• Korean Journal of Materials Research
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• v.29 no.12
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• pp.735-740
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• 2019

The purpose of this study is to fabricate an ophthalmic lens by copolymerizing two types of carbon nanotubes and hydrophilic hydrogel lens materials, and to investigate its application as an ophthalmic lens material by analyzing its physical properties and antimicrobial effect. For polymerization, HEMA (2-hydroxyethyl methacrylate), EGDMA (ethylene glycol dimethacrylate), a crosslinking agent, and AIBN (azobisisobutyronitrile), an initiator, are used as a basic combination, and a single-walled carbon nanotube and a single-walled, carboxylic-acid-functionalized carbon nanotube are used as additives. To analyze the physical properties, the water content, refractive index, breaking strength, and antimicrobial effect of the fabricated lenses are measured. The fabricated lenses satisfies all the basic properties of the basic hydrogel ophthalmic lens. The water content increases with increasing amount of additive and decreases with addition of 0.2 % ratio of nanoparticles. The refractive index is inversely proportional to the water content result. As a result of the antimicrobial test of the fabricated lens, the addition of carbon nanotubes shows an excellent antimicrobial effect. Therefore, it is considered that the fabricated lens can be applied as a functional material for basic ophthalmic hydrogel lenses.

• Textile Coloration and Finishing
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• v.12 no.1
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• pp.61-67
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• 2000

This study was carried out to develope antimicrobial artificial suede by coating with water soluble polyurethane resin and the copolymer of N,N'-dialkyl-N,N'-dialkyl ammonium chloride (DADAAC) and acrylamide as a antimicrobial additve. The copolymer of DADAAC and acrylamide was synthesized by free radical initiation and intra-intermolecular propagation, and the prepared copolymers had sufficient compatibility with water soluble polyurethane resin. The MIC values of the prepared copolymers and antimicrobial characteristics of the artificial suede coated by polyurethane were evaluated. With the increase in the proportion of DADAAC, which is antimicrobially active part in the DADAAC/acrylamide copolymers, the MIC value becomes lower. The MIC value of DADAAC-AA (1 : 1) copolymer is below 30 ppm against S. aureus, and below 90 ppm against K pneumoniae. The artificial suede coated by water soluble polyurethane resin with 1.0% owl concentration of DADAAC/acrylamide copolymer has good antimicrobial fastness as to show colony reduction of above 90% and 80% against S. aureus and K. pneumoniae respectively in the shake flask test after 10 times of washing, and above 95% and 85% after 10 times of dry-cleaning. The elastic recovery of coated suede fabric is not affected up to 1.0% owf concentration of DADAAC-AA copolymer in the polyurethane coating.

• Fisheries and Aquatic Sciences
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• v.6 no.1
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• pp.27-33
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• 2003

A lactic acid bacterium showing antimicrobial activity against fish pathogen was isolated from gastrointestinal tract of flounder for the purpose of use as an aquaculture probiotics. From the analysis of morphological and physiological characteristics, the isolated strain was named as Lactococcus sp. HM58. Antimicrobial substance (AMS) from Lactococcus sp. HM58 showed strong growth inhibitory activity against Streptococcus sp., which is a fish pathogenic bacterium. AMS was presumed a proteinaceous compound with stability in heat and wide pH range from 2 to 10. It was started to produce in exponential growth phase and was not produced any more in stationary phase. It showed comparatively broad antimicrobial spectrum against most of gram positive bacteria used for this study. About $84\%$ of Lactococcus sp. HM58 was able to survive in the artificial gastric juice though it was low to the extent in the artificial bile juice. In the sensitivity test for various antibiotics, this strain was highly sensitive for doxycycline, erythromycin, amoxicillin clavu1anic acid and ampicillin.

• Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.221-227
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• 2013

In total, 131 Escherichia coli isolates from surface seawater of the Gomso Bay, of Korea, were analyzed for their susceptibility to 22 different antimicrobials and for genes associated with antimicrobial resistance and virulence. According to the disk diffusion susceptibility test, the resistance to tetracycline was most prevalent (33.6%), followed by that to ampicillin (22.1%), ticarcillin (22.1%), and trimethoprim (16.8%). More than 46.6% of the isolates were resistant to at least one antimicrobial, and 22.9% were resistant to three or more classes of antimicrobials; these were consequently defined as multidrug resistant. We further found that 29 ampicillin-resistant isolates possessed genes encoding TEM-type (93.1%) and SHV-type (6.9%) ${\beta}$-lactamases. Among the 44 tetracycline-resistant isolates, tetA and tetC were found in 35 (79.5%) and 19 (43.2%), respectively, whereas tetB was detected in only three isolates (6.8%). With regard to virulence genes, merely 0.8% (n = 1) and 2.3% (n = 3) of the isolates were positive for the enteroaggregative E. coli-associated plasmid (pCVD432) gene and the enteropathogenic E. coli-specific attaching and effacing (eae) gene, respectively. Overall, these results not only provide novel insight into the necessity for seawater sanitation in Gomso Bay, but they help reduce the risk of contamination of antimicrobial-resistant bacteria.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.696-699
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• 2009

In present work, the antimicrobial effect of silver-nanoparticles/celite (SN/C) and silver carbonate/celite (SC/C) composites on Escherichia coli (E. coli) by use of silver nanoparticles and silver carbonate has been studied. Characteristics of the SN/C and SC/C composites were identified by scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS). SN/C and SC/C composites showed antimicrobial activity and the minimum inhibitory concentration of E. coli were 0.541, 0.344 ppm and the complete sterilizing concentration for the test organism were 1.427, 1.623 ppm. From the results we identified that SN/C and SC/C composites have antimicrobial activity to E. coli.

