coliisolates were obtained. Only a small proportion (5/119) carried enteropathogenic virulence genes. In contrast, 71.42% (85/119) of the isolates harbored multiple extraintestinal virulence genes. Among these,iucCandsitA, which are associated with systemic infections, were present in 68.24% (58/85) and 43.53% (37/85) of the isolates, respectively. Furthermore, 47.06% (56/119) of the isolates carrying at least two extraintestinal virulence genes were classified as ExPEC. Additionally, 94.6% (54/56) of ExPEC isolates were multidrug resistant (MDR), showing resistance to over three antibiotic classes, raising concerns about the spread of antibiotic resistance. MALDI-TOF MS profiling revealed significant heterogeneity among the ExPEC isolates, with no distinct clustering patterns based on processing environment or sampling site. These findings underscore the public health risks posed by ExPEC in poultry and emphasize the need for improved surveillance, stringent hygiene practices, and responsible antibiotic use in poultry production.
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MOLECULAR BIOTECHNOLOGY
·
2021
·Vol. 63
·期 6
·491-501
·
IF 2.695
Tang Wanggang,Lian Chaoqun,Si Yu,Chang Jianrong
2,3-Butanediol dehydrogenase (BDH), also known as acetoin/diacetyl reductase, is a pivotal enzyme for the formation of 2,3-butanediol (2,3-BD), a chiral compound with potential roles in the virulence of certain pathogens. Here, a NAD(H)-dependent (2 R ,3 R )-BDH from Neisseria gonorrhoeae FA1090 (NgBDH), the causative agent of gonorrhoea, was functionally characterized. Sequence analysis indicated that it belongs to zinc-containing medium-chain dehydrogenase/reductase family. The recombinant NgBDH migrated as a single band with a size of around 45 kDa on SDS-PAGE and could be confirmed by Western blotting and mass spectrometry. For the oxidation of either (2 R ,3 R )-2,3-BD or meso -2,3-BD, the enzyme exhibited a broad pH optimum between pH 9.5 to 11.5. For the reduction of (3 R /3 S )-acetoin, the pH optimum was around 6.5. The enzyme could catalyze the stereospecific oxidation of (2 R ,3 R )-2,3-BD ( K m = 0.16 mM, k cat / K m = 673 s −1 · mM −1 ) and meso -BD ( K m = 0.72 mM, k cat / K m = 165 s −1 · mM −1 ). Moreover, it could also reduce (3 R /3 S )-acetoin with a K m of 0.14 mM and a k cat / K m of 885 s −1 · mM −1 . The results presented here contribute to understand the 2,3-BD metabolism in N. gonorrhoeae and pave the way for studying the influence of 2,3-BD metabolism on the virulence of this pathogen in the future.
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JOURNAL OF FOOD PROTECTION
·
2021
·
IF 2.077
Bing Han,Xiaoyu Han,Mengmeng Ren,Yilin You,Jicheng Zhan,Weidong Huang
ABSTRACT Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environmentally friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H 2 O 2 -Ag + ) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900, and Salmonella Typhimurium SL 1344. The MICs and MBCs against S. aureus were found to be 0.014% H 2 O 2 –3.125 mg/L Ag + , and for both E. coli O157:H7 and Salmonella Typhimurium they were 0.028% H 2 O 2 –6.25 mg/L Ag + . Results of the time-kill trial suggest that HSC could inhibit the growth of the tested bacteria, because 99.9% of viable cells were killed following treatment at 1 MIC for 3 h. The mechanism of antibacterial action of HSC was found to include the disruption of the bacterial cell membrane, followed by reduction of intracellular ATP concentration and inhibition of the activity of antioxidases, superoxide dismutase, and catalase. The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.
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BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Li-Qun Jin,Bo Yang,Wei Xu,Xian-Xiao Chen,Dong-Xu Jia,Zhi-Qiang Liu,Yu-Guo Zheng
In this study, recombinant E. coli BL21(DE3)/pCDFDuet-1-XR-GDH harboring xylose reductase (XR) and glucose dehydrogenase (GDH) were immobilized and applied for the production of xylitol from xylose mother liquor (XML). Various immobilization methods were screened and the cross-linking approach with diatomite and polyetherimide as the raw materials and glutaraldehyde as the cross-linking agent was the optimal one, and the recovery activity reached of 80.3% after immobilization. The half-life of immobilized cells was 1.52 times to that of free cells. Batch experiments showed that the enzyme activity of immobilized cells remained 70.5% of the initial activity after 10 batches and the space-time yield of xylitol reached of 11.5 g/(L h). The production of xylitol from xylose mother liquor by immobilized E. coli cells containing xylose reductase and glucose dehydrogenase was reported for the first time, which paved a foundation for industrial production of xylitol from waste xylose mother liquor.
