• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.125-132
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• 2009

In order to develop probiotics which may be a viable alternative of antibiotic use in pig industry, five bacterial strains (Lactobacillus sp. HN 52, 92, 98, 235 and AP 116) possessing antimicrobial properties were selected from 500 strains isolates of pig intestines. The bacteriocin produced by Lactobacillus sp. HN 235 displayed a relative broad spectrum of inhibitory activity against all Enterococcus strains, Pseudomonas aeruginosa, Listeria monocytogenes and Clostridium perfringens using the spot-on-lawn method. The production of antimicrobial substance started in the middle of the exponential growth phase, reached maximum levels (6,400 AU/mL) in the stationary phase, and then declined. Bacteriocin activity remained unchanged after 30 min of heat treatment at $95^{\circ}C$ and stable from pH 2.0 to 10 for 1 h, or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.457-463
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• 2013

The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of dressing. The hazard analysis examined the main materials, industrial water, microbial evaluation, and airborne microorganisms of each working area, as well as the pathogenic microbial contamination risk. The survey was conducted at SJ Company in Jincheon (Chungchengbuk-do), Korea for 30 days from April 1, 2012 to April 30, 2012. The results showed that raw material microorganisms had a total plate count in industrial water below $3.00{\times}10$ CFU/mL in working room I, working room II, the packing room, washing water, and the inspection room for five times in each place. During dressing production (including heat treatment and mixing), general bacteria were detected at an average of $3{\times}10$ CFU/mL, but yeast, mold, and pathogenic bacteria were not detected. Airborne microbiological evaluation (for total plate count, yeast, and mold) found levels below the legal limit at each working area. While workers were positive for microbes in total plate counts, coliform and Staphylococcus aureus were not detected. In conclusion, standards for hygienic management should be established to prevent and decrease hazards, such as general bacteria and pathogenic microorganisms (for example, E. coli, B. cereus, Listeria spp, Salmonella spp, Staph. aureus, Clostridium perfringens, yeast, and mold), and to found critical limits for microorganisms with an HACCP system.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1035-1043
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• 1999

Bacteriocins are natural antimicrobial compounds produced by many microorganisms associated with foods, so that there is currently much interest in their use as food biopreservatives. Goal of this study was to partially evaluate lacticin NK24 as a food biopreservative by showing antimicrobial activity of L. lactis NK24 and lacticin NK24 against food-borne spoilage and pathogenic bacteria, respectively. Lactic acid bacteria NK24 isolated from jeot-gal, Korean fermented fish foods, was tentatively identified as Lactococcus lactis and showed broad spectrum of activity against all of spoilage and pathogenic bacteria tested by deferred method. Bacteriocin production in jar fermenter was detected at the mid-log growth phase, and reached the maximum at the early stationary phase, but decreased after the stationary phase. Lacticin NK24 was partially purified by 75% ammonium sulfate precipitation followed by subsequent dialysis. This partially purified lacticin NK24 showed antimicrobial activity against Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Clostridium perfringens, some bacilli, Listeria monocytogenes, Listeria ivanovii, Sphin-gomonas pausimobilis, Escherichia coli and Pseudomonas aeruginosa. Thus, lacticin NK24 examined in this study show promise as a biopreservative be-cause of their broad spectrum of activity.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.184-191
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• 2020

