• 대한미생물학회지
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• 제34권6호
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• pp.543-554
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• 1999

The purpose of this study was to evaluate the existence of amoxicillin, clarithromycin, and metronidazole resistance Helicobacter pylori and to determine the in-vitro MIC of two and three kinds of antibiotic concominant administration in the isolates. The antimicrobial agents tested against 169 H. pylori included metronidazole, amoxicillin, ciprofloxacin, clarithromycin, omeprazole, josamycin, erythromycin, and tetracycline. MIC of each antimicrobial agents was determined by broth microdilution method. The 169 strains of H. pylori were isolated from biopsy specimens of patients with gastric cancer. $MIC_{50}$ of clarithromycin, amoxicillin, metronidazole, omeprazole, erythromycin, josamycin, tetracycline, and ciprofloxacin was 2.0, 1.0, 4.0, 8.0, 0.5, 0.5, and $0.5\;{\mu}g/ml$, respectively. $MIC_{90}$ of clarithromycin, amoxicillin, metronidazole, omeprazole, erythromycin, josamycin, tetracycline, and ciprofloxacin was 64.0, 64.0, 32.0, 16.0, 8.0, 2.0, and $1.0\;{\mu}g/ml$, respectively. H. pylori isolates were detected in the following resistaince rates: 34.3% to clarithromycin, 31.9% to metronidazole, 20.7% to amoxicillin, 12.4% to erythromycin, and 10.1% to josamycin. The prevalence of the antibiotic resistant strains of H. pylori were detected 18.1% for two kind of antibiotics and 9.6% for three kind of antibiotics, and 3.9% for four kind of antibiotics. The $MIC_{90}$ of clarithromycin-, metronidazole-, and amoxicillin-resistant H. pylori was decreased under the $1\;{\mu}g/ml$ by the two or three kind of antibiotic concomitant administration in-vitro. These results suggest that two or three antibiotics concomitant administration could be more effective for the treatment of clarithromycin-, amoxicillin-, metronidazole-, and josamycin-resistant H. pylori strains.

• 한국임상수의학회지
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• 제25권4호
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• pp.231-235
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• 2008

Various kinds of antibiotic intramammary infusions are used for treatment of bovine mastitis. As antibiotic-resistant bacteria are increased, the therapeutic rate for bovine mastitis is decreased. The goal of this research is to detect significant synergic effects of combination of antibiotics with sulbactam, $\beta$-lactamase inhibitor, on methicilin-resistant Staphylococcus aureus (MRSA). We used 5 strains of MRSA isolated from bovine mastitis with clinical and subclinical signs. All of the bacteria isolated had resistance to oxacillin and showed multi-resistant patterns in the antimicrobial susceptibility tests. Minimal bactericidal concentrations of ampicillin, amoxicillin, cephalexin, ampicillin/sulbactam(2:1), amoxicillin/sulbactam (2:1), and cephalexin/sulbactam (1:1) were measured according to broth microdilution method suggested by National Committee for Clinical Laboratory Standards (NCCLS, M31-A2) to compare the synergic effects of sulbactam combination with each antibiotic alone. Ampicillin and amoxicillin showed synergic antibacterial activity to 4 and 3 respectively in 5 strains of MRSA in combination with sulbactam. This study demonstrates that ampicillin/sulbactam and amoxicillin/sulbactam can be therapeutic choices for mastitis associated with MRSA.

• Archives of Plastic Surgery
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• 제42권1호
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• pp.68-72
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• 2015

For recent years, use of autologous fat injection has increased significantly in facial contouring surgery. Along with such increase in use, complications like atypical mycoplasma infection have been also on the increasing trend. The authors report two cases of Mycobacterium chelonae infection that occurred after autologous fat injection. Patients were treated as infection that resistant to common antibiotics and results were negative to routine culture and Gram staining. Acid-fast bacillus stain, polymerase chain reaction (PCR) test and mycobacterial cultures were conducted for diagnosis under suspicion of atypical mycoplasma infection. Then, combination antibiotics therapy, surgical treatment, and steroid injection were performed for treatment. Both patients were diagnosed with Mycobacterium chelonae in PCR test. They were positive to mycobacterial cultures. Combination antibiotics therapy was repeated to improvement of symptom. However, they could not be free from side effects such as deformation in facial contour, scar and pigmentation even after full recovery. When chronic wound infections after autologous fat injection, we must suspect atypical or mycobacterial infection and conduct examinations for a early diagnosis and proper antibiotic therapy that is effective to the nontuberculous mycobacteria.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1263-1272
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• 2009

Danshen (Salvia miltiorrhiza Bunge) is a traditional Korean medicine that is commonly used for the treatment of inflammatory diseases such as edema, arthritis, hepatitis, and endangitis. The several extracts of danshen were tested for antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) isolated in clinic by broth microdilution method, the checkerboard, and time-kill methods to evaluate the synergistic effects of the combination of the extracts with antibiotics. The chloroform ($CHCl_3$) and n-hexane (HEX) extracts [minimum inhibitory concentration (MIC), 0.0078-0.3125${\mu}g/mL$; minimum bactericidal concentration (MBC), 0.019-0.625${\mu}g/mL$] were found to have strong antibacterial activity against MRSA. Additionally, when the $CHCl_3$ and HEX extracts were co-administered with ampicillin or oxacillin, a synergistic effect against MRSA was observed. Furthermore, a time-kill study evaluating the effects of the extracts against MRSA indicated that treatment with the $CHCl_3$ extract in combination with ampicillin or oxacillin produced rapid bactericidal activity. These results suggest that danshen extracts may have potently antimicrobial activity and thus, it can be a suitable phytotherapeutic agent for treating MRSA infections.

