Publications by authors named "Yi-Cheng Su"

34 Publications

Deep Neck Infection in Systemic Lupus Erythematosus Patients: Real-World Evidence.

Sci Rep 2020 03 5;10(1):4133. Epub 2020 Mar 5.

Department of Otolaryngology - Head and Neck Surgery, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan.

Systemic lupus erythematosus (SLE) might increase deep neck infection (DNI) risk, but evidence supporting this hypothesis is limited. In this retrospective follow-up study, the SLE-DNI association was investigated using data from the Registry for Catastrophic Illness Patients, which is a subset of the Taiwan National Health Insurance Research Database. All patients newly diagnosed as having SLE in 1997-2011 were identified, and every SLE patient was individually matched to four patients without SLE according to sex, age, and socioeconomic status. The study outcome was DNI occurrence. DNI treatment modalities and prognoses in SLE and non-SLE patients, along with the association of steroid dose with DNI risk, were also studied. In total, 17,426 SLE and 69,704 non-SLE patients were enrolled. Cumulative DNI incidence was significantly higher in the SLE cohort than in the non-SLE cohort (p < 0.001). The Cox regression model demonstrated that SLE significantly increased DNI risk (hazard ratio: 4.70; 95% confidence interval: 3.50-6.32, p < 0.001). Moreover, in the sensitivity and subgroup analyses, the effect of SLE on DNI was stable. Relatively few SLE-DNI patients received surgical interventions (15.6% vs. 28.6%, p = 0.033). The between-group differences in tracheostomy use and hospitalisation duration were nonsignificant. In SLE patients, high steroid doses significantly increased DNI incidence (≥3 vs. <3 mg/day = 2.21% vs. 0.52%, p < 0.001). This is the first study demonstrating that SLE increases DNI risk by approximately five times and that high steroid dose increases DNI incidence in SLE patients.
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http://dx.doi.org/10.1038/s41598-020-61049-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7058067PMC
March 2020

Corrigendum to "Efficacy of Vibrio parahaemolyticus depuration in oysters" [Food Microbiol. 79 (2019) 35-40].

Food Microbiol 2020 06 21;88:103334. Epub 2019 Sep 21.

Angelo DePaola Consulting, Coden, AL, 36523, USA.

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http://dx.doi.org/10.1016/j.fm.2019.103334DOI Listing
June 2020

Efficacy of Vibrio parahaemolyticus depuration in oysters (Crassostrea gigas).

Food Microbiol 2019 06 18;79:35-40. Epub 2018 Oct 18.

Angelo DePaola Consulting, Coden, AL, 36523, USA.

This study investigated the influences of seawater to oyster ratio on depuration for decontaminating V. parahaemolyticus in raw oysters with a goal of identifying the proper ratio of oyster to seawater capable of improving the efficacy of the depuration process. The water to oyster ratios tested in this study ranged from 1.0 to 2.5 L of artificial seawater (ASW) per oyster (40 oysters in 40, 60, 80 and 100 L ASW). The depuration efficacy for purging V. parahaemolyticus from oysters was highest when we applied a 2:1, followed by 1.5:1, 2.5:1, and 1:1 L of ASW/oyster. Further studies of depuration with 2:1 L of ASW/oyster found that the concentration of V. parahaemolyticus in oysters decreased in a nonlinear manner. The depuration curve was fitted to a one phase decay model with a coefficient of determination (R) of 0.933. The time for a 3 log reduction was 1.75 days with a 95% confidence interval from 1.65 to 1.85 days, which meets the FDA's requirement of larger than a 3.0 log (MPN/g) reduction as a post-harvest process for V. parahaemolyticus control. After 4 days levels in all trials were <100 MPN/g meeting performance standards established by Japan and Canada. Furthermore, the time for a 3.52 log reduction was 3.17 days with a 95% confidence interval from 2.92 to 3.54 days but it took 5 days to reduce levels to <30 MPN/g, which satisfies FDA's requirement as a post-harvest control process (>3.52 log MPN/g reduction) for the purpose of making safety added labeling claims for V. parahaemolyticus.
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http://dx.doi.org/10.1016/j.fm.2018.10.005DOI Listing
June 2019

Metal-Organic Framework Nanocomposite Thin Films with Interfacial Bindings and Self-Standing Robustness for High Water Flux and Enhanced Ion Selectivity.

ACS Nano 2018 Sep 30;12(9):9253-9265. Epub 2018 Aug 30.

Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering , Tsinghua University , Beijing 100084 , P. R. China.

Metal-organic framework (MOF)-based materials are promising candidates for a range of separation applications. However, the fabrication of self-standing MOF-based thin films remains challenging. Herein, a facile solution casting strategy is developed for fabricating UiO-66 nanocomposite thin films (UiO66TFs) with thicknesses down to ∼400 nm. Nanosizing UiO-66 and incorporating sulfonated polysulfone additives render high dispersity and interfacial bindings between MOFs and polymer matrices, so UiO66TFs are more mechanically robust and thermally stable than their pure-polymer counterparts. Enhanced microporosity with sub-nanometer pore sizes of the self-standing membranes enables the direct translation of UiO-66-based sorption and ion-sieving properties, thus increasing water flux and separation performance (NaSO rejection of 94-96%) under hydraulic pressure-driven processes and eliminating internal concentration polarization in osmotic pressure-driven processes. Enhanced separation performances are achieved with water/NaSO permselectivity of 13.5 L g and high osmotic water permeability up to 1.41 L m h bar, providing 3-fold higher water/NaSO permselectivity and 56-fold-higher water flux than polymer membranes for forward osmosis.
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http://dx.doi.org/10.1021/acsnano.8b03994DOI Listing
September 2018

Structural characterization and osteogenic bioactivity of a sulfated polysaccharide from pacific abalone (Haliotis discus hannai Ino).

