• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.264-274
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• 2023

To evaluate functional biomaterials of 5 invasive alien plants, total polyphenol and flavonoid contents, antioxidant activity, anti-inflammatory activity, and antibacterial effect were measured. The total polyphenol and flavonoid contents of the extracts were in the order of Rumex acetosella L. > Hypochaeris radicata L. ≥ Lactuca scariola L. > Humulus japonicus Siebold & Zucc. ≥ Solanum viarum Dunal. The DPPH and ABTS radical scavenging activities of the extract were the highest in R. acetosella and correlated well with the total polyphenol contents. In RAW 264.7 cells stimulated with lipopolysaccharide (LPS), nitric oxide (NO) and prostaglandin E₂ (PGE₂) production inhibitory effect of the extracts (100 ㎍ SE/mL) were 20~60% and 10~70%, respectively, showing the highest inhibitory effect in R. acetocella. The extracts of R. acetosella, H. japonicus and S. viarum showed antibacterial activity against food poisoning-causing microorganisms such as Bacillus subtilis, Escherichia coli, Vibrio parahaemolyticus and Vibrio vulnificus. Furthermore, the H. japonicus extract was found to have effective antibacterial activity against oral microorganisms such as Enterococcus faecalis, Lacticaseibacillus casei, Rothia dentocariosa, Staphylococcus epidermidis and Streptococcus mutans, and its major active ingredients were predicted to be pentadecylic acid, palmitic acid and clionasterol. These results suggest that alien plants have potential as biomaterials with antioxidant, anti-inflammation and antibacterial effects.

• Korean Journal of Pharmacognosy
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• v.54 no.2
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• pp.72-79
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• 2023

MRSA is Staphylococcus aureus resistant to β-lactam antibiotics, and is a worldwide infectious disease. Even with the discovery of new antibiotics, resistance develops rapidly, so new alternatives are needed. Jakyakgamcho-tang (JGT) is a combination of Jakyak and Gamcho, and has been mainly used as an antispasmodic and analgesic in oriental medicine. This study was conducted to find out whether there is an effect on MRSA in relation to the anti-inflammatory effect of JGT and the antibacterial effect of Jakyak and Gamcho found in previous studies. In this study, in order to investigate the antibacterial activity of JGT and the combined effect of existing antibiotics, after extracting JGT with 70% EtoH, the disc diffusion method, minimum inhibitory concentration (MIC), drug combination effect (FICI), and time-kill analysis (Time-kill assay), metabolic inhibition, Western blot and qRT-PCR analysis were used to confirm the antibacterial activity mechanism of MRSA of JGT. As a result of the experiment, all of MRSA showed antibacterial activity in JGT's disc diffusion method, and the MIC was 250-1000 ㎍/mL. When existing antibiotics and JGT were combined with drugs, most had synergy or partial synergy. In addition, it was confirmed that the degree of bacterial growth was suppressed over time when simultaneous administration for 24 hours. JGT showed a synergistic effect when administered together with the ATPase-inhibitor DCCD, suggesting that it affected the inhibition of ATPase. As a result of observing the expression of PBP2a, and hla protein in the JGT-treated group and the untreated control group through wstern blot, it was confirmed that the protein expression of the JGT-treated group was significantly suppressed, and the expression levels of mecA, mecR1 and hla genes were also suppressed during JGT treatment. was observed by qRT-PCR. Combining the results of the experiment, it can be seen that JGT has antibacterial activity in MRSA, and when combined with existing antibiotics, the effect was increased compared to treatment with the drug alone. This suggests that JGT can be an alternative to treatment for antibiotic resistance of MRSA.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.988-1000
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• 2023

