• Food Science and Preservation
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• v.11 no.1
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• pp.117-121
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• 2004

We investigated antimicrobial effects of commercial vinegar on the harmful food-born organisms. As a result, antimicrobial effects of brown rice vinegar showed stronger than persimmon and artificial vinegar. In 10${\mu}$L/mL concentration of brown rice vinegar was completely inhibited about 5 strains except for V. parahaemolyticus, it was inhibited 15${\mu}$L/mL concentration. Therefore vinegars were effective for inhibition acitivity against food borne organisms. S. aureus and E. coli treated with 25${\mu}$L/mL concentratioin brown rice vinegar was observed by scanning electron micrographs(SEM). The cells were expanede and a part of cell wall was completely destructed by brown rice vinegar.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.495-504
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• 2022

This study examined the antimicrobials properties of bacteria using the minimum inhibitory concentration method. The bacteria were isolated from 30 shellfish (oysters and short neck clams) collected from Jawol-myeon, Ongjin-gun, Incheon and Iwon-myeon, Taean-gun, Chungcheongnam-do, on the west coast of Korea. A total of 528 bacteria were isolated from June to October 2020 and were classified into land-originating (LB; 264 strains) and marine-originating (MB; 264 strains) bacterial groups. Of the LB strains, 10 genera were identified, of which nine were Enterobacteriaceae. All MB strains were identified as species of the genus Vibrio spp.. Antimicrobial resistance to one or more agents was observed in 77.3% of the LB strains, and 90-100% of them were resistant to ampicillin Escherichia spp. were not resistant to ampicillin. The overall multidrug resistance rate of the LB strains was 49.2%, with 85 resistance patterns. Antimicrobial resistance to one or more agents was observed in 98.1% of the MB strains, because most of the V. alginolyticus and V. parahaemolyticus strains were resistant to ampicillin. The overall multidrug resistance rate of the MB strains was 1.9% with 19 resistance patterns.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.133-139
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• 2023

The advantage of biofloc technology (BFT) in aquaculture is in the prevention of pathogenic transmission. In this study, we performed an investigation on viral, bacterial, and microsporidian parasite infections targeting a total of 194 whiteleg shrimp Litopenaeus vannamei reared in seven BFT-farms on the west coast of Korea in 2021. Hepatopancreatic and cuticular epithelium and pereiopods tissues of shrimp were tested for the four pathogens, Enterocytozoon hepatopenaei (EHP), Vibrio parahaemolyticus causing Acute Hepatopancreatic necrosis disease (VP_AHPND), white spot syndrome virus (WSSV), and hepatopancreatic parvovirus (HPV). The microsporidian parasite EHP was detected in the hepatopancreatic tissue of BFT whiteleg shrimp in the Ganghwa region, whereas no other pathogenic bacteria or virus was detected on the shrimp in the seven BFT-farms. As a result of bacterial flora in the rearing water of BFT whiteleg shrimp using DNA microbiome technology, V. chemaguriensis and V. alfacsensis were contained at 0.05% and 0.01%, respectively, but no VP_AHPND was detected. These findings will serve as a basis for supporting safe BFT-aquaculture of whiteleg shrimp.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.348-354
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• 2013

To investigate the effect of tagatose on the growth of intestinal bacteria, various species were cultivated individually on m-PYF medium containing tagatose as a carbon source. The tagatose inhibited the growth of intestinal harmful microorganisms such as Staphylococcus aureus subsp. aureus, Listeria monocytogenes, Vibrio parahaemolyticus, Salmonella Typhimurium, and Pseudomonas fluorescens. In the case of beneficial microorganisms found in the intestine, Lactobacillus casei grew effectively on m-PYF medium containing tagatose, while Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc citreum, and Lactobacillus acidophilus did not. To examine the effect of tagatose on fermentation by Lactobacillus casei, yogurt was prepared with tagatose as a carbon source. The resulting acid production stimulated a remarkable growth of lactic acid bacteria in the yogurt. After fermentation for 24 hours, the viable cell count and viscosity of yogurt were above 8.49 log CFU/mL and 1,266 cps, respectively. Moreover, sensory evaluations showed that the yogurt supplemented with tagatose was as acceptable as control yogurt prepared with glucose as a carbon source. The changes in pH, titratable acidity and lactic acid bacteria in yogurt prepared with tagatose did not show any significant changes during storage for 15 days at $4^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.183-188
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• 2003

