• Title/Summary/Keyword: Foodborne Pathogen

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Inhibition of Foodborne Pathogens on Polystyrene, Sausage Casings, and Smoked Salmon Using Nonthermal Plasma Treatments (비열 플라즈마 처리를 이용한 polystyrene, 소시지 케이싱, 그리고 훈제연어에서의 식중독균 저해)

  • Lee, Hahn-Bit;Noh, Young-Eun;Yang, Hee-Jae;Min, Sea-Cheol
    • Korean Journal of Food Science and Technology
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    • v.43 no.4
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    • pp.513-517
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    • 2011
  • The effects of nonthermal plasma treatments against Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes living on polystyrene (PS), sausage casings, and smoked salmon were investigated. Inoculated PS, casings, and salmon were treated with nonthermal plasma generated with helium (5 L/min) or with both helium (5 L/min) and oxygen (100 mL/min) at 60 Hz and 30 kV/cm for 2, 5, or 10 min. S. Typhimurium exhibited the highest sensitivity to the helium-used treatment. The greatest reduction (3.9${\pm}$0.8 log$CFU/cm^2$) was observed with L. monocytogenes on PS after the treatment with the mixed gas for 5 min. The treatment with the mixed gas inhibited L. monocytogenes on casings and salmon by 0.5${\pm}$0.3 log$CFU/cm^2$ and 1.0${\pm}$0.3 log CFU/g, respectively. Different treatment times did not result in different reductions of L. monocytogenes on both casings and salmon. The types of treatment gas and material of contamination need to be considered for evaluating the antimicrobial effects of nonthermal plasma treatments.

Seasonal Changes in the Microbial Communities on Lettuce (Lactuca sativa L.) in Chungcheong-do, South Korea

  • Woojung Lee;Min-Hee Kim;Juyeon Park;You Jin Kim;Eiseul Kim;Eun Jeong Heo;Seung Hwan Kim;Gyungcheon Kim;Hakdong Shin;Soon Han Kim;Hae-Yeong Kim
    • Journal of Microbiology and Biotechnology
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    • v.33 no.2
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    • pp.219-227
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    • 2023
  • Lettuce is one of the most consumed vegetables worldwide. However, it has potential risks associated with pathogenic bacterial contamination because it is usually consumed raw. In this study, we investigated the changes in the bacterial community on lettuce (Lactuca sativa L.) in Chungcheong-do, South Korea, and the prevalence of foodborne pathogens on lettuce in different seasons using 16S rRNA gene-based sequencing. Our data revealed that the Shannon diversity index showed the same tendency in term of the number of OTUs, with the index being greatest for summer samples in comparison to other seasons. Moreover, the microbial communities were significantly different between the four seasons. The relative abundance of Actinobacteriota varied according to the season. Family Micrococcaceae was most dominant in all samples except summer, and Rhizobiaceae was predominant in the microbiome of the summer sample. At the genus level, the relative abundance of Bacillus was greatest in spring samples, whereas Pseudomonas was greatest in winter samples. Potential pathogens, such as Staphylococcus and Clostridium, were detected with low relative abundance in all lettuce samples. We also performed metagenome shotgun sequencing analysis on the selected summer and winter samples, which were expected to be contaminated with foodborne pathogens, to support 16S rRNA gene-based sequencing dataset. Moreover, we could detect seasonal biomarkers and microbial association networks of microbiota on lettuce samples. Our results suggest that seasonal characteristics of lettuce microbial communities, which include diverse potential pathogens, can be used as basic data for food safety management to predict and prevent future outbreaks.

