查找使用阿拉丁产品的科研文献

Inhibitory effects of lactobionic acid on Vibrio parahaemolyticus planktonic cells and biofilms

Qiuxia Fan,Yahong Yuan,Ting Zhang,Wei Song,Qinglin Sheng,Tianli Yue

Vibrio parahaemolyticus is the primary pathogenic bacteria associated with seafood-borne illnesses . Lactobionic acid (LBA) is an organic acid with multiple biological activities that has recently been a focus of interest as an antibacterial agent. The aim of this study was to investigate the inhibitory effects of LBA on Vibrio parahaemolyticus planktonic cells and biofilms. The minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of LBA against Vibrio parahaemolyticus were both identified as 4 mg/mL. LBA exerted antimicrobial effects against planktonic Vibrio parahaemolyticus cells by damaging their membranes, as revealed by reduced intracellular ATP concentrations, increased protein leakage, abnormal cell morphology and diminished membrane integrity after treatment. At 1/16 × MIC and 1/8 × MIC, LBA inhibited biofilm formation and downregulated the expression of some biofilm-related genes, which was confirmed by crystal violet staining, field-emission scanning electron microscopy (FESEM) observations, and real-time quantitative PCR analysis. Moreover, LBA inactivated Vibrio parahaemolyticus cells within biofilms (on polystyrene and stainless steel surfaces), destroyed biofilm structures on stainless steel surfaces, and also reduced the levels of polysaccharides and proteins in the biofilms. Therefore, LBA is a potential low-cost agent that can be used to control planktonic Vibrio parahaemolyticus and its biofilms.

Inhibitory effect of Vibrio parahaemolyticus phage-functionalized PCL films on the host bacterium

Han Deng,Tian Shi,Liang Ke,Wei Xu,Mengni Zhou,Huajuan Wang,Min Zhou

An environmentally stable Vibrio parahaemolyticus phage 475s1 was isolated. • Phage 475s1 was stably immobilized onto biodegradable PCL films. • The films displayed strong antibacterial efficacy in vitro and in salmon. Vibrio parahaemolyticus ( V. parahaemolyticus ) is recognized as a major foodborne pathogen with global prevalence. The overuse of traditional antibiotics has not only induced the emergence of drug-resistant strains, but also posed a potential threat to human health through the food chain. Therefore, the development of green and precisely targeted antibacterial agents is urgent. In this study, a V. parahaemolyticus phage 475s1 was isolated and exhibited remarkable stability over a broad temperature range (0-70 °C), pH range (4–11) and ultraviolet (UV) irradiation durations (0-60 min). It was capable of lysing 12 out of 23 tested V. parahaemolyticus strains, with a burst size of 110 plaque-forming units (PFU) per infected cell. The phage 475s1 was immobilized onto the surface of biodegradable polycaprolactone (PCL) films. The results showed that the binding density of phage on the PCL films reached 0.04 phages/μm 2 , while the host-capturing density was approximately 0.05 cells/μm 2 . After ultrasonic treatment for 20 min, 35% of the phages remained stably adsorbed on the PCL films. The phage-functionalized PCL films were further applied to artificially contaminated salmon samples. At an incubation temperature of 37 °C, the phage-functionalized PCL films exhibited significant antibacterial efficacy. Compared with the control group, the bacterial concentration decreased by 1.72 log CFU/mL at 2 h and 1.60 log CFU/mL at 3 h, respectively. Therefore, these findings indicate that the V. parahaemolyticus phage-functionalized PCL films hold great promise as a novel and effective antibacterial packaging material. This work provides a feasible green antibacterial strategy against seafood-borne V. parahaemolyticus , offering valuable theoretical support for the development of biodegradable active packaging for industrial aquatic preservation.

