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Effect of environmental stresses on the survival and cytotoxicity of Shiga toxin-producing Escherichia coli

Food Quality and Safety 2017年第2期1卷 139-146页

作者： Brian Byongkwon Yoo Yanhong Liu Vijay Juneja Lihan Huang Cheng-An Hwang residue chemistry and predictive microbiology research unit and Molecular Characterization of Foodborne Pathogens research unit Eastern Regional Research CenterAgricultural Research ServiceUnited States Department of AgricultureWyndmoorPennsylvaniaUSA Present address:Clinical and Environmental microbiology Branch Division of Healthcare Quality and PromotionNational Center for Emerging and Zoonotic Infectious DiseasesCenters for Disease Control and Prevention1600 Clifton Rd.NEAtlantaGA 30329USA

The objective of this study was to determine the effect of environmental stresses on the cytotoxicity of Shiga toxin-producing Escherichia coli (STEC). STEC O157:H7 and six non-O157 STEC strains (O26:H11, O103:H1, O104:H4, O111:NM, O121:NM, and O145:NM) were subjected to osmotic (aw 0.95-0.98), acid (pH 4-7), and chlorine (1-5 ppm) stresses. After stress treatments, bacterial populations, expression of virulence-associated genes, and Vero-cytotoxicity were determined. Among the strains, O145:NM survived at aw 0.97 longer than other serotypes, while O111:NM was significantly more sensitive to osmotic stress. At pH 4, O103:H1 was more resistant to the stress, while O26:H11 and O111:NM had significantly less growth. For 2 ppm chlorine stress, O26:H11, O103:H1, and O145:NM had higher populations (>3 log) than other strains. Stressed strains showed a significant increase in relative gene expression levels of stx1, stx2, and eae in O103:H1, O104:H4, and O145:NM than non-stressed control. Additionally, significantly higher Vero-cytotoxicity, as indicated by lactate dehydrogenase assay, of stressed O26:H11, O103:H1, O104:H4, and O145:NM was observed. The results suggest that the growth and cytotoxicity of selected pathogenic E. coli may be enhanced after being exposed to environmental stresses.

关键词： Pathogenic Escherichia coli stress growth virulence genes Vero-cytotoxicity.

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Effects of Sodium Lactate on the Survival of Listeria Monocytogenes, Escherichia coliO157:H7, and Salmonellaspp. in Cooked Ham at Refrigerated and Abuse Temperatures

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Food and Nutrition Sciences 2011年第5期2卷 464-470页

作者： Cheng-An Hwang Shiowshuh Sheen Vijay Juneja residue chemistry and predictive microbiology research unit Eastern Regional Research Center Agricultural Research Service United States Department of Agriculture Wyndmoor USA

The objective of this study was to determine the effect of sodium lactate on the survival of Listeria monocytogenes, Escherichia coli O157: H7, and Salmonella spp. in cooked ham during storage at refrigerated and abuse temperatures. Cooked ham was added with 0% - 3% lactate, inoculated with a multiple-strain mixture of L. monocytogenes, E. coli O157: H7, or Salmonella spp. and stored at 4oC - 15oC for up to 35 day. The growth of the three pathogens was inhibited in ham containing 3% lactate, and no growth of E. coli O157: H7 and Salmonella spp. occurred at the lowest storage tem- peratures of 6 and 8oC, respectively. In ham containing no lactate, the average growth rates were 0.256 - 0.380 log CFU/day for L. monocytogenes at 4oC - 8oC, 0.242 - 0.315 log CFU/day for E. coli O157: H7 at 8oC - 15oC, and 0.249 - 0.328 log CFU/day for Salmonella spp. at 10oC - 15oC. The addition of 1% or 2% lactate significantly (P < 0.05) reduced the growth rates of the three pathogens, and the effect was more profound at lower temperatures. Salmonella spp. were more sensitive to the effect of lactate than L. monocytogenes and E. coli O157: H7. Polynomial models were developed to describe the growth rates of the three pathogens as affected by the lactate concentration and storage tem- perature. Results from this study demonstrate the effect of lactate on the growth of L. monocytogenes, E. coli O157: H7, and Salmonella spp. in cooked ham and indicate the effective lactate concentrations and storage temperatures that can be used to enhance the microbiological safety of ready-to-eat ham products.