Bactericidal effect of $Green-Zone^{(TM)}$ was observed, when Staphylococcus aureus, E. coli O157:H7, Salmonella typhimurium, S. enteritidis, Listeria monocytogenes, the causative bacteria of food poisoning, Vibrio parahaemolyticus, and Shigella sonnei were treated with the diluted solution of $Green-Zone^{(TM)}$(33.3%~4.1%) for 30min at $20^{\circ}C$. All the bacteria were killed in 30 sec, when 33.3%-diluted $Green-Zone^{(TM)}$ was applied, except for S. aureus. Coronavirus, the same virus with SARS virus taxonomically, was also lilled with the 20%-diluted $Green-Zone^{(TM)}$. Canine parvovirus and Canine distermper virus were also killed even in the organic matter and hard water when treated with $Green-Zone^{(TM)}$. When applied to food such as raw fish, chilled meat, vegetables, $Green-Zone^{(TM)}$ could also decrease the number of microorganism, expecially for E. Coli. From these results, $Green-Zone^{(TM)}$ is thought to be effective for killing virus and bacteria, and also was proved to be safe when applied directrly to food.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.50-56
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• 2017

The purpose of this study was to investigate the microbiological contamination of water and drinking cups in springs and to estimate the toxin gene, enterotoxin production ability and antibiotic susceptibility of foodborne pathogens. Ten spring water and 34 drinking cups were tested. The average number of total aerobic bacteria and coliform bacteria in spring water were 1.8 log CFU/mL and 1.2 log CFU/mL, and in drinking cups were $4.7log\;CFU/100cm^2$ and $1.7log\;CFU/100cm^2$. Salmonella spp., Staphylococcus aureus, E. coli O157:H7, Listeria monocytogenes, Vibrio parahaemolyticus, Yersinia enterocolitica were not isolated from all of samples but Bacillus cereus was detected in 5 (14.7%) of 34 drinking cups. The nheA and entFM genes were major enterotoxin genes in B. cereus isolated from drinking cups. All of B. cereus tested in this study produce non-heamolytic enterotoxin but only 2 isolates possessed heamolysin BL enterotoxin producing ability. B. cereus was resistant to ${\beta}-lactam$ antibiotics. These results revealed that the sanitary conditions of drinking cups in spring should be improved promptly. The substitution carrying a personal drinking cup for the public drinking cups equipped in springs is suggested to prevent food-borne illness.

• Journal of Life Science
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• v.27 no.4
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• pp.430-434
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• 2017

Essential oils are fragrant oils extracted from the leaves, stems, peels, petals and roots of aromatic plants cultivated by natural means or using organic agricultural techniques. Essential oils have commonly been used as antibacterial and antifungal agents. In the present study, essential oil was extracted from lisianthus (Eustoma grandiflorum [Raf.] Shinn.) and tested for antifungal activities against three eumycetes (Penicillium pinophilum, Chaetomium glogosum and Aspergillus niger). Lisianthus essential oil showed high antifungal activities against three eumycetes, especially against Aspergillus niger, for which the resulting minimum inhibitory concentration (MIC) was 0.005 mg/ml. In addition, the extracted essential oil was shown to have antimicrobial activity against ten intestinal pathogenic bacteria (Escherichia coli, Salmonella typhimurium, Klebsiella pneumonia, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Bacillus subtilis, Enterococcus faecalis and Vibrio parahaemolyticus) according to the disc diffusion method and was also shown to exhibit strong antibacterial activity against an additional three pathogenic bacteria (Bacillus subtilis, Listeria monocytogenes and Vibrio parahaemolyticus). These results indicate that lisianthus essential oil could be used as an antibiotic against harmful bacteria that produce intestinal illnesses. From the present study, we suggest that lisianthus extracts can be utilized as potential antifungal and antibacterial agents and for the development of pharmaceutical and cosmetic products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.97-100
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• 1992

