• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.12
• /
• pp.1848-1856
• /
• 2008

In order to enhance the functionality of a cotton fabric actually used as the clothing material for patients, the fabrics are treated with chitosan/nanosilver mixed solution. The nanosilver has excellent biocompatibility, not causing an environmental pollution as a natural polymer, provides expectation of an additional performance, does not harm human beings, and shows a strong antibacterial activity even in a small amount, and supplements chitosan, which is disadvantaged if used alone for fabric treatment. This study evaluates functional improvement of the clothing material for patients and observes through hygienic characteristics which are the most important function. In antibacterial activity of the fabrics treated with chitosan/nanosilver mixed solution against Staphylococcus aureus, higher ratio of chitosan was observed to achieve better antibacterial activity. In antibacterial activity against Klebsiella pneumoniae, higher ratio of nanosilver was observed to achieve better activity. Regarding laundry durability of antibacterial activity after repeated laundering, activity against Staphylococcus aureus was little reduced, but was greatly lowered against Klebsiella pneumoniae. Deodorization activity was excellent as the mixed ratio of chitosan was increased, and air permeability, moisture permeability and moisture regain were reduced as the mixed ratio of nanosilver was increased.

• Journal of Food Hygiene and Safety
• /
• v.16 no.2
• /
• pp.125-132
• /
• 2001

The present study was conducted to investigate biological degradability of phosphamidon and profenfos. In the biodegradation test of two pesticides by the modified river die-away method from May 20 to July 29, 1999, the biodegradation rate was determined in Nakdong (A) and Kumho(B) River. The residual percentages of phosphamidon were 74.9%, 68.8% and 62.7% in control, A and B samples 7 days after applicaton, respectively. Biodegradation constants and half-lives of phosphamidon were 25.1%, 21.9% and 11.9% in control, A and B samples 7 days after application. Biodegradation constants and half-lives of profenofos were 0.0005 and 58.4 days in A, 0.0013 and 21.6 days in B, respectively. The biodegradation rates of phosphamidon and profenofos were higher in the Kumho River (B) than in the Nackdong River(A). The strains of microorganisms for the degradation of phosphamidon and profenofos were identified as Klebsiella pneumoniae, Aeromonas hydrophila and Acinetobacter calcoaceticus, all Gram-negative bacteria. In order to identify biodegradate products, the extracts of cultivates were analyzed by GC/MS. The mass spectra of biodegradate roducts of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the biodegradate metabolites of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.

• Korean Journal of Microbiology
• /
• v.31 no.3
• /
• pp.245-254
• /
• 1993

Distribution and variation of bacterial densities of heterotrophic plate count (HPC) and Enterobacteriaceae in the water supply systems comprising raw, treated, and three tap water samples of a water treatment plant in Seoul were studied 23 times from 1991 to 1992. HPC bacteria of raw. treated, and tap waters on $R_{2}A$ agar media were at a density of $1.22{\times}10^{3} to 3.05{\times}10^{5}$, $1.50{\times}10^{1} to 4.29{\times}10^{3}$ and 2 to $5.41{\times}10^{3}$ cfu/ml, respectively. Densities of Enterobacteriaceae in raw, treated, and tap waters on mENDO-LES agar media ranged from 0.] to 8200 cfu/ml, 0 to 17.5 cfu/JOO mI. and 0 to 47.5 cfu/IOO ml, respectively. Injured Enterobacteriaceae of treated and tap waters on m-T7 agar media were at a density of o to 27 and 0 to 35 cfu/100 mI. These results showed that the density of bacteria in the treated water outflowing from the water plant significantly increased as the water flowed along the distribution sytems, which is so-called bacterial regrowth. The predominant bacteria] types in the water supply system were Pw'udomonas and Acinerobacter. In raw water, the ratio of Pseudomonas was higher than that of Acinetobaeter, but in treated and tap waters. both ratios were reversed. The most predominant species of Enterobacteriaceae was Enterobacter agglomerans. Some species such as Citrobacter freundii. Escherichia coli. Klebsiella pneumoniae. and Shigella dysenteriae which are opportunistic pathogens or pathogens were not found in the treated water but additionally detected in tap waters.

• The Korean Journal of Food And Nutrition
• /
• v.22 no.3
• /
• pp.396-401
• /
• 2009

Microorganisms or their toxins can be transferred to eggs and cause food poisoning in humans. Therefore, this study was conducted to detect microbial contamination of eggs and to identify microorganisms in any contaminated eggs. Four different brands of eggs were collected from hypermarkets in the northern Gyeonggi area. The total bacterial counts on the shells of the eggs varied greatly between brands. In addition, various bacterial species including Klebsiella pneumoniae, Pseudomonas mendocina, Alcaligenes xylosoxidans, Alcaligenes faecalis, and Enterobacter cloacae were identified on eggshells. Furthermore, mean of total bacterial counts of four brands was $3.4{\times}10^4 cfu/m{\ell}$ and E. coli was detected on the eggshell of one brand egg. However, Salmonella was not identified on all brands of collected eggs. We also demonstrated that the E. coli isolated from the eggshell was not pathogenic based on the absence of pathogen-specific gene expression patterns. Taken together, the result of this study indicate that strict quality control and improved distribution controls are required to decrease microbial contamination and improve human health.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.6
• /
• pp.741-755
• /
• 1999