Carbohydr Polym 2018 Feb 6;182:207-214. Epub 2017 Nov 6.

School of Food Science and Technology, Dalian Polytechnic University, National Engineering Research Center of Seafood, Dalian 116034, PR China; National & Local Joint Engineering Laboratory for Marine Bioactive Polysaccharide Development and Application, Dalian Polytechnic University, Dalian 116034, PR China. Electronic address:

Bone morphogenic protein-2 (BMP-2) is known to promote osteogenesis. To find novel adjuvants to enhance the activity of BMP-2, the present study investigated the structure BMP-2-induced osteogenic activity of a water-soluble polysaccharide from the gonad of pacific abalone (Haliotis discus hannai Ino) named AGSP. Through analysis of aldobiouronic acids released from AGSP, monosaccharide composition comparison of AGSP and its reduced product, and methylation analysis and NMR analysis of AGSP and its desulfated derivative, the main structure residue of AGSP was determined as →3)-GlcA(1→3)-Gal(1→ with sulfated branches comprised of prevelant Gal and minor Glc, and →4)-β-GlcA(1→2)-α-Man(1→ residue was also found. AGSP possessed a sulfate content of 12.4% with a relative molecular weight of 6.6kDa. AGSP strengthened alkaline phosphatase activity induced by BMP-2 in a dose dependent manner at 10-200μg/mL with 425% enhancement being observed at 200μg/mL, indicating AGSP could be an adjuvant candidate to enhance osteogenic activity of BMP-2.
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http://dx.doi.org/10.1016/j.carbpol.2017.11.022DOI Listing
February 2018

Degradation of Histamine by Lactobacillus plantarum Isolated from Miso Products.

J Food Prot 2017 10;80(10):1682-1688

2 Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 811, Taiwan, Republic of China.

Histamine is a toxic chemical and is the causative agent of food poisoning. This foodborne toxin may be degraded by the oxidative deamination activity of certain microorganisms. In this study, we isolated four histamine-degrading Lactobacillus plantarum bacteria from miso products. Among them, L. plantarum D-103 exhibited 100% degradation of histamine in de Man Rogosa Sharpe (MRS) broth containing 50 ppm of histamine after 24 h of incubation at 30°C. The optimal growth, histamine oxidase, and histamine-degrading activity of L. plantarum D-103 were observed in histamine MRS broth at pH 7.0, 3% NaCl, and 30°C. It also exhibited tolerance to broad ranges of pH (4 to 10) and salt concentrations (0 to 12%) in histamine MRS broth. Therefore, the histamine-degrading L. plantarum D-103 might be used as an additive culture to prevent histamine accumulation in miso products during fermentation.
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http://dx.doi.org/10.4315/0362-028X.JFP-17-135DOI Listing
October 2017

Characterizing the Adherence Profiles of Virulent Vibrio parahaemolyticus Isolates.

Microb Ecol 2018 Jan 17;75(1):152-162. Epub 2017 Jul 17.

Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, 97331, USA.

The human pathogen Vibrio parahaemolyticus is a leading cause of seafood-borne illness in the USA, and infections with V. parahaemolyticus typically result from eating raw or undercooked oysters. V. parahaemolyticus has been shown to be highly resistant to oyster depuration, suggesting that the bacterium possesses specific mechanisms or factors for colonizing oysters and persisting during depuration. In this study, we characterized eight different V. parahaemolyticus strains for differences in resistance to oyster depuration, biofilm formation, and motility. While each strain exhibited distinct phenotypes in the various assays, we determined that biofilm formation on abiotic surfaces, such as glass or plastic, does not directly correlate with bacterial retention in oysters during depuration. However, we did observe that the motility phenotype of a strain appeared to be a better indicator for persistence in the oyster. Further studies examining the molecular mechanisms underlying the observed colonization differences by these and other V. parahaemolyticus strains may provide beneficial insights into what critical factors are required for proficient colonization of the Pacific oyster.
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http://dx.doi.org/10.1007/s00248-017-1025-8DOI Listing
January 2018

Characterization of clinical Vibrio parahaemolyticus strains in Zhoushan, China, from 2013 to 2014.

PLoS One 2017 5;12(7):e0180335. Epub 2017 Jul 5.

Key Laboratory of Health Risk Factors for Seafood of Zhejiang Province, Zhoushan, Zhejiang, China.

Vibrio parahaemolyticus is recognized as major cause of foodborne illness of global public health concern. This study collected 107 strains of V. parahaemolyticus during active surveillance of diarrheal diseases in hospitals in Zhoushan during 2013 to 2014 and investigated their serotypes, virulence genes (tdh, trh, and orf8), antimicrobial resistance, and genotypes. The dominant serotypes of the 107 clinical strains were O3:K6, O4:K8, and O4:KUT with 87.9% and 3.7% of the strains carrying the virulence genes tdh and trh, respectively. Molecular typing by pulsed-field gel electrophoresis indicated divergence among the clinical strains. Most isolates were sensitive to the common antimicrobial agents used against the Vibrio species except ampicillin. We conclude that continuous surveillance of V. parahaemolyticus in diarrhea patients is a public health priority and is useful for conducting risk assessment of foodborne illnesses caused by V. parahaemolyticus.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0180335PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5498046PMC
October 2017

Behavior of and in Raw Yellowfin Tuna during Cold Storage.

Foods 2016 Mar 2;5(1). Epub 2016 Mar 2.

Seafood Research and Education Center, Oregon State University, Astoria, OR 97103, USA.