关键词： Ham Lactate Listeria Monocytogenes Escherichia Coli O157: H7 Salmonella spp.

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Modeling the Surface Cross-Contamination of Salmonellaspp. on Ready-to-Eat Meat via Slicing Operation

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Food and Nutrition Sciences 2011年第9期2卷 916-924页

作者： Shiowshuh Sheen Cheng-An Hwang Food Safety and Intervention Technologies research unit Eastern Regional Research Center Agricultural Research Service United States Department of Agriculture residue chemistry and predictive microbiology research unit Eastern Regional Research Cente

Salmonella spp. surface transfer patterns/models between ready-to-eat (RTE) deli meat and a typical meat slicer are presented. A five-strain cocktail of Salmonella spp. was inoculated directly onto the rim of a round slicer blade at an initial level of ca. 4, 5, 6, 7 or 8 log CFU/blade (ca. 3, 4, 5, 6 or 7 log CFU/cm2 of the blade edge area). Thereafter, a RTE deli meat (ham) was sliced to a thickness of 1.5 - 2.0 mm. In another cross-contamination scenario, a clean blade was initially used to slice ham, which was pre-surface-inoculated with the Salmonella cocktail (ca. 2, 3, 4, 5, 6 or 7 log CFU/cm2 with a total area of 100 cm2), followed by slicing of an un-inoculated ham. The log CFU of Salmonella per ham slice was determined and empirical models were developed. The models, follow the decreasing Power law, predict the surface cross-contamination of Salmonella spp. (at any initial level) for sliced deli meat (ham) and will provide a useful tool in developing RTE meat risk assessments. Surface transfer patterns of three foodborne pathogens, i.e. Listeria monocytogenes, E. coli O157:H7 and Salmonella predicted by models are also presented.

关键词： Salmonella Surface Transfer Cross-Contamination Modeling Slicing

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Impact of Chlorine, Temperature and Freezing Shock on the Survival Behavior of Escherichia coliO157:H7 on Ready-to-Eat Meats

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Food and Nutrition Sciences 2012年第4期3卷 530-538页

作者： Shiowshuh Sheen Cheng-An Hwang Vijay K. Juneja Food Safety and Intervention Technologies research unit USDA Agricultural Research Service Research Facility Eastern Regional Research Center Wyndmoor USA residue chemistry and predictive microbiology research unit USDA Agricultural Research Service Research Facility Eastern Regional Research Center Wyndmoor USA.

Foodborne pathogens continue to pose a potential food safety hazard in ready-to-eat (RTE) meat. Chlorine is commonly used to sanitize processing equipment where Escherichia coli O157:H7 (Ec) may survive and contaminate food products. The objective of this study was to characterize the survival behavior of Ec with different stresses on RTE meats. A multi-strain cocktail of Ec was pre-treated with freezing shock for 15 - 20 h and/or chlorine (0, 25, and 50 ppm) for one hour, and then inoculated onto RTE meat surfaces to obtain about 3.0 log CFU/g. Samples were stored at three abuse temperatures (12℃, 18℃, and 24℃) and Ec was enumerated during the storage. The freezing shock impact was studied using the Ec cocktail stored in a freezer overnight followed by chlorine exposure for one hour. The lag phase and growth rate of Ec were estimated using DMFit (Combase, Baranyi’s model). Results indicated that Ec growth was suppressed by chlorine treatment. Freezing shock was found to have little impact in terms of lag time and growth rate. The lag phase of Ec after exposure to 0 ppm of chlorine (50.3 h) was shorter than that of Ec treated with 25 ppm (54.6 h) and 50 ppm (164.1 h) at 12℃. However, the lag phase decreased with an increase in temperature, e.g. at 25 ppm, lag times were 54.6, 51.1 and 48.9 h for 12℃, 18℃ and 24℃, respectively. Lag times increased with an increase in chlorine concentration. At 24℃, lag times were 15.8, 48.9, and 52.4 h for 0, 25, and 50 ppm, respectively. The growth rate increased with an increase in temperature for 0 and 25 ppm chlorine levels, but decreased at 50 ppm level. Growth rate and lag phase as a function of temperature and chlorine concentration can be described by polynomial models and modified Ratkowsky-type and Zwietering-type models. Results of this study will contribute to risk assessment of RTE meats.