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MICROCHIMICA ACTA
·
2023
·Vol. 191
·期 1
·1-10
·
IF 5.7
Chen Jiawei,Zeng Yan,Zhang Dun,Qi Peng,Liu Xuguang,Song Ruiguo,Wang Peng
A direct and ultra-sensitive surface-enhanced Raman scattering (SERS) immunoassay method is introduced for the detection of Escherichia coli and Staphylococcus aureus . This methodology is based on a sandwich-structured complex probe (SCP) mechanism, combined with target-induced strand displacement. Moreover, by leveraging the amplified SERS signal from gold nanoparticles (AuNPs) corresponding to an increase in bacterial count, we achieve quantitative determination. The SCP demonstrates remarkable specificity, sensitivity, and anti-interference capability in bacterial detection. The detection limits for both bacterial strains are as low as 10 CFU/mL. In our selectivity tests, all peak intensities had standard deviations ( n = 3) below 6%. Recoveries in normal human serum were 101–110% for E. coli and 96–101% for S. aureus . In milk, the recoveries were 102–105% for E. coli and 100–105% for S. aureus , respectively, demonstrating a high level of accuracy and resistance to interference. In addition, the SCP offers a dual-detection capability, enabling simultaneous diagnosis of multiple targets, which greatly simplifies the testing procedure. The findings underscore that this immunoassay platform fulfills the demand for rapid and precise pathogenic bacterial diagnosis, holding substantial potential for practical applications. Graphical abstract
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Membranes
·
2025
·Vol. 15
·期 5
·141
·
IF 3.6
Ning Li,Hongbo Xin,Keyu Deng
Outer membrane vesicles (OMVs) are extracellular vesicles secreted by Gram-negative bacteria with diameters of 20–250 nm. OMVs contain various biologically active substances from their parent bacteria, such as proteins, lipids, and nucleic acids.Escherichia coliNissle 1917 (EcN) is a Gram-negative probiotic that resides in the human intestine. EcN-derived OMVs are pivotal in modulating intestinal immune responses. However, few studies have addressed the heterogeneity of EcN-derived OMVs in terms of size, significantly limiting the research on their clinical applications. Currently, there are a lack of feasible methods for obtaining EcN-derived OMVs of different sizes. To address this knowledge gap, we developed a membrane filtration method to isolate EcN-derived OMVs of varying sizes. In this study, we first used gradient filtration to isolate high-purity EcN-derived OMVs and conducted a proteomic analysis. Subsequently, we used membrane filtration to separate the EcN-derived OMVs by size. We successfully obtained EcN-derived OMVs of three specific sizes: <50 nm, 50–100 nm, and 100–300 nm. We then performed proteomic analyses of these EcN-derived OMVs and compared their protein profiles. Finally, we compared the ability of each EcN-derived OMV type to induce RAW264.7 macrophages to secrete the pro-inflammatory factor interleukin (IL)-1β and the anti-inflammatory factor IL-10. The EcN-derived OMVs contained 646 different proteins overall; those of different sizes contained different protein types. Among them, the EcN-derived OMVs in the <50 nm group contained significantly fewer proteins (262 different types in total) than those in the 50–100 nm (1603 types) and 100–300 nm (1568 types) groups. Furthermore, the <50 nm group had fewer membrane proteins (40) than the 50–100 nm (215) and 100–300 nm (209) groups. We also found that RAW264.7 macrophages secreted different concentrations of IL-1β and IL-10 following co-incubation with the three EcN-derived OMV types. The 50–100 nm EcN-derived OMV group showed a stronger effect in terms of inducing inflammatory cytokine secretion compared to the other two groups. This study provides direct experimental evidence that EcN-derived OMVs of different sizes exhibit heterogeneous properties.
