• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.303-311
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• 2002

Isolation and identification of causative microorganisms and susceptibility testing are important in selecting appropriate antimicrobial agent. The purpose of this study was to determine the antimicrobial susceptibility patterns and identification of bacteria for the selection of a therapeutic antibiotic agent for treatment. Specimens were cultured aerobically from dog patients brought to the veterinary medical teaching hospital of Seoul National University between July 1999 and September 2000. A total of 157 isolates were from skin(63), urine(45), ear canal(31) and conjunctiva(18). The result is that the most common organisms isolated from dog patients were S. intermedius was the most common isolates from the skin, ear canal, and conjunctiva. E. coli was the most common isolated from urine. Most of gram-positive isolates were resistant to ampicillin(80.6%), erythromycin(68.8%), penicillin(86.2%), tetracycline(89.2%). Otherwise most of gam-negative isolates were resistant to ampicillin(73.4%), trimethoprim-sulfa(53.3%). E. coli was resistant to ciprofloxacin(61.5%), piperacillin (69.2%). Antimicrobial susceptibility pattern by the sampling site was not remarkably different except 5. aureus isolated from urine.

• Journal of Marine Life Science
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• v.4 no.1
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• pp.29-37
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• 2019

In order to control disease caused by multi-drug resistant bacteria in the aquaculture, the use of veterinary antibiotics, which are prohibited to fish, is increasing, instead of the existing fisheries antibiotics. Among them, tiamulin is illegally used in some cultured fish because it exhibits effective antibacterial activity against Gram-positive bacteria. To prevent unauthorized use, treatment of fish should be accompanied by a prescription from veterinarians or fisheries disease managers through research on fish of tiamulin. Tiamulin was injected intramuscularly at 5, 10 and 15 mg kg^-1 for the streptococcus-infected starry flounder, but did not show any therapeutic effect. Oral administration at a concentration of 15 and 30 mg kg^-1 was similarly ineffective. The concentrations of 30 and 60 mg kg^-1 resulted in death due to toxicity of antibiotics. Therefore, it is inappropriate to treat antibiotics with streptococcus-infected starry flounder.

• Journal of Life Science
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• v.33 no.10
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• pp.842-850
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• 2023

Pyrrolnitrin, pyrrolomycin, and pyoluteorin are functional halogenated phenylpyrrole derivatives (HPDs) derived from microorganisms with diverse antimicrobial activities. Pyrrolnitrin is a secondary metabolite produced from L-tryptophan through four-step reactions in Pseudomonas fluorescens, Burkholderia cepacia, Serratia plymuthica, etc. It is currently used for the treatment of superficial dermatophytic fungal infections, has high antagonistic activities against soil-borne and foliar fungal infections, and has many industrial applications. Since pyrrolnitrin is easily decomposed by light, it is difficult to widely use it outdoors. As an alternative, fludioxonil, a synthetically produced non-systemic surface fungicide that is structurally similar and has excellent light stability, has been commercialized for seed and foliar treatment of plants. However, due to its high toxicity to aquatic organisms and adverse effects in human cell lines, many countries have established maximum residue levels and strictly control its levels. Pyrrolomycin and pyoluteorin, which have antibiotic/antibiofilm activity against Gram-positive bacteria and high anti-oomycete activity against the plant pathogen Pythium ultimum, respectively, were isolated and identified from microorganisms. This review summarizes the biosynthesis and production of natural pyrrolnitrin derived from bacteria and the characteristics of synthetic fludioxonil and other natural phenylpyrrole derivatives among the HPDs. We expect that a plethora of highly effective, novel HPDs that are safe for humans and environments will be developed through the generation of an HPD library by microbial biosynthesis and chemical synthesis.