Behavior of and in raw yellowfin tuna during refrigeration and frozen storage were studied. Growth of was inhibited in tuna during refrigerated storage, while was able to multiply significantly during refrigerated storage. Populations of in tuna were reduced by 1 to 2 log after 12 days of storage at 5-7 °C, regardless levels of contamination. However, populations of Scott A, M0507, and SFL0404 in inoculated tuna (10⁴-10⁵ CFU/g) increased by 3.31, 3.56, and 3.98 log CFU/g, respectively, after 12 days of storage at 5-7 °C. Similar increases of cells were observed in tuna meat with a lower inoculation level (10²-10³ CFU/g). Populations of and declined gradually in tuna samples over 84 days (12 weeks) of frozen storage at -18 °C with Newport 6962 being decreased to undetectable level (<10 CFU/g) from an initial level of 10³ log CFU/g after 42 days of frozen storage. These results demonstrate that tuna meat intended for raw consumption must be handled properly from farm to table to reduce the risks of foodborne illness caused by and .
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http://dx.doi.org/10.3390/foods5010016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5224575PMC
March 2016

Effect of spatial constraints on Hardy-Weinberg equilibrium.

Sci Rep 2016 Jan 14;6:19297. Epub 2016 Jan 14.

Department of Physics, National Chung Cheng University, 168, Sec. 1, University Rd., Chia-Yi 621, Taiwan.

Panmixia is a key issue in maintaining genetic diversity, which facilitates evolutionary potential during environmental changes. Additionally, conservation biologists suggest the importance of avoiding small or subdivided populations, which are prone to losing genetic diversity. In this paper, computer simulations were performed to the genetic drift of neutral alleles in random mating populations with or without spatial constraints by randomly choosing a mate among the closest neighbours. The results demonstrated that the number of generations required for the neutral allele to become homozygous (Th) varied proportionally to the population size and also strongly correlated with spatial constraints. The average Th for populations of the same size with spatial constraints was approximately one-and-a-half times longer than without constraints. With spatial constraints, homozygous population clusters formed, which reduced local diversity but preserved global diversity. Therefore, panmixia might be harmful in preserving the genetic diversity of an entire population. The results also suggested that the gene flow or gene exchange among the subdivided populations must be carefully processed to restrict diseases transmission or death during transportation and to monitor the genetic diversity. The application of this concept to similar systems, such as information transfer among peers, is also discussed.
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http://dx.doi.org/10.1038/srep19297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4725899PMC
January 2016

Analysis of Apoptosis in Ultraviolet-Induced Sea Cucumber (Stichopus japonicus) Melting Using Terminal Deoxynucleotidyl-Transferase-Mediated dUTP Nick End-Labeling Assay and Cleaved Caspase-3 Immunohistochemistry.

J Agric Food Chem 2015 Nov 20;63(43):9601-8. Epub 2015 Oct 20.

Seafood Research and Education Center, Oregon State University , Astoria, Oregon 97103, United States.

The sea cucumber body wall melting phenomenon occurs under certain circumstances, and the mechanism of this phenomenon remains unclear. This study investigated the apoptosis in the ultraviolet (UV)-induced sea cucumber melting phenomenon. Fresh sea cucumbers (Stichopus japonicus) were exposed to UV radiation for half an hour at an intensity of 0.056 mW/cm(2) and then held at room temperature for melting development. The samples were histologically processed into formalin-fixed paraffin-embedded tissues. The apoptosis of samples was analyzed with the terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling (TUNEL) assay and cleaved caspase-3 immunohistochemistry. The emergence of TUNEL-positive cells speeds up between 0.5 and 2 h after UV irradiation. Cleaved caspase-3 positive cells were obviously detected in sample tissues immediately after the UV irradiation. These results demonstrated that sea cucumber melting induced by UV irradiation was triggered by the activation of caspase-3 followed by DNA fragmentation in sea cucumber tissue, which was attributed to apoptosis but was not a consequence of autolysis activity.
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http://dx.doi.org/10.1021/acs.jafc.5b03453DOI Listing
November 2015

Analysis of Vibrio vulnificus Infection Risk When Consuming Depurated Raw Oysters.

J Food Prot 2015 Jun;78(6):1113-8

Food Process Engineering Group, Department of Food Science and Technology, Oregon State University, Corvallis, Oregon 97331, USA.

A beta Poisson dose-response model for Vibrio vulnificus food poisoning cases leading to septicemia was used to evaluate the effect of depuration at 15 °C on the estimated health risk associated with raw oyster consumption. Statistical variability sources included V. vulnificus level at harvest, time and temperature during harvest and transportation to processing plants, decimal reductions (SV) observed during experimental circulation depuration treatments, refrigerated storage time before consumption, oyster size, and number of oysters per consumption event. Although reaching nondetectable V. vulnificus levels (<30 most probable number per gram) throughout the year and a 3.52 SV were estimated not possible at the 95% confidence level, depuration for 1, 2, 3, and 4 days would reduce the warm season (June through September) risk from 2,669 cases to 558, 93, 38, and 47 cases per 100 million consumption events, respectively. At the 95% confidence level, 47 and 16 h of depuration would reduce the warm and transition season (April through May and October through November) risk, respectively, to 100 cases per 100 million consumption events, which is assumed to be an acceptable risk; 1 case per 100 million events would be the risk when consuming untreated raw oysters in the cold season (December through March).
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http://dx.doi.org/10.4315/0362-028X.JFP-14-421DOI Listing
June 2015

Efficacy of low-temperature high hydrostatic pressure processing in inactivating Vibrio parahaemolyticus in culture suspension and oyster homogenate.

Int J Food Microbiol 2015 Mar 29;196:11-5. Epub 2014 Nov 29.