Hesperetin(HT) is a potent antioxidant flavonoid aglycone derived from hesperidin(HD). The antioxidant, anti-inflammatory, and antimicrobial activities of HT and its cyclodextrin(CD) inclusion complexes were compared in vitro. HT was prepared by enzymatic hydrolysis of HD, and HT/CD complexes were prepared using 𝛽-cyclodextrin(𝛽-CD) and hydroxypropyl-𝛽-cyclodextrin(HP-𝛽-CD) by solvent co-evaporation method. The solubility of the HT/HP-𝛽-CD inclusion complex increased 93.5-fold compared to HT, and the solubility of HT/𝛽-CD increased 22.5-fold. The HT/HP-𝛽-CD inclusion complex showed a similar effect as HT on radical scavenging activity in antioxidant assays, whereas the HT/𝛽-CD inclusion complex showed slightly lower activity than HT. Cytotoxicity was low in the following order; HT/HP-𝛽-CD, HT/𝛽-CD, and HT in murine macrophage RAW264.7 cells. Treatment with HT and HT/CD inclusion complexes reduced the levels of inflammatory mediators such as nitric oxide(NO), tumor necrosis factor-𝛼(TNF-𝛼) and interleukin-6(IL-6) in the cells. HT and HT/HP-𝛽-CD inclusion complex were more effective than HT/𝛽-CD inclusion complex at relatively low concentrations. Inhibitory effects were tested on skin-pathogenic bacteria, Staphylococcus aureus and Pseudomonas aeruginosa, and they showed an antimicrobial effect on S. aureus in the order of HT = HT/HP-𝛽-CD > HT/𝛽-CD, but they did not show any significant inhibitory effect on P. aeruginosa. In conclusion, HT, the aglycone form of HD, and its CD inclusion complexes showed various biological activities. HT/HP-𝛽-CD inclusion complex, which is the highly soluble form of HT, showed relatively higher activity compared to HT/𝛽-CD inclusion complex.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.48-56
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• 2024

Objectives: The coronavirus pandemic that began in 2019(COVID-19) has been one of the worst pandemics of the 21st century. Masks have been used to prevent COVID-19, but there are currently no standards for the long-term use of masks in the Republic of Korea. This study was conducted to assess the microbiological safety of KF94(Korea Filter 94) disposable face masks according to wearing duration by evaluating the bacterial filtration efficiencies of masks worn by research participants. Methods: A commercially available KF94 mask certified by the Ministry of Food and Drug Safety(MFDS) in the Republic of Korea was selected as the test mask. The research participants(n = 15) wore masks for the durations of one, three, and seven days. Participants also reported several parameters, including wearing time, makeup frequency, and storage. Bacterial filtration efficiencies of the worn masks were measured by a mask bioaerosol filtration tester. Staphylococcus aureus(S. aureus) was used as the test bacteria and quantitatively measured through the cultivation method. Then, bacterial filtration efficiency was calculated using the formula suggested by the MFDS. Results: All worn masks showed over 99.98% of mean bacterial filtration efficiency for S. aureus. There were no significant differences among bacterial filtration efficiencies of face masks according to wearing duration. There was also no significant difference among bacterial filtration efficiencies among participants. There was no correlation between the results of bacterial filtration efficiencies and reported parameters from participants. Conclusions: In the absence of significant external damage to the mask, the bacterial filtration efficiency of the mask can be maintained even after seven days of wearing. This result suggests that KF94 masks certified by the MFDS can be used repeatedly for about a week without loss of bacterial filtration efficiency.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.102-112
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• 2024

Background: Despite the rise in the number of domestic indoor climbing gyms, there is a lack of specific hygiene standards and research on the holds installed in them. Holds can act as vectors for microbial transmission through the hands, posing a risk of infectious diseases, especially with damaged skin. Objectives: The aim of this study is to investigate the contamination level and species of microorganisms on holds according to the management methods practiced in indoor climbing gyms and identify effective strategies for reducing microbial contamination. Methods: We investigated factors that may influence microbial contamination of holds, including hold management methods, user information, and hygiene management at three climbing gyms in Seoul. A total of 72 holds were sampled, 18 for each management method of brushing, high-pressure washing, and ethanol disinfection. Samples were cultured on LB and blood agar at 37℃ for 48 hours to calculate CFUs. PCR assay targeting 16S rRNA was carried out to identify microorganisms. Dunn-Bonferroni was employed to see the microbial reduction effect of the management method and the difference in microbial contamination by management method and climbing gym. Results: As a result of microbial identification, microorganisms such as Bacillus, Staphylococcus, and Micrococcus, which were derived from various environments such as skin and soil, were discovered on the surface of the climbing hold. Among the discovered microorganisms, some species had potential pathogenic properties that could cause food poisoning, gastrointestinal disease, bacteremia, and sepsis. All hold management methods were effective in reducing microorganisms (p<0.05), with ethanol disinfection being the most effective (p<0.001). Conclusions: Our results indicate that there are potential pathogens on holds that demand thorough management for microbial prevention. Proposed methods include regular brushing and ethanol disinfection in addition to high-pressure washing with long cycles, which are the existing forms of hold management. Further studies on shoe management are advised to curb soil-derived microorganisms.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.17-23
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• 2024