关键词： Chlorine Lag Time Growth Rate E. coli O157:H7 Modeling

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Characteristics and mechanism of Ni^(2+)and Cd^(2+)adsorption by recovered perlite from agar extraction residue

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Chinese Journal of Chemical Engineering 2024年第8期72卷 141-152页

作者： Juan Wang Yanbing Zhu Zedong Jiang Xiping Du Mingjing Zheng Lijun Li Hui Ni Yuanpeng Wang Zhipeng Li Qingbiao Li College of Ocean Food and Biological Engineering Jimei UniversityXiamen 361021China Fujian Provincial Key Laboratory of Food microbiology and Enzyme Engineering Xiamen 361021China research Center of Food Biotechnology of Xiamen City Xiamen 361021China Xiamen Ocean Vocational College Xiamen 361021China College of chemistry and Chemical Engineering Xiamen UniversityXiamen 361021China

Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human *** of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar *** previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial ***,the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption *** adsorption process of Ni^(2+)and Cd^(2+)by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation,and the relevant adsorption mechanism was mainly *** with commercial perlite,the adsorption removal rate of Ni^(2+)and Cd^(2+)by enzymatic recovered perlite could reach 92.9%and 89.2%,respectively,and were improved by 12.63%and 13.03%.Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni^(2+)and Cd^(2+),and the relevant adsorption mechanism was mainly monolayer *** X-ray photoelectron spectroscopy(XPS)results indicated that the decrease of Si—O Si^(2+)hydroxyl coordination bond and the increase of C—Si bond might make the binding effect of recovered perlite with heavy metals *** competitive adsorption of Ni^(2+)and Cd^(2+)by recovered perlite was still dominated by chemisorption and monolayer *** study was expected to provide a theoretical basis and technical support for the removal of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite from seaweed residue.

关键词： Agar extraction residue Recovered perlite Heavy metal ion Adsorption property

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Multi-omics analysis of attenuated variant reveals potential evaluation marker of host damaging for SARS-CoV-2 variants

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Science China(Life Sciences) 2024年第1期67卷 83-95页

作者： Guangshan Xie Lin Zhu Siwen Liu Cun Li Xin Diao Yanhao Zhang Xiuli Su Yuanyuan Song Guodong Cao Li Zhong Pui Wang Xiaojuan Liu Bobo Wing-Yee Mok Shusheng Zhang Dong-Yan Jin Jie Zhou Honglin Chen Zongwei Cai State Key Laboratory of Environmental and Biological Analysis Hong Kong Baptist UniversityHong Kong SARChina State Key Laboratory for Emerging Infectious Diseases and Department of MicrobiologyLi Ka Shing Faculty of MedicineThe University of Hong KongHong Kong SARChina College of chemistry Zhengzhou UniversityZhengzhou 450001China School of Biomedical Sciences The University of Hong KongHong Kong SARChina HKBU Shenzhen Institute of research and Continuing Education Shenzhen 518000China

SARS-CoV-2 continues to threaten human society by generating novel variants via mutation and *** high number of mutations that appeared in emerging variants not only enhanced their immune-escaping ability but also made it difficult to predict the pathogenicity and virulence based on viral nucleotide *** markers for evaluating the pathogenicity of new variants are therefore *** comparing host responses to wild-type and variants with attenuated pathogenicity at proteome and metabolome levels,six key molecules on the polyamine biosynthesis pathway including putrescine,SAM,dc-SAM,ODC1,SAMS,and SAMDC were found to be differentially upregulated and associated with pathogenicity of *** validate our discovery,human airway organoids were subsequently used which recapitulates SARS-CoV-2 replication in the airway epithelial cells of COVID-19 *** ODC1 as a proof-ofconcept,differential activation of polyamine biosynthesis was found to be modulated by the renin-angiotensin system(RAS)and positively associated with ACE2 *** experiments demonstrated that ODC1 expression could be differentially activated upon a panel of SARS-CoV-2 variants of concern(VOCs)and was found to be correlated with each VOCs’pathogenic ***,the presented study revealed the discriminative ability of key molecules on polyamine biosynthesis as a predictive marker for virulence evaluation and assessment of SARS-CoV-2 variants in cell or organoid *** work,therefore,presented a practical strategy that could be potentially applied as an evaluation tool for the pathogenicity of current and emerging SARS-CoV-2 variants.