Detection of Vibrio parahaemolyticus Based on Magnetic and Upconversion Nanoparticles Combined with Aptamers

Xinjie Song,Wei Li,Li Wu,Tianfeng Lv,Yao Zhang,Juan Sun,Xuping Shentu,Xiaoping Yu,Yuanfeng Wu

Vibrio parahaemolyticusis a halophilic and heat-labile gram-negative bacterium and is the most prevalent foodborne bacterium in seafood. In order to develop a rapid and sensitive method for detecting the foodborne pathogenic bacteriumVibrio parahaemolyticus, an aptamer-modified magnetic nanoparticle and an aptamer-modified upconversion nanoparticle were synthesised and used as a capture probe and a signal probe, respectively. The aptamer-modified magnetic nanoparticle,V. parahaemolyticuscell, and aptamer-modified upconversion nanoparticle formed a sandwich-like complex, which was rapidly separated from a complex matrix using a magnetic force, and the bacterial concentration was determined by fluorescence intensity analysis. The results showed that the fluorescence intensity signal correlated positively with the concentration ofV. parahaemolyticusin the range of 3.2 × 102to 3.2 × 105CFU/mL, with a linear equation of y = 296.40x − 217.67 and a correlation coefficient of R2= 0.9610. The detection limit of the developed method was 4.4 CFU/mL. There was no cross-reactivity with other tested foodborne pathogens. This method is highly specific and sensitive for the detection ofV. parahaemolyticus, and can achieve the qualitative detection of this bacterium in a complex matrix.Keywords:Vibrio parahaemolyticus;aptamer;magnetic nanoparticles;upconversion nanoparticles;detection

Self-clearance efficiency and mechanisms of photodynamic-driven antibacterial films against Vibrio parahaemolyticus biofilms

Manning Lan,Huajian Ou,Lu Chen,Yueqi Wang,Zhi Lu,Hao Dong,Xu Zhang,De He,Qiaohui Zeng,Jing Jing Wang

This study explored the self-removal efficiency and mechanisms of a photodynamically mediated 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized chitin grafted with 5-aminolevulinic acid (ALA) film against Vibrio parahaemolyticus biofilms via an endogenous photosensitization pathway. Results showed that the grafted ALA induced the production of endogenous protoporphyrin IX (PpIX), which in situ generated much reactive oxygen species (ROS) under blue LED irradiation. The ROS damaged the structural integrity and induced the unfolding of extracellular proteins, key component of extracellular polymeric substances (EPS), as well as decreased their hydrophobicity and adhesion work by 43.3%, which attenuated the interfacial adhesion of proteins. All the changes caused significant reduction in the colloidal stability and adhesive strength of EPS matrix on the surfaces of films, which eventually disintegrated the biofilms. Consequently, the films achieved over 99.6% inactivation of viable cells and 78.0% reduction of biofilm biomass. This study fabricated a novel antibacterial packaging film that initiates attacks from internal cells to eradicate biofilms.

A Dual-Mode (Fluorometric and Colorimetric) Aptasensor for Vibrio parahaemolyticus Detection Using Multifunctional Nanoparticles

Wu Zhengzong

Reliable detection of foodborne pathogen is of great importance in guaranteeing food safety. In the present work, based on the multifunctional properties of platinum-coated gold nanorods (AuNR@Pt), we developed a dual-mode aptasensor based on inner filter effect (IFE) and color change strategies and applied it for Vibrio parahaemolyticus ( V. parahaemolyticus ) detection. Under optimal conditions, in the range of 5 × 10 1 –10 7  cfu/mL and 10 2 –10 6  cfu/mL, the concentration of V. parahaemolyticus exhibited good linear relationship ( R 2  = 0.9898 and 0.9844) with changed fluorescence signal intensity and color signal intensity, respectively. In addition, the practicability of the novel aptasensor was successfully validated by detecting different concentrations of V. parahaemolyticus spiked in tap water and shrimp samples. With its satisfactory performances, this aptasensor is expected to be a promising candidate for determining V. parahaemolyticus . This assay could also be extended for the analysis of other targets (pathogens or harmful substances) in food products by using the corresponding aptamer.

A Visual Protocol for Sensitive Vibrio parahaemolyticus Detection Based on Hybridization chain reaction cascaded DNAzyme

