• Preventive Nutrition and Food Science
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• v.6 no.1
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• pp.10-15
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• 2001

Antimicrobial activities of volatile flavor, water and methanol extracts from Agastache rugosa were investigated. The volatile flavor extract was obtained from A. rugosa by simulataneous distillation-extraction (SDE) method. Antimicrobial activity was investigated by disc diffusion method against several microorganisms, four species of Gram positive, three species of Gram negative and tow species of yeast. The volatile flavor extracts had strong antimicrobial activity againstc. utilisand S. cerevisiae. During the growth period, a difference in antimicrobial activity among volatile flavor extracts from A. rugosa was not shown. The water extract of above 10 mg/disc showed antimicrobial activity. Methanol extracts from A. rugosa harvested in June showed antimicrobial activity against tested Gram positive and Gram negative bacteria, showed weak antimicrobial activity against the bacteria from those harvested in July and August. In particular, antimicrobial activity against V. parahaemolyticus was stronger than that against other bacteria. Water and methanol extracts did not inhibit yeast. C. utilis and S. cerevisiae. To further elucidate the effective components, volatile flavor extracts was analyzed by GC/MS. harvested in June, the components included 8 phenols (93.031%), 18 terpenes (5.230%), 12 alcohols (1.300%) 8 alkanes (0.181%), 1 ester (0.056%), 2 ketones (0.033%), 2 aldehydes (0.011%) and 1 pyrrole (0.007%). In July, the components included 6 phenols (94.366%), 19 terpenes (3.394%), 11 alcohols (2.045%), 1 ester (0.039%), 2 ketones (0.028%), 1 furan (0.005%) and 1 aldehyde (0.005%). And in August, the components included 7 phenols (95.270%), 19 terpenes (2.951%), 13 alcohols (1.399%), 1 ester (0.063%), 2 aldehydes (0.016%), 2 ketones (0.011%), 1 alkane (0.006%), 1 acid (0.005%) and 1 pyrrole (0.005%). The major component of volatile flavors was estragole, a phenolic compound.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.528-533
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• 2013

This study evaluated the impact of antimicrobial resistant bacteria produced by inland pollution sources on coastal areas, and investigates antimicrobial resistance profiles of bacteria isolated from marine filter feeders. A total of 107 shellfish (short-necked clams Ruditapes philippinarum, ark shells Scapharca broughtonii, and oysters Crassostrea gigas) were collected from the southern coast of Korea, from which 204 Escherichia coli strains were isolated. The antimicrobial susceptibility patterns of isolated strains were analyzed for 15 antimicrobial agents used in Korea for clinical or veterinary therapy. Antimicrobial resistance was present in 44.6% of E. coli isolates against at least one antimicrobial agent. The rate of antimicrobial resistance in the Narodo area was higher than isolates from the Gangjinman area and Kamak Bay. E. coli isolates had a higher rate of resistance against: tetracycline (29.9%), streptomycin (25.5%), and trimethoprim (14.2%). Of 204 isolates, 29 (14.2%) were resistant to multiple antimicrobial agents.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.620-631
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• 2015

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC $43971^T$, Micrococcus luteus ATCC $4698^T$ and Escherichia coli ATCC $11775^T$ were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at $100^{\circ}C$), but the antimicrobial activity was eliminated after treatment at $121^{\circ}C$ for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

• International Journal of Oral Biology
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• v.39 no.4
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• pp.169-176
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• 2014

A positional scanning synthetic peptide combinatorial library (PS-SCL) was screened in order to identify antimicrobial peptides against the cariogenic oral bacteria, Streptococcus mutans. Activity against Streptococcus gordonii and Aggregatibacter actinomycetemcomitans was also examined. The library was comprised of six sub-libraries with the format $O_{(1-6)}XXXXX-NH_2$, where O represents one of 19 amino acids (excluding cysteine) and X represents equimolar mixture of these. Each sub-library was tested for antimicrobial activity against S. mutans and evaluated for antimicrobial activity against S. gordonii and A. actinomycetemcomitans. The effect of peptides was observed using transmission electron microscopy (TEM). Two semi-mixture peptides, RXXXXN-$NH_2$ (pep-1) and WXXXXN-$NH_2$ (pep-2), and one positioned peptide, RRRWRN-$NH_2$ (pep-3), were identified. Pep-1 and pep-2 showed significant antimicrobial activity against Gram positive bacteria (S. mutans and S. gordonii), but not against Gram negative bacteria (A. actinomycetemcomitans). However, pep-3 showed very low antimicrobial activity against all three bacteria. Pep-3 did not form an amphiphilic ${\alpha}$-helix, which is a required structure for most antimicrobial peptides. Pep-1 and pep-2 were able to disrupt the membrane of S. mutans. Small libraries of biochemically-constrained peptides can be used to generate antimicrobial peptides against S. mutans and other oral microbes. Peptides derived from such libraries may be candidate antimicrobial agents for the treatment of oral microorganisms.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.637-642
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• 2010