关键词： SARS-CoV-2 multi-omics attenuated variant predictive pathogenic marker polyamine biosynthesis

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Design and prediction for highly efficient SO_(2) capture from flue gas by imidazolium ionic liquids

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Green Energy & Environment 2022年第1期7卷 130-136页

作者： Lili Jiang Ke Mei Kaihong Chen Rina Dao Haoran Li Congmin Wang Department of chemistry Zhejiang UniversityHangzhou310027China Key Laboratory of Biomass Chemical Engineering of Ministry of Education Zhejiang UniversityHangzhou310027China

An efficient method for prediction in the capture of SO_(2)from flue gas by imidazolium ionic liquids was reported,where the concentration of SO_(2)is 2000 *** the basis of quantitative calculations through a combination of Langmuir simulation,theoretical calculation and quantum chemical method,SO_(2)absorption and desorption performance from flue gas by twelve kinds of imidazolium ionic liquids with different anions were designed and ***,among them,five kinds of imidazolium ionic liquids were chosen and prepared to investigate their behavior of SO_(2)absorption capacity,desorption residue,and available absorption *** results indicated that the experimental values were in good agreement with the predicted ***,an ideal ionic liquid[Emim][Tetz]was obtained through the predictive method for the capture of SO_(2)of 2000 ppm,which showed high available absorption capacity of 0.24 g SO_(2)per g ionic liquid and excellent reversibility.

关键词： Ionic liquids Desulfurization Quantum calculation Langmuir simulation Prediction

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Level of Contamination of Fishponds Water in Pesticide residues and Metallic Trace Elements (Pb, Cd, As, Hg): Case of Fishponds of ZEPREGUHE (Daloa, Côte d’Ivoire)

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Journal of Agricultural chemistry and Environment 2022年第4期11卷 307-317页

作者： Kacou Alain Paterne Dalogo Ano Guy Serge Ehouman James Halbin Kouadio David Leonce Kouadio Edi Jean Frejus Ehui Karim Sory Traore Laboratory of Environmental Sciences and Technology Jean Lorougnon GUEDE University Daloa C&ocirc te d’Ivoire Laboratory of Environmental Sciences Nangui Abrogoua University Abidjan C&ocirc te d’Ivoire Agroforestry Training and research unit Biochemistry-microbiology Department Agrovalorisation Laboratory Jean Lorougnon GUEDE University Daloa C&ocirc te d’Ivoire

Fishponds waters intended to satisfy the nutritional needs of the populations in terms of supply of fish resources are strongly and unfortunately exposed to the mobility and dispersion of metallic trace elements (TMEs) or to the persistence in the environment and in the form of pesticide residues from human activities. The objective of this work is to evaluate, on the one hand, the levels of identified pesticide residues and, on the other hand, those of researched TMEs (lead, cadmium, mercury and arsenic) in the waters of ponds used for fish farming in Zépréguhé, a locality located 9 km from the town of Daloa in the centre-west of Côte d’Ivoire. The dosage of the samples carried out by means of a gas chromatograph coupled to a mass spectrometer (GC/MS) made it possible to detect nine (9) pesticide molecules, including eight (8) organochlorines and a single molecule from the pyrethroid family, obtained from the detection limit of 0.006 μg/L and the quantification limit of 0.018 μg/L. The maximum average concentration was obtained with α-endosulfan for a content reaching 0.8038 μg/L and well above the maximum admissible concentration of 0.1 μg/L. The TMEs were quantified using an atomic absorption spectrophotometer (AAS). Arsenic is the most abundant metal with an average concentration of 9.497 μg/L. With the exception of lead, these measured levels are above the acceptable limit values for freshwater. This study showed that human activities such as the use of fertilisers and plant protection products in plantations, sand extraction and road traffic have a negative impact on the quality of the water in ponds used for fish breeding.