Effect of Combination of Chitosan Coating and Gamma Irradiation on the Foodborne Pathogen Reduction and Nutritional Properties of Chicken Egg (키토산 코팅 및 감마선 조사에 의한 계란에 오염된 위해 미생물 제어 및 영양학적 특성 평가)

  • Kim, Hyun-Joo;Yun, Hye-Jeong;Jung, Samooel;Jung, Yeon-Kuk;Ham, Jun-Sang;Jin, Shil;Jo, Cheorun
    • Korean Journal of Poultry Science
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    • v.37 no.1
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    • pp.35-41
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    • 2010
  • The effect of combination of chitosan coating and gamma irradiation on Escherichia coli inactivation and nutritional properties of shell egg was investigated. The E. coli inoculated on shell egg was not detected by 2 kGy of gamma irradiation at day 0 and/or chitosan coating (1%, pH 5.0) after 3 days of storage. There was no E. coli detected thereafter. In the contents of moisture, crude fat, crude protein, ash, retinol, phospholipid, and minerals, no difference was found by treatment combination. However, the contents of cholesterol and carotenoids were reduced by irradiation of 2 kGy (P<0.05). Results suggest that the combination of gamma irradiation (2 kGy) and chitosan coating (1%) can be a good method to improve the safety and prolonged shelf-life of egg because of effective pathogen inactivation without significant adverse changes in nutritional quality.

Growth Inhibition Effects of Ethanol and Sodium Chloride on Bacillus cereus (Ethanol과 NaCl에 의한 Bacillus cereus 생육저해 영향)

  • Jang, Ji-Hyun;Jang, Jung-Soon;Lee, Sang-Yun;Kim, Hyun-Su;Kang, Sang-Mo;Park, Jong-Hyun
    • Korean Journal of Food Science and Technology
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    • v.35 no.5
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    • pp.998-1002
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    • 2003
  • Agricultural foodstuffs, usually consumed without sterilization, are frequently contaminated with foodborne pathogen B. cereus. Ethanol and sodium chloride were used to inhibit this pathogen for its effective control. Though five minutes of exposure to 20% ethanol did not inhibit the growth of B. cereus, inhibition was detected to 30% ethanol solution. As exposed longer, B. cereus was more effectively inhibited than E. coli and S. typhimurium. B. cereus, E. coli and S. typhimurium were not inhibited when exposed in a 10% sodium chloride solution for five minutes. However, these bacteria were inhibited with a combination of 10% sodium chloride and 20% ethanol solution for five minutes. Much synergistic growth inhibition on B. cereus was found at the treatment. Its viable count was reduced from $10^8cfu/ml$ to $10^2cfu/ml$ after five minutes and showed no count after ten minutes. This trend was also confirmed for the wild types of B. cereus. This method may be applied for the effective pre-treatment of many agricultural foodstuffs, especially uncooked foodstuffs, without the hazards that accompany special sanitizers and the nutritional loss from harsh sterilization.

Antioxidant and Antimicrobial Activities of the Ethanol Extract of Allium victoriallis L. var. platyphyllum

  • Choi, Soo-Im;Hong, Eun-Young;Lee, Je-Hyuk;Lee, Yong-Soo;Kim, Gun-Hee
    • Food Science and Biotechnology
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    • v.17 no.2
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    • pp.313-318
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    • 2008
  • This study was conducted to evaluate in vitro antioxidative and antimicrobial properties of ethanolic extracts from Allium victoriallis L. var. platyphyllum (AVP) with 6 different parts. The antioxidative activities of these samples were determined using the 4 separate methods that involved reducing power, DPPH, hydrogen radical scavenging, and lipid peroxidation with use of a $\beta$-carotene/linoleic acid system. The leaf part ethanolic extracts (1,000 ppm) showed the strongest inhibitory potential for reducing power, DPPH, and hydroxyl radicals to 99.8, 49.4, and 52.8%, respectively. Inhibition values of linoleic oxidation were calculated as 58.0, 39.5, and 38.0% for seed, flower, and leaf ethanolic extracts (1,000 ppm), respectively, from AVP. In addition, the ethanolic extracts of the root part showed the most effective antimicrobial activity. The inhibition zones of the root ethanolic extracts ($200\;{\mu}g/disc$) of AVP against Bacillus cereus and Staphylococcus aureus were 17 and 14 mm, respectively. In a micro-dilution assay, B. cereus, S. aureus, and Vibrio parahaemolyticus exhibited sensitivity to root part ethanolic extracts with an minimum inhibition concentration (MIC) value of 20, 28, and 18 mg/mL, respectively. Therefore, the AVP extracts may be suitable as antimicrobial and antioxidative agents in the food industry.