Objectives: This study was performed to analyze cases of food poisoning outbreaks reported in Chungcheongnamdo Province in 2019 and report it as effective data for preventing food poisoning in the future. Methods: Food poisoning outbreaks were analyzed to detect virus, bacteria, and protozoa according to the Manual for Detection of Foodborne Pathogens in Outbreaks to clarify the causes of food poisoning that occurred in Chungcheongnam-do Province in 2019. Results: Among the 79 cases of food poisoning outbreaks, 59 cases (74.7%) were in general restaurants, 15 cases (19.0%) in food service institutions, three cases at banquets, and two cases in take-out food. The 42 cases at general seafood restaurants made up the majority of food poisoning in Chungcheongnam-do. Food poisoning pathogens were shown in 13 cases (86.7%) out of the 15 cases at food service institutions, and 10 cases were related to Norovirus. Among the 79 cases, food-borne pathogens were identified in 35 cases of outbreaks, accounting for 44.3%. The confirmed pathogens were as follows: bacteria (24 cases), Norovirus (12 cases) and Kudoa septempunctata. (five cases). The food-borne bacteria were pathogenic E. coli (12 cases), Staphylococcus aureus (six cases), Salmonella spp. (two cases), Campylobacter jejuni, Bacillus cereus, Clostridium perfringens, and Vibrio parahaemolyticus (one case). Conclusions: To prevent food poisoning, it is necessary to analyze regional characteristics and environments and to hold a campaign for the prevention of food poisoning based on that analysis. In addition, when food poisoning occurs, the results of analyzing its cause and spread based on accurate epidemiological survey need to be shared.

• Journal of Environmental Health Sciences
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• v.43 no.6
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• pp.499-508
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• 2017

Objective: This study was conducted to investigate changes in microbiological quality according to various storage conditions in the drinking process of bottled mineral water. Methods: Heterotrophic plate counts ($21^{\circ}C$ and $36^{\circ}C$) and pathogenic indicators (total coliforms, fecal Streptococcus, Pseudomonas aeruginosa, Clostridium perfringens, Salmonella, and Shigella) were analyzed in commercial bottled mineral water stored under different conditions ($4^{\circ}C$, $20-25^{\circ}C$, $36^{\circ}C$) after injecting saliva. The heterotrophic plate counts were analyzed twice per day for the first week and once per day for the three weeks after. Pathogenic indicators were analyzed at the beginning and end (initial and final). Results: The results of the microbiological quality of the bottled mineral water in contact with saliva showed that heterotrophic plate counts ($21^{\circ}C$) had a tendency to be sustained or decrease slightly after 10 days. Heterotrophic plate counts ($36^{\circ}C$) had a high population in the initial samples and gradually decreased at $4^{\circ}C$ storage, but it remained constantly high in storage at $20-25^{\circ}C$ and $36^{\circ}C$. In the general drinking condition, the population was slightly higher than the control, but the overall trend was similar. Conclusions: As a result of the microbiological quality of mineral bottled water in contact with saliva during the process of drinking, heterotrophic plate counts ($21^{\circ}C$ and $36^{\circ}C$) showed a high population compared to the control, which was only opened and not in contact with saliva. In some samples, pathogenic indicators were also detected. Therefore, it is desirable to consume bottled mineral water as soon as possible after opening.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.490-494
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• 2011

Although bacterial outbreaks from ready-to-eat foods have increased, little information is available on microbial quality of sprouts in markets. Fifty sprouts and 30 salads were collected from wholesale markets. Total aerobic count (TAC), coliform, Escherichia coli, and some pathogens were detected. TAC for sprouts was 7.95 log CFU/g and 6.70 for salads, indicating that sprouts were more contaminated by 1 log CFU/g than that of salads. The numbers of coliform were 6.69 log CFU/g for sprouts and 5.42 for salads. E. coli was detected in 16 of 50 sprout samples at 2.38 log CFU/g and eight of 30 salads at 2.21 log CFU/g. Bacillus cereus was detected in 29 of 50 sprout samples and 16 of 30 salads, and the counts were mostly <3 log CFU/g. Salmonella, Staphylococcus aureus, Listeria monocytogenes, Campylobacter jejuni, and Clostridium perfringens were not detected. Therefore, although pathogens may not be a high risk for these foods, the high TAC and E. coli contamination require improved production and distribution methods, particularly for sprouts.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.341-345
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• 2010

Three-hundred samples of powdered infant formula milk and related products from four different manufacturers in 2010 were collected and surveyed their contaminations for aerobic bacteria, coliform, Enterobacter(Cronobacter) sakazakii, and food-borne pathogens. Fifteen samples of sterilized infant formula milk were all negative on these microorganisms. In all collected products of un sterilized infant formulas and follow-on infant formulas, aerobic bacteria were detected at 239 (83.9%) among 285 samples, and they all were found below $10^3$ cfu/g. Coliform bacteria were also detected at four among 285 samples. Salmonella spp. and Ent. sakazakii, weren't detected at the all samples. Bacillus cereus was detected at 24 (8.4%) among 285 samples. The level of B. cereus was below 100 cfu/g but it was suitable for the range of specification of B. cereus in infant formulas. Clostridium perjringens, Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes weren't also detected. In consequence, it was suitable for total viable count, coliform and potential pathogen to the specification of infant formulas and related products.