关键词： Fishpond Water Metallic Trace Elements Pesticide residues Maximum residue Levels

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Elucidating the clinical and immunological value of m6A regulatormediated methylation modification patterns in adrenocortical carcinoma

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Oncology research 2023年第5期31卷 819-831页

作者： WENHAO XU HAOMING LI YASIR HAMEED MOSTAFA A.ABDEL-MAKSOUD SAEEDAH MUSAED ALMUTAIRI AYMAN MUBARAK MOHAMMED AUFY WAEL ALTURAIKI ABDULAZIZ J.ALSHALANI AYMAN M.MAHMOUD CHEN LI Department of Urology Urological Surgery Research InstituteFirst Affiliated HospitalArmy Medical University(Third Military Medical University)ChongqingChina Department of Urology Affiliated Hospital of Guilin Medical UniversityGuilinChina Department of Applied Biological Sciences Tokyo University of ScienceTokyoJapan Department of Botany and microbiology College of ScienceKing Saud UniversityRiyadhSaudi Arabia Department of Pharmaceutical Sciences Division of Pharmacology and ToxicologyUniversity of ViennaViennaAustria Department of Medical Laboratory Sciences College of Applied Medical SciencesKing Saud UniversityRiyadhSaudi Arabia Department of Life Sciences Faculty of Science and EngineeringManchester Metropolitan UniversityManchesterUK Department of Biology ChemistryPharmacyFree University of BerlinBerlinGermany

N6-methyladenosine methylation(m6A)is a common type of epigenetic alteration that prominently affects the prognosis of tumor ***,it is unknown how the m6A regulator affects the tumor microenvironment(TME)cell infiltration in adrenocortical carcinoma(ACC)and how it affects the prognosis of ACC patients *** m6A alteration patterns of 112 ACC patients were evaluated,furthermore,the association with immune infiltration cell features was *** unsupervised clustering method was applied to typify the m6A alteration patterns of ACC *** principal component analysis(PCA)technique was taken to create the m6A score to assess the alteration pattern in specific *** found two independent patterns of m6A alteration in ACC *** TME cell infiltration features were significantly in accordance with phenotypes of tumor immune-inflamed and immune desert in both *** m6Ascore also served as an independent predictive factor in ACC *** somatic copy number variation(CNV)and patients prognosis can be predicted by m6A alteration ***,the ACC patients with high m6A scores had better overall survival(OS)and higher efficiency in immune checkpoint blockade *** work demonstrated the significance of m6A alteration to the ACC patients *** individual m6A alteration patterns analysis might contribute to ACC patients prognosis prediction and immunotherapy choice.

关键词： m6A Tumor microenvironment Adrenocortical carcinoma Immunotherapy Prognosis

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A Proximity-Triggered Strategy toward Transferable Proteolysis Targeting Chimeras

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CCS chemistry 2023年第6期5卷 1433-1442页

作者： Yuena Wang Rongtong Zhao Chuan Wan Wei Kang Rui Wang Chengyao Chiang Xiaochun Guo Qi Chang Zhanfeng Hou Yuxin Ye Qinhong Luo Ziyuan Zhou Jianbo Liu Shuiming Li Dongyuan Wang Feng Yin Zigang Li State Key Laboratory of Chemical Oncogenomics School of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055 Shenzhen Bay Laboratory Shenzhen 518055 Pingshan Translational Medicine Center Shenzhen Bay LaboratoryShenzhen 518055 Guangdong Provincial Key Laboratory of Regional Immunity and Diseases Shenzhen University International Cancer CenterDepartment of Cell Biology and GeneticsSchool of MedicineShenzhen UniversityShenzhen 518055 Shenzhen Key Laboratory of microbiology and Gene Engineering Shenzhen UniversityShenzhen 518055 Department of Pharmacy Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030

Over the past 20 years,great efforts have been invested in developing site-specific approaches to protein modification to dissect protein functions directly and ***,we report a proximitytriggered group transfer strategy from a sulfonium warhead to a Cysteine(Cys)residue of the target *** a guiding ligand,cargoes could be transferred selectively from a sulfonium center onto the Cys residue in the vicinity of their binding *** successful thalidomide transfer of sulfonium 1-X could be applied intracellularly for epidermal growth factor receptor degradation,highlighting the potential of group transfer strategy as a suite of chemical biology studies,including cell imaging,protein profiling,and protein degradation by simply employing different transferrable groups.

关键词： sulfonium protein covalent modification proteolysis targeting chimeras site-specific modification degradation

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