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PROCESS BIOCHEMISTRY
·
2021
·
IF 3.757
Fang-Ying Zhu,Jia Zhong,Qi Shen,Dong-Xu Jia,Shi-Jin Ma,Jun Du,Hui Wu,Qing Yang,Min Cao,Zhi-Qiang Liu,Yu-Guo Zheng
d -(+)-pantothenic acid (DPA) has been widely used in feed and food additives and pharmaceutical industries. d -(−)-pantolactone ( D PL) is a key intermediate in the production of DPA . The bio-asymmetric synthesis of D PL from ketopantoyl lactone (KPL) by conjugated polyketone reductases is an attractive route. In this study, high expression of a conjugated polyketone reductase from Candida glabrata ( Cgl CPR) in Escherichia coli was achieved after optimization of vectors. The optimum temperature and pH of purified Cgl CPR were 40 °C and 4.5, respectively. The Michaelis-Menten constant K m and V max of purified Cgl CPR for KPL are 73.09 μM and 2.29 μmol mg −1 s −1 , respectively. To circumvent the spontaneous degradation of KPL in biocatalytic reaction of synthesizing DPL, the reaction was performed by a strategy combing fed-batch addition of whole cell catalyst with substrate semi-continuous feeding. At the final KPL loading of 1000 mM, DPL with an isolated yield of 94.24 % was obtained after 13-h reaction and enantiomeric excess ( e.e. ) achieved > 99 %. The space-time yield of DPL reached to 228 g L −1 d −1 .
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CHEMOSPHERE
·
2020
·
IF 5.778
Ye Yang,Kun Wan,Zhipeng Yang,Dailin Li,Guoxin Li,Songlin Zhang,Lei Wang,Xin Yu
Emerging contaminants such as antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) are becoming a global environmental problem. In this study, the glow discharge plasma (GDP) was applied for degrading antibiotic resistant Escherichia coli ( E. coli ) with resistance genes (tetA, tetR, aphA) and transposase gene (tnpA) in 0.9% sterile saline. The results showed that GDP was able to inactivate the antibiotic resistant E. coli and remove the ARGs and reduce the risk of gene transfer. The levels of E. coli determined by 16S rRNA decreased by approximately 4.7 logs with 15 min of discharge treatment. Propidium monoazide - quantitative polymerase chain reaction (PMA-qPCR) tests demonstrated that the cellular structure of 4.8 more logs E. coli was destroyed in 15 min. The reduction of tetA, tetR, aphA, tnpA genes was increased to 5.8, 5.4, 5.3 and 5.5 logs with 30 min discharge treatment, respectively. The removal of ARGs from high salinity wastewater was also investigated. The total abundance of ARGs was reduced by 3.9 logs in 30 min. Scavenging tests indicated that hydroxyl radicals (·OH) was the most probable agents for bacteria inactivation and ARGs degradation. In addition, the active chlorine (Cl· and Cl 2 ) which formed during the discharge may also contribute to the inactivation and degradation.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2019
·
IF 3.571
Chunfang Zhu,Meng Zhang,Qiaoling Tang,Qian Yang,Jing Li,Xuan He,Yong Ye
Sapogenin is the main block of Camellia oleifera saponin, which was purified and structurally modified by the C28 acylation reaction to synthesize 19 new derivatives. The growth and biofilm inhibition of Staphylococcus aureus and Escherichia coli was measured to evaluate their antibacterial effects. A three-dimensional quantitative structure–activity relationship (3D-QSAR) assay indicated that the antibacterial activities were significantly enhanced after sapogenin was modified with an aromatic ring or heterocyclic ring and electron-withdrawing substituents at the meta or para position. Among them, the derivative of sapogenin with a 2-mercapto-4-methyl-5-thiazolyl acetyl group obviously destroyed bacterial biofilm and made bacteria lysis. 3D-QSAR provides practical information for the structural design of sapogenin derivatives with strong antibacterial activity, and the C. oleifera sapogenin derivative 28-O-(2-mercapto-4-methyl-5-thiazolyl)-3β,16α,21β,22α-O-tetrahydroxy-oleantel-2-ene-23-aldehyde (S-16) is an effective candidate as an antibacterial agent for the prevention of bacterial resistance against antibiotics.
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Synthetic and Systems Biotechnology
·
2025
·
IF 4.4
Yanghao Liu,Changgeng Li,Yu Miao,Zhichao Chen,Tangen Shi,Ling Ma,Siyu Zhao,Zichen Yu,Lanxiao Li,Qingyang Xu
5-Aminolevulinic acid (5-ALA) is an important non-proteinogenic amino acid with wide applications in agriculture and medicine. To achieve high-level microbial production, this study established a dual-pathway reconstruction strategy in Escherichia coli by integrating the endogenous C5 pathway with an inducible exogenous C4 pathway. Multi-copy overexpression of gltX , hemA , and hemL , combined with enhanced glutamate supply and the introduction of a non-oxidative glycolysis pathway, effectively increased the C5 pathway flux and carbon efficiency, while product toxicity was significantly alleviated by strengthening efflux mechanisms and oxidative stress tolerance. A quorum sensing–based regulatory system was employed to dynamically regulate hemB expression, thereby balancing cell growth and 5-ALA biosynthesis, and a controlled glycine feeding strategy specifically activated the C4 pathway during the later fermentation stage, forming a stage-specific dynamic activation mechanism. Promoter regulation of sucC/sucD expression and enhanced endogenous PLP biosynthesis further stabilized the C4 flux. Fed-batch fermentation in a 5 L bioreactor resulted in a final 5-ALA titer of 37.34 g/L, demonstrating the industrial potential of this systems metabolic engineering strategy combining dual pathways and stage-specific activation control.