• Journal of Veterinary Clinics
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• v.34 no.3
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• pp.161-164
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• 2017

Bovine respiratory disease (BRD) is one of the most important diseases in calves. It causes a huge economic loss in farms. BRD in calves is concentrated during winter because of the cold weather and lack of ventilation. However, BRD during summer in calves has continuously been a problem in farms. But there is no study about pathogens of summer pneumonia in calves and antimicrobial susceptibility in Korea. Therefore, aims of this study were to identify the pathogens and their antimicrobial susceptibility in calves with summer pneumonia. One hundred and one calves (2 weeks to 5 months after birth) with clinical sign of BRD from 5 farms were selected. After sampling by deep nasal swab, bacterial isolation and identification was conducted. Also, antimicrobial susceptibility test was performed. Pasteurella spp (49.4%), Staphylococcus spp (21.5%), Actinomyces spp (12.9%), E coli (10.7%), and Mannheimia haemolytica (5.3%) were isolated. The patterns of isolated pathogens from each farm were various. Also, the susceptibility of bacteria to antibiotics was showed a variety of patterns in each farm.

• Journal of Life Science
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• v.18 no.3
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• pp.369-373
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• 2008

Staphylococcus intermedius (S. intermedius) has been rarely isolated from horse. In this study, we investigated the antimicrobial susceptibility patterns of S. intermedius isolated from skin lesions of Thoroughbred horse in Daegu Equestrian Association. The skin lesions were showed with dehairing and slight purulent inflammation. Bacteria were isolated from skin lesions and identified as S. intermedius by biochemical tests and MicroLog (BIOLOG, California, USA). Antimicrobial susceptibility test of S. intemedius isolates was performed with 33 antimicrobial agents (BBL, Maryland, USA) by using the agar disk diffusion method. It showed a high sensibility in the amikacin, amoxycillin/clavuramic acid, ampicillin, cefoxitin, cephalothin, chloramphenicol, ciprofloxacin, enrofloxacin, florfenicol, kanamycin, neomycin, nitrofurantoin, norfloxacin, ofloxacin, oxacillin, penicillin G, tetracycline and vancomycin. The horse was treated with penicillin, and cured completely after two weeks. The present results showed valuable information for treatment and prevention of skin disease in horse.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.235-241
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• 1991

- A phthalic acid derivative and basic macrolide antibiotics, with antimicrobial activity against Gram positive bacteria and phytopathogenic fungi, respectively, were found to be produced by a strain 88-GT-161 identified as being a variety of Streptomyces melanosporofaciens. This paper describes an isolation procedure of the active compounds produced by this strain, their in vitro and in vivo (pot test) antimicrobial activites, and structure determination of one of the compounds, bis (2-ethylhexyl) phthalate, a phthalic acid derivative antibiotic. This compounds, upon cornparision with authentic bis (2-ethylhexyl) phthalate, dioctyl phthalate, revealed a difference in antimicrobial activity even though physico-chemical properties of these two compounds seemed indentical. This is the first report that dioctyl phthalate is biosynthetically produced by a Streptomyces sp. and shows antimicrobial activity.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.300-305
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• 2004

Antioxidative and antimicrobial activities of essential oils of cassia (Cinnamomum cassia) and dill (Anethum graveolens L.) were investigated. Essential oils used in this study were added to soybean oil and stored at $65^{\circ}C$ for 9 days to examine their antioxidant activities using peroxide value (POV). The results showed that dill essential oil possessed a higher antioxidant activity than cassia essential oil. Strong antimicrobial activity was observed in cassia essential oil, whereas low activity was observed in dill essential oil against the test microorganisms. Heat stability and cell growth inhibitions were investigated with different concentrations of cassia oil. Results showed that cassia oil had thermal stability in a wide range of $70-160^{\circ}C$. Cassia inhibited cell growth of Bacillus cereus KCTC 1022, Micrococcus luteus A TCC 9341 and Escherichia coli ATCC 25922, but not great on Salmonella typhimurium ATCC 14028 at level of 200 ppm. In conclusion, the results indicate that dill essential oil could be a potential candidate for an antioxidative agent, while cassia essential oil could be suitable for use as an antimicrobial agent in the food industry.

• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.113-120
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• 2007

In this study, researches for the development of antibiotics and antimicrobial concrete were conducted to reduce biochemical corrosion of sewage concrete. First of all, desired performance, such as watertightness, antibiosis, homogeneity, workability and harmlessness, was proposed and performance of antibiotics and antimicrobial concrete were evaluated by them. As results of this study, dispersibility and antibiosis of liquid antibiotics superior to powdery antibiotics. Antibiosis of antimicrobial concrete was verified, and amount of elution of harmful and effective ingredients was little. In workability, setting time of antimicrobial concrete was delayed. Compressive strength and resistance to carbonation of antimicrobial concrete were more increased than ordinary concrete. Also, as little pore volume and closed structure of antimicrobial concrete were observed, watertightness of it was verified. Finally artificial accelerating test for biochemical corrosion was proposed, and its suitability was experimentally proved.