The incidence of multidrug-resistant strains of Staphylococcus aureus continues to increase in hospitals and the community all over the world. As the importance of miner surgery in dentistry gets greater recently, the frequency in use of antibiotics has been increasing. Although several cases of acquired infection in oral cavity in dental hospital has been reported, the research on isolation of S. aureus and evaluation of its antibiotic resistance from outpatients in the dental clinic has not been found yet. The aim of this study was to evaluate the antimicrobial resistance of S. aureus isolates. The isolation rate of S. aureus were 41.7% in dental hospital personnel, 60.4% in outpatients and 62% in dental hygiene students. S. aureus which showed resistance to penicillin were 88.6%, ampicillin 88.6%, erythromycin 8.6%, tetracycline 4.3%, oxacillin 4.3%, cefoteten 4.3%. Six strains of S. aureus showed the susceptible to all antibiotics tested. Sixty-four(91.4%) strains were multiple antibiotic resistance. Fifty-two strains(72.8%) resisted to AM-P. and Seven strains(10.0%) resisted to AM-P-E, AM-P-GM, AM-P-TE.

Oleanolic acid is a natural triterpenoid that exists widely in foods and some medicinal herbs. The purpose of this study was to determine the antimicrobial activity of oleanolic acid against Streptococcus mutans strains isolated from a Korean population. Antimicrobial activity against these bacteria was evaluated by minimal inhibitory concentration (MIC) and time kill curves. The tolerance of human gingival fibroblasts and human periodontal ligaments to oleanolic acid was tested using a methyl thiazolyl tetrazolium (MTT) assay. The MIC90 value of oleanolic acid for both S. mutans and S. sobrinus isolated from Koreans was 8μg/mℓ. Oleanolic acid showed bactericidal effects against S. mutans ATCC 25175T and S. sobrinus ATCC 33478T at 1 × MIC(8μg/mℓ) and had no cytotoxic effects against KB cells at this dose. The results suggest that oleanolic acid could be useful in the future development of oral hygiene products for the prevention of dental caries.

In the previous molecular cloning study from human salivary gland cDNA l ibrary a novel clone (C77-091) was known as a candidate gene for antimicrobial protein by GenBank database search and RNA in situ hybridization. This study is aimed to identify the molecular characteristics of C77-091 protein, which showed an antimicrobial activity on E.coli, thereby named as salivary antimicrobial protein (SAMP). SAMP consisted of a typical hydrophobic amino acid rich domain in the N-terminus, a cluster of basic amino acids, carbohydrate attachment site, a possible transglutaminase catalyzed cross-linking site, and multiple consensus sequences of phosphorylation site in the C-terminus. Western blot analysis of human organs and tissue with the monospecific antibody to the synthetic SAMP peptide showed strong interacting protein from the extracts from submandibular gland and parotid saliva but absent in the mixed saliva, and the immunohistochemical staining detected a strong positive regions in the secretory granules in the luminal cytoplasm of interlobular ductal cells of salivary gland. The SAMP was also distributed in the human sebaceous gland and prostate. These data suggest that C77-091 named SAMP gene is a novel antimicrobial protein in human salivary gland, which may play a role for the innate immunity by protecting and stabilizing the mucosal epithelium to maintain homeostasis of oral mucosa.

서울시내에서 유통되는 식품과 식품접객업소(집단급식소 포함)의 조리식품을 대상으로 식중독 원인균 분석 및 위생미생물 검사를 실시한 결과, 분리된 대장균의 항생제 감수성 시험을 통하여 이들의 내성 정도를 파악하고, 내성 유전자와 병원성유전자의 분포도 알아보았다. 모두 1313건 의 샘플 중 50건에서 대장균이 검출되어 3.8%의 검출률을 보였다. 이중 육회 1건에서 장출혈성대장균 O26 1건, 김밥 에서 장병원성대장균 1건이 각각 검출되었다. 50건의 대장 균중 50%가 16종의 항생제에 모두 감수성을 보였으며 내성이 높게 나타난 항생제는 ampicillin(36%), amoxicillin/ clavulanic acid(32%) 그리고 tetracycline(22%)의 순이었다. 이들의 내성유전자 분포는 TEM이 1건, tetB 4건이 각각 검출되었다.