Seafood Research and Education Center, Oregon State University, 2001 Marine Dr., #253, Astoria, OR 97103, USA. Electronic address:

Culture suspensions of five clinical and five environmental Vibrio parahaemolyticus strains in 2% NaCl solution were subjected to high pressure processing (HPP) under various conditions (200-300MPa for 5 and 10 min at 1.5-20°C) to study differences in pressure resistance among the strains. The most pressure-resistant and pressure-sensitive strains were selected to investigate the effects of low temperatures (15, 5 and 1.5°C) on HPP (200 or 250MPa for 5 min) to inactivate V. parahaemolyticus in sterile oyster homogenates. Inactivation of V. parahaemolyticus cells in culture suspensions and oyster homogenates was greatly enhanced by lowering the processing temperature from 15 to 5 or 1.5°C. A treatment of oyster homogenates at 250MPa for 5 min at 5°C decreased the populations of V. parahaemolyticus by 6.2logCFU/g for strains 10290 and 100311Y11 and by >7.4logCFU/g for strain 10292. Decreasing the processing temperature of the same treatment to 1.5°C reduced all the V. parahaemolyticus strains inoculated to oyster homogenates to non-detectable (<10CFU/g) levels. Factors including pressure level, processing temperature and time all need to be considered for developing effective HPP for eliminating pathogens from foods. Further studies are needed to validate the efficacy of the HPP (250MPa for 5 min at 1.5°C) in inactivating V. parahaemolyticus cells in whole oysters.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2014.11.018DOI Listing
March 2015

Effects of frozen storage on survival of Staphylococcus aureus and enterotoxin production in precooked tuna meat.

J Food Sci 2014 Aug 17;79(8):M1554-9. Epub 2014 Jul 17.

Seafood Research and Education Center, Oregon State Univ, 2001 Marine Drive, Room 253, Astoria, OR, 97103, U.S.A.

This study investigated the survival of Staphylococcus aureus in precooked tuna meat for producing canned products during frozen storage (-20 ± 2 °C) as well as its growth and enterotoxin production at 35 to 37 °C after the storage. Samples (50 ± 5 g) of precooked albacore (loin, chunk, and flake) and skipjack (chunk and flake) tuna were inoculated with 5 enterotoxin-producing strains of S. aureus at a level of approximately 3.5 log CFU/g and individually packed in a vacuum bag after 3 h incubation at 35 to 37 °C. Vacuum-packed samples were stored in a freezer (-20 ± 2 °C) for 4 wk. The frozen samples were then thawed in 37 °C circulating water for 2 h and incubated at 35 to 37 °C for 22 h. Populations of S. aureus in all precooked tuna samples decreased slightly (<0.7 log CFU/g) after 4 wk of storage at -20 ± 2 °C, but increased rapidly once the samples were thawed and held at 35 to 37 °C. Total S. aureus counts in albacore and skipjack samples increased by greater than 3 log CFU/g after 6 and 8 h of exposure to 35 to 37 °C, respectively. All samples became spoiled after 10 h of exposure to 35 to 37 °C, while no enterotoxin was detected in any samples. However, enterotoxins were detected in albacore loin and other samples after 12 and 24 h of incubation at 35 to 37 °C, respectively. Frozen precooked tuna meat should be used for producing canned tuna within 6 to 8 h of thawing to avoid product spoilage and potential enterotoxin production by S. aureus in contaminated precooked tuna meat.
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http://dx.doi.org/10.1111/1750-3841.12530DOI Listing
August 2014

Persistence of Vibrio parahaemolyticus in the Pacific oyster, Crassostrea gigas, is a multifactorial process involving pili and flagella but not type III secretion systems or phase variation.

Appl Environ Microbiol 2013 May 8;79(10):3303-5. Epub 2013 Mar 8.

Department of Biomedical Sciences, Oregon State University, Corvallis, OR, USA.

Vibrio parahaemolyticus can resist oyster depuration, suggesting that it possesses specific factors for persistence. We show that type I pili, type IV pili, and both flagellar systems contribute to V. parahaemolyticus persistence in Pacific oysters whereas type III secretion systems and phase variation do not.
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http://dx.doi.org/10.1128/AEM.00314-13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3685240PMC
May 2013

Effect of salt concentrations and drying methods on the quality and formation of histamine in dried milkfish (Chanos chanos).

Food Chem 2012 Nov 12;135(2):839-44. Epub 2012 May 12.

Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan, ROC.

The effects of salt concentrations (0-15.0%) and drying methods on the quality of dried milkfish were studied. The results showed that the levels of aerobic plate counts, total coliform, water activity, moisture contents, total volatile basic nitrogen (TVBN) and thiobarbituric acid (TBA) of the dried milkfish samples prepared with the same drying method decreased with increased salt concentrations. The samples prepared with the cold-air drying method had better quality in term of lower TVBN and TBA values than those of samples prepared with other drying methods. The histamine contents in all samples, except two, prepared with various salt concentrations by different drying methods were less than 1.9 mg/100 g. Two unsalted samples prepared with hot-air drying at 35 °C and sun drying methods were found to contain histamine at levels of 249.7 and 67.4 mg/100 g, respectively, which were higher than the potential hazard level of 50 mg/100 g.
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http://dx.doi.org/10.1016/j.foodchem.2012.05.035DOI Listing
November 2012

Reductions of Vibrio parahaemolyticus in Pacific oysters (Crassostrea gigas) by depuration at various temperatures.

Food Microbiol 2012 Aug 16;31(1):51-6. Epub 2012 Feb 16.

Seafood Research and Education Center, Oregon State University, Astoria, OR 97103, USA.

Consumption of raw oysters has been linked to several outbreaks of Vibrio parahaemolyticus infection in the United States. This study investigated effects of ice storage and UV-sterilized seawater depuration at various temperatures on reducing V. parahaemolyticus in oysters. Raw Pacific oysters (Crassostrea gigas) were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (10290, 10292, 10293, BE 98-2029 and 027-1c1) at levels of 10⁴⁻⁶ MPN/g. Inoculated oysters were either stored in ice or depurated in recirculating artificial seawater at 2, 3, 7, 10, 12.5, and 15 °C for 4-6 days. Holding oysters in ice or depuration of oysters in recirculating seawater at 2 or 3 °C for 4 days did not result in significant reductions (P > 0.05) of V. parahaemolyticus in the oysters. However, depuration at temperatures between 7 and 15 °C reduced V. parahaemolyticus populations in oysters by >3.0 log MPN/g after 5 days with no loss of oysters. Depuration at refrigerated temperatures (7-15 °C) can be applied as a post-harvest treatment for reducing V. parahaemolyticus in Pacific oysters.
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http://dx.doi.org/10.1016/j.fm.2012.02.004DOI Listing
August 2012

Reduction of pesticide residues on fresh vegetables with electrolyzed water treatment.

