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A family of pyrazinone metabolites (1-11) were characterized from Staphylococcus xylosus ATCC 29971. Six of them were hydroxylated or methoxylated, which were proposed to be produced by the rare noncatalytic oxa-Michael addition reaction with a water or methanol molecule. It was confirmed that isopropyl alcohol can also be the Michael donor of the reaction. 1-7 and the synthetic precursor 2a showed significant inhibition of breast cancer cell migration.
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Pirazinas , Staphylococcus , Humanos , Movimento Celular/efeitos dos fármacos , Estrutura Molecular , Pirazinas/química , Pirazinas/farmacologia , Staphylococcus/efeitos dos fármacosRESUMO
INTRODUCTION: The use of 3-dimensional (3D) printing techniques in fabricating crowns has increased the demand for bracket bonding onto these surfaces. The objective was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded onto 3D-printed crowns using primer-incorporated orthodontic adhesives and 3D printing materials as orthodontic adhesives. METHODS: A total of 160 crowns were printed with two 3D printing materials, DentaTOOTH (Asiga, Sydney, Australia) (group A) and NextDent C&B Micro Filled Hybrid (3D Systems, Soesterberg, Netherlands) (group N). Each group was randomly divided into 4 adhesive subgroups (n = 20): Transbond XT (for groups A [ATX] and N [NTX]; 3M Unitek, Monrovia, Calif), Ortho Connect (for groups A [AOC] and N [NOC]; GC Corporation., Tokyo, Japan), Orthomite LC (for groups A [AOM] and N [NOM]; Sun Medical, Co Ltd, Moriyama, Shiga, Japan), and unpolymerized liquid state of 3D printing resin (for groups A [AA] and N [NN]). SBS was measured with a universal testing machine at a crosshead speed of 0.5 mm/min. The adhesive remnant index and the mode of failure were analyzed under the microscope. Statistical analysis was performed at a significance level of α = 0.05. RESULTS: When used as adhesives (AA and NN), 3D printing materials showed no statistically significant difference in SBS compared with Transbond XT (ATX and NTX, respectively). In group N, NN showed a significantly higher SBS than primer-incorporated orthodontic adhesives (NOC and NOM; P <0.001). Adhesive failures were only observed in primer-incorporated orthodontic adhesives (AOC, NOC, AOM, and NOM). CONCLUSIONS: Primer-incorporated orthodontic adhesives, as well as unpolymerized 3D printing materials employed as orthodontic adhesives on 3D-printed crowns, exhibited comparable bonding strength to Transbond XT without surface modification. Despite variations in adhesive-related factors, all measurements stayed within clinically acceptable ranges, highlighting the potential of these materials for orthodontic bonding on 3D-printed crowns, simplifying clinical procedures without compromising bond strength.
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Coroas , Braquetes Ortodônticos , Impressão Tridimensional , Resistência ao Cisalhamento , Humanos , Colagem Dentária/métodos , Cimentos Dentários/química , Teste de Materiais , Análise do Estresse Dentário , Cimentos de Resina/químicaRESUMO
The gut microbiota plays a pivotal role in metabolic disorders, notably type 2 diabetes mellitus (T2DM). In this study, we investigated the synergistic potential of combining the effects of Bifidobacterium longum NBM7-1 (CKD1) with anti-diabetic medicines, Lobeglitazoneâ (LO), Sitagliptinâ (SI), and Metforminâ (Met), to alleviate hyperglycemia in a diabetic mouse model. CKD1 effectively mitigated insulin resistance, hepatic steatosis, and enhanced pancreatic ß-cell function, as well as fortifying gut-tight junction integrity. In the same way, SI-CKD1 and Met- CKD1 synergistically improved insulin sensitivity and prevented hepatic steatosis, as evidenced by the modulation of key genes associated with insulin signaling, ß-oxidation, gluconeogenesis, adipogenesis, and inflammation by qRT-PCR. The comprehensive impact on modulating gut microbiota composition was observed, particularly when combined with Metforminâ. This combination induced an increase in the abundance of Rikenellaceae and Alistipes related negatively to the T2DM incidence while reducing the causative species of Cryptosporangium, Staphylococcaceae, and Muribaculaceae. These alterations intervene in gut microbiota metabolites to modulate the level of butyrate, indole-3-acetic acid, propionate, and inflammatory cytokines and to activate the IL-22 pathway. However, it is meaningful that the combination of B. longum NBM7-1(CKD1) reduced the medicines' dose to the level of the maximal inhibitory concentrations (IC50). This study advances our understanding of the intricate relationship between gut microbiota and metabolic disorders. We expect this study to contribute to developing a prospective therapeutic strategy modulating the gut microbiota.