We investigated the prevalence and the molecular characteristics of vancomycin-intermediate Staphylococcus aureus (VISA) among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from clinical samples at tertiary or general hospitals participating in a nationwide surveillance program for VISA and vancomycin-resistant Staphylococcus aureus (VRSA) in Korea during an 8-week period in each year from 2001 to 2006. Of 41,639 MRSAs isolated, 37,856 were screened and 169 grew on brain heart infusion agar supplemented with 4 ${\mu}g/ml$ vancomycin. A vancomycin MIC of 4 ${\mu}g/ml$ was confirmed for 33 VISA isolates of the 169 isolates. Eighteen of the 33 isolates were classified as hetero-VISA (hVISA) by the population analysis profile (PAP) method. All VISA isolates were susceptible to linezolid, tigecycline, and quinupristin-dalfopristin. Most VISA isolates (MIC 4 ${\mu}g/ml$) showed a PFGE C pattern with sec, seg, and sei enterotoxin genes, including ST5-SCCmec type II, or a PFGE A pattern with sea, including ST239-SCCmec type III.

• Herbal Formula Science
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• v.27 no.4
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• pp.257-267
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• 2019

Objectives: The purpose of this study was to establish experimental evidence for the antimicrobial effects of 51 herbal formulae commonly used in traditional Korean medical institutions. Methods: The antimicrobial activities of herbal formulae were screened using the disc diffusion method against 10 pathogenic microorganisms (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Vibrio parahaemolyticus, Escherichia coli DH5α, E. coli O157, Salmonella enteritidis, Yersinia enterocolitica, Shigella flexneri, and Helicobacter pylori). Of the 51 herbal formulae, 13 herbal formulae with antimicrobial activity were selected and their dose-dependency were confirmed. Results: Nine herbal formulae, including Gyeji-tang, Dangguisu-san, Saengmaek-san, Samul-tang, Ssanghwa-tang, Socheongryong-tang, Yukmijihwang-tang, Jakyakgamcho-tang, and Paljung-san, presented antibacterial activity against B. cereus. The effects of Saengmaek-san and Paljung-san was sustained for 48 hr. On L. monocytogenes, Dangguisu-san and Hyangsapyeongwi-san showed antimicrobial activity, but only Hyangsapyeongwi-san maintained the activity for 48 hr. Thirteen herbal formulae such as Galgeun-tang, Gyeji-tang, Dangguisu-san, Mahwang-tang, Banhasasim-tang, Saengmaek-san, Socheongryong-tang, Yukmijihwang-tang, Jakyakgamcho-tang, Cheonwangbosim-dan, Palmijihwang-tang, Paljung-san, and Hwanglyeonhaedok-tang showed antimicrobial activity against V. parahaemolyticus, and the activity was maintained for 48 hr. The 51 herbal formulae did not show any antimicrobial activity against seven strains such as E. coli DH5α, E. coli O157, S. aureus, S. enteritidis, Y. enterocolitica, S. flexneri, and H. pylori. Conclusions: Nine, two, and thirteen herbal formulae showed antimicrobial activities against B. cereus, L. monocytogenes, and V. parahaemolyticus in a dose-dependent manner, respectively. The results of antimicrobial activity of 51 herbal formulae against 10 microorganisms might be used as the basis for new application of herbal formulae.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.17-29
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• 2008

In this study, antimicrobial resistance of E coli isolated from domestic beef on sale in Busan and Gyeongnam province was investigated from March to October 2007. A total of 600 beef samples were collected for the monitoring of antimicrobial resistance, and 92 (15.3%) strains of E coli were isolated. Antimicrobial resistance test was carried out by agar disc diffusion method with 17 antimicrobials. In general, E coli isolates showed the highest antimicrobial resistance to doxycycline (73.9%), followed by tetracycline (70.7%) andcefazolin (63.0%). Then they showed higher resistance to several antimicrobials like norfloxacin (48.9%). However, They had low antimicrobial resistance to amikacin (4.3%), colistin (1.1%). Of 92 isolates, 82 (89.1%) were resistant to more than 2 antimicrobials. Among 17 antimicrobials examined, tetracyclines were the most resistant, followed by cephalosporins, quinolone. The resistance was seemed to be correlated to amounts of antimicrobial use. In the result of this study, we suggest that there be need to regulate the abuse of antimicrobial on food-producing animals in Korea because the concern on antimicrobial resistant is gradually increased worldwide.