The optimum condition for the extraction of antimicrobial substance from Lithospermi radix was investigated. For the purpose of obtaining basic data for the development of natural preservatives and for the prevention of food poisoning accidents, its antimicrobial activity was tested against several kinds of saprophytic microbes and food poisoning bacteria. The optimum condition for extraction of antimicrobial substance was to steep Lithospermi radix into 95% ethanol for 24 hours at room temperature. Antimicrobial activity was observed at the pH range $5.0{\sim}8.0$, but its activity became stronger at acidic condition. The result of ion exchange chromatography was showed that the antimicrobial activity of anionic portion was more apparent than that of cationic portion. The antimicrobial activity against Gram positive bacteria was stronger than that of Gram negative bacteria and the growth of food poisoning bacteria such as S. aureus and V. parahaemolyticus was inhibited in the concentration of 0.1% for 48 hours. As for mold and yeast, the growth of some kinds of these organisms was inhibited in the concentration of 0.1 % for 48 hours and the growth of nearly all the fungi was inhibited in the concentration of 0.15% for 96 hours.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.335-343
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• 2009

Antimicrobial resistance patterns of Vibrio species isolated from brackish water in Geoje, Tongyeong and Goseong, Gyeongsangnamdo province into which streams, sewage and leachate all flowed. Only 19 strains (10.7%) of 177 V. parahaemolyticus were susceptible to 15 antimicrobials. 146 strains (69.5%) proved resistant against more than one antimicrobial and 12 strains (6.8%) were multi-drug resistant. The resistance rate of 152 strains were 85.9% against AM and 26.6% against RA, 16.4% against AN, 13.6% against Sand 13.0% against TMP. 86 strains of 129 V. cholerae non-O1 (66.7%) were susceptible to antimicrobials and 31 strains (24.0%) were resistant to more than one antimicrobial and 12 strains (9.3%) were multi-drug resistant. The antimicrobial resistance rate of 129 strains against 15 antimicrobials, with the exception of C, CIP, E and GM, i.e. 11 antimicrobials, was 0.7-16.2%, 16.2% of 129 strains proved resistant against RA and 13.9% against AM, 9.3% against TMP, 7.7% against SXT and 6.9% against TE. 19 of 49 strains of V. mimicus (38.8%) were susceptible to antimicrobials and 31 strains (61.2%) were resistant against more than one antimicrobial; none of the strains were multi-drug resistant. 15 strains of V. mimicus were resistant against only RA, AmC and TE. The resistance rate was 59.2% against RA (highest) 4.1% against AmC and 2.0% against TE.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.120-125
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• 1994

The genes, trpB, trpA and 3’ trpC(F) of Vibrio metschnikovii strain RH530 were cloned and sequenced. The trpB and trpA genes had open reading frames of 1,173 bp and 804 bp encoding 391 and 268 amino acids, respectively. The trpB and trpA genes had conventional ribosome-binding sequences and overlapped with each other by one nucleotide, suggesting that these two genes are translationally coupled. 115 nucleotide upstream the trpB start codon, tjere was an incomplete open reading frame of the 3’-end of the trpC(F). The amino acid sequences of trpB, trpA and trpC(F) of V. metschnikovii RH530 had identities of 64.2%, 82.4% and 73.7% respectively, for those of V. parahaemolyticus; 58.7%, 72.3% and 54.9%, respectively, for Salmonella typhimurium; and 42.6%. 54.1% and 12.5%, respectively, for brevibacterium lactofermentum. The genetic organization of these genes, especially in the noncoding region between trpC(F) and trpB, was distinct from that of Enterobacteriaceae.