• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.683-687
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• 2004

Raw beefs used fer Jangzorim production were evaluated fur contamination of pathogenic bacteria and microorganisms related to spoilage and food safety. Eleven groups of mesophilic, psychrotrophic, and anaerobic microorganisms, and total coliforms were selected to evaluate degree of food contamination. Nine strains including Bacillus cereus, Clostridium botulinum, C. perfringens, and Listeria monocytogenes were selected to evaluate incidences of pathogenic bacteria. Raw beefs harbored large populations of microorganisms, which decreased greatly after heat treatment. Psychrotrophic microorganisms were found to be more abundant than other microorganisms. B. cereus, C. perfringens, and L. monocytogenes were isolated from raw beefs, whereas C. botulinum, Escherichia coli O157:H7, Salmonella spp., Shigella spp., Staphylococcus aureus, and Yersinia enterocolitica were not isolated. Isoiates from Cereus selective agar, clostridium Perfringens agar, and Oxford agar were in 99.8, 99.9 and 98.6% agreements with B. cereus, C. perfringens, and L. monocytogenes at species level, respectively. B. cereus produced enterotoxin with CRET-RPLA method, whereas C. perfringens did not produce enterotoxin with PET-RPLA method.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.408-414
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• 2014

The antimicrobial and antioxidant activities of different cultivars and parts of broccoli were investigated. The screening of antimicrobial activities for the floret and leaf extracts of 11 cultivars against selected gram positive (Staphylococcus aureus and Listeria monocytogenes) and gram negative bacteria (Escherichia coli O157:H7 and Salmonella enteritidis) were conducted. The AMG cultivar showed the highest antimicrobial activity against S. aureus with the floret and leaf extracts (12.83 and 13.00 mm). Antibacterial activity against L. monocytogenes was strongest with floret extract of NJ cultivar (13.58 mm) and leaf extract of YDR cultivar (13.92 mm). Moreover, the size of inhibition zone against L. monocytogenes was bigger than those of 4 kinds of pathogenic bacteria. Both floret and leaf extracts of Grd cultivar showed the highest antimicrobial activity against E. coli O157: H7, but there was no difference between floret and leaf extracts. Floret extract o f NJ cultivar and leaf extract of NY and 0c cultivars were effective against S. enteritidis whereas leaf extract exhibited better antimicrobial effect than floret extract. These results showed that floret extract of NJ and leaf extract of 0c had the highest antioxidant activity which was 39.90 and 43.64%, respectively. The antioxidant activity of leaf extract was 1.5 times higher than that of floret extract. All cultivars except NJ showed that electron donating ability of leaf extract was higher than that of floret extract.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.538-546
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• 2017

The occurrence of various pathogenic microorganisms on farms is a concern if they are able to contaminate fresh produce, which provides entry into the food supply. This study was undertaken to assess the microbiological quality and prevalence of pathogens in Chinese cabbage cultivated soil in Korea. A total of 57 Chinese cabbage cultivated soils were collected in 4 locations in Korea from February to August 2017. The soils were analyzed for the presence of total aerobic bacteria, Escherichia coli, coliforms, Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus. The total aerobic plate counts in soils were in the range of 5.7 to $8.7log\;CFU\;g^{-1}$. The coliforms and E. coli were detected in 39 and 8 out of 57 soil samples, respectively, in the range of 1.1 to $6.3log\;CFU\;g^{-1}$ and 0.7 to $4.0log\;CFU\;g^{-1}$. Salmonella spp., E. coli O157:H7, L. monocytogenes, and S. aureus were not detected from any samples. Results from these studies may help control the spread of bacterial species such as E. coli and Salmonella spp. through the farm environment.

• Biomedical Science Letters
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• v.13 no.1
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• pp.71-73
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• 2007

For the rapid detection of objective pathogenic bacteria from colon biopsy specimens, multiplex PCR (polymerase chain reaction) method was developed. The major objective bacteria in this study were Shiga-like toxin producing E. coli O157:H7, Staphylococcus aureus, Vibrio parahaemolyticus, Listeria monocytogenes, Shigella spp. Salmonella spp. and Yersinia spp.. To detect simultaneously 7 kinds of pathogenic bacteria in single reaction tube, multiplex PCR system was executed using 6 sets of primers used in single PCR system for the respective bacteria. The results in this research might be applied for the detection of pathogenic bacteria form colon biopsy samples.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.177-184
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• 2009

Three hundred lactic acid bacteria isolated from human feces were studied their probiotic characters to develop potential probiotics. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, thermal stability, antimicrobial, anticancer cell, and antiviral activity. Strain Miny-148 was selected as a potential probiotic bacterium which showed resistance to low pH, bile salts and thermal stability. On the basis of fatty acid profiles and 16S rDNA sequences analysis, the strain was identified as Lactobacillus pentosus (similarity 99.9%). The strain, L. pentosus Miny-148, showed broad antimicrobial spectrum against E. coli O157:H7, Shigella flexneri, Bacillus anthracis, Staphylococcus aureus, E. coli, Vibrio cholerae, V. vulnificus, Salmonella typhimurium, and Methicillin-resistant S. aureus (MRSA). Cell-free culture supernatant of the strain also inhibited against the growth of HT-29 colon cancer cell and transmissible gastroenterits virus.