• KSBB Journal
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• v.15 no.6
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• pp.594-599
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• 2000

The adsorption of the antimicrobial agents and their heat-resistance were investigated for the packaging film manufacture, wherein, the antimicrobial agents were adsorbed on a ceramic component. The naturally sourced antimicrobial agents were produced by methylotropic actinomycetes strains MO-16 and MO-17, extracted with ethylacetate. Antimicrobial action was stable to $121^{\circ}C$ and 1 atm. for 30 min., showing wide-ranging activity to the Gram(+) and the Gram(-) bacteria. Antimicrobial agents, adsorbed on ceramic Ce-1, retained activity to the Gram(+) and the Gram(-) species at $105^{\circ}C$ and $230^{\circ}C$ heat treatment, and methanol extracted antimicrobial agents from Ce-1 treated at $230^{\circ}C$ for 30min., retained activity to Gram(+) bacteria. In the presence of oxygen during the heat treatment process, antimicrobial agents adsorbed on ceramic Ce-1 showed antimicrobial activity to Gram(+) and the Gram(-) bacteria.

• Food Science and Preservation
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• v.10 no.4
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• pp.574-583
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• 2003

There have been a lot of research efforts on development of active food packaging structures and materials in the form of plastic films and containers, along with investigating novel polymers and bioactive compounds for packaging purpose, in order to improve storage stability and safety of foods during distribution and sale. Recently, great interests focus on antimicrobial package films, as an active packaging system, made from synthetic plastic polymer% and natural biopolymers containing various antimicrobial substances for food packaging applications. In this active system, substances are slowly released onto the food surface. However, antimicrobial activity as well as physical properties of the films can be significantly influenced by several factors such as polymer matrix, antimicrobial compounds, and interactions between polymers and compounds. Thus, this study reviews present status of antimicrobial food packaging films in overall performance aspects including types of polymers and active substances, test for antimicrobial activity, and changes in mechanical and antimicrobial properties by preparation method.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.330-336
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• 2000

A large number of streptococci that do not fit readily into any of the established classification schemes have been relegated to a large heterogeneous group called the Streptococcus viridans, which are members of the normal flora of the mucous membranes of the body, including the oral cavity, the nasopharynx, and genitourinary tract. This group includes S. mitis, S. oralis, S. sanguis, S. salivarius, S. milleri, etc. Surveying on the literature, it has been reported that infective endocarditis, meningitis, rhabdomyolysis, cholangitis, appendicitis caused by Streptococcus viridans, which were the most important pathogen in children with malignant hematologic disease. Various antibiotics has been chosen for treatment or prophylaxis for these infections, but were generally lower antimicrobial susceptibilities because of an abuse of antibiotics and advent of resistant group. Therefore, surveillant culture must be performed to evaluate personal antimicrobial susceptibilities of intraoral microbes for proper antimicrobial choice for dental procedures. This study examined sampling from subgingival plaque of 60 chidren's microbes. The cultured bacterial isolates, Streptococcus viridans were examined 10 antimicrobial drugs with the Kirby-Bauer agar disk diffusion method. The used drugs were Penicillin, Ampicillin, Oxacillin, Cephalothin, Imipenem, Gentamicin, Erythromycin, Vancomycin, Ciprofloxacin, Clindamycin. The results were as follows : 1. Sampling Streptococcus viridans were S. mitis(65%), S. oralis(22%), S. sanguis(5%), S. intermedius(3%), S. salivarius(2%), S acidominimus(2%), Unidentified streptococcus(2%). 2. The antimicrobial susceptibility of total Streptococcus viridans : Oxacillin< Erythromycin< Pencillin=Ciprofloxacin< Cephalothin< Ampicillin< Clindamycin< Gentamicin< Imipenem=Vancomycin. 3. The antimicrobial susceptibility of S. mitis : Oxacillin=Erythromycin< Ciprofloxacin< Cephalothin< Penicillin=Ampicillin< Gentamicin< Clidamycin< Imipenem=Vancomycin. 4. The antimicrobial susceptibility of S. oralis : Oxacillin< Erythromycin< Penicillin=Ciprofloxacin=Clindamycin< Cephalothin=Gentamicin< Ampicillin< Imipenem=Vancomycin. 5. There was no significant difference in the antimicrobial susceptibility among each Streptococcus viridans group.