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Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Resistência à Insulina , Metformina , Camundongos , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Regulação para Cima , Diabetes Mellitus Experimental/tratamento farmacológico , Metformina/farmacologia , Metformina/uso terapêuticoRESUMO
Pedestrian detection is a critical task for safety-critical systems, but detecting pedestrians is challenging in low-light and adverse weather conditions. Thermal images can be used to improve robustness by providing complementary information to RGB images. Previous studies have shown that multi-modal feature fusion using convolution operation can be effective, but such methods rely solely on local feature correlations, which can degrade the performance capabilities. To address this issue, we propose an attention-based novel fusion network, referred to as INSANet (INtra-INter Spectral Attention Network), that captures global intra- and inter-information. It consists of intra- and inter-spectral attention blocks that allow the model to learn mutual spectral relationships. Additionally, we identified an imbalance in the multispectral dataset caused by several factors and designed an augmentation strategy that mitigates concentrated distributions and enables the model to learn the diverse locations of pedestrians. Extensive experiments demonstrate the effectiveness of the proposed methods, which achieve state-of-the-art performance on the KAIST dataset and LLVIP dataset. Finally, we conduct a regional performance evaluation to demonstrate the effectiveness of our proposed network in various regions.
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Type 2 diabetes (T2D) is known as adult-onset diabetes, but recently, T2D has increased in the number of younger people, becoming a major clinical burden in human society. The objective of this study was to determine the effects of Bifidobacterium and Lactiplantibacillus strains derived from the feces of 20 healthy humans on T2D development and to understand the mechanism underlying any positive effects of probiotics. We found that Bifidobacterium longum NBM7-1 (Chong Kun Dang strain 1; CKD1) and Lactiplantibacillus rhamnosus NBM17-4 (Chong Kun Dang strain 2; CKD2) isolated from the feces of healthy Korean adults (n = 20) have anti-diabetic effects based on the insulin sensitivity. During the oral gavage for 8 weeks, T2D mice were supplemented with anti-diabetic drugs (1.0-10 mg/kg body weight) to four positive and negative control groups or four probiotics (200 uL; 1 × 109 CFU/mL) to groups separately or combined to the four treatment groups (n = 6 per group). While acknowledging the relatively small sample size, this study provides valuable insights into the potential benefits of B. longum NBM7-1 and L. rhamnosus NBM17-4 in mitigating T2D development. The animal gene expression was assessed using a qRT-PCR, and metabolic parameters were assessed using an ELISA assay. We demonstrated that B. longum NBM7-1 in the CKD1 group and L. rhamnosus NBM17-4 in the CKD2 group alleviate T2D development through the upregulation of IL-22, which enhances insulin sensitivity and pancreatic functions while reducing liver steatosis. These findings suggest that B. longum NBM7-1 and L. rhamnosus NBM17-4 could be the candidate probiotics for the therapeutic treatments of T2D patients as well as the prevention of type 2 diabetes.
