• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.429-432
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• 2012

According to the requirement of novel antimicrobial agents for the rapidly increasing emergence of multi-drug resistant pathogenic microbes, a number of researchers have found new antibiotics to overcome this resistance. Among them, antimicrobial peptides (AMPs) are host defense molecules found in a wide variety of invertebrate, plant, and animal species, and are promising to new antimicrobial candidates in pharmatherapeutic fields. Therefore, this review introduces the antimicrobial action of antimicrobial peptide and ongoing development as a pharmetherapeutic agent.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.343-351
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• 2020

BACKGROUND: Irrigation water is known to be one of the major sources of bacterial contamination in agricultural products. In addition, anti-microbial resistance (AMR) bacteria in food products possess serious threat to humans. This study was aimed at investigating the prevalence of foodborne bacteria in irrigation water and evaluating their anti-microbial susceptibility. METHODS AND RESULTS: Surface water (n = 66 sites) and groundwater (n = 40 sites) samples were collected from the Gyeongi and Gangwon provinces of South Korea during April, July, and October 2019. To evaluate the safety of water, fecal indicators (Escherichia coli) and foodborne pathogens (E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were examined. E. coli isolates from water were further tested for antimicrobial susceptibility using VITEK2 system. Overall, detection rate of foodborne pathogens in July was highest among three months. The prevalence of pathogenic E. coli (24%), Salmonella (3%), and L. monocytogenes (3%) was higher in surface water, while only one ground water site was contained with pathogenic E. coli (2.5%). Of the 343 E. coli isolates, 22.7% isolates were resistant to one or more antimicrobials (ampicillin (18.7%), trimethoprim-sulfamethoxazole (7.0%), and ciprofloxacin (6.7%)). CONCLUSION: To enhance the safety of agricultural products, it is necessary to frequently monitor the microbial quality of water.

• Korean Journal of Medicinal Crop Science
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• v.25 no.2
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• pp.108-114
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• 2017

Background: The study was conducted to investigate the distributions of faecal bacteria in commercial oriental medicine herb products. Methods and Results: A survey was conducted on the microbial contamination levels and antimicrobial specificity of Bacillus cereus and other microbes using 106 oriental medicine herb products on sale in Seoul. Pouring and isolation methods such as standard plate counts were used to identify the bacteria. The isolated bacterias included coliforms, Bacillus spp., Enterococcus spp., Staphylococcus spp., Listeria spp.were identified by using gram staining and an API (analytical profile index) kit. Antimicrobial drugs discs were determined by CLSI (clinical and laboratory standards institute). Conclusions: The bacterial isolates present in the herbal medicines included 98 coliforms, 45 Bacillus spp., 29 Enterococcus spp., and 2 Listeria spp. Among these, there were nine Bacillus cereus strains, one Enterococcus faecium strain, and one Enterococcus faecalis strain present. The 9 Bacillus cereus strains were tested for susceptibility to 36 types of antibiotics products by the disc diffusion method. The strains showed resistance to 13 of these antibiotic products and semi-resistance to 5 antibiotic products. On the basis of these results, any oriental medicine herb product can be assumed to be contain resistant or semi-resistant bacterial strains. Therefore, we suggest prescribing guidelines and special management for the use of antibiotics in farms producing oriental medicine herb products.

• Proceedings of the Costume Culture Conference
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• 2003.02a
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• pp.24-25
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• 2003

Water-soluble chitosan and water-insoluble chitosan with molecular weight of 2,000,000, 500,000, 80,000, and 40,000 and more than 90% degree of deacetylation were controlled to evaluate the antibacterial activity of chitosan against a pathogenic bacteria, methicillin resistant Staphylococcus aureus(MRSA), which is being issued in the world. The Shake Flask Method and Modified Shake Flask Method were used to find out the antibacterial activities of 5types of chitosan/acetic acid solution, and the other antibacterial activities test with the cotton filter treated with chitosan /acetic acid solution. Those test methods showed the great differences ,but the results of the antibacterial activites showed the same difference.