Vibrio parahaemolyticus (V. parahaemolyticus) has been recognized as a significant food-borne pathogen around the world. In this study, we investigated the prevalence and antimicrobial resistance of V. parahaemolyticus isolated from raw fishes. A total of 64 samples of raw fishes purchased from a traditional seafood market in Seoul, Korea. were examined for the presence of V. parahaemolyticus using intestines, gills, and fins. Twenty five grams of all samples were enriched in 225ml of alkaline peptone water at 37℃ for 24h and then streaked onto thiosulfate citrate bile sucrose agar. Suspected colonies were inoculated into triple sugar iron agar for biochemical screening test and were finally confirmed with API 20NE strip. Antimicrobial resistance tests were performed with disc diffusion method in accordance with National Committee for Clinical Laboratory Standard. Thirty three V. parahaemolyticus strains were isolated from raw fishes among 33 out of 64 (51.6%). Among 33 isolates, 16 isolates (48.5%) were resistant to ampicillin, 7 isolates (21.2%) were resistant to amikacin, and all isolates were not resist to other antibiotics such as amoxicillin & clavulanic acid, sulfamethoxazole & trimethopenem, ciprofloxacin, cefotaxime and cefepime. Although the prevalence of V. parahaemolyticus was high in raw fishes compared to other studies, antimicrobial resistance rate of the isolates was relatively low. These results could be useful information for risk assessment of V. parahaemolyticus in raw fishes.

Bioaerosols, airborne particles of biological origin, are omnipresent in the common surroundings of humans. In antimicrobial filter system, as particles or organic materials are deposited on the filter surface, the bacteria come into contact with the antimicrobial material less, and thus they can easily grow on particles or organic materials. We selected a carbon fiber ionizer which generated air ions as antimicrobial agent. Antimicrobial effect of carbon fiber ionizer on the outlet air and condensate water was tested using application of carbon fiber ionizer in a small-scale commercial air conditioner. In conclusion, the application of carbon fiber ionizer in the air conditioner showed more increasing antimicrobial efficiency.

The present study was evaluated the antibacterial effect of the combination of Coptidis rhizoma,Lonicerae Flos, and Paeonia japonica (1:1:1) extracts (CLP1000). Also, the effectiveness of CLP1000, dioctahedral smectite (DHS), and the combination of CLP1000 and DHS (CLPS1000) against E. coli O157:H7 infection was studied using ICR female mice. During the incubation period, the dose of 10% and 20% CLP1000 were inhibited the growth of E. coli O157:H7 by 30% and 47%, respectively. For 7 days after single challenge with E. coli O157:H7, forty female ICR mice were divided into four experimental groups which were orally administered with saline, 10% CLP1000, 10% DHS, and 10% CLPS1000, respectively. On the 3rd day, the number of E. coli O157:H7 in mouse feces was significantly decreased by administration of CLP1000 (p < 0.05), DHS (p < 0.05) and CLPS1000 (p < 0.001). On the 7th day, CLP1000 (p < 0.05) and CLPS1000 (p < 0.001) administration significantly decreased the number of E. coli O157:H7. According to the results of the present study, administration of CLPS1000 to mice can reduce the severity of E. coli O157:H7 infection. Also, it is suggested that CLPS100 represents a good candidate for the treatment of enteric infections in domestic animals.

From April 2008 to January 2009, a total 458 raw milk samples were randomly collected from 15 stock raising farms located in northern area of Kyunggi province and cultured for the presence of Enterococci spp. A total 170 enterococcal isolates were recovered from the raw milk samples. Enterococcus faecalis was predominant species recovered (64.7%), followed by E. faecium (18.8%), E. avium (5.9%), E. gallinarum (5.9%) and E. durans (4.7%). Antimicrobial resistance patterns of 170 Enterococci spp. against ampicillin, erythromycin, tetracyclin, chloramphenicol, vancomycin, ciprofloxacin and streptomycin were tested. According to the result, they showed high level resistance to erythromycin and streptomycin (82,9% and 93,5% respectively), moderately resistance to ampicillin, chloramphenicol and tetracyclin (50%, 45.9% and 32%, respectively) but fortunately, vancomycin and ciprofloxacin are still effective against this species.