Jiali Wang,Qian Cui,Shu Zeng,Danfeng Fu,Daoyun Peng,Fei Chen,Yi Wan,Anwei Wang

Vibrio parahaemolyticus (V. parahaemolyticus) is one of the most harmful pathogenic bacteria derived from seafood and could cause great damage to aquaculture and human health even at low concentrations. Rapid and accurate detection of V. parahaemolyticus in clinic samples is essential but still remains a challenge. Herein, we developed a highly sensitive, simple and visual method for V. parahaemolyticus detection. First, V. parahaemolyticus specific aptamer, its block stands named initiator (I), and magnetic beads (MB) composed the capture probe. Then in the present of V. parahaemolyticus, the aptamer on the probe specifically recognize and bind to V. parahaemolyticus, lead to the separation of I strand. Next, the I strand sequentially initiates hybridization chain reaction (HCR) for signal amplification, releases the G-quadruplex DNAzyme which was blocked in hairpin H2 and recovers its peroxidase-mimicking activity. Thus, the results are visualized through the color variation of 2,2’-azino-di-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS2−), which displays green for V. parahaemolyticus contained samples while colorless for negative samples. With the signal amplification of HCR, this proposal could achieve a detection limit down to 0.82 CFU/mL with a wide linear detection range from 100 to 106 CFU/mL. Besides, it also exhibited excellent specificity against common non-target bacteria in aquaculture and performed well in the detection of V. parahaemolyticus-spiked pacific white shrimp. Furthermore, this method realized accurate detection in shrimp seedlings from six of different breeding bases in Wenchang, which indicates tremendous potential for early disease diagnosis and prevention.

Rapid Inference of Distinct Genotypes in Vibrio parahaemolyticus by SVM-Assisted Surface-Enhanced Raman Spectroscopy

Hao Jiang,Han-Quan Qiu,Heng-Su Liu,Shi-Ying Fu,Jia-Sheng Lin,Ze-Hui Chen,Yue-Jiao Zhang,Jian-Feng Li,Zhong-Qun Tian

Vibrio parahaemolyticus is a kind of Gram-negative bacteria widely distributed in estuarine and coastal areas. It was discovered in dried mackerel in Osaka and has now become one of the main pathogens causing foodborne diseases. The seafood contamination caused by it poses a serious threat to human health and safety. Although most V. parahaemolyticus strains are non-pathogenic, they are often ignored in the routine detection process. The thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) encoded by the tdh and trh genes, respectively, are considered its main virulence factors. Different genotypes of strains are closely related to antibiotic resistance phenotypes. Therefore, the related tdh and trh genes are considered the main virulence markers in the epidemiology of V. parahaemolyticus . Here, based on label-free surface-enhanced Raman spectroscopy (SERS), V. parahaemolyticus with different tdh and trh expression were directly detected. By combining support vector machine (SVM), the test samples were divided into four categories according to different genotypes, and the inference of different genotypes from phenotypic spectra was achieved within 7 min, and the classification accuracy of the model was 98.46%. The results of this work demonstrate that the combination of label-free SERS spectroscopy and SVM algorithms has great potential in the field of bacterial classification.

A novel fluorescence immunoassay based on inner filter effect and gold nanoclusters for Vibrio parahaemolyticus determination

Guangxin Yang,Chunhao Wei,Yunyu Tang,Jingru Zhang,Xuan Zhang,Hai Chi,Leren Tao,Cong Kong

A novel and sensitive fluorescence immunoassay was developed for the determination of Vibrio parahaemolyticus (VP) based on gold nanoclusters (BSA-AuNCs). The assay signal was originated from inner filter effect (IFE) between BSA-AuNCs and p-nitrophenol (PNP). A double emission peak fluorescent gold nanocluster with good property was quickly synthesized, which was used as fluorescent probe in this method. To achieve the IFE, Alkaline phosphatase labeled second antibody (IgG-ALP), which could generate PNP with the substrate of PNPP (p-nitrophenyl phosphate), was used in the immune reaction. According the competitive reaction, VP could be detected indirectly by the change of fluorescence signal. Under the optimal conditions, the limit of detection (LOD) for VP was 5 × 10 2 CFU/mL. The linear detection range was 10 3 -10 7 CFU/mL. Furthermore, the proposed method was successfully applied to detect VP in real samples, giving recoveries in the range of 82.5%–113.0%, and the coefficient of variation was 5.46%–9.88%.

The two-component system TtrRS boosts Vibrio parahaemolyticus colonization by exploiting sulfur compounds in host gut

Xiaojun Zhong,Fuwen Liu,Tianqi Liang,Ranran Lu,Mengting Shi,Xiujuan Zhou,Menghua Yang