Background: Honey bees play a crucial role in pollination and ecological balance. Apis mellifera L. colonies, especially those located in specific geographic regions, such as the palm garden in Eastern Thailand, are susceptible to potential threats from microbial contaminants. Understanding and detecting microbial organisms in these beehives is essential for the preservation of bee health, honey production, and the broader ecosystem. However, the problem of microbial infection and antibiotic-resistant bacteria is more severe and continuously increasing, resulting in a health, economic, and social crisis. The purpose of this study is to determine the prevalence of microorganisms in A. mellifera beehives in palm gardens in Rayong province, Eastern Thailand. Results: Ten swabs in transport media were swabbed and obtained from different parts of each beehive (1 swab per beehive), for a total of 10 hives. Traditional microbial culture-based methods, biochemical tests, and antimicrobial susceptibility (disc-diffusion) tests were used to detect microbial organisms and antibiotic resistance in bacteria. The swab tests from nine beehives resulted in the detection of Gram-positive bacteria (63.64%), Gram-negative bacteria (27.27%), and fungi/yeast (9.09%). These microorganisms are classified as a group of coagulase-negative Staphylococcus spp. and made up 40.91% of the bacteria discovered. Other bacteria found were Coryneform bacteria (13.64%), Pantoea spp. (13.64%), Bacillus spp. (9.09%), yeast (9.09%), glucose non-fermentative Gram-negative bacilli (9.09%), and Pseudomonas spp. (4.55%). However, due to the traditional culture-based and 0biochemical tests usually used to identify the microbial organisms in clinical specimens and the limitation of identifying some environmental microbial species, the results of the antimicrobial susceptibility test cannot reveal if the organism is resistant or susceptible to the drug. Nevertheless, drug-sensitive inhibition zones were formed with each antibiotic agent. Conclusions: Overall, the study supports prevention, healthcare, and public health systems. The contamination of microorganisms in the beehives may affect the quality of honey and other bee products or even the health of the beekeeper. To avoid this kind of contamination, it is therefore necessary to wear personal protective equipment while harvesting honey and other bee products.

• Journal of Food Hygiene and Safety
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• v.39 no.3
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• pp.266-272
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• 2024

This study assessed the contamination level of food poisoning bacteria on handles of food service equipment in childcare centers to prevent food poisoning and analyzed toxin genes and antibiotic resistance of isolated strains. The isolates used in this study were collected from 101 childcare centers in Jeollanam-do. Four strains of Bacillus cereus and two strains of Staphylococcus aureus were isolated on the handles of food service equipment (refrigerators and freezers). The toxin genes of B. cereus were detected as nheA, nheB, nheC, entFM, and cytK. No toxin genes of S. aureus were detected. B. cereus showed resistance to β-lactam antibiotics, such as ampicillin and cefepime. S. aureus also showed resistance to antibiotics such as ampicillin and cefepime. Therefore, microbial safety and hygiene management, such as periodic sterilization of handles, should be strengthened to prevent food poisoning caused by cross-contamination of food service equipment handles in childcare centers.