Virulence Factors of Staphylococcus aureus Isolated from Korean Pork bulgogi: Enterotoxin Production and Antimicrobial Resistance

  • Jung, Byeong Su;Lee, Yong Ju;Lee, Na-Kyoung;Kim, Hyoun Wook;Oh, Mi-Hwa;Paik, Hyun-Dong
    • Food Science of Animal Resources
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    • v.35 no.4
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    • pp.502-506
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    • 2015
  • The aim of this study was to investigate the antimicrobial resistance profiles of and the enterotoxin gene distribution in 4 strains of Staphylococcus aureus (S10-2, S10-3, S12-2, and S13-2) isolated from 90 bulgogi samples. The S. aureus enterotoxin H gene (seh) was found in all the strains, while the S. aureus enterotoxin A gene (sea) was found only in 3 of the 4 strains. The S10-2 strain expressed a combination of enterotoxin genes - seg, seh, sei, sej, selm, and seln. The strains S10-2 and S13-2 were resistant to ampicillin and penicillin G, and all the isolated strains were resistant to tetracycline. The S10-2 strain was the only mecA-positive strain; it was also resistant to β-lactam antibiotics. Thus, genes encoding enterotoxin as well as those conferring antibiotic resistance were identified in the S. aureus strains isolated from pork bulgogi. These results represents the potential occurrence of MRSA in pork bulgogi, and the need for a monitoring system for pork bulgogi in order to prevent an outbreak of staphylococcal food poisoning.

Antibiotic Resistance and Genetic Diversity of Listeria monocytogenes Isolated from Chicken Carcasses in Korea

  • Jang Sung-Sik;Choo Eui-Young;Han Ki-Seon;Miyamoto Takahisa;Heu Sung-Gi;Ryu Sang-Ryeol
    • Journal of Microbiology and Biotechnology
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    • v.16 no.8
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    • pp.1276-1284
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    • 2006
  • Listeria monocytogenes is a well-known high-risk foodborne pathogen that grows at refrigeration temperature and is responsible for outbreaks of listeriosis. We report here the incidence of L. monocytogenes in fresh chicken carcasses and present genetic diversity of L. monocytogenes isolates. In this study, 25 g of chicken carcasses from markets in Korea were examined according to the FDA method, and presumptive isolates were confirmed by multiplex PCR assay. L. monocytogenes isolates were analyzed by Pulsed-Field Gel Electrophoresis using restriction enzymes, ApaI and AscI, to obtain strain-specific DNA fragments profiles. Antimicrobial resistance of L. monocytogenes strains against generally used antibiotics (Penicillin G, Kanamycin, Tetracycline, Vancomycin, Cephalothin, Rifampicin, Erythromycin, Ampicillin, Gentamicin, Streptomycin, and Chloramphenicol) were analyzed by NCCLS protocols to examine the presence of antimicrobial resistance in natural L. monocytogenes. Of a total 274 chicken samples, 81 samples (29.6%) were positive for L. monocytogenes. Listeria innocua (50.1%), Listeria welshimeri (6.9%), and Listeria grayi (11.3%) were also detected. PFGE analysis, using restriction enzymes ApaI and AscI, showed 27 pulsotypes of L. monocytogenes. Antimicrobial resistance analysis confirmed the existence of antimicrobial resistance for penicillin G and tetracycline in isolated L. monocytogenes strains.

Estimation of Antibacterial Properties of Chlorophyta, Rhodophyta and Haptophyta Microalgae Species