• KSBB Journal
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• v.27 no.1
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• pp.9-15
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• 2012

Antimicrobial peptides are widely used in various organisms as a defense system against infection. The peptides are lethal towards bacteria and fungi, however have minimal toxicity in mammalian and plant cells. In this aspect, it is considered that antimicrobial peptides are new alternative materials for defensing against microbial infection. Here, we describe overall characteristics of antimicrobial peptides based on the mechanism of action, classification of the peptides, report detection/screening methods and chemical/biological production. It is expected that understanding of innate immune system based on antimicrobial peptides tends to develop novel natural antimicrobial agents, which might be applied for defensing pathogenic microorganisms resistant to conventional antibiotics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.605-611
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• 2011

This study examined the suitability of characteristics of potential strains of probiotic bacteria. Among 25 lactic acid bacteria isolated from Korean traditional fermented food, the Hard Clam Meretrix meretrix Shikhae, the SH-10 strain, which exhibited superior resistance to low pH and bile salts, was selected as a potential probiotic bacteria. By examining carbohydrate utilization, morphological properties, and the 16S rRNA gene sequence, the SH-10 strain was identified as Pediococcus pentosaceus (hereafter, P. pentosaceus SH-10). P. pentosaceus SH-10 was resistant to amikacin, cefotetan, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, and vancomycin. Tests of antimicrobial activities against pathogens such as Bacillus cereus, Listeria monocytogenes, Salmonella choleraesuis, and Staphylococcus aureus, indicated that P. pentosaceus SH-10 inhibited the growth of pathogenic bacteria. These results suggest that P. pentosaceus SH-10 can be developed as a probiotic bacteria.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.40-50
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• 2008

Spread of pathogenic micro-organisms through contaminated hands is a well recognized way of transmitting disease such as food poisoning. We investigated the prevalence of aerobic plate counts, coliform bacteria, and food-poisoning bacteria on hands in various age groups. The average number of aerobic plate counts was 3.3 log CFU/hand in kindergarteners, 3.4 log CFU/hand in elementary students, 3.2 log CFU/hand in middle school students, 3.4 log CFU/hand in high school students, and 3.3 log CFU/hand in adults. Two kindergarteners, 6 elementary students, and 2 adults were positive for the coliform bacteria. Among the food poisoning bacteria we tested, S. aureus was isolated from 47 individuals. Eight isolates of B cereus were all from kindergarteners. C. perfringens was isolated from 7 individuals. Among 47 isolates of S. aureus, 25 isolates produced toxins. Seven of eight isolates of B. cereus produced toxins. None of seven C. peifringens isolates produced toxins. All 47 isolates of S. aureus were sensitive to ciprofloxacin, trimethoprim/sulfamethoxazole, clindamyccin, imipenem, rifampin and vancomycin. Four isolates (8.5%) were resistant to cefepime, chloramphenicol, cefotetan, and gentamycin. Five isolates (10.6%) were resistant to oxacillin and 6 isolates were resistant to tetracycline. This study shows that it is needs to be established policy of school lunch and personal sanitation management.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.4
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• pp.457-464
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• 2005

The optimal concentration of ethanol to separate a high quantity of propolis was $60\%$ but that for the best flavonoids extraction was $80\%$ We compared the yields of propolis from different countries. In this study we used $60\%$ ethanol concentration as a standard. The yield of propolis was proportional to the contents of flavonoids. Namely, Polish propolis which showed the highest yield with $56\%$ by the extraction with $60\%$ ethanol revealed also the highest flavonoids content with $3.49\%$ among all the samples tested The major constituents of propolis differed from country to country. It has been suggested that the different geographical origin influenced the efficacy and the constituents of propolis. Antibacterial activity of ethanol extracted propolis from different countries was tested against 6 microbial strains of type cultures including Gram-positive (Staphylococcus aureus, Streptococcus uberis, Streptococcus agalactiae) and Gram- negative bacteria (Klebsiella pneumoniae, Proteus vulgaris and E coli) in vitro. Propolis extract showed anti-microbial activity against all the tested bacterial strains. In addition, propolis was sensitive to E coli which was resistant to broad spectrum antibiotics like ampicillin. These results showed that propolis may substituted for commercial antibiotics. The efficiency of anti-microbial activity of the propolis was slightly higher in $80\%$ than $97\%$ ethanol extract.