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In this study, genetic variations and characteristics of Listeria monocytogenes isolates from enoki mushrooms (23), smoked ducks (7), and processed ground meat products (30) were examined with respect to hemolysis, virulence genes, growth patterns, and heat resistance. The isolates that showed the highest pathogenicity and the lowest pathogenicity were analyzed to obtain the whole-genome sequence, and the sequences were further analyzed to identify genetic variations in virulence, low-temperature growth-related, and heat resistance-related factors. All isolates had ß-hemolysis and virulence genes (actA, hlyA, inlA, inlB, and plcB). At low temperatures, isolates with high growth (L. monocytogenes strains SMFM 201803 SD 1-1, SMFM 201803 SD 4-2, and SMFM 201804 SD 5-3) and low growth (L. monocytogenes strains SMFM 2019-FV43, SMFM 2019-FV42, and SMFM 2020-BT30) were selected. Among them, L. monocytogenes SMFM 201804 SD 5-3 showed the highest resistance at 60°C and 70°C. The strains SMFM 201804 SD 5-3 (high-risk) and SMFM 2019-FV43 (low-risk) harbored 45 virulence genes; 41 single nucleotide variants (SNVs) were identified between these two isolates. A comparison of 26 genes related to low-temperature growth revealed 18 SNVs between these two isolates; a comparison of the 21 genes related to heat resistance revealed 16 SNVs. These results indicate that the differences in the pathogenicity of L. monocytogenes SMFM 201804 SD 5-3 and L. monocytogenes SMFM 2019-FV43 are associated with the SNVs identified in virulence genes, low-temperature growth-related genes, and heat resistance-related genes.
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BACKGROUND: The Patient Health Questionnaire-2 (PHQ-2) and Insomnia Severity Index-2 (ISI-2) are screening assessments that reflect the past 2-week experience of depression and insomnia, respectively. Retrospective assessment has been associated with reduced accuracy owing to recall bias. OBJECTIVE: This study aimed to increase the reliability of responses by validating the use of the PHQ-2 and ISI-2 for daily screening. METHODS: A total of 167 outpatients from the psychiatric department at the Yongin Severance Hospital participated in this study, of which 63 (37.7%) were male and 104 (62.3%) were female with a mean age of 35.1 (SD 12.1) years. Participants used a mobile app ("Mental Protector") for 4 weeks and rated their depressive and insomnia symptoms daily on the modified PHQ-2 and ISI-2 scales. The validation assessments were conducted in 2 blocks, each with a fortnight response from the participants. The modified version of the PHQ-2 was evaluated against the conventional scales of the Patient Health Questionnaire-9 and the Korean version of the Center for Epidemiologic Studies Depression Scale-Revised. RESULTS: According to the sensitivity and specificity analyses, an average score of 3.29 on the modified PHQ-2 was considered valid for screening for depressive symptoms. Similarly, the ISI-2 was evaluated against the conventional scale, Insomnia Severity Index, and a mean score of 3.50 was determined to be a valid threshold for insomnia symptoms when rated daily. CONCLUSIONS: This study is one of the first to propose a daily digital screening measure for depression and insomnia delivered through a mobile app. The modified PHQ-2 and ISI-2 were strong candidates for daily screening of depression and insomnia, respectively.