• Journal of dental hygiene science
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• v.4 no.1
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• pp.7-11
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• 2004

The purpose of this study was to investigate the distribution of microorganisms and the degree of contamination in the air of the dental clinics and to offer basic data as to the contamination of medical equipment and the prevention of the clinics. With this in mind, the researcher gathered air samples from the waiting rooms and medical offices of nine dental clinics in the city of J, South Korea with the use of a method of natural inattention and an air sampler and cultivated the samples on the plain table and drew from it bacteria falling and separated and sorted out the colony with the help of ATB and detected the distribution of the germs. The results are following, The number of bacteria falling in the air of the dental clinics was less than 10(CFU/Plate) with the exception of one dental clinic. This implies that they fit in with standards for hygiene. The number of bacteria falling in the air of the medical offices was less than 10(CFU/Plate) with the exception of one dental clinic. This implies that they fit in with standards for hygiene. The survey on the detection of staph. aureus reveals that all the dental clinics with the exception of B dental clinic proving to be positive had non-pathogenic staphylococci detected. The survey on the detection of pathogenic gram negative bacilli indicates that all the dental clinics but one were none detected. The survey on the distribution of germs shows that germs in 7 out of 9 dental clinics were none detected, and that they in four out of 9 waiting rooms were none detected. All the germs detected in the others were mostly non-pathogenic. The study shows that all the subject dental clinics but one were hygienically controlled and that there was a difference in accordance with cleaning and sterilization. This means that dental clinics should be equipped with systematic programs for cleaning and sterilization designed to prevent infection.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.345-352
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• 1998

The diagnosis of brucellosis is currently based on serological and microbiological tests. However, the microbiological isolation and identification have several disadvantages such as time-consuming and laborious, and the serological methods have been reported to cross-react with antigens other than those from Brucella spp. To develop a sensitive and rapid diagnostic method for detection of Brucella species, the genus-specific primers were designed and synthesized from the sequence of gene encoding a 31kDa cell surface protein(BCSP) and a 36kDa outer membrane protein(OMPB) of B abortus. The amplified 711bp and 982bp DNA fragments were only visible in each species of Brucella by PCR method using the BCSP and OMPB primers, respectively. However, PCR product was not obtained with DNA from other Gram-negative bacteria. As little as 1pg of the B abortus genomic DNA could be detected by this PCR method. Using the PCR technique, semen samples from 185 bulls of Brucella-seronegative herds in Cheju island were examined for comparison of this PCR method with conventional methods in 1995. The semen samples from 5 bulls were positive by culture method and PCR, and one was positive and 5 were suspect by semen plasma agglutination test. However, the semen samples obtained from 177 bulls were negative by semen plasma agglutination, culture and PCR methods in 1996. The results of comparison tests suggested that PCR was a better test than agglutination test against semen of bulls. This study indicated that the PCR technique was a valuable for the diagnosis of bovine brucellosis, particulary in bull semens.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.4
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• pp.444-452
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• 2019

Carbapenem resistance, mediated by the major acquired metallo-β-lactamase (MBL) genes, has been increasingly reported, particularly for clinical isolates of Acinetobacter spp. Of the 191 nonduplicate clinical isolates of the carbapenem-nonsusceptible Acinetobacter spp. evaluated, 125 isolates (65.4%) were positive for the modified imipenem or meropenem-Hodge test, and 49 isolates (25.7%) were positive for the imipenem-EDTA+SMA double disk synergy test (DDS). PCR and sequencing of the bla_VIM-2-allele and bla_IMP-1-allele showed that 29 A. baumannii isolates and 1 A. calcoaceticus isolate had bla_VIM-2, whereas 16 A. baumannii isolates and 2 A. calcoaceticus isolates had bla_IMP-6; 1 isolate of the A. genomospecies 3 had bla_VIM-2 and bla_AIM-1. All the above MBL genes belong to class 1 integron. The size of class 1 integron encompassing bla_VIM-2 or bla_IMP-6 ranges from 2.8 kb to 3.2 kb in clinical isolates of A. baumannii, and 3.2 kb to 3.5 kb in clinical isolates of A. genomospecies 3. bla_VIM-2 was most often located first or second in the class 1 integron, and these integrons often included aacA4. Due to dispersion of the MBL-producing Acinetobacter spp. as well as integron, which may encompass various resistance genes, there is an expectation for the increase of multidrug resistant Gram-negative bacteria, including resistance of carbapenems such as imipenem or meropenem. Hence, the development of new antimicrobial agents for treating severe Acinetobacter spp. infections is needed.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1210-1217
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• 2021

