• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.755-761
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• 2006

Recently, there is growing interest in ultraviolet (UV) irradiation as a disinfection technic in drinking water production due to its effectiveness to inactivate microorganisms such as Crytosporidium parvum without forming disinfection byproducts. However, UV disinfection is known for its drawback such as photoreactivation. Despite many works concerning the photoreactivation, most of works were focused on indicator or non pathogenic microorganisms. The objective of this study is to examine the photoreactivation of Pseudomonas aeruginosa which is an opportunistic pathogen as UV radiation by LP and MP UV lamp was applied. The result showed that P. aeruginosa had high photo repair efficiency regardless of the type of UV irradiation. Both of the effective log repair values of LP and MP UV irradiation were found approximately 2.6 log. In addition, photo repaired P. aeruginosa was not significantly different in forming biofilm in comparison with non treated P. aeruginosa.

• Biomedical Science Letters
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• v.25 no.4
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• pp.321-330
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• 2019

Carbapenem is recently considered as the last resort of the therapeutics for gram negative bacterial infection. Increasing of organisms producing metallo-β-lactamase (MBL), we have difficulty in choosing the antimicrobial agents. Among 345 clinical isolates of Pseudomonas spp., 61 isolates (17.7%) were positive for the modified imipenem or meropenem-Hodge test and 55 isolates (15.9%) were positive for the imipenem-EDTA + SMA double disk synergy test (DDS). PCR and sequencing of bla_VIM-2-allele and bla_IMP-1-allele showed that 17 isolates of Pseudomonas aeruginosa, 9 isolates of Pseudomonas taiwnensis and 2 Pseudomonas plecoglossicida had bla_VIM-2, and 22 isolates of P. aeruginosa and one Pseudomonas otitidis had bla_IMP-6. These MBL genes were all in class 1 integron. The size of class 1 integron with bla_VIM-2 ranged from 3.5 kb to 5.5 kb in clinical isolates of Pseudomonas spp. including P. aeruginosa. bla_VIM-2 was most often located first in the class 1 integron, sometimes in the second or third position, and these integrons often had aacA4 or aadA1. Strict infection control measures are needed to more effectively prevent further spread of these MBL-producing Pseudomonas spp. In addition, MBL-producing Pseudomonas spp. is expected to continue to spread in various countries and regions.

• KSBB Journal
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• v.13 no.5
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• pp.511-517
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• 1998

Temperature and pH conditions were studied for an effective biosurfactant production by Pseudomonas aeruginosa YPJ-80. Efficient methods of biosurfactant separation were also investigated. pH-uncontrolled experiments at 35$^{\circ}C$ and an initial pH of 8 resulted in the best cell growth (3.6 g/L) and biosurfactant production (0.073 g biosurfactant/g cell). Biosurfactant separation was most efficient using solvent extraction with chloroform/methanol (2:1 vol%) followed by acidification using 1N HCl.

• Journal of Microbiology and Biotechnology
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• v.3 no.1
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• pp.12-18
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• 1993

Pseudomonas aeruginosa strain B5 with antagonistic activity against Phytophthora capsici and Magnaporthe grisea, was isolated from pepper-growing soil. From the culture of P. aeruginosa strain B5 grown on King's medium B, antibiotic substances were purified using XAD-2 column chromatography. XAD-2 eluates inhibited not only the mycelial growth of P. capsid and M. grisea, but also the development of Phytophthora blight on pepper plants. The crude antibiotic substances were further purified by using silica gel column chromatography, Sephadex LH-20 column chromatography, thin layer chromatography on silica gel plates, and high performance liquid chromatography. Silica gel column chromatogrphy gave good separation of the four antibiotic substances. The pure antibiotics P1, P2, and P3 finally purified by preparative HPLC inhibited the mycelial growth of P. capsici, at concentrations from 7 to 10 $\mu g/ml$. Only P1 and P2 had antifungal activity against M. grisea at 8 $\mu g/ml$. P1 and P3 were highly inhibitory to the mycelial growth of Botryosphaeria dothidea and Botrytis cinerea at relatively low concentrations. However, the three antibiotics had no antifungal activity against Rhizoctonia solani. The chemical structures of these antibiotics are being identified.

• KSBB Journal
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• v.18 no.6
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• pp.529-535
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• 2003

We studied degradation effects of hydrophobic substrate such as kerosene and diesel by adding a biosurfactant originated from Pseudomonas aeruginosa F722 and chemical surfactants (Tween 80 and detergent) with aeration. The surface tensions of the biosurfactant, Tween 80 and detergent were 30mN/m, 39mN/m and 31mN/m, respectively. When the concentration of biosurfactant added in C-medium was 0.01 and 0.15%(w/v), the ratios of hydrocarbon degradation were 94.3％ and 94.2% respectively. It was 6.2%(w/v) higher than when the concentrations of added biosurfactant were 0.05, 0.1 and 0.2％. The degradation ratios of the chemical surfactants (Tween 80 and detergent) were 94.5％ and 93.5％ respectively. The effects of the biosurfactant and chemical surfactants were similar on the degradation ratio in mixtures of kerosene and diesel. However, the population of viable p. aeruginosa F722 at the end of the cultivation period was twice as higher in the biosurfactant than that in the chemical surfactant. We also studied the effect of aeration (0.5vvm) on the degradation ratio. The biosurfactant addition experiment was conducted with 0.5vvm air, 35$^{\circ}C$, 150rpm, pH 8.0, 3days, 1.0% (w/v) substrate. When p. aeruginosa F722 and 0.15%(w/v) biosurfactant were added, the degradation ratio of hydrocarbon was 94.8％. Without p. aeruginosa F722, it was 68%. Thus, with aeration, the degradation ratio of hydrocarbon was increased by 26.8％. In addition, the cultivation time was shortened by 1/3. The degradation ratios of hydrocarbon in shaking culture (cultivation time; 3days) and stationary culture (cultivation time; 10days) were 94.8 and 93.7％ respectively. Thus, the addition of biosurfactant and aeration enhanced the degradation of hydrocarbon originated kerosene and diesel.