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MICROCHEMICAL JOURNAL
·
2026
·
IF 5.2
Minhang Zhu,Jiaxin Shi,Jing Huang,Fasheng Zhang,Yubo Gao,Shuai Chen,Shengrong Du,Zufang Huang
A suspended liquid membrane-assisted SERS biosensing platform was developed for ultrasensitive E. coli detection. • Dual-recognition “magnetic bead– E. coli –SERS tag” complexes enabled specific E. coli capture and signal amplification. • Under optimized conditions, a limit of detection of 10 CFU/mL was achieved. • The SERS platform enables favorable detection of E. coli in complex matrices. Sensitive detection of pathogenic bacteria with a shorter turnaround than conventional culture-based methods is essential for clinical diagnosis, public health monitoring, and food safety. Herein, we developed a magnetically enriched suspended liquid membrane (SLM)-assisted surface-enhanced Raman scattering (SERS) biosensing platform for the sensitive detection of Escherichia coli ( E. coli ). Wheat germ agglutinin (WGA)-functionalized carboxylated magnetic beads were used to capture and enrich bacteria, while aptamer-modified Au@4-mercaptobenzoic acid (MBA)@Ag core–shell nanoparticles served as SERS tags for specific recognition and signal amplification. By combining magnetic enrichment with the directional concentration effect of the SLM, the platform enabled favorable Raman detection with enhanced signal intensity and improved quantitative performance. Under optimized conditions, the platform enabled detection of E. coli at a lowest experimentally verified concentration of 10 colony-forming units per milliliter (CFU/mL), provided an 8–10-fold SERS signal enhancement compared with the non-enriched system, and exhibited a quantitative linear response over the range of 1 × 10 3 to 1 × 10 8 CFU/mL with an R 2 of 0.9634. The platform showed proof-of-concept feasibility for E. coli detection in pretreated and post-spiked complex matrices, including human seminal plasma (HSP), human urine and commercial fruit juice, with apparent recoveries ranging from 85.76% to119.94% for juice, 93.26% to 114.82% for human urine, and 79.38% to115.40% for HSP. Download: Download high-res image (173KB) Download: Download full-size image
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SENSORS AND ACTUATORS B-CHEMICAL
·
2026
·
IF 8.3
Luoyuan Shi,Xinying Jiang,Shuang Sun,Chunping Jia,Xiaojun Bian,Jianlong Zhao
Rapid and reliable detection of foodborne pathogens is essential for ensuring food safety, yet achieving high selectivity and sensitivity in complex matrices remains challenging. Herein, we report a sensitive and selective electrochemical sensing platform integrating a bacteria-imprinted polymer (BIP) capture interface with concanavalin A-functionalized Fe 3 O 4 (Fe 3 O 4 -ConA) for the detection of Escherichia coli O157:H7 ( E. coli O157:H7). The BIP film was electropolymerized in situ on glassy carbon electrode to generate recognition sites for efficient capture of E. coli O157:H7. Subsequently, Fe 3 O 4 -ConA bound to surface glycans on the captured bacteria through lectin-glycan interactions, forming a sandwich-like sensing interface. The anchored Fe 3 O 4 nanozyme catalyzed the H 2 O 2 -mediated oxidation of o -phenylenediamine, producing amplified electrochemical signals for bacterial quantification. Benefiting from the combination of imprinting-based recognition and catalytic amplification, the sensor achieved an ultrasensitive detection limit of 2.8 CFU mL −1 and a linear range from 10 1 to 10 5 CFU mL −1 . Recoveries of 93.29–113.62% were obtained in spiked milk, fish, and juice samples, with reliable detection down to 10 CFU mL −1 in complex food matrices. This work provides an effective strategy for constructing nanozyme-amplified electrochemical sensors for sensitive and selective monitoring of foodborne pathogens.
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