  • Imran Bashir, Khawaja Muhammad;Lee, Jae-Hyeon;Petermann, Maike Julia;Shah, Abid Ali;Jeong, Su-Jin;Kim, Moo-Sang;Park, Nam-Gyu;Cho, Man-Gi
    • Microbiology and Biotechnology Letters
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    • v.46 no.3
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    • pp.225-233
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    • 2018
  • In this exploratory study, eight types of microalgae from different phyla (Chlamydomonas reinhardtii, Chlorella species, Haematococcus pluvialis, Porphyridium purpureum, Porphyridium cruentum, Isochrysis species, Isochrysis galbana, and Pavlova lutheri) were tested for their antibacterial activities against eight target pathogenic bacterial strains. The agar well diffusion method and broth micro dilution assay were conducted to estimate the antibacterial activity. Microalgae cell-free supernatants, exopolysaccharides (EPS), water, and organic solvent extracts were used for inhibition analysis. EPS extracted from P. lutheri showed activity against Bacillus subtilis and Pseudomonas aeruginosa. Inhibition zone diameters of 14-20 mm were recorded on agar plates, while the minimum inhibitory concentrations in the broth micro dilution assay were $0.39-25mg\;ml^{-1}$. During this study, haptophyte microalgae, Isochrysis species, and P. lutheri extracts showed the highest activity against most of the tested pathogenic bacterial strains, while most of the extracts were active against the important foodborne pathogen P. aeruginosa. This study showed promising results regarding important microalgae phyla, which will further aid research related to extracts and exploitation of bioactive metabolic compounds in the food and pharmaceutical industries.

The Correlation between NaCl Adaptation and Heat Sensitivity of Listeria monocytogenes, a Foodborne Pathogen through Fresh and Processed Meat

  • Lee, Jeeyeon;Ha, Jimyeong;Kim, Sejeong;Lee, Soomin;Lee, Heeyoung;Yoon, Yohan;Choi, Kyoung-Hee
    • Food Science of Animal Resources
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    • v.36 no.4
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    • pp.469-475
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    • 2016
  • This study examined the relationship between NaCl sensitivity and stress response of Listeria monocytogenes. Nine strains of L. monocytogenes (NCCP10805, NCCP10806, NCCP10807, NCCP10808, NCCP10809, NCCP10810, NCCP10811, NCCP10920 and NCCP 10943) were exposed to 0%, 1%, 2% and 4% NaCl, and then incubated at 60℃ for 60 min to select strains that were heat-sensitized (HS) and non-sensitized (NS) by NaCl exposure. After heat challenge, L. monocytogenes strains were categorized as HS (NCCP 10805, NCCP10806, NCCP10807, NCCP10810, NCCP10811 and NCCP10920) or NS (NCCP10808, NCCP10809 and NCCP10943). Total mRNA was extracted from a HS strain (NCCP10811) and two NS strains (NCCP10808 and NCCP10809), and then cDNA was prepared to analyze the expression of genes (inlA, inlB, opuC, betL, gbuB, osmC and ctc) that may be altered in response to NaCl stress, by qRT-PCR. The expression levels of two invasion-related genes (inlA and inlB) and two stress response genes (opuC and ctc) were increased (p<0.05) in NS strains after NaCl exposure in an NaCl concentration-dependent manner. However, only betL expression was increased (p<0.05) in the HS strains. These results indicate that the effect of NaCl on heat sensitization of L. monocytogenes is strain dependent and that opuC and ctc may prevent NS L. monocytogenes strains from being heat sensitized by NaCl. Moreover, NaCl also increases the expression of invasion-related genes (inlA and inlB).

Proteome analysis: Salmoenlla enteritidis antigen proteins (Proteomics 기법을 이용한 Salmonella enteritidis의 항원 단백질 분석)

  • Park, Mi-rim;Shin, Yong-seung;Han, Dae-yong;Kim, Yong-hwan;Jung, Tae-sung;Lee, Hu-Jang;Lee, Eung-Goo;Kim, Jong-su;Kim, Eun-hee;Kim, Gon-Sup
    • Korean Journal of Veterinary Research
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    • v.44 no.1
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    • pp.57-64
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    • 2004
  • The common pathogen Salmonella enteirtidis (S. enteritidis) is the major cause of foodborne disease. Protein identification by peptide mass fingerprinting using the matrix-assisted laser desorption ionization time of fight (MALDI-TOF) mass spectrometry (MS) can analysis unambiguously identity the spots from 2-dimensional electrophoresis (2-DE) gel. In this report, we examined protein components from patterns of S. enteritidis proteins. In addition, antigens that are recognized by sera can be identified by immunoblotting. This study that 2-DE analysis of S. enteritidis yields useful information concerning S. enteritidis proteome, the results that have been obtained led to a more detailed understanding of Salmonella pathology and open further interesting fields for future work.