• Journal of Environmental Science International
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• v.11 no.1
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• pp.33-40
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• 2002

An antimicrobial substance-producing microorganism was isolated from soil samples. Based of the taxonomic characteristics of its morphological, cultural, physiological properties and 16s rRNA sequence alignment, this microorganism was identified as Pseudomonas aeruginosa, and we named Pseudomonas aeruginosa EL-KM. The optimal culture condition for production of antimicrobial substance was 1% mannitol, 0.4% yeast extract, 0.5% Nacl, 0.2% $K_2SO_4$, 100$\mu$M $MgSO_4$.$7H_2O$, 10$\mu$M $CaCl_2$.$2H_2O$, 1$\mu$M $FeSO_4$.$7H_2O$, 1$\mu$M $MnSO_4$.$4-5H_2O$, initial pH 7 and 200 rpm at 3$0^{\circ}C$. The purification of the antimicrbial substance was performed by silica gel column chromatographys, and fraction with TLC $R_f$ 0.77 value represented good antimicrobial activity. The crude antimicrbial substance was stable within a pH range of 3-10 and temperature range of 4$^{\circ}C$-121$^{\circ}C$ autoclaving. This crude antibacterial substance acted as bacteriolytic agent against Vibrio cholerae non-Ol ATCC 25872, and also exhibited excellent properties, when the substance was demonstrated against many other gram-positive, gram-negative bacteria, yeast and fungi.

• Journal of Life Science
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• v.22 no.9
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• pp.1268-1276
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• 2012

The emergence and dissemination of carbapenem-resistant bacteria have resulted in limitations of antibiotic treatment and potential outbreaks of metallo-${\beta}$-lactamase (MBL) producing Pseudomonas aeruginosa resistant to carbapenems. In this study, we conducted molecular characterization of the MBL genes of the ${\beta}$-lactam drug-resistant P. aeruginosa and prepared basic data for treatment and prevention of proliferation of antimicrobial-resistant bacterial infections. Forty-two P. aeruginosa isolates of 254 were resistant to imipenem or meropenem. Among the 42 isolates, 28 isolates were positive for the Hodge test, and 23 isolates were positive for the EDTA-disk synergy test (EDST). MBLs were detected in 59.5% (25/42) of P. aeruginosa isolates. Eight isolates harbored $bla_{IMP-6}$, whereas 17 isolates harbored $bla_{VIM-2}$. The $bla_{IMP-6}$ gene was in a class 1 integron containing five gene cassettes: $bla_{IMP-6}$, qac, aacA4, $bla_{OXA-1}$, and aadA1. Some strains that produce IMP-6 and VIM-2 showed epidemiological relationships. The $bla_{IMP-6}$ gene in carbapenem-resistant P. aeruginosa showed an identical pattern to a gene cassette that was reported at a hospital in Daegu, Korea. Therefore, MBL-producing P. aeruginosa is already endemic in the community. We are concerned that the existence of carbapenem-resistant bacteria containing the blaMBL gene may increase pressure on antibiotic selection when treating infections. We believe that we should select appropriate antibiotics based on the antibiotic susceptibility test and continue the research to prohibit the emergence and spread of antibiotics resistant bacteria.

• Journal of Veterinary Clinics
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• v.36 no.5
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• pp.245-247
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• 2019

Taylorella equigenitalis (T. equigenitalis), Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) are sexually transmittable bacteria known to cause venereal diseases (VD) in horses. T. equigenitalis causes contagious equine metritis (CEM), which is a considerable concern for equine breeding industry. K. pneumoniae and P. aeruginosa may cause endometritis and infertility in susceptible mares. The purpose of this study was to investigate the prevalence of these bacteria among breeding Thoroughbreds in South Korea. External genital swabs were collected from 178 breeding Thoroughbreds, including 11 stallions and 167 mares. The samples were tested using a commercial multiplex real-time PCR kit. T. equigenitalis, P. aeruginosa, and K. pneumoniae were present in 5.6%, 7.3%, and 5.6% of tested Thoroughbreds, respectively. The results highlight the need for regular testing of South Korean Thoroughbreds, particularly those used for breeding, for these bacteria. The regular pre-breeding test for these bacteria will prevent health complications for the horse and financial losses for the owner as a result of VD.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.415-420
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• 2016

Chemical study of an Arctic bacterium, Pseudomonas aeruginosa (Pseudomonadaceae) led to the isolation of two diketopiperazines 1 and 2, two phenazine alkaloids 3 and 4, and an indole carbaldehyde 5, along with a benzoic acid derivative 6. The structures of the compounds were confirmed by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. Among the isolates, compounds 5 and 6 were isolated for the first time from P. aeruginosa of the seawater of Arctic Chuckchi Sea. Antimicrobial activities of compounds 1‒6 against a Staphylococcus aureus and Candida albicans were evaluated.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.434-437
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• 2018

Pseudomonas aeruginosa accounts for a significant proportion of nosocomial infections. This study examined the antimicrobial susceptibility pattern and clonal relatedness of P. aeruginosa isolates of clinical and environmental origin. These isolates displayed susceptibility to levofloxacin, ciprofloxacin, gentamicin, imipenem, and ceftazidime of 65.0%, 62.5%, 90.0%, 100%, and 85%, respectively. PCR-RAPD analysis of the P. aeruginosa isolates revealed marked variation. No correlation was observed between the antibiotic resistance profiles and the DNA typing patterns.