Two gram-negative, catalase-positive, strictly aerobic, and white colony-forming bacteria, strains H242^T and B156^T, were isolated from soil in South Korea. Cells of strain H242^T were oxidase-positive and non-motile short rods, while those of strain B156^T were oxidase-negative and long non-motile rods. Ubiquinone-8 was identified as the sole isoprenoid quinone in both strains. C_16:0, cyclo-C_17:0, andsummed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol were identified in both strains as the major cellular fatty acids and polar lipids, respectively. The DNA G+C contents of strains H242^T and B156^T were 69.4 mol% and 69.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA and 92 concatenated core gene sequences revealed that strains H242^T and B156^T formed distinct phylogenic lineages from other Ramlibacter type strains. The DNA-DNA hybridization (DDH) value between strains H242^T and B156^T was 24.6%. Strains H242^T and B156^T were most closely related to Ramlibacter ginsenosidimutans BXN5-27^T and Ramlibacter monticola G-3-2^T with 98.4% and 98.6% 16S rRNA gene sequence similarities, respectively. Digital DDH values between strain H242^T and R. ginsenosidimutans and between strain B156^T and R. monticola were 23.5% and 26.1%, respectively. Phenotypic, chemotaxonomic, and molecular analyses indicated that strains H242^T and B156^T represent two novel species of the genus Ramlibacter, for which the names Ramlibacter terrae sp. nov. and Ramlibacter montanisoli sp. nov., respectively, are proposed. The type strains of R. terrae and R. montanisoli are H242^T (=KACC 21667^T=JCM 33922^T) and B156^T (=KACC 21665^T=JCM 33920^T), respectively.

• Microbiology and Biotechnology Letters
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• v.41 no.2
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• pp.228-235
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• 2013

Radish (Raphanus sativus) is a common cruciferous vegetable, and its aerial parts, called Mu-chung in Korean, have plentiful nutritional components such as vitamins, minerals and dietary fibers. Mu-chung has been used as a kimchi, a traditional Korean fermented dish, and dried Mu-chung is an important component of soups commonly consumed during winter in Korea. Since the advent of the mass production of radish in Korea, with the segregation of farm areas and towns and changing diets, Mu-chung has mostly been discarded instead of utilized. In addition, studies concerning the efficient utilization and useful bioactivities of Mu-chung are still lacking worldwide. In this study, we prepared the ethanol extract of Mu-chung and its subsequent solvent fractions. Antimicrobial, antioxidation, and anticoagulation activities were then evaluated in the hopes of developing a functional biomaterial from Korean radishes' aerial parts. The ethanol extraction yield for hot-air dried Mu-chung was 5.6%, and the fraction yields of n-hexane (H), ethylacetate (EA), butanol (B) and water residue were 25.3, 3.6, 19.4, and 51.7%, respectively. Analysis of total polyphenol and total flavonoid contents showed that the EA fraction had the highest content (97.57 and 152.91 mg/g) amongst the fractions. In antimicrobial activity assays, the H and EA fractions were effective against gram positive bacteria (Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis), but not effective against gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The B fraction also exhibited moderate antibacterial activity, suggesting that the extract of Mu-chung has various antibacterial components. In antioxidation activity assays, the EA fraction showed strong DPPH, ABTS and nitrite scavenging activities ($69-222{\mu}g/ml$ of $IC_{50}$), including reducing power. In anticoagulation activity assays, the EA fraction demonstrated strong inhibition activity against human thrombin and prothrombin. Prominent anticoagulation activity was found in aPTT assays; the aPTT of the EA fraction was extended 15-fold compared than that of the solvent control. Our results suggest that Mu-chung is an attractive nutritional food material possessing useful bioactivities, and the EA fraction of Mu-chung could be developed as a functional food ingredient.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.36-44
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• 2002

