• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.501-506
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• 2004

Microflora and contamination process of Saengshik products were investigated to ensure microbial safety of Saengshik. Food-borne pathogenic bacteria, such as Staphylococcus aureus, Bacillus cereus, and Clostridium perfringens detected mainly from grains were not removed by washing with tap water and freeze-drying. Contaminations of food-borne pathogenic bacteria occurred through raw material powder processed at other factories and during actual product manufacturing process, because detection rates of final products were higher than those of raw materials. Concentration of food-borne pathogenic bacteria increased with advancing of process after first pulverization. Dusts of powder and powder attached to machine were good media for air-borne microorganisms and caused to increase of food-borne pathogenic bacteria during process. Improvement of manufacturing process and sanitary control of machines arc necessary to ensure microbial safety of Saengshik.

• Journal of fish pathology
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• v.17 no.1
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• pp.39-55
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• 2004

Hundreds of medicinal herbs have been using for the purpose of diseases treatment and immune enhancement for human being and other animals including fishes. Among them, 49 species of medicinal herbs were selected and tested for antibacterial activities against 19 strains of fish pathogenic bacteria in different 4 species. The 49 medicinal herbs were extracted by water and ethyl alcohol. The extracts were freeze dried and some paper discs from the extracts were prepared for the evaluation of antibacterial activity. The tested pathogenic bacteria were 5 strains of Edwardsiella tarda, 5 strains of Vibrio sp., 4 strains of Lactococcus garvieae, 1 strain of Lactococcus raffinose, 1 strain of Streptococcus parauberius, and 3 strains of Streptococcus iniae. The Galla rhois (Obaeja), Gaeonnamu and Hwangleyon showed antibacterial activities on both gram negative and gram positive fish pathogenic bacteria. The Youkgae, Sangbaekpi, Bogolji and Gamcho showed very effective antibacterial activities on gram positive pathogens while Jiyu, Aeyoeb and Yeonkyo showed very effective on gram negative pathogens.

• Journal of Life Science
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• v.32 no.6
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• pp.438-446
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• 2022

Some flowers have a high sensual appeal owing to their unique shape, color, smell, and taste and have been used as functional food and oriental medicine. Recently, edible dry flowers (EDFs) have attracted social attention as noble sources of functional teas. In this study, for the risk assessment of EDFs, pathogenic bacteria, heavy metals, and pesticide residues were monitored in 23 types of commercial EDF. No Enterobacteria spp. and Listeria spp. were found in all EDF products. However, common aerobic bacteria (3.24~3.85 Log CFU/g) were found in EDF, namely, Pueraria lobata, Chamaemelum nobile, Acacia decurrens, Rhododendron mucronulatum Turcz, Oenothera lamarckiana, Brassica napus, and Prunus serrulata. Staphylococcus aureus was found in 11 and Salmonella sp. was found in 8 of the 23 EDFs. Considering the cold extraction of EDF for tea and beverages, the regulation of pathogenic bacteria in EDFs is necessary. No heavy metals such as Pb, Cd, Co, Cr, Cu, Ni, and As were found in all EDFs, except the dry flower of Hemerocallis fulva, which contained Pb at 0.08 ppm. Different pesticides and fungicides were found in EDFs, but their concentrations were very low (0.01~0.08 ppm) and below the maximal residue level. Only the dry flower of Chrysanthemum morifolium had a high content of chlorpyrifos (0.215 ppm), which is long-lasting pesticide. Our results suggest that the establishment of EDF regulations for pesticide residue, culture separation between edible and garden flowers, and guidelines for preventing pathogenic microbial contamination are necessary.

• Safety and Health at Work
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• v.11 no.4
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• pp.517-525
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• 2020

Background: The study was planned to show the status of indoor microorganisms and the status of the reduction device in the military dog clinic. Methods: Airborne microbes were analyzed according to the number of daily patient canines. For identification of bacteria, sampled bacteria was identified using VITEK^®2 and molecular method. The status of indoor microorganisms according to the operation of the ventilation system was analyzed. Results: Airborne bacteria and fungi concentrations were 1000.6 ± 800.7 CFU/m³ and 324.7 ± 245.8 CFU/m³. In the analysis using automated identification system, based on fluorescence biochemical test, VITEK^®2, mainly human pathogenic bacteria were identified. The three most frequently isolated genera were Kocuria (26.6%), Staphylococcus (24.48%), and Granulicatella (12.7%). The results analyzed by molecular method were detected in the order of Kocuria (22.6%), followed by Macrococcus (18.1%), Glutamicibacter (11.1%), and so on. When the ventilation system was operated appropriately, the airborne bacteria and fungi level were significantly decreased. Conclusion: Airborne bacteria in the clinic tend to increase with the number of canines. Human pathogenic bacteria were mainly detected in VITEK^®2, and relatively various bacteria were detected in molecular analysis. A decrease in the level of bacteria and fungi was observed with proper operation of the ventilation system.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.41-45
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• 1999