As a material of metal-ceramic prosthesis, nickel as a form of Ni-Cr alloy has been used for many dental prostheses in many cases. However, several problems in use of the alloy have been revealed (ex : tissue stimulation, skin allergy, hypersensitivity, cytotoxicity and carcinogenecity). Little is known about nickel with respect to the relationship between Ni-prosthesis and gaining of Ni-resistance in oral microorganisms. The present study was undertaken to check wheather use of Ni-prosthesis leads to occurrence of Ni-resistant microorganisms. So this study may suggest the possible relationships between the oral microorganisms and nickel-resistance in oral environment. Bacteria were isolated from the gingival crevicular fluid on the pateints wearing Ni-Cr prosthesis. The isolated bacteria were tested for their Ni-resistance in nickel containing media at different concentration from 3mM to 110mM. E. coli HB101 was used as control. The Ni-resistant bacteria were isolated and biochemically identified. The Ni-resistant bacteria were tested several bio-chemical, molecular-biological tests. Performed tests were ; measuring the growth curve, antibiotic test, growth ability test in liquid media, isolation of the chromosome and plasmid, digestion of DNA by restriction enzyme, electrophoresis of chromosome and plasmid DNA, identification of Ni-resistant genes by the DNA hybridization. The results were as follows: 1) The bacteria isolated from gingival crevicular fluid on the patients wearing Ni-Cr alloy pros-thesis showed nickel-resistance. 2) The isolated microorganisms grew at nickel containing media of high concentrations (60mM-110mM). 3) Based on the biochemical tests, the isolated microorganisms were identified as Enterococcus faecalis(13 cases), Klebsiella pneumoniae(1 case) and Enterobacter gergeviae(1 case). 4) Enterococcus faecalis expressed not only nickel resistance but also the multi-drug resistance to several antibiotics ; chloramphenicol, kanamicin, streptomycin, lincomycin, clindamycin. However, all strain showed the sensitivity against the tetracycline. 5) DNA hybridization result suggest that there is no homology between the previousely known gene of nickel resistance in Klebsiella pneumoniae and chromosomal DNA of Enterococcus faecalis.

• The Korean Journal of Mycology
• /
• v.23 no.2 s.73
• /
• pp.153-160
• /
• 1995

As part of our search for less toxic antimicrobial agents from natural resources, the antimicrobial activity of Elfvingia applanata $(P_{ers.})\;K_{arst.}$ extract was examined alone and in combination with naringenin. EA, the aqueous extract from the carpophores of E. applanata, was lyophilized and a dark brownish powder was obtained. Antimicrobial activity of EA was tested in vitro against nineteen strains of bacteria and eleven strains of fungi by serial broth dilution method, and expressed by minimal inhibitory concentration (MIC). Among nineteen strains of bacteria tested, the antimicrobial activity of EA was the most potent against Proteus vulgaris showing MIC of 1.125 mg/ml. EA also inhibited the growth of the selected fungi at higher concentrations ranging from 7.5 mg/ml to 15.0 mg/ml. To investigate the effect of antimicrobial combinations of EA with naringenin, the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of EA with naringenin resulted in partial synergism against Staphylococcus aureus only, and showed additive effect in two strains including Klebsiella pneumoniae and Salmonella typhi. Antagonism was not found.

• Korean Journal of Microbiology
• /
• v.45 no.1
• /
• pp.86-90
• /
• 2009

The definition of edible ice is frozen water for the use of food manufacturing, processing, or cooking, as well as for the direct eating. It has been reported that in the process of ice manufacturing and its selling, edible ice is contaminated with some microorganisms, which causes food poisoning and gastroenteritis. It was shown that besides in the edible ice, germ growth caused by various reasons occurred in the mineral water, tap water, water filtering system, and water purifier. With public awareness, in order to examine the sanitary conditions of edible ice in the Northern area of Daegu metropolitan city, 15 places were randomly selected. As a result, 14 places were found to be contaminated with microorganisms. After incubating on the Brain Heart Infusion (BHI) agar plate, 80% of Gram-negative bacilli, 17% of Gram-positive cocci, and 3% of Gram-negative cocci were cultured. Enterobacter cloacae, Chryseomonas luteola, Pantoea spp., Klebsiella pneumoniae, Acinetobacter baumannii, Acinetobacter calcoaceticus or Providencia rettgeri were detected. Gram-positive cocci cultured in BHI agar plate from 5 specimens were identified as Staphylococcus aureus or Staphylococcus xylosus, which is well known bacteria causing strong food poisoning. This present paper raises questions on the importance and awareness of sanitary conditions of edible ice and the identification of pathogenic microorganisms living in the edible ice in relation to their distribution. The examination of sanitary conditions of edible ice in other areas in Daegu seems to be also needed to find out if there are similar cases.