Bee venom contains a variety of toxic enzymes and peptides. One of the major components of bumblebee venom is bombolitin, which is the most abundant venom constituent and biologically similar to melittin. Here, we first show the molecular cloning and antimicrobial activity of the venom bombolitin from the bumblebee Bombus ignitus. The B. ignitus venom bombolitin gene consists of 2 exons, encoding 56 amino acid residues. The bombolitin purified from B. ignitus venom was the 2104 Da mature peptide with 18 amino acid residues, which are created by cleavage of the probombolitin domain between Ala38 and Leu39. We examined the pattern of bombolitin expression to confirm that it is a component of bumblebee venom. B. igniutus venom bombolitin exhibits venom gland-specific expression. We also investigated the venom bombolitin for antimicrobial properties against bacteria and fungi. The venom bombolitin showed high antibacterial activity against both Gram-negative and Gram-positive bacteria. Most interestingly, the venom bombolitin showed high antifungal activity against Fulvia falva, a leaf mold, and Alternaria radicia, a black rot. These antimicrobial profiles of B. ignitus venom bombolitin reported herein will be useful in the application for potential antimicrobial agents.

The purpose of this study was to investigate the antimicrobial activities of natural antimicrobials (10 formulas, F1~F10) against yeasts in functional beverages. The growth rates of yeasts were different with the ten different natural antimicrobial formulas tested. Yeasts grew for 14 days and the antimicrobial effect was observed between 14 and 18 days. Levels of S. cerevisiae, Z. bailii, and P. membranaefaciens were reduced to the limit of detection (ND) < 10 CFU/mL) after 28 days. Resistance against the antimicrobial effect was greatest for P. membranaefaciens, which grew to a level of 0.12~1.48 log10 CFU/mL after 14 days and was reduced to a level of 1.61~3.55 log10 CFU/mL after 28 days. The resistance of C. albicans was also high with a growth level of 0.13~1.28 log10 CFU/mL after 14 days and reduction to 1.51~5.30 log10 CFU/mL after 28 days. The antimicrobial effect of F10 was strongest for P. membranaefaciens. Every treatment reduced the microbial levels to 2.68~5.62 log10 CFU/mL after 6 months. F2, F4, F5, F6, and F10 reduced the C. albicans level to ND after 28 days while F1, F3, F8, and F9 reduced yeasts to the ND level after 6 months. The antimicrobial activities observed here will be useful for development of natural antimicrobials.

Cecropin is an antimicrobial peptide that is synthesized in fat body cells and hemocytes of insect in response to a hypodermic injury or bacterial infection. A 503 bp cDNA encoding a cecropin-like antimicrobial peptide was isolated by employing annealing control primer (ACP)-based differential display PCR and 5'-RACE from immunized Papilio xuthus larvae. The open reading frame (ORF) of isolated cDNA encoded a 63 amino acid prepropeptide with a putative 22-residue signal peptide, a 3-residue propeptide and a 38-residue mature peptide with a theoretical mass of 4060.89 Da. The deduced amino acid sequence of peptide showed significant identities with other Lepidopteran cecropins. This peptide was named as papiliocin. RT-PCR revealed that the papiliocin transcript was detected at significant level after injection with bacterial lipopolysaccharide (LPS). Based on the deduced amino acid sequence of papiliocin, a 38-mer mature peptide was chemically synthesized by Fmoc method, and analyzed antimicrobial activity. The synthetic papiliocin peptide had a broad spectrum of activity against fungi, Gram-positive and negative bacteria, and also showed no hemolytic activity against human red blood cell.

An endoparasitoid wasp, Cotesia plutellae, parasitizes larvae of the diamondback moth, Plutella xylostella, with its symbiotic polydnavirus, C. plutellae bracovirus (CpBV). This study analyzed the role of Inhibitor-kB (IkB)-like genes encoded in CpBV in suppressing host antiviral and antimicrobial responses. Identified eight CpBV-IkBs are scattered on different viral genome segments and showed high homologies with other bracoviral IkBs in their amino acid sequences. Compared to an insect ortholog (e.g., Cactus of Drosophila melanogaster), they possessed a shorter ankyrin repeat domain without any regulatory domains. The eight CpBV-IkBs are, however, different in their promoter components and expression patterns in the parasitized host. To test their inhibitory activity on host antiviral response, a midgut response of P. xylostella against baculovirus infection was used as a model reaction. When the larvae were orally fed the virus, they exhibited melanotic responses of midgut epithelium, which increased with baculovirus dose and incubation time. Parasitized larvae exhibited a significant reduction in the midgut melanotic response, compared to nonparasitized larvae. Micro-injection of each of the four CpBV genome segments containing CpBV-IkBs into the hemocoel of nonparasitized larvae showed the gene expressions of the encoded IkBs and suppressed the midgut melanotic response in response to the baculovirus treatment. When nonparasitized larvae were orally administered with a recombinant baculovirus containing CpBV-IkB, they showed a significant reduction in midgut melanotic response and an enhanced susceptibility to the baculovirus infectivity. The transiently expressed CpBV-IkB3 inhibited expression of hemolin, but did not those of lysozyme and cecropin in P. xylostella, while both lysozyme and cecropin were inhibited in the treated Spodoptera exigua. When the recombinant AcNPV was mixed with Bacillus thuringiensis subsp. kurstaki (Bt), the bacterial pathogenicity was significantly enhanced in a dose-dependent manner, compared to a Bt mixture with an AcMNPV recombined with an enhanced green fluorescence protein gene.