J Food Sci 2011 May;76(4):C520-4

College of Food Science and Nutritional Engineering, China Agricultural Univ., P. O. Box 40, No.17 Qinghuadonglu, Haidian, Beijing 100083, PR China.

Degradation of the 3 pesticides (acephate, omethoate, and dimethyl dichloroviny phosphate [DDVP]) by electrolyzed water was investigated. These pesticides were commonly used as broad-spectrum insecticides in pest control and high-residual levels had been detected in vegetables. Our research showed that the electrolyzed oxidizing (EO) water (pH 2.3, available chlorine concentration:70 ppm, oxidation-reduction potential [ORP]: 1170 mV) and the electrolyzed reducing (ER) water (pH 11.6, ORP: -860 mV) can reduce the pesticide residues effectively. Pesticide residues on fresh spinach after 30 min of immersion in electrolyzed water reduced acephate by 74% (EO) and 86% (ER), omethoate by 62% (EO) and 75% (ER), DDVP by 59% (EO) and 46% (ER), respectively. The efficacy of using EO water or ER water was found to be better than that of using tap water or detergent (both were reduced by more than 25%). Besides spinach, the cabbage and leek polluted by DDVP were also investigated and the degradation efficacies were similar to the spinach. Moreover, we found that the residual level of pesticide residue decreased with prolonged immersion time. Using EO or ER water to wash the vegetables did not affect the contents of Vitamin C, which inferred that the applications of EO or ER water to wash the vegetables would not result in loss of nutrition.
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http://dx.doi.org/10.1111/j.1750-3841.2011.02154.xDOI Listing
May 2011

Validation of high pressure processing for inactivating Vibrio parahaemolyticus in Pacific oysters (Crassostrea gigas).

Authors:
Lei Ma Yi-Cheng Su

Int J Food Microbiol 2011 Jan 4;144(3):469-74. Epub 2010 Nov 4.

Seafood Research and Education Center, Oregon State University, 2001 Marine Drive, Room 253, Astoria, OR 97103, USA.

This study identified and validated high hydrostatic pressure processing (HPP) for achieving greater than 3.52-log reductions of Vibrio parahaemolyticus in the Pacific oysters (Crassostrea gigas) and determined shelf life of processed oysters stored at 5°C or in ice. Raw Pacific oysters were inoculated with a clinical strain of V. parahaemolyticus 10293 (O1:K56) to levels of 10(4-5) cells per gram and processed at 293 MPa (43 K PSI) for 90, 120, 150, 180 and 210 s. Populations of V. parahaemolyticus in oysters after processes were analyzed with the 5-tube most probable number (MPN) method. Negative results obtained by the MPN method were confirmed with a multiplex PCR detecting genes encoding thermolabile hemolysin (tl), thermostable direct hemolysin (tdh) and TDH-related hemolysin (trh). A HPP of 293 MPa for 120 s at groundwater temperature (8±1°C) was identified capable of achieving greater than 3.52-log reductions of V. parahaemolyticus in Pacific oysters. Oysters processed at 293 MPa for 120 s had a shelf life of 6-8 days when stored at 5°C or 16-18 days when stored in ice. This HPP can be adopted by the shellfish industry as a post harvest process to eliminate V. parahaemolyticus in raw oysters.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2010.10.037DOI Listing
January 2011

Refrigerated seawater depuration for reducing Vibrio parahaemolyticus contamination in pacific oyster (Crassostrea gigas).

J Food Prot 2010 Jun;73(6):1111-5

Seafood Research and Education Center, Oregon State University, Astoria, Oregon 97103, USA.

The efficacy of refrigerated-seawater depuration for reducing Vibrio parahaemolyticus levels in Pacific oyster (Crassostrea gigas) was investigated. Raw Pacific oysters were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (10(5) to 10(6) most probable number [MPN] per g) and depurated with refrigerated seawater (5 degrees C) in a laboratory-scale recirculation system equipped with a 15-W gamma UV sterilizer. Depuration with refrigerated seawater for 96 h reduced V. parahaemolyticus populations by >3.0 log MPN/g in oysters harvested in the winter. However, 144 h of depuration at 5 degrees C was required to achieve a 3-log reduction in oysters harvested in the summer. Depuration with refrigerated seawater at 5 degrees C for up to 144 h caused no significant fatality in the Pacific oyster and could be applied as a postharvest treatment to reduce V. parahaemolyticus contamination in Pacific oysters. Further studies are needed to validate the efficacy of the depuration process for reducing naturally accumulated V. parahaemolyticus in oysters.
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http://dx.doi.org/10.4315/0362-028x-73.6.1111DOI Listing
June 2010

Purification and characterization of pepsin-solubilized collagen from skin and connective tissue of giant red sea cucumber (Parastichopus californicus).

J Agric Food Chem 2010 Jan;58(2):1270-4

College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, People's Republic of China.