• Journal of the Korean Society of Food Culture
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• v.30 no.6
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• pp.783-789
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• 2015

In recent years, consumers have become more interested in convenient lifestyles, leading to increased use of salted cabbages for preparation of kimchi. This study aimed to investigate the safety of heavy metals, pesticide residues, and foodborne pathogens in commercial salted cabbages in Seoul from August to November, 2014. The survey, which was conducted to determine whether or not salted cabbages were prepared under the highest sanitary conditions, showed that Seoulites are interested in purchasing hygienic and safe salted cabbages. The average amounts (range) of Pb and Cd found in 30 salted cabbage samples were 0.007 (0.000~0.063) mg/kg and 0.004 (0.000~0.012) mg/kg, respectively. The cabbages were analyzed for residues from 285 types of pesticides using the multiresidue method. Residues for pesticides were not detected. Major foodborne pathogens, specifically Escherichia coli, Salmonella spp., Listeria monocytogenes, Campylobacter jejuni, Staphylococcus aureus, Vibrio parahaemolyticus, Enterohemorrhagic Escherichia coli, Bacillus cereus, Clostridium perfringens and Norovirus, were also not detected.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.437-444
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• 2016

Rapid and reliable identification of microorganisms is important to maintain food quality and to control safety. MALDI-TOF MS-based identification methods are relatively fast and simple compared to other conventional methods including gram staining and biochemical characterization. A colony on subcultured media can be directly prepared on the analysis plate without further complex treatments. In this study, we confirmed the applicability of MALDI-TOF MS-based identification of foodborne pathogens such as Salmonella Enteritidis/Typhimurium, Staphylococcus aureus, Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, Yersinia enterocolitica, Bacillus cereus, Campylobacter jejuni, Campylobacter coli, and Cronobacter sakazakii on the Korea Food Standard Codex. MALDI-TOF MS data of the pathogenic reference strains were incorporated into a commercial MicroID (ASTA Inc.) database. Other pathogenic reference strains and seven isolates from various food samples were correctly identified to the species level by using the MicroID database. In conclusion, MALDI-TOF MS is comparable with commercial biochemical identification.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.896-903
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• 2021

For the safety assessment of microbiological and chemical hazards in raw short-neck clam Ruditapes philippinarum distributed in the Yeongnam and Honam areas during the spring season, the contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine pathogenic bacteria (Staphylococcus aureus, Salmonella spp., Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, enterohemorrhagic Escherichia coli, Yersinia enterocolitica, Bacillus cereus, Campylobacter jejuni) as microbiological hazards, and heavy metals (lead, cadmium, total mercury), benzopyrene, shellfish poison (paralytic, diarrhetic, amnesic), and radioactivity (¹³¹I, ¹³⁴Cs+¹³⁷Cs) were also analyzed in 15 samples based on the methods of the Korean Food Code. The average contamination levels of total viable bacteria were 3.11 (1.40-4.49) log CFU/g, and coliforms were detected in 5 out of 15 samples (1.18-1.85 log CFU/g). E. coli and S. aureus were not detected in all samples. Furthermore, the presence of 8 pathogens were not detected in all samples. The average contamination levels of lead, cadmium, and total mercury were 0.155 (0.079-0.264), 0.160 (0.040-0.287), and 0.017 (0.008-0.026) mg/kg, respectively. Benzo(a)pyrene, shellfish poison, and radioactivity were not detected in all samples. The results of this study suggest that the safety against all microbiological and chemical hazard factors in raw short-neck clams distributed in markets has been assured.