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The objective of this study was to evaluate the anti-inflammatory effect of Latilactobacillus sakei SMFM2017-NK1 (LS1), L. sakei SMFM2017-NK3 (LS2), and Limosilactobacillus fermentum SMFM2017-NK2 (LF) on colitis using an animal model. DSS (dextran sulfate sodium salt) was orally injected into C57BL/6N mice to induce inflammation in the colon for seven days. Colitis mice models were treated with LS1, LS2, and LF, respectively, and Lacticaseibacillus rhamnosus GG (LGG) was used as a positive control. During oral administration of lactic acid bacteria, the weights of the mice were measured, and the disease activity index (DAI) score was determined by judging the degree of diarrhea and bloody stool. When comparing the differences between the minimum weight after DSS administration and the maximum weight after lactic acid bacteriaadministration were compared, the LF-treated group showed the highest weight gain at 8.91%. The DAI scores of the LF, LS2, and LGG groups were lower than that of the control group. After sacrifice, mRNA expression levels for proinflammatory cytokines (TNF-α, IL-1ß, IL-6, and IFN-γ) and mediators (iNOS and COX-2) in the colon were measured. LF was selected as a superior strain for anti-inflammation in the colon. It was further analyzed to determine its biochemical characteristics, cytotoxicity, and thermal stability. Catalase and oxidase activities for LF were negative. In cytotoxicity and heat stability tests, the LF group had higher cell viability than the LGG group. The genome of LF was obtained, and 5682 CDS, 114 tRNA, 2 RNA, and 5 repeat regions were predicted. Especially, LF could be distinguished from the other three L. fermentum strains based on taxonomic profiling, specific orthologous genes of the strain, and genomic variants. The results of this study suggest that L. fermentum SMFM2017-NK2 is a novel strain with an anti-inflammatory effect on colitis.
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Customer demands for product search are growing as a result of the recent growth of the e-commerce market. According to this trend, studies on object-centric retrieval using product images have emerged, but it is difficult to respond to complex user-environment scenarios and a search requires a vast amount of data. In this paper, we propose the Video E-commerce Retrieval Dataset (VERD), which utilizes user-perspective videos. In addition, a benchmark and additional experiments are presented to demonstrate the need for independent research on product-centered video-based retrieval. VERD is publicly accessible for academic research and can be downloaded by contacting the author by email.
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Comércio , Armazenamento e Recuperação da Informação , Reconhecimento Automatizado de Padrão/métodosRESUMO
In this paper, multispectral pedestrian detection is mainly discussed, which can contribute to assigning human-aware properties to automated forklifts to prevent accidents, such as collisions, at an early stage. Since there was no multispectral pedestrian detection dataset in an intralogistics domain, we collected a dataset; the dataset employs a method that aligns image pairs with different domains, i.e. RGB and thermal, without the use of a cumbersome device such as a beam splitter, but rather by exploiting the disparity between RGB sensors and camera geometry. In addition, we propose a multispectral pedestrian detector called SSD 2.5D that can not only detect pedestrians but also estimate the distance between an automated forklift and workers. In extensive experiments, the performance of detection and centroid localization is validated with respect to evaluation metrics used in the driving car domain but with distinct categories, such as hazardous zone and warning zone, to make it more applicable to the intralogistics domain.
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Condução de Veículo , Pedestres , Humanos , Acidentes de Trânsito/prevenção & controle , BenchmarkingRESUMO
STATEMENT OF PROBLEM: How postpolymerization conditions affect the color and mechanical properties of 3-dimensional (3D)-printed prostheses is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the color, microhardness, and flexural strength of 3D-printed interim resin materials and to assess the effect of postpolymerization devices, polymerizing locations, and thermocycling on those properties. MATERIAL AND METHODS: A total of 270 disk-shaped specimens and 180 bar-shaped specimens were designed and 3D-printed with interim resin material (NextDent C&B). The specimens were postpolymerized in 1 of 3 devices (Group ND; NextDent, Group CR; Carima, and Group FL; Formlabs). Each group was divided into 3 circular zones of the polymerizing plate (central, medial, and lateral). Half of the specimens were subjected to 10 000 thermocycles. Color measurement, Vickers microhardness test, and 3-point flexural strength test were performed. Data were statistically analyzed by using the Kruskal-Wallis and Mann-Whitney tests (α=.05). RESULTS: The L∗a∗b∗ color coordinates exhibited significant differences among the 3 zones (P<.05). The color and translucency differences according to CIELab and CIEDE among the zones exceeded the clinically perceptible levels in group CR. ΔE and ΔTP between with and without thermocycling were significantly different among the devices (P<.05). Microhardness and flexural strength were significantly different among the zones for those affected by thermocycling (P<.05). CONCLUSIONS: Different locations in postpolymerization devices influenced the color, translucency, and mechanical properties of 3D-printed interim resin materials. Thermocycling induced color and translucency changes and the mechanical weakening of postpolymerized resins, and the impact differed according to the device type.