• Korean Journal of Veterinary Research
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• v.20 no.2
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• pp.85-92
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• 1980

The antimicrobial drug susceptibility of 439 isolates of animal pathogens recovered from various clinical cases during 1978-79 has been investigated by the use of disk diffusion technique. The majority of 308 strains of Eschericihia coli were highly resistant to bacitracin, erythromycin, penicillin, streptomycin and tetracyclinon while only 0.3 per cent of them were resistant to gentamicin and 3.2 per cent to colistin. The percentages of strains resistant to ampicillin, carbenicillin, cephalothin, chloramphenicol and neomycin were 30.5%, 24.7%, 11:4%, 28.2% and 26.2% and repectively. However, none of E. coli cultures of ovine origin were resistant to ampicillin, carbenicillin, chloramphenicol, colistin, gentamicin, kanamycin, and neomycin. A total of 39 patterns of multipe drug1 resistance of 308 strains E. coli against 9 drugs in general use such as ampicillin, cephalothin, chloramphenicol, colistin, gentamicin, kanamycin, neomycin, streptomycin and tetracycline were observed and the most common multiple resistance patterns were SM, TC pattern (20.5%) and AM, CP, KM, NM, SM, TC pattern (9.7%). None of the 43 cultures of salmonella organism from pigs and chickens were resistant to ampicillin, carbenicillin, cephalothin, colistin, gentamicin and kanamycin; and the majority of the cultures were susceptible to chloramphenicol (90.0%), neomycin (97.7%) and tetracycline (93.0%). All the cultures were found to be resistant to bacitracin and penicillin and the rate of resistant strains to erythromycin and s treptomycin being 79.1% and 41.9% respectively. It was found that the majority of 63 cultures of staphylococcal isolates were resistant to lincomycin, penicillin, streptomycin and tetracycline. The percentages of 63 staphylococcal isolates susceptible to gentamicin, nitrofurantoin, cephalothin, ampicillin, methicillin, bacitracin and chloramphenicol were 98.4%, 98.4%, 95.2%, 93.7%, 93.7%, 92.1% and 92.1% respectively. The 25 cultures of streptococcal isolates were resistant in order of prevalence to streptomycin(88.0%), kanamycin(68.0%), gentamicin (44.0%), tetracycline (44.0%) and methicillin (40.0%) wihle the majority of them were sensitive to ampicillin, bacitracin, chloramphenicol and penicillin.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.115-121
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• 2002

To develop a new method of conjugation and to determine the distribution of R plasimds, we isolated multi-drug resistant strains from fish pathogenic bacteria in the farms of south and east seacoasts of Korea. Out of the 134 isolates examined, 10 showed resistance to chloramphenicol, tetracycline, streptomycin, ampicillin, colistin, nalidixic acid, oxolinic acid and kanamycin. One out of 10 multi-drug resistance bacteria, Vibfio damsela JE1 (V. damsela JE1), contained transferable R plasmid of chlorarnphenicol- tetracycline resistance genes and other nucleic acids encoding ampicillin and kanamycin resistance. The presence of the R plasmid was confirmed by conjugation using the chromocult medium (CC) as a selective and differential medium for transconiugants with identification based on the growth or colors of the colonies. The frequency of R plasmid transfer with filter mating method was come out much higher than that of broth mating method and appeared to be dependent upon the mating time and temperature. The optimum conditions for filter mating method were found to be 30$^{\circ}C$ and 24hrs as mating temperature and period, respectively, Moreover, donor cells with R plasmid, both isolate and standard bacteria, were shown to have an ability to transfer the plasmid against Escherichia coli K-12 HB101 (E. coli HB101) and Edwardsiella tarda (E. tarda) RE14 at fairly high frequencies, finally, we isolated 3 isolates of Sphingomonas sp., carrying R plasmid from 12 multi-drug resistant bacteria in normal microflora of the flounder (Paralichthys olivaceus) group used for the isolation of V emsela JE1 four months before. The same size and gene transfer chayateristics of R plasimds with those of V damsela JE1 confirmed that normal microflora have the reservoir activity for R plasmid in natural aquatic environment.