• Korean Journal of Microbiology
• /
• v.37 no.1
• /
• pp.1-8
• /
• 2001

Spiders are carnivores that prey upon insects and other small arthropods through digestion of food outside the body. Although spider poison may contain proteolytic enzymes, these are thought to play an insignificant role in actual digestion. The source of active proteolytic enzymes can be either the digestive tract cells of spider, or natural microbial flora in the digestive tract of spider. In this study, digestive tracts from the spider, Nephila clavata, were screened for bacteria that have protease or lipase activity. A total of $10^3-10^5$ CFU was recovered from a spider and more than 90% of them showed protease and lipase activity respectively. Of the microbial isolates, 63.3% showed protease or lipase activity, and 50% of these showed both protease and lipase activity. Some of the isolates were characterized using a battery of chemical, phenotypic and genotypic methods. Eleven Gram negative bacteriaa (Acinetobacter calcoaceticus, A. haemolyticus, Alcaligenes faecalis, Cedecea davisae, C. neteri, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas fluorescens, Serratia marcescens, Stenotrophomonas maltophilia, Suttonella indologenes) and 11 Gram positive bacteria (Bacillus cereus, B. coagulans, B. pasteurii, B. thuringiensis, Cellulomonas flavigena, Corynebacterium martruchotii, Enterococcus durans, E. faecalis, Micrococcus luteus, Staphylococcus hominis, S. sciuri) were identified.

• The Journal of Korean Academy of Prosthodontics
• /
• v.41 no.2
• /
• pp.207-222
• /
• 2003

As a material of metal-ceramic prosthesis, nickel as a form of Ni-Cr alloy has been used for many dental prostheses in many cases. However, several problems in use of the alloy have been revealed (ex ; tissue stimulation, skin allergy, hypersensitivity cytotoxicity and carcinogenecity). Little is known about nickel with respect to the relationship between Ni-prosthesis and gaining of Niresistance in oral microorganisms. The present study was undertaken to check whether use of Ni-prosthesis leads to occurrence of Ni-resistant microorganisms. So this study may suggest the possible relationships between the oral microorganisms and nickel-resistance in oral environment. Bacteria were isolated from the gingival crevicular fluid on the patients wearing Ni-Cr prosthesis. The isolated bacteria were tested fir their Ni-resistance in nickel containing media at different concentration from 3mM to 110mM. E. coli HB101 was used as control. The Ni-resistant bacteria were isolated and biochemically identified. The Ni-resistant bacteria were tested several biochemical, molecular-biological tests. Performed tests were : measuring the growth curve, antibiotic test, growth ability test in liquid media, isolation of the chromosome and plasmid, digestion of DNA by restriction enzyme, electrophoresis of chromosome and plasmid DNA, identification of Ni-resistant genes by the DNA hybridization. The results were as follows 1) The bacteria isolated from gingival crevicular fluid on the patients wearing Ni-Cr alloy prosthesis showed nickel-resistance. 2) The isolated microorganisms grew at nickel containing media of high concentrations (60mM-110mM). 3) Based on the biochemical tests, the isolated microorganisms were identified as Enterococcus faecalis(13 cases), Klebsiella pneumoniae(1 case) and Enterobacter gergoviae(1 case). 4) Enterococcus faecalis expressed not only nickel resistance but also the multi-drug resistance to several antibiotics ; chloramphenicol, kanamicin, streptomycin, lincomycin, clindamycin, However, all strain showed the sensitivity against the tetracycline. 5) DNA hybridization result suggests that there is no homology between the previously known gene of nickel resistance in Klebsiella pneumoniae and chromosomal DNA of Enterococcus faecalis.

• Journal of Life Science
• /
• v.21 no.12
• /
• pp.1710-1715
• /
• 2011

The bactericidal effect of nano plasma ion (NPi) which was generated by NPi was analyzed using different kinds of microorganisms, exposure times, chamber sizes, ion amounts and distance. As the result of Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella pneumoniae, Staphylococcus aureus and Bacillus subtilis were shown different in decrement. Gram-negative bacteria E. coli showed the highest percentage (96.57%) and Gram-positive bacteria B. subtilis which produced spore has the lowest percentage (57.41%). From the exposure time of NPi most of the microorganisms were extinct at an early stage. According to the size of the chamber we compared the loss of E.coli and the experiment result shown, analyzed NPi using 5 chambers $0.005m^3$ to $30m^3$ for 2 hr, that when volume of the chamber increased, saturation ion and bactericidal effect was decreased. In addition, an NPi generator installed in the $1m^3$ chamber investigated the decrement of E. coli. Saturation ion concentration increased with decrement. Finally, E. coli showed a similar reduction according to the distance from NPi generator.