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With the impact of the COVID-19 pandemic, the number of patients suffering from depression is rising around the world. It is important to diagnose depression early so that it may be treated as soon as possible. The self-response questionnaire, which has been used to diagnose depression in hospitals, is impractical since it requires active patient engagement. Therefore, it is vital to have a system that predicts depression automatically and recommends treatment. In this paper, we propose a smartphone-based depression prediction system. In addition, we propose depressive features based on multimodal sensor data for predicting depressive mood. The multimodal depressive features were designed based on depression symptoms defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The proposed system comprises a "Mental Health Protector" application that collects data from smartphones and a big data-based cloud platform that processes large amounts of data. We recruited 106 mental patients and collected smartphone sensor data and self-reported questionnaires from their smartphones using the proposed system. Finally, we evaluated the performance of the proposed system's prediction of depression. As the test dataset, 27 out of 106 participants were selected randomly. The proposed system showed 76.92% on an f1-score for 16 patients with depression disease, and in particular, 15 patients, 93.75%, were successfully predicted. Unlike previous studies, the proposed method has high adaptability in that it uses only smartphones and has a distinction of evaluating prediction accuracy based on the diagnosis.
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ABSTRACT: In this study, Bacillus cereus was isolated from soft soybean curds, and a dynamic model was developed to describe the kinetic behavior of these isolates during transfer and storage. B. cereus isolates recovered from soft soybean curds were inoculated into soft soybean curd, and the levels were determined during storage at 10 to 30°C. The B. cereus counts were fitted to the Baranyi model to calculate maximum growth rate (µmax) and lag-phase duration (LPD). These kinetic parameters were then analyzed with a polynomial equation to evaluate the effects of temperature on the kinetic parameters. The developed model was validated with observed values, and the differences between predicted and observed values were determined by calculating the root mean square error (RMSE). A dynamic model was then developed with a combination of primary and secondary models to describe B. cereus growth under changing temperature conditions. B. cereus was detected in two soft soybean curd samples (5.1%) at 0.7 log CFU/g. The µmax was -0.04 to 0.47 log CFU/g/h, and the ln(LPD) was 3.94 to 0.04 h, depending on the storage temperature. The model performance was appropriate with a 0.216 RMSE and accurately described the kinetic behavior of B. cereus in soft soybean curd samples. These results suggest that B. cereus can contaminate soft soybean curds and that the models developed with the B. cereus isolates are useful for describing the kinetic behavior of B. cereus in soft soybean curd.
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Bacillus cereus , Glycine max , Contagem de Colônia Microbiana , Microbiologia de Alimentos , TemperaturaRESUMO
This study aimed at determining the genetic and virulence characteristics of the Listeria monocytogenes from smoked ducks. L. monocytogenes was isolated by plating, and the isolated colonies were identified by PCR. All the obtained seven L. monocytogenes isolates possessed the virulence genes (inlA, inlB, plcB, and hlyA) and a 385 bp actA amplicon. The L. monocytogenes isolates (SMFM2018 SD 1-1, SMFM 2018 SD 4-1, SMFM 2018 SD 4-2, SMFM 2018 SD 5-2, SMFM 2018 SD 5-3, SMFM 2018 SD 6-2, and SMFM 2018 SD 7-1) were inoculated in tryptic soy broth (TSB) containing 0.6% yeast extract at 60°C, followed by cell counting on tryptic soy agar (TSA) containing 0.6% yeast extract at 0, 2, 5, 8, and 10 min. We identified five heat resistant isolates compared to the standard strain (L. monocytogenes ATCC13932), among which three exhibited the serotype 1/2b and D-values of 5.41, 6.48, and 6.71, respectively at 60°C. The optical densities of the cultures were regulated to a 0.5 McFarland standard to assess resistance against nine antibiotics after an incubation at 30°C for 24 h. All isolates were penicillin G resistant, possessing the virulence genes (inlA, inlB, plcB, and hlyA) and the 385-bp actA amplicon, moreover, three isolates showed clindamycin resistance. In conclusion, this study allowed us to characterize L. monocytogenes isolates from smoked ducks, exhibiting clindamycin and penicillin G resistance, along with the 385-bp actA amplicon, representing higher invasion efficiency than the 268-bp actA, and the higher heat resistance serotype 1/2b.