• Food Science and Preservation
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• v.20 no.3
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• pp.419-423
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• 2013

The objective of this study was to characterize the bactericidal effect of 461nm visible-light LED on three common foodborne bacteria: Escherichia coli O157:H7, Staphylococcus aureus and Vibrio parahaemolyticus. Tests were conducted against pathogen strains that were treated with 461nm LED for 10 h at $15^{\circ}C$. The E. coli (ATCC 43894, ATCC 8739 and ATCC 35150) and the S. aureus (ATCC 27664, ATCC 19095 and ATCC 43300) had average reductions of 2.5, 6.6, 1.5, 2.5 and 2.0 log CFU/mL, respectively, after they were exposed for 10 h to 461nm LED light (p<0.05). In contrast, V. parahaemolyticus (ATCC 43969) had 6 log CFU/mL reductions after it was exposed for 4 h to 461nm LED light. The results showed that both the Gram-positive and Gram-negative bacteria were inactivated with 461nm LED light exposure. Also, the Gram-negative bacteria were more sensitive to the LED treatment than the Gram-positive bacteria. These results show the potential use of 461nm LED as a food preservation and application technology.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.179-191
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• 2007

The purpose of this study was to monitor and compare the contamination levels of heterotrophic bacteria and pathogenic bacteria (total coliforms, Escherichia coli O157:H7, Salmonella spp., Vibrio parachaemolyticus, Staphylococcus aureus and Bacillus cereus). The samples collected at fish farms located in the Jeju-island were investigated from March to August in 2006. The contamination levels of S. aureus, B. cereus and Salmonella spp. ranged $0-3.3{\times}10^2 CFU/ml,\;0-2.2{\times}10^2 CFU/ml\;and\;0-5.1{\times}10^1CFU/ml$, respectively, and 85% of moist pellet feeds were contaminated with S. aureus, B. cereus and total coliforms. But total coliforms and E. coli O157:H7 were not detected in oliver flounder (Paralichthys olivaceus). For the production of safe oliver flounder (Paralichthys olivaceus), education of sanitation for employees, control of fish feed, and continuous monitoring for microorganism will be required.

• Microbiology and Biotechnology Letters
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• v.28 no.5
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• pp.279-284
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• 2000

This study was per-formed to screen lactic acid bacteria poultry for the probiotic use. Among the previously obtained acid tolerant, 139 strains, 111 strains were selected with MRS medium containing 0.3% oxgall. 34 strains of 111 was re-selected by Gram-staining and acid producing ability. These strains was identified by MIDI Sherlock Microbial Identification System. Among the identified 34 strains Lactobacillus fermenum YL-3 was selected for the final pro-biotic use because of the good growth and high survival rate at pH 2.0. 60%, 50% and 40% cells of Lactobacillus fermentum YL-3 survived at pH 3.0, 2.5 and 2.0, respectively. More than $10^{7}$ / CFU/ml survived when exposed with the number of $10^{8}$ CFU/ml at pH 2.0 after 12 hr. L.fermenum YL-3 maintained growth in MRS broth containing 0.3, 0.5, 1.0 and 2.0% oxgall for 24 hr. L.fermenum YL-3 showed an inhibitory effect against pathogenic strains of Sal. enteritidis and E. coli O157:H7. In mixed culture with L.fermenum YL-3 Sal. enteritidis lost ability com-pletely in 15 hrs and E. coil O157:H7 in 16 hrs.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.99-106
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• 2016

This study was aimed to assess microbiological contamination level of Liriope platyphylla farms (A, B, and C) located in Cheongyang, Chungnam province. Specimens sampled from those farms and L. platyphylla tuberous roots were assessed for sanitary indication bacteria such as total aerobic bacteria, coliforms, and Escherichia coli and pathogenic bacteria such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus and Bacillus cereus, quantitatively and qualitatively. As a result, those farms are not contaminated by E. coli O157:H7, L. monocytogenes, Salmonella spp., at all. And S. aureus was only found qualitatively from workers' gloves at a farm. As a whole, those farms (soil, harvest container, harvester, cleanser, washing water and tray) were maintained in a low level of microbiological contamination. However a cleanser was contaminated by coliforms ($4.35log\;CFU/100cm^2$), and it is required to improve farm hygiene. Microbiological contamination level of L. platyphylla tuberous root was decreased in the postharvest process including washing and drying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1725-1732
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• 2015

The bactericidal effects of 642, 521, and 461 nm LED were investigated on Escherichia coli O157:H7 and Staphylococcus aureus strains in TSB with pH 7.2, 4.0, and 3.5 for 10 h at $15^{\circ}C$. The bactericidal effect of 461 nm blue LED was the most pronounced compared to 642 nm and 521 nm LEDs at pH 3.5. When E. coli was exposed to pH 3.5 with 461 nm LED, populations of E. coli O157:H7 ATCC 43894 and 35150 decreased by 4 and 5 log CFU/mL for 2 h, respectively. Populations of E. coli ATCC 8739 decreased by 5 log CFU/mL for 2 h. Further, S. aureus ATCC 27664, 43300, and 19095 were inactivated by 4, 5 and 5 log CFU/mL for 2 h, respectively, at pH 3.5 with 461 nm LED. In conclusion, combined treatment with 461 nm LED and acidic conditions at low-temperature ($15^{\circ}C$) showed the greatest antimicrobial effects. This study suggests that LEDs may be potentially used as a method to maintain the safety of the food preservation technology.