• Korean Journal of Microbiology
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• v.38 no.4
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• pp.265-265
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• 2002

Iron increased the susceptibilities of clinical isolates Pseudomonas aeruginosa to quinolones. In the presence of iron, increased susceptibilities to ofloxacin were observed in twenty-six out of thirty isolates and with no change in four isolates. In the case of norfloxacin, iran increased susceptibilities of twelve isolates but did not render any change in eighteen isolates. In the case of ciprofloxacin, iron decreased the MICs (Minimal Inhibitory Concentration) of twenty isolates, increased the MIC of one isolate, and did net change the MICs of nine isolates. To find out how iron increased susceptibility to ofloxacin, bacterial cells were grown in Muller Hinton (MH) media and succinate minimal media (SMM) to induce iran acquisition systems and the intracellular ofloxacin concentrations were assayed in the presence of iron. The addition of iron to the media decreased the MICs of cells whether they were grown in MH or SMM. Siderophores, carbonyl cyanide m-chlorophenylhydrazone (an inhibiter of proton motive force), and ouabain (an inhibitor of ATPase) did not decrease the effect of iron. Results suggested that the increase in the intracellular ofloxacin concentration by iron is accomplished not by decreasing the efflux but by increasing the of ofloxacin permeability.

• Natural Product Sciences
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• v.23 no.1
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• pp.5-8
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• 2017

An antimicrobial compound has been isolated from the leaves of Glochidion superbum. The compound was determined as methyl 3, 4, 5-trihydroxybenzoate (methyl gallate), based on ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopy (MS) analysis. The isolated compound exhibited potent antimicrobial activity against three clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) by qualitative agar disc diffusion method and quantitative broth dilution method. Agar disc diffusion was done in a dose-dependent manner for each bacterial isolate at disc potencies of 25, 50, 100, and $150{\mu}g/disc$. The zones of inhibition were on average equal to 12.27, 14.20, 15.43, and 24.17 mm respectively. The inhibition zones were compared with that of vancomycin disc at $30{\mu}g$ as a reference standard. The MIC and MBC values were $50{\mu}g/ml$ and $100{\mu}g/ml$ respectively. The results of anti MRSA activity were analyzed using one-way ANOVA with Turkey's HSD and Duncan test. In conclusion, methyl gallate which was isolated from G. superbum showed the inhibition activity against methicillin resistant S. aureus.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.299-304
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• 2001

Teicoplanin is a kind of glycopeptide antibiotics produced by Actinoplanes teichomyceticus, and used in the clinical antibiotic such as vancomycin against methicillin-resistant Stabphylococcus aureus (MRSA). Actino planes teichomyceticus ATCC 31121 was mutated with UV to obtain a superior mutant strain with increased level of teicoplanin production. In this investigation, lethal curve was obtained and the optimal condition to induce mutagenesis was determined to isolate the desirable mutant strain. It was also confirmed that teicoplanin activities by agar diffusion method was compared with the parent strain. One mutant strain, T991014-1 with the highest productivity, was finally selected, and was characterized through the various tests such as amylase activity, protease activity, halotolerance, antibiotic resistance, autotoxicity, and productivity. Ad fermentation characteristics of the mutant strain were also studied.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.464-469
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• 2000

An epizootic of calf diarrhea occurred in a Korean native cattle farm located in Chonbuk province. The calves that had either bloody or watery diarrhea were 1 to 30 days old. Some of these animals died during the acute course of the disease. Five calves with predominant clinical signs were examined in more detail. Hematological and serum chemical findings were suggestive of dehydration and nutritional insufficiency. Fecal material from the calve was cultured on/in brilliant green agar (BGA), xylose-lysine deoxycholate (XLD) medium, MacConkey agar, eosin methylene blue (EMB) agar and triple sugar iorn (TSI) A bacteria was isolated. which was subsequently identificed as belonging to Salmonella spp. To differentiate Salmoenlla serotype, rfbs gene of S. dublin was amli- find (720 bp) by multiplex (PCR). The rfbS gene sequences of S, dublin ficld isolate(SDC-1) was com- pared with that off S. dublin(S-37) S, dublin(Ahn et al, 1996), S enteritidis(Ahn et al 1996)and S. typhi (Generbak accession No M29682). The identities of nucleotide sequences were 100%. 99.6%, 99.6%, 97.5% respectively.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.37-42
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• 2008

Riemerellosis, contagious disease of domestic ducks in Korea, occurred in December of 2007 in a farm located in Eumsung, Chungbuk province. The affected ducks were 22 days old and the owner reported that almost one hundred of ducks had died everyday for a few days after infection. Clinical signs were listlessness, ocular and nasal discharge, greenish diarrhea, ataxia, tremor of head and legs, and coma. On necropsy we found fibrinous exudate, which involved serosal surfaces in general, but most evidences were in the pericardial cavity and over the surface of the liver. The causative agent was isolated from the liver of the affected ducks and identified as Riemerella anatipestifer using biochemical tests. Also, the isolate was susceptible to ampicillin, cephalothin, sulfamethazole/trimethoprim, Florfenicol among the 23 species antibiotics (AST Discs, OXOID) used in our laboratory. Further studies should be needed for the more effective control and better epidemiological information such as pathogenicity, serotype, genotype and treatment.