One of the greatest challenges encountered by enteric pathogens is responding to rapid changes of nutrient availability in host. However, the mechanisms by which pathogens sense gastrointestinal signals and exploit available host nutrients for proliferation remain largely unknown. Here, we identified a two-component system in Vibrio parahaemolyticus , TtrRS, which senses environmental tetrathionate and subsequently activates the transcription of the ttrRS - ttrBCA-tsdBA gene cluster to promote V. parahaemolyticus colonization of adult mice. We demonstrated that TsdBA confers the ability of thiosulfate oxidation to produce tetrathionate which is sensed by TtrRS. TtrRS autoregulates and directly activates the transcription of the ttrBCA and tsdBA gene clusters. Activated TtrBCA promotes bacterial growth under micro-aerobic conditions by inducing the reduction of both tetrathionate and thiosulfate. TtrBCA and TsdBA activation by TtrRS is important for V. parahaemolyticus to colonize adult mice. Therefore, TtrRS and their target genes constitute a tetrathionate-responsive genetic circuit to exploit the host available sulfur compounds, which further contributes to the intestinal colonization of V. parahaemolyticus . Access to host nutrients is regarded as a critical step for the pathogen infection. However, the human gastrointestinal tract is colonized by an enormous number of microbes, which limits pathogens’ access to nutrient supplies. Sulfur is one of the most abundant elements on Earth and is also essential to all living organisms. The mechanisms by which bacteria, especially intestinal pathogens, regulate the bioavailability of utilizable sulfur in the host are poorly understood. Here, we characterized a tetrathionate-responsive genetic circuit, which was involved in the utilization of sulfur compounds including tetrathionate and thiosulfate in V. parahaemolyticus , and thus contributed to the bacterial intestinal colonization. Our study provides new insight into the ability of bacterial pathogens to sense gastrointestinal signals and exploit host nutrients for their colonization, which contributes to a better understanding of the pathogenesis of enteric pathogens.

Ultrasensitive Detection of Vibrio parahaemolyticus Based on Boric Acid-Functionalized Eu (III)-Based Metal–Organic Framework

Jingyi Xiao,Yi Ren,Menglong Liu,Yiyao Liu,Litao Chen,Jiayan Gao,Jinyang Li,Xue Gao

This study intends to create a ratiometric fluorescence probe utilizing aptamers for the detection of Vibrio parahaemolyticus ( V. parahaemolyticus ) in aquatic products. In this design, aptamer-functionalized magnetic nanoparticles specifically capture V. parahaemolyticus , while boric acid on Eu (III)-Based Metal-Organic Framework (Eu-MOF) interacts with glycolipids present on bacterial cells, thereby achieving dual recognition of V. parahaemolyticus . This fluorescent probe quantitatively detects V. parahaemolyticus by measuring the intensity of ratio fluorescence. The sensor demonstrates a detection range from 77 to 7.7×10 7 CFU/mL, possessing a detection threshold down to 1 CFU/mL. Moreover, the developed method based on Eu-MOF had been successfully applied to real samples. To achieve rapid on-site detection of V. parahaemolyticus , the study designed a portable smartphone sensor that confirms its capability for rapidly detecting pathogens and contributes significantly to establishing a system for regulating safety in detecting food and environment.

Rapid and accurate sensing platform based on lanthanide metal-organic framework and aptamer for Vibrio parahaemolyticus diagnosis

Kuiyu Wang,Lanxiang Zeng,Liangke Gong,Yusheng Ouyang,Tao Yang,Tianying Sun,Hui Zeng

In this study, a rapid visual analysis strategy for pathogens was constructed based on lanthanide metal–organic frameworks (LnMOFs) and FAM-aptamer. The dual fluorescence signal changes were realized by the competitive binding effect of the target and LnMOFs on the FAM-aptamer. The nitrocellulose membrane (NC membrane) is used as the signal output platform, and the G/R value in Red, Green, Blue (RGB) of negative and positive signals is collected to output the detection results. Using Vibrio parahaemolyticus in seafood as model target, the detection performance of dual fluorescence sensing strategy was verified. Under the optimal conditions, the G/R difference between the positive and negative signals and the concentration of Vibrio parahaemolyticus was linear in the range of 10 2 -10 5 colony forming units (CFU)/mL, and the detection limit was 10 2 CFU/mL. The method is simple to operate and the detection time can be controlled within 20 min. It can be developed as a portable detection kit, providing a new technical means for the safety and quality control of food supply chain.

A multichromatic colorimetric detection method for Vibrio parahaemolyticus based on Fe3O4-Zn-Mn nanoenzyme and dual substrates

Wenteng Qiao,Luliang Wang,Kun Yang,Yushen Liu,Quanwen Liu,Feng Yin