Copper alloy metal fiber was incorporated into the conventional water-soluble metal working fluids to increase the antimicrobial activity. Fluid treated by copper alloy metal fiber is shown that bacteria is disappeared whereas that untreated metal fiber is increased bacteria as increasing the life time. When the electrochemical potential of Cu/Zn ion is -268mV, radicals with molecular oxygen are easily made. Especially, hydroperoxide radical shows strong toxicity to the strains, leading to the conformational change of plasma membrane. As a result antimicrobial activity of copper alloy metal fiber in metal working fluid is superior to that of copper fiber.

마늘을 각종 기능성 식품 재료로 이용하기 위한 기초자료를 제공하기 위하여 산지별 마늘의 화학성분 및 항균활성을 조사하였다. 색도 중 L값은 53.41∼57.15, a값은 -3.49∼-4.38 및 b값은 11.47∼17.55였으며, 일반성분 중 수분, 조단백질, 조지방, 가용성 무질소물, 조섬유 및 회분 함량은 각각 65.24∼71.96, 6.24∼9.35, 0.21∼0.49, 19.01∼22.72, 0.58∼0.95 및 1.01∼2.01%로 나타났다. 산지별 마늘의 주요 무기성분으로는 Na, Mg, K, Ca 및 P였으며, 그 함량은 각각 27.22∼112.03, 18.17∼32.56, 242.16∼569.28, 28.60∼63.93 및 117.72∼265.21 mg%였고, 유리당은 sucrose, glucose 및 fructose였다. 마늘은 17종의 아미노산이 분석되었으며, 그 중 proline, arginine, glutamic acid 및 aspartic acid가 주요 아미노산으로 나타났고, 총 아미노산 함량은 2,709.33∼4,561.04 mg%이었다. 비타민 C 함량은 2.966∼8.673 mg%이었다. 산지별 마늘의 주요 지방산으로는 linoleic acid, oleic acid 및 palmitic acid였으며, 불포화지방산이 72.18∼74.35%였고, 포화지방산은 25.65∼27.82%였다. 산지별 마늘 물 추출물을 이용하여 항균활성을 측정한 결과, 농도 의존적으로 그램 음성 및 양성 모든 세균에서 높은 항균활성을 보였다.

Continentalic acid (CA, (-)-pimara-8(14), 15-diene-19-oic acid) was isolated from the roots of Aralia cordata (Araliaceae) using bioassay-guided fractionation of a crude chloroform extract. The antibacterial activity of CA against Enterococcus faecalis and Enterococcus gallinarium was estimated by determining minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). CA exhibited potent activity against standard vancomycin-resistant enterococci (VRE) and vancomycin-susceptible enterococci (VSE), with MICs and MBCs values between 4 and 8μg/mL and 4 and 16μg/mL, respectively. This compound exhibited potent activity against strains of VRE, which are highly resistant to clinically useful antibiotics. These findings suggest that continentalic acid may be useful in controlling enterococcal infection.

It has been reported that the antimicrobial susceptibility patterns of viridans streptococci vary according to geographical region. Although several studies on the antibiotic resistance of viridans streptococci in foreign countries have been reported, little is known about the distribution of resistance among viridans streptococci in Korea. In this study, 88 isolates of viridans streptococci from Korean students' dental plaque were identified as 12 different species. The susceptibility of these isolates to 8 antibiotics was investigated. The in vitro antibiotic activity of penicillin G, ampicillin, vancomycin, streptomycin, gentamicin, erythromycin, amoxicillin, and tetracycline was measured by the broth microdilution method. The range of the minimum inhibitory concentrations (MIC), MIC50, MIC90, and the percentage of the susceptible isolates were determined. Streptococcus mutans and Streptococcus salivarius were susceptible to the 8 antibiotics. Isolates with resistance to vancomycin, streptomycin, and amoxicillin were not found. The overall resistance rates of the 88 isolates to penicillin G, ampicillin, gentamicin, erythromycin, and tetracycline were 12.5%, 62.5%, 62.5%, 26.1%, and 26.1%, respectively.