Pepsin-solubilized collagen (PSC) was extracted from giant red sea cucumbers ( Parastichopus californicus ) and characterized for denaturation temperature (T(d)), maximum transition temperature (T(m)), enzyme-digested peptide maps, and gel-forming capability. SDS-PAGE showed that PSCs from giant red sea cucumber skin and connective tissue were both type I collagens, consisting of three alpha(1) chains of approximately 138 kDa each. The amino acid composition and peptide maps of PSCs digested by V8 protease were different from those of calf skin type I collagen. The T(d) and T(m) are 18.5 and 33.2 degrees C, respectively, for skin PSC and are 17.9 and 32.7 degrees C, respectively, for connective tissue PSC. Both skin and connective tissue PSCs exhibited good gel-forming capability at pH 6.5 and at an ionic strength of 300 mM salt (NaCl). Collagen isolated from giant red sea cucumbers might be used as an alternative to mammalian collagen in the food and pharmaceutical industries.
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http://dx.doi.org/10.1021/jf9032415DOI Listing
January 2010

Effect of temperature on uptake and survival of Vibrio parahaemolyticus in oysters (Crassostrea plicatula).

Int J Food Microbiol 2009 Nov 22;136(1):129-32. Epub 2009 Sep 22.

East China Sea Fisheries Research Institute, Chinese Fisheries Academy of Fishery Science, Shanghai, China.

This study investigated accumulation of Vibrio parahaemolyticus in Zhe oyster (Crassostrea plicatula) from culture water and effectiveness of frozen and chilled storage on reducing V. parahaemolyticus in oysters. Freshly harvested oysters were placed in artificial seawater containing V. parahaemolyticus (10(4)CFU/mL) at 16, 20, 26, and 32 degrees C for 96 h. Contaminated oysters were stored at chilled temperatures (0, 5, and 15 degrees C) and frozen at -18 and -30 degrees C and changes of V. parahaemolyticus populations in oysters were determined using the most probable number (MPN) method. Accumulations of V. parahaemolyticus in C. plicatula reached the peaks at 6.66 (32 degrees C), 5.72 (26 degrees C), 5.04 (20 degrees C), 4.72 (16 degrees C) log MPN/g after 32 h in contaminated artificial seawater. Holding contaminated Zhe oysters at 5 and 0 degrees C reduced V. parahaemolyticus populations in both shell stock and shucked oysters. Populations of V. parahaemolyticus in shell stock and shucked oysters declined by 1.42 and 2.0 log MPN/g, respectively, after 96 h of storage at 5 degrees C and by 2.11 and 2.38 log MPN/g, respectively, after 96 h of storage at 0 degrees C. However, populations of V. parahaemolyticus increased by 2.44 log MPN/g in shell stock oysters and by 1.64 og MPN/g in shucked oysters when stored at 15 degrees C for 60 h. Frozen storage was effective in inactivating V. parahaemolyticus. Populations of V. parahaemolyticus in shell stock and shucked oysters decreased from 5.46log MPN/g to 1.66 and 0.38 log MPN/g, respectively, after 75 days of storage at -30 degrees C. No V. parahaemolyticus cells were detected (<3 log MPN/g) in the shucked oysters after 60 days of storage at -18 degrees C. These results demonstrated that accumulation of V. parahaemolyticus in cultured C. plicatula increases as water temperature increases. Harvested C. plicatula should be stored at 5 degrees C or lower to control the hazard of V. parahaemolyticus.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2009.09.012DOI Listing
November 2009

Effects of flash freezing, followed by frozen storage, on reducing Vibrio parahaemolyticus in Pacific raw oysters (Crassostrea gigas).

J Food Prot 2009 Jan;72(1):174-7

College of Food Science and Technology, Shanghai Ocean University, Shanghai, 200090, People's Republic of China.

This study investigated the effects of flash freezing, followed by frozen storage, on reducing Vibrio parahaemolyticus in Pacific raw oysters. Raw Pacific oysters were inoculated with a five-strain cocktail of V. parahaemolyticus at a total level of approximately 3.5 x 10(5) most probable number (MPN) per gram. Inoculated oysters were subjected to an ultralow flash-freezing process (-95.5 degrees C for 12 min) and stored at -10, -20, and -30 degrees C for 6 months. Populations of V. parahaemolyticus in the oysters declined slightly by 0.22 log MPN/g after the freezing process. Subsequent storage of frozen oysters at - 10, -20, and -30 degrees C resulted in considerable reductions of V. parahaemolyticus in the oysters. Storing oysters at -10 degrees C was more effective in inactivating V. parahaemolyticus than was storage at -20 or -30 degrees C. Populations of V. parahaemolyticus in the oysters declined by 2.45, 1.71, and 1.45 log MPN/g after 1 month of storage at -10, -20, and -30 degrees C, respectively, and continued to decline during the storage. The levels of V. parahaemolyticus in oysters were reduced by 4.55, 4.13, and 2.53 log MPN/g after 6 months of storage at -10, -20, and -30 degrees C, respectively. Three process validations, each separated by 1 week and conducted according to the National Shellfish Sanitation Program's postharvest processing validation-verification interim guidance for Vibrio vulnificus and Vibrio parahaemolyticus, confirmed that a process of flash freezing, followed by storage at -21 +/- 2 degrees C for 5 months, was capable of achieving greater than 3.52-log (MPN/g) reductions of V. parahaemolyticus in half-shell Pacific oysters.
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http://dx.doi.org/10.4315/0362-028x-72.1.174DOI Listing
January 2009

Effects of sources of carbon and nitrogen on production of α-glucosidase inhibitor by a newly isolated strain of Bacillus subtilis B2.

Food Chem 2008 Aug 17;109(4):737-42. Epub 2008 Jan 17.