Bacterial population densities on soybean pods from Chungnam province ranges 105~106 CFU/$\textrm{cm}^2$, whereas those of bacteria causing sprout rot ranged 0~103 CFU/$\textrm{cm}^2$. Erwinia chrysanthemi, Xanthomonas campestris pv. glycines, Staphylococcus sp., and Micrococcus sp. were identified as pathogenic bacteria causing soybean sprout rot. The population density of X. campestris pv. glycines was higher than those of other bacteria.

• Journal of Dairy Science and Biotechnology
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• v.39 no.2
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• pp.51-62
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• 2021

Escherichia coli are the predominant facultative bacteria found in the gastrointestinal tract of animals and humans. Some strains of E. coli that acquire virulence factors and cause foodborne and waterborne diseases in humans are called pathogenic E. coli and can be divided into five pathotypes according to the virulence mechanism: EAEC, EHEC, EIEC, EPEC, and ETEC. Although selective media have been developed to detect E. coli, distinguishing pathogenic strains from non-pathogenic ones is difficult because of their similar biochemical properties. Therefore, it is very important to find a new and effective diagnostic method to identify pathogenic E. coli. With recent advances in molecular biology and whole genome sequencing, the use of polymerase chain reaction (PCR) is increasing rapidly. In this review paper, we provide an overview of pathogenic E. coli and present a review on PCR detection methods that can be used to diagnose pathogenic E. coli. In addition, the possibility of real-time PCR incorporating IAC is introduced. Consequently, this review paper will contribute to solving the current challenges related to the detection of pathogenic E. coli.

• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.287-295
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• 2020

The differences between luminal microbiota (LM) and mucosal microbiota (MAM) were little known, especially in duodenum. In this study, LM and MAM in colon and duodenum of mice were investigated through 16S rRNA high-throughput sequencing. The lowest bacterial diversity and evenness were observed in duodenal LM (D_LM), followed by duodenal MAM (D_MAM). Meanwhile, the bacterial diversity and evenness were obviously increased in D_MAM than these in D_LM, while no significant difference was observed between colonic MAM (C_MAM) and colonic LM (C_LM). PCoA analysis also showed that bacterial communities of LM and MAM in duodenum were completely separated, while these in colon overlapped partly. The ratio of Firmicutes to Bacteroidetes (F/B) in D_MAM was significantly higher than that in D_LM. Lactobacillus was largely enriched and was the characteristic bacteria in D_LM. The characteristic bacteria in D_MAM were Turicibacter, Parasutterella, Marvinbryantia and Bifidobacterium, while in C_LM they were Ruminiclostridium_6, Ruminiclostridium_9, Ruminococcaceae_UCG_007 and Lachnospiraceae_UCG_010, and in C_MAM they were Lachnospiraceae_NK4A136, Mucispirillum, Alistipes, Ruminiclostridium and Odoribacter. The networks showed that more interactions existed in colonic microbiota (24 nodes and 74 edges) than in duodenal microbiota (17 nodes and 29 edges). The 16S rDNA function prediction results indicated that bigger differences of function exist between LM and MAM in duodenum than these in colon. In conclusion, microbiota from intestinal luminal content and mucosa were different both in colon and in duodenum, and bacteria in colon interacted with each other much more closely than those in duodenum.