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[This corrects the article DOI: 10.5851/kosfa.2020.e64.].
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This study evaluated the anti-obesity effects of lactic acid bacteria. Thirty-one lactic acid bacteria were examined in vitro for their ability to inhibit α-glucosidase activity, lipase activity, and 3T3-L1 cell differentiation. Four selected lactic acid bacteria were administered to obese C57BL/6J mice models for 8 weeks. The degree of improvement in obesity was determined by weight gain and serum biochemical analysis. The expression levels of genes (Fas and Cpt-2) related to obesity in the liver were analyzed by quantitative reverse transcription (qRT)-PCR. In addition, antioxidant protein levels (SOD-2, CAT, and GPx-1) in the liver were evaluated. The lactic acid bacteria-treated groups (PPGK1, LFNK3, LPNK2, and LFNK4) showed lower weight increase rate than the control group. The total cholesterol (T-chol), triglyceride (TG), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in the blood serum of the LFNK4 group were the lowest among other groups, compared to the control group. The expression levels of lipid metabolism-related genes (Fas and Cpt-2) in the liver of the LFNK4 group were lower in Fas and higher in Cpt-2 than in the control group. The antioxidant protein expression levels (SOD-2, CAT, and GPx-1) in the liver tissue were also higher in the LFNK4 group. These results indicate that L. fermentum SMFM2017-NK4 has anti-obesity effects.
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BACKGROUND: Campylobacter jejuni is a major gastroenteritis-causing foodborne pathogen. However, it is difficult to isolate when competing bacteria or cold-damaged cells are present. OBJECTIVE: Herein, a medium (Campylobacter selective agar, CSA) was developed and supplemented with catalase, L-serine, L-cysteine, and quercetin for the selective detection of C. jejuni in food. METHOD: The C. jejuni-detection efficiency in media broth and chicken tenders was evaluated. The pathogen was enumerated on modified charcoal-cefoperazone-deoxycholate agar (mCCDA), CSA supplemented with 4 µM catalase (CSA-C4), 8 µM catalase (CSA-C8), 20 mM L-serine (CSA-S20) or 50 mM L-serine (CSA-S50), and mCCDA supplemented with 0.5 mM L-cysteine (mCCDA-LC0.5), 1 mM L-cysteine (mCCDA-LC1), 40 µM quercetin (mCCDA-Q40) or 320 µM quercetin (mCCDA-Q320). The detection efficiency was then evaluated by counting colonies on the selective agar media. Quantitative assessment was also performed using chicken and duck carcasses. RESULTS: The C. jejuni detection efficiencies were higher (P < 0.05) in the groups CSA-C4 or CSA-C8, and CSA-S20 or CSA-S50, than mCCDA, and the detection efficiencies were maintained even in the presence of Acinetobacter baumannii, a competing bacterium. In the quantitative test, CSA-C8 and CSA-S50 demonstrated higher C. jejuni-detection efficiencies than mCCDA (control). CONCLUSIONS: Therefore, CSA-C8 and CSA-S50 improved the detection efficiency of C. jejuni in poultry products by promoting the recovery of cold-damaged cells. HIGHLIGHTS: When using CSA-C8 or CSA-S50 developed in this study for detection of C. jejuni in food, detection efficiency was higher than mCCDA.