College of Food Science and Nutritional Engineering, Post Box 40, China Agricultural University, East Campus, No. 17 Qinghua Dong Lu, Haidian District, Beijing 100083, China. Electronic address:

This study examined production of α-glucosidase inhibitors by Bacillus subtilis B2 in Luria-Bertani (LB) fermentation with okara, soy powder, starch or pectin as additional source of carbon and nitrogen. All the fermentation broths of B. subtilis B2 exhibited gradual increase in α-glucosidase inhibitory activity during the fermentation process with or without supplemented source of carbon or nitrogen. Addition of okara into the LB medium greatly enhanced the strength (nearly twice as much of that without okara supplement) of α-glucosidase inhibitory activity of fermentation broth. The α-glucosidase inhibitory activity of B. subtilis B2 fermentation broth was positively correlated (p<0.05) with the bacterial populations grown in LB medium containing okara. Glucose and sucrose were not detected in LB medium during the entire fermentation process and were both reduced drastically in media containing okara, soy powder, starch or pectin after 6days of fermentation. The fermented LB medium containing okara by B. subtilis B2 possessed very strong α-glucosidase inhibitory activity and contained little glucose and sucrose, suggesting that fermentation of B. subtilis B2 in LB added with okara might be considered as a strategy for preparing functional foods for diabetic patients.
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http://dx.doi.org/10.1016/j.foodchem.2008.01.006DOI Listing
August 2008

Characteristics of virulent vibrio parahaemolyticus isolated from Oregon and Washington.

J Food Prot 2007 Apr;70(4):1011-6

Department of Food Science, National PengHu University, No. 300, Liu-Ho Road, Makung City, PengHu County, Taiwan, Republic of China.

Thirty-four virulent strains of Vibrio parahaemolyticus containing tdh and/or trh genes isolated from Oregon and Washington coastal water were analyzed for O-group antigens and urease activity, and by pulsed-field gel electrophoresis. Six O serotypes (O1, O3, O4, O5, O10, and O11) were identified among the isolates, with the O5 group (19 isolates) being the most prevalent, followed by the 01 group (9 isolates). Nearly all (33 of 34) isolates were capable of producing urease, which reaffirmed the correlation between urease production and virulence factors of V. parahaemolyticus strains isolated from the Pacific Northwest. Pulsed-field gel electrophoresis analysis with NotI and SfiI digestions of the 34 V. parahaemolyticus isolates plus five clinical strains revealed 22 patterns (NlS1 to N20S22), with NIS1 (25.6%) being the most common, followed by N2S2 (10.3%). Nine Oregon isolates were grouped with a 1997 Oregon outbreak strain (027-1C1) with the same serotype (O5), virulence factors (tdh+ and trh+), and genotype (N S 1). Three Washington isolates were found to share the same serotype (O1), virulence factors (tdh' and trh'), and genotype (N2S2) with a 1997 Washington outbreak strain (10293). The repetitive isolation of virulent strains of V. parahaemolyticus identical to clinical strains involved in previous outbreaks indicates potential hazards associated with oyster consumption. These data may be useful in risk assessment of V. parahaemolyticus infections associated with raw oyster consumption in Oregon and Washington.
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http://dx.doi.org/10.4315/0362-028x-70.4.1011DOI Listing
April 2007

Vibrio parahaemolyticus: a concern of seafood safety.

Food Microbiol 2007 Sep 30;24(6):549-58. Epub 2007 Jan 30.

OSU Seafood Laboratory, Oregon State University, 2001 Marine Drive, Room 253, Astoria, OR 97103, USA.

Vibrio parahaemolyticus is a human pathogen that is widely distributed in the marine environments. This organism is frequently isolated from a variety of raw seafoods, particularly shellfish. Consumption of raw or undercooked seafood contaminated with V. parahaemolyticus may lead to development of acute gastroenteritis characterized by diarrhea, headache, vomiting, nausea, and abdominal cramps. This pathogen is a common cause of foodborne illnesses in many Asian countries, including China, Japan and Taiwan, and is recognized as the leading cause of human gastroenteritis associated with seafood consumption in the United States. This review gives an overview of V. parahaemolyticus food poisoning and provides information on recent development in methods for detecting V. parahaemolyticus and strategies for reducing risk of V. parahaemolyticus infections associated with seafood consumption.
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http://dx.doi.org/10.1016/j.fm.2007.01.005DOI Listing
September 2007

Effects of electrolyzed oxidizing water treatment on reducing Vibrio parahaemolyticus and Vibrio vulnificus in raw oysters.

J Food Prot 2006 Aug;69(8):1829-34

OSU Seafood Laboratory, Oregon State University, 2001 Marine Drive, Room 253, Astoria, Oregon 97103, USA.

Contamination of Vibrio parahaemolyticus and Vibrio vulnificus in oysters is a food safety concern. This study investigated effects of electrolyzed oxidizing (EO) water treatment on reducing V. parahaemolyticus and V. vulnificus in laboratory-contaminated oysters. EO water exhibited strong antibacterial activity against V. parahaemolyticus and V. vulnificus in pure cultures. Populations of V. parahaemolyticus (8.74 x 10(7) CFU/ml) and V. vulnificus (8.69 x 10(7) CFU/ml) decreased quickly in EO water containing 0.5% NaCl to nondetectable levels (> 6.6 log reductions) within 15 s. Freshly harvested Pacific oysters were inoculated with a five-strain cocktail of V. parahaemolyticus or V. vulnificus at levels of 10(4) and 10(6) most probable number (MPN)/g and treated with EO water (chlorine, 30 ppm; pH 2.82; oxidation-reduction potential, 1131 mV) containing 1% NaCl at room temperature. Reductions of V. parahaemolyticus and V. vulnificus in oysters were determined at 0 (before treatment), 2, 4, 6, and 8 h of treatment. Holding oysters inoculated with V. parahaemolyticus or V. vulnificus in the EO water containing 1% NaCl for 4 to 6 h resulted in significant (P < 0.05) reductions of V. parahaemolyticus and V. vulnificus by 1.13 and 1.05 log MPN/g, respectively. Extended exposure (> 12 h) of oysters in EO water containing high levels of chlorine (> 30 ppm) was found to be detrimental to oysters. EO water could be used as a postharvest treatment to reduce Vibrio contamination in oysters. However, treatment should be limited to 4 to 6 h to avoid death of oysters. Further studies are needed to determine effects of EO water treatment on sensory characteristics of oysters.
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http://dx.doi.org/10.4315/0362-028x-69.8.1829DOI Listing
August 2006

Bactericidal effects of wine on Vibrio parahaemolyticus in oysters.