• Korean Journal of Veterinary Research
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• v.64 no.2
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• pp.17.1-17.10
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• 2024

This study examined the colostrum nutritive composition, immunoglobulin (Ig), and microbial community in Holstein and Jersey dairy cows according to the time after calving. The experiment used seven Holstein and three Jersey dairy cows. Colostrum was collected immediately after calf calving, 12, and 24 hours, and stored at -80℃ until analysis. An analysis of the nutritive composition in colostrum was performed using LactoScop. The immune indicators were analyzed using an ELISA Kit, and the microbial community was assessed using a Macrogen Inc. The protein level was high in all colostrum samples from Holstein dairy cows compared with Jersey dairy cows, but there was no significant difference according to the time after calving. Immune index analysis revealed high IgG and IgA concentrations in the colostrum of Holstein cows immediately after calving and 12 and 24 hours after calving, but the differences were not significant. The microbial community at the genus level revealed Staphylococcus to be predominant at a high rate in the colostrum of Holstein dairy cows and Enterococcus in Jersey dairy cows 12 hours after calving. Pseudomonas was predominant at a high rate in the colostrum of Jersey lactating cows immediately and 12 hours after calving. Chryseobacterium was predominant at a high rate in Holstein dairy cows 12 and 24 hours after calving. In conclusion, these results are expected to be used as research data on the correlation between quality, immunity, and microbial community in the colostrum.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.2
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• pp.93-100
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• 2009

This research was performed to figure out the optimal mixing ratio of food- to livestock wastewater for the best degradation of organic matter in the anaerobic digestion. The presence of various microorganisms, such as Escherichia coli and Staphylococcus aureus, was also investigated in both wastewater in this process. Enteric bacteria were only found in livestock wastewater, whereas pathogenic bacteria like S. aureus were detected in both wastewater. The optimal mixing ratio of food- to livestock wastewater for the best mineralization was found to fifty to fifty, with reduction ratios of $BOD_5$, CODcr SS as 23.2%, 24.7%, 19.7%, respectively. Hygiene of the digested sludge was also analyzed by counting the number of total colonies and various pathogens. Enterobacteriaceae including E. coli were barely detected in 10 days after reaction. Meanwhile, S. aureus was gradually reduced during reaction, even showing 1,000~5,000 CFU/mL in final days.

• Journal of agricultural medicine and community health
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• v.30 no.2
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• pp.137-149
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• 2005

Objectives and Methods: This study was performed to investigate the etiologic bacterial, viral and protozoal organisms for the diarrhea from hospitals in Chungnam area from January to December in 2004. Total of 787 fecal samples were collected and examined. Results and Conclusions: In test for enteropathogenic bacteria, total of 79 cases out of 787 samples from hospitals showed positive isolation. Among 79 positive samples, 27 cases were confirmed as Salmonella spp.. 20 cases as pathogenic E. coli, 18 cases as Clostridium perfringens, 6 cases as Staphylococcus aureus, 4 cases as Shigella spp. and 4 cases as Vibrio parahaemolyticus. In test for enteropathogenic virus, 190 cases out of 787 samples from hospitals showed positive reaction. Among 190 samples, 115 cases were confirmed as rotavirus, 55 cases as norovirus, 5 case as astrovirus, 4 case as rotavirus & norovirus, 3 cases as adenovirus, 2 case as rotavirus & astrovirus. In test for enteropathogenic protozoa, 6 cases out of 787 samples from hospitals showed positive result. Among 6 samples, 5 cases were confirmed as Entamoeba histolytica and 1 cases as Giardia lamblia. When we classified the positive results by the age of the patients, the highest isolation rate was noted in a group of age under 10 and over 60 for bacterial, viral and protozoal pathogens. Especially, patient below age of 5 showed high positive rate. When we classified the positive results by the time, pageathogenic bacteria were isolated throughout the year, and the highest frequency was noted in August. On the other hand, pathogenic viruses were detected more frequently during the colder season from December to April. Antimicrobial susceptibility test for the isolated bacteria resulted as follows; Salmonella strains showed high drug resistance rates against ampicillin, chloramphenicol, tetracycline, nalidixic acid, ticarcillin. Shigella strains showed high drug resistance rates against ampicillin, trimethoprim/sulfamethoxazole, chloramphenicol, tetracycline, ampicillin/sulbactam, ticarcillin. Pathogenic E. coli strains showed high drug resistance rates against ampicillin, cephalothin, gentamicin, tetracycline, nalidixic acid, ampicillin/sulbactam, ticarcillin.