GC-l00X is non-corrosive alkaline ionic water (pH 12). It is composed of hydroxyl radicals and supplemented with xylitol. Its antimicrobial activity was examined against 6 major food-borne pathogens; Staphylococcus aureus FRI 913, Salmonella enterica serova Enteritidis ATCC 13076, S. enterica serova Typhimurium Korean isolate, Vibrio parahaemolyticus ATCC 17803, Escherichia coli O157:H7 ATCC 43894 and Pseudomonas aeruginosa KCTC 1637 at three different temperatures (4$^{\circ}C$, $25^{\circ}C$ and 36$^{\circ}C$) with or without an organic material (2% yeast extract), respectively. The antimicrobial activities showed over 4 log-reductions (1.0$\times$10$^4$CFU/ml reduction) against all pathogens reacted at 37$^{\circ}C$ for 3 hours in the absence of the organic material. The activities showed same results when GC-l00X was diluted with same volume of distilled water or standard hard water (CaCO$_3$300 ppm). Its antimicrobial activity was more effective and quicker in Gram-negative bacteria than Gram-positive bacteria. Its washing efficacy against E. coli O157:H7 exposed to the surfaces of tomatoes (grapes) was compared with that of the other sanitizers such as other kitchen synthetic detergent and 100-ppm chlorine water. For the toxicological evaluation of the sanitizers, viable counts of E. coli O157:H7 penetrated into the core of tomatoes after washing products were also compared. The result revealed that GC-100X stock solution and its 5% diluted solution had similar washing effects to 100-ppm chlorine water and more effective than the other kitchen synthetic detergent. This result indicated that GC- l00X had antimicrobial activity and no toxicological side effects, therefore, could be useful for a new sanitizer to use in flood safety and kitchen hygiene.

• Pediatric Infection and Vaccine
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• v.24 no.2
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• pp.71-78
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• 2017

Purpose: The aim of this study was to identify the pathogens of blood stream infection (BSI) in children with hemato-oncologic disorders, to analyze susceptibility patterns of microorganisms to guide empirical antimicrobial therapy, and to compare temporal trends of the pathogen and antimicrobial susceptibility with those of previous studies. Methods: We retrospectively analyzed the medical records of children with hemato-oncologic disorders whose blood culture grew pathogens at the Seoul National University Children's Hospital between 2011 and 2015. Results: A total of 167 patients developed 221 episodes of bacteremia. Among 229 pathogens, gram-negative bacteria (GNB) accounted for 69.0% (64.0% in 2002 to 2005, 63.4% in 2006 to 2010); gram-positive bacteria (GPB) accounted for 28.8% (31.3% in 2002 to 2005, 34.6% in 2006 to 2010); and fungus accounted for 2.2%. Among GNB, Klebsiella species (53.2%, 84/158) and Escherichia coli (19.6%, 31/158) were common. Staphylococcus aureus (48.5%, 32/66) and viridans streptococci (21.2%, 14/66) were frequently isolated among GPB. The susceptibilities of oxacillin and vancomycin in GPB were 54.8% and 96.9% (51.5% and 95.5% in 2002 to 2005; 34.1% and 90.5% in 2006 to 2010), respectively, whereas in GNB, the susceptibilities of cefotaxime, piperacillin/tazobactam, and imipenem were 73.2%, 77.2%, and 92.6% (75.9%, 82.8%, and 93.4% in 2002 to 2005; 62.8%, 82.9%, 93.8% and in 2006 to 2010), respectively. There were no significant differences in the proportion of etiologic agents or the antimicrobial susceptibilities between the current study and that of the previous two studies from 2002 to 2010. Overall fatality rate was 13.1%. Conclusions: GNB predominated in BSI among children with hemato-oncologic disorders. The etiology of bacteremia and antimicrobial susceptibility were comparable to those of the previous studies. Thus, piperacillin/tazobactam can be used as the initial empirical antimicrobial agent in febrile neutropenia.