J Food Prot 2006 Aug;69(8):1823-8

College of Food Science and Technology, Shanghai Fisheries University, 334 Jungong Road, Shanghai 200090, People's Republic of China.

The bactericidal effects of wines on Vibrio parahaemolyticus in oysters were studied to evaluate potential inactivation of V. parahaemolyticus in contaminated oysters by wine consumption. Shucked whole oyster and oyster meat homogenate were inoculated with V. parahaemolyticus and mixed with red or white wine. Survivals of V. parahaemolyticus in inoculated oysters were determined at 7 and 25 degrees C. Populations of V. parahaemolyticus in inoculated whole oysters (5.52 log most probable number [MPN] per g) decreased slightly to 4.90 log MPN/g (a 0.62-log reduction) after 24 h at 7 degrees C but increased to 7.37 log MPN/g over the same period at 25 degrees C. However, the populations in wine-treated whole oysters decreased by >1.7 and >1.9 log MPN/g after 24 h at 7 and 25 degrees C, respectively. Both red and white wines were more effective in inactivating V. parahaemolyticus in oyster meat homogenate than in whole oyster. Populations of V. parahaemolyticus in oyster meat homogenate (7.8 x 10(3) MPN/g) decreased rapidly to nondetectable levels (< 3 MPN/g) after 30 min of mixing with wine at 25 degrees C (a 3.89-log MPN/g reduction). These results suggest that chewing oysters before swallowing when eating raw oysters may result in greater inactivation of V. parahaemolyticus if wine is consumed. More studies are needed to determine the bactericidal effects of wine on V. parahaemolyticus in the complicated stomach environment.
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http://dx.doi.org/10.4315/0362-028x-69.8.1823DOI Listing
August 2006

Efficiency of electrolyzed oxidizing water on reducing Listeria monocytogenes contamination on seafood processing gloves.

Int J Food Microbiol 2006 Jul 11;110(2):149-54. Epub 2006 May 11.

College of Food Science and Technology, Shanghai Fisheries University, 334 Jungong Road, Shanghai 200090, PR China.

Food processing gloves are typically used to prevent cross-contamination during food preparation. However, gloves can be contaminated with microorganisms and become a source of contamination. This study investigated the survival of Listeria monocytogenes on gloves and determined the efficacy of electrolyzed oxidizing (EO) water for reducing L. monocytogenes contamination on seafood processing gloves. Three types of reusable gloves (natural rubber latex, natural latex, and nitrile) and two types of disposable gloves (latex and nitrile) were cut into small pieces (4 x 4 cm(2)) and inoculated with 5-strain L. monocytogenes cocktail (5.1 x 10(7) CFU/cm(2)) with and without shrimp meat residue attached to surfaces. L. monocytogenes did not survive well on clean reusable gloves and its populations decreased rapidly to non-detectable levels within 30 min at room temperature. However, high levels of Listeria cells were recovered from clean disposable gloves after 30 min of inoculation. Presence of shrimp meat residue on gloves enhanced the survival of L. monocytogenes. Cells of L. monocytogenes were detected on both reusable and disposal gloves even after 2 h at room temperature. Soaking inoculated gloves in EO water at room temperature for 5 min completely eliminated L. monocytogenes on clean gloves (>4.46 log CFU/cm(2) reductions) and significantly (p<0.05) reduced the contamination on soil-containing gloves when compared with tap water treatment. EO water could be used as a sanitizer to reduce L. monocytogenes contamination on gloves and reduce the possibility of transferring L. monocytogenes from gloves to RTE seafoods.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2006.02.004DOI Listing
July 2006

Effects of electrolyzed oxidizing water on reducing Listeria monocytogenes contamination on seafood processing surfaces.

Int J Food Microbiol 2006 Feb 10;106(3):248-53. Epub 2005 Oct 10.

College of Food Science and Technology, Shanghai Fisheries University, 334 Jungong Road, Shanghai 200-090, P.R. China.

The effects of electrolyzed oxidizing (EO) water on reducing Listeria monocytogenes contamination on seafood processing surfaces were studied. Chips (5 x 5 cm(2)) of stainless steel sheet (SS), ceramic tile (CT), and floor tile (FT) with and without crabmeat residue on the surface were inoculated with L. monocytogenes and soaked in tap or EO water for 5 min. Viable cells of L. monocytogenes were detected on all chip surfaces with or without crabmeat residue after being held at room temperature for 1 h. Soaking contaminated chips in tap water resulted in small-degree reductions of the organism (0.40-0.66 log cfu/chip on clean surfaces and 0.78-1.33 log cfu/chip on dirty surfaces). Treatments of EO water significantly (p<0.05) reduced L. monocytogenes on clean surfaces (3.73 log on SS, 4.24 log on CT, and 5.12 log on FT). Presence of crabmeat residue on chip surfaces reduced the effectiveness of EO water on inactivating Listeria cells. However, treatments of EO water also resulted in significant reductions of L. monocytogenes on dirty surfaces (2.33 log on SS and CT and 1.52 log on FT) when compared with tap water treatments. The antimicrobial activity of EO water was positively correlated with its chlorine content. High oxidation-reduction potential (ORP) of EO water also contributed significantly to its antimicrobial activity against L. monocytogenes. EO water was more effective than chlorine water on inactivating L. monocytogenes on surfaces and could be used as a chlorine alternative for sanitation purpose. Application of EO water following a thorough cleaning process could greatly reduce L. monocytogenes contamination in seafood processing environments.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2005.06.020DOI Listing
February 2006
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