• Clinical and Experimental Reproductive Medicine
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• v.13 no.2
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• pp.195-200
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• 1986

In order to know when the cumulus cells of mouse follicles get ability to expand in vitro, the oocyte cumulus complexes obtained from different growing ages of mice were cultured in the medium containing HCG and their rate of expansion were observed and at the same time their maturation rate was examined. The growth of follicles was also checked by histological method. It was impossible to isolate the oocyte-cumulus complexes from 13 or 15 days old mouse ovaries. The oocyte-cumulus complexes collected from 17 days old mouse were partially induced to expanded by HCG, and from 19 days, most of the complexes were induced to full expansion. The rate of cumulus cell expansion by HCG and the oocyte maturation increased steadly during the growing ages to adult. Thus, the time for follicles to get competence for expansion and maturation seems to be closely related. Antral follicles were appeared from 17 days old mice and Graafian follicles were seen from 21 days old mice. The competence for cumulus expansion increased during follicle growth up to 21 days old mice.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.561-569
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• 2004

To detect viral agents and isolate porcine circovirus 2 (PCV2), 60 samples of lung and lymph node were collected from 5 to 12 week-old pigs that had showed clinical signs of postweaning multisystemic wasting syndrome (PMWS). Polymerase chain reactions (PCRs) were conducted to identify the viral pathogens including PCV1, PCV2, porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV) that have been considered to be the causal agents of PMWS. Among 60 samples, PCV 2 was detected from 57 samples but no PCV 1 was detected. PRRSV and/or PPV were also detected from 27 (47.4%) samples and 1 (1.8%) sample of these 57 PCV 2-positive samples, respectively. Tissue homogenates were inoculated onto PCV-free PK-15 cell monolayers. Seven isolates were confirmed as PCV 2 by multiplex PCR, indirect immunofluorescence assay, and transmissible electron microscopy. These date suggest that PRRSV is a major cofactors causing PMWS in pigs that were infected with PCV2 in Korea.

• Journal of fish pathology
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• v.12 no.1
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• pp.49-55
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• 1999

To detect birnavirus from cultured marine fish, RT-PCR assay was developed. This method was specific for aquatic birnaviruses that include IPNV Sp., IPNV Ab, IPNV VR-299 and MBV Y6. The birnavirus gene was detected (birnavirus positive samples detected 46/50) from clinical samples signed with abdominal distension and overall darkening even though the samples gave negative results in virus isolation (birnavirus isolate with CHSE-214 cell showed 12/50).

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.212-218
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• 2000

The recruitment of leukocytes to a site of inflammation is dependent on a complex interplay of a number of cytokines. Monocyte chemoattractant protein-1 (MCP-1) is a potent chemoattractant for monocytes, whereas interleukin-8 (IL-8) has chemotactic activity for neutrophils, lymphocytes, and basophils. The purpose of this study was to determine the effects of several microbes found in infected root canal systems on the production of inflammatoy cytokines, interleukin 8 and monocyte chemoattractant protein-1 from human peripheral blood mononuclear cells (PBMC). Monocytes isolated from peripheral blood were stimulated by group A streptococci (GAS, ATCC 19615), Enterococcus faecalis (ATCC 29212), Streptococcus mutans (ATCC 10449), Streptococcus sanguis (clinical isolate), and Candida albicans (ATCC 90029) respectively. Each of these bacteria induced dose-dependent induction in IL-8 and MCP-1 determined by ELISA. IL-8 production by each bacteria was decreased in the range of the microbe-to-PBMC ratios of 0.1-1.0. Group A streptococci was the week inducer of MCP-1 production. These results suggest that different oral pathogens induce specific dose-dependent patterns of cytokine release. Such patterns may provide a means of control of the type of immune celles particularly with regard to inflammatory leukocyte recruitment.

• Korean Journal of Plant Resources
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• v.31 no.6
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• pp.719-724
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• 2018

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium responsible for a number of infections in humans that are difficult to treat, and as a result, is a substantial contributor to morbidity and mortality. In the present study, in search of natural products capable of inhibiting this multidrug-resistant bacterium, we investigated the antimicrobial activity of Lysimachia clethroides Duby root. The antibacterial activities of EtOH extract of Lysimachia clethroides Duby root and its n-hexane, EtOAc, n-BuOH and water fractions were evaluated against 15 strains of methicillin-resistant staphylococcus aureus (MRSA) and 1 standard methicillin-susceptible S. aureus (MSSA) strain by using the minimal inhibitory concentrations (MICs) assay, colorimetric assay using MTT test, checkerboard dilution test. Antimicrobial activity of n-hexane fraction of Lysimachia clethroides Duby root was remarkable. Against the 16 strains, the minimum inhibitory concentrations (MICs) were in the range of $31.25-62.5{\mu}g/ml$ and FICI values for n-hexane fraction of Lysimachia clethroides Duby root+AM and n-hexane fraction of Lysimachia clethroides Duby root+OX were checkerboard method performed using the MRSA, MSSA and one clinical isolate strains via MICI 0.12-1 and 0.25-0.75, showing the increase of synergistic effect. When combined together, these antibiotic effects were dramatically increased. These effective combinations could be new promising agents in the management of MRSA.