• Journal of dental hygiene science
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• v.18 no.1
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• pp.18-23
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• 2018

Propolis has been used as a natural remedy in folk medicine worldwide. The antibacterial, antiviral, antifungal, and antiprotozoal aspects of its antimicrobial properties have been widely investigated. However, few studies focused on its applications in dentistry. Many dental diseases are related to various microorganisms in the oral cavity. In this study, we assessed the antimicrobial activity of Korean propolis extract, collected from 6 different regions, on oral pathogenic microorganisms. The propolis samples, collected from 6 different regions (P1: Uijeongbu, P2: Ansan, P3: Hongcheon, P4: Iksan, P5: Gwangju, and P6: Sangju), were dissolved in ethanol at two different concentrations (10 and 50 mg/ml). Three oral bacteria (Streptococcus mutans, Staphylococcus aureus, and Enterococcus faecalis) and one fungus (Candida albicans) were activated in general broth for 24 hours. Microorganisms were diluted and spread onto agar plates, onto which sterilized 6 mm filter papers with or without each propolis sample were placed. After 24 hours of incubation, clear zones of inhibition were observed. All tests were performed in triplicate. The propolis samples showed significant antibacterial and antifungal activity on oral pathogenic microorganisms; in addition, low-concentration groups showed outstanding antimicrobial efficacy on the 4 different microorganisms. Among the samples, P6 had significantly higher antibacterial activity than that of the others against three different bacteria. In particular, a high concentration of P6 showed a significant antifungal effect. In conclusion, we confirmed that Korean propolis has an inhibitory effect on oral pathogenic bacteria and fungi. Therefore, we suggest the possibility of developing oral medicine and oral care products based on Korean propolis.

• Journal of the Korean Dietetic Association
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• v.24 no.4
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• pp.330-343
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• 2018

Recently, there has been a growing demand for natural preservatives because of increased consumer interest in health. In this study, we produced Lactobacillus rhamnosus cell-free supernatant (LCFS) and evaluated and compared its antimicrobial activity with existing natural preservatives against pathogenic microorganisms and in chicken breast meat contaminated with Escherichia coli and Staphylococcus aureus. Lactobacillus rhamnosus cell-free supernatant possessed 30 units of lysozyme activity and contained 18,835 mg/L of lactic acid, 2,051 mg/L of citric acid and 5,060 mg/L of acetic acid. Additionally, LCFS inhibited the growth of fourteen pathogenic bacteria, S. aureus, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, Listeria innocua, S. epidermidis, L. ivanovii, E. coli, Pseudomonas aeruginosa, Shigella sonnei, Shi. flexneri, Proteus vulgaris, Pseudomonas fluorescens, and Klebsiella pneumoniae. The antibacterial activity of LCFS was stronger than that of egg white lysozyme (EWL), Durafresh (DF) and grapefruit seed extract (GSE). Additionally, LCFS maintained its antimicrobial activity after heat treatment at $50^{\circ}C{\sim}95^{\circ}C$ and at pH values of 3~9. Moreover, LCFS inhibited the growth of E. coli and S. aureus in chicken breast meat. In conclusion, it is expected that LCFS, which contains both lysozyme and three organic acids, will be useful as a good natural preservative in the food industry.

• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.255-261
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• 2006

Experimental animals have been used to biological and medical purposes and the animals must be, for these purposes, healthy and clean to microbial infection. However, the animals can be easily exposed to pathogenic microorganism via several routes. Of the routes, environmental conditions are the most important factors to keep the animals healthy and clean, especially air condition. Monitoring of air-condition has been required to keep the animal healthy and clean. However, any guideline is not available for experimental conditions with pigs. Therefore, the sampling times and points were compared in different conditions to establish an optimal protocol for monitoring of air borne bacteria. Tryptic soy agar(TSA), blood agar containing 5% defibrinated sheep blood and Sabraud dextrose agar(SDA) were used as media to capture total bacteria, pathogenic bacteria and fungi, respectively. Two methods, compulsive capture using an air-sampler and capturing fall-down bacteria were used to capture the microorganisms in the air. The points and time of capturing were different at each experiment. Air borne microorganisms were captured at three and five points in the open and closed equipments, respectively. Air was collected using an air-sampler for 1 min and 5 min and the agar plates as open status were left from 30 min to 2hr. At first, we monitored an experimental laboratory which dealt with several pathogenic bacteria and then, a protocol obtained from the investigation was applied to open or close experimental conditions with pigs. Number of bacteria was high from 10:00 to 15:00, especially on 13:30-15:30 but sharply decreased after 17:00. The tendency of the number of bacteria was similar between two methods even though the absolute number was higher with air sampler. Critical difference in the number of cells was observed at 5 min with air sampler and 2 hr with fall-down capturing method. However, 1 min with air sampler and 1 hr with fall-down capturing were the best condition to identify bacterial species collected from the air. Number of bacteria were different depending on the sampling points in closed condition but not in opened condition. Based on our results, a guide-line was suggested for screening air-borne microorganism in the experimental conditions with pigs.