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Campylobacter jejuni , Campylobacter , Ágar , Animais , Galinhas , Meios de Cultura , Microbiologia de AlimentosRESUMO
The objective of this study was to conduct QMRA (quantitative microbial risk assessment) of Clostridium perfringens through soy sauce consumption. Four hundred and ninety soy sauce samples from markets were analyzed to detect C. perfringens. Temperature and time were also measured during transportation and display of soy sauce. A primary model was developed by fitting the Weibull model to the C. perfringens cell counts in soy sauce at 7-35°C, and δ (the time needed to decrease 1 log CFU/ml) and ρ (curve shape) were calculated. The parameters were analyzed, using the Exponential model (secondary model) as a function of temperature. The consumption amount and percentage of soy sauce were surveyed, and a dose-response model was searched. Using all collected data, a simulation model was prepared in the @RISK program to estimate the probability of C. perfringens foodborne illness by soy sauce consumption. C. perfringens were negative in 490 samples. Thus, the initial contamination level was estimated to be -2.9 log CFU/ml. The developed predictive models showed that C. perfringens cell counts decreased during transportation and display. The average consumption amounts, and the percentage of soy sauce were 7.81 ml and 81.2%, respectively. The simulation showed that the probability of C. perfringens foodborne illness by consumption of soy sauce was 1.7 × 10-16 per person per day. Therefore, the risk of C. perfringens by consumption of soy sauce is low in Korea.
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OBJECTIVE: The objective of this study was to evaluate the antimicrobial effects of fermented Maillard reaction products made by milk proteins (FMRPs) on Clostridium perfringens (C. perfringens), and to elucidate antimicrobial modes of FMRPs on the bacteria, using physiological and morphological analyses. METHODS: Antimicrobial effects of FMRPs (whey protein plus galactose fermented by Lactobacillus rhamnosus [L. rhamnosus] 4B15 [Gal-4B15] or Lactobacillus gasseri 4M13 [Gal-4M13], and whey protein plus glucose fermented by L. rhamnosus 4B15 [Glc-4B15] or L. gasseri 4M13 [Glc-4M13]) on C. perfringens were tested by examining growth responses of the pathogen. Iron chelation activity analysis, propidium iodide uptake assay, and morphological analysis with field emission scanning electron microscope (FE-SEM) were conducted to elucidate the modes of antimicrobial activities of FMRPs. RESULTS: When C. perfringens were exposed to the FMRPs, C. perfringens cell counts were decreased (p<0.05) by the all tested FMRPs; iron chelation activities by FMRPs, except for Glc-4M13. Propidium iodide uptake assay indicate that bacterial cellular damage increased in all FMRPs-treated C. perfringens, and it was observed by FE-SEM. CONCLUSION: These results indicate that the FMRPs can destroy C. perfringens by iron chelation and cell membrane damage. Thus, it could be used in dairy products, and controlling intestinal C. perfringens.
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ABSTRACT: An investigation of the pathogenic characteristics of isolates of Vibrio parahaemolyticus was conducted by identifying the pathogenic tdh gene and then performing adherence and cytotoxicity assays. Genome sequences of the seafood isolates were analyzed using the Illumina HiSeq 2500 platform. The isolated strains were then mapped by comparing the genomes to the reference genome, and variations in the nucleotide sequences and amino acids were identified with the CLC Genomics Workbench program. The tdh gene was identified in four isolates of V. parahaemolyticus, of which three-SMFM201809-CPC7-3, SMFM201809-CF8-2, and SMFM201809-CF8-3-showed high cytotoxicity and differences in cell adhesion. These isolates were selected to identify virulence factors and genomic variations. All three isolates had the same virulence factors, such as adherence, secretion system, and toxin. In addition, amino acid variants were identified in the regions of type IV pilus, T3SS1 and T3SS1 secreted effectors, and thermolabile hemolysin. These results indicate that variations in amino acids found in regions related to adherence and cytotoxicity result in differences in adhesion efficiency and cytotoxicity; therefore, the isolates with these variations may cause more serious foodborne illness compared with other strains.