• Journal of Microbiology
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• 제45권5호
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• pp.473-477
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• 2007

The in vitro antibacterial activity against antibiotic-resistant Propionibacterium acnes of kaempferol isolated from the Impatiens balsamina alone and in combination with erythromycin or clindamycin antibiotics was investigated. The antibiotic combination effect against antibiotic-resistant P. acnes was studied by checkerboard test. Kaempferol and quercetin demonstrated antibacterial activities against P. acnes. Minimum inhibitory concentrations (MICs) for both compounds were ${\leq}32\;{\mu}g/ml\;and\;{\leq}64{\mu}g/ml$ for clindamycin-sensitive and -resistant P. acnes, respectively. The four combination formulations (kaempferol and either erythromycin or clindamycin; quercetin and either erythromycin or clindamycin) exhibited a synergic inhibition of P. acnes growth. The combination of kaempferol with quercetin showed an indifferent effect. The combination of clindamycin with kaempferol or quercetin showed a greater synergic effect than that of erythromycin with kaempferol or quercetin. Thus, these combinations demonstrated the potential to treat acne.

• Journal of Microbiology and Biotechnology
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• 제23권7호
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• pp.953-958
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• 2013

Selaginella tamariscina is a traditional herb used in medicine. Phytochemical amentoflavone, a biflavonoid class of flavonoids, was isolated from the plant of Selaginella tamariscina. In this study, the antibacterial effects and combination effects of amentoflavone and conventional antibiotics such as ampicillin, cefotaxime, and chloramphenicol were investigated. These results showed that amentoflavone had a considerable antibacterial effect and synergistic interaction with antibiotics against various bacterial strains (fractional inhibitory concentration index ${\leq}$ 0.5), except for Streptococcus mutans. To study the mechanism(s) involved in the synergistic activities between amentoflavone and antibiotics, we detected hydroxyl radical formation using 3'-(p-hydroxyphenyl) fluorescein and measured the $NAD^+/NADH$ ratio by $NAD^+$ cycling assay. The results indicated that the formation of hydroxyl radical would be a cause of the synergistic effect and that this oxidative stress originated from a transient NADH depletion. This study suggests that amentoflavone synergizes with antibiotics and has potential as a therapeutic agent for antimicrobial chemotherapy.

• Archives of Pharmacal Research
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• 제17권6호
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• pp.438-442
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• 1994

Antimicrobial activity of GL (the aqueous extract from the carpophores of Ganoderma lucidum ($F_RK_{KARST}$) was tested in vitro aginst Gram positive and Gram negative bacteria by serial broth dilution method, and the antimicrobial activity was expressed by minimal inhibitory concentration (MIC). Among fifteeen species of bacteria tested, the natimicrobial activity of GL was of antimicrobial combinations of GL with four kinds of antibiotics (ampicilin, cefazolin, oxytet-racycline and chloramphenicol), the fractional inhibitory concentraction index (FICI) was determined by checkerboard assy for each stain. The antimicrobial combinations of GL with four antibiotics resulted in additive effect in most instances, synergism in two instances, and antagonism in two instances. Synergism was obversed when GL was combined with cefazolin against Bacillus subtilis and Klebsiella oxytoca.

• Natural Product Sciences
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• 제9권3호
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• pp.183-185
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• 2003

The combination of hexane extract (E4) of rhizome of Acorus gramineus with chloramphenicol (Cm) was applied to Gram negative Cm resistant microbials to find the possibility of clinical use and to clarify the relationship of the activity of chloramphenicol acetyltransferase (CAT). The combination of $1,000\;{\mu}g/ml$ of E4 and $8\;{\mu}g/ml$ of Cm entirely ceased the growth of S. aureus SA2, a gram positive resistant strain to 10 antibiotics. But in Gram negative strains which possess CAT activity, some showed considerably strong resistances to Cm and some did weakly.

• 한국식품위생안전성학회지
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• 제5권3호
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• pp.159-164
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• 1990

To detect and quantitation residual antibiotics and antibacterial agents in meats, we performed a biological assay employing the three microorganisms Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, and Bacillus cereus var. mycoides ATCC 11778 for the screening purpose and developed a Gas Chromatography-mass Spectrometry(GC/MS) analysis for the confirmation and quantiation. In the biological assay (paper disk method), three test solution are used depending on the character of the residual antibiotics and antibacterial agents, follow by a simple clean up procedure which includes homogenization with Mcilvaine buffer, defatting with includes homogenization with Mcilvaine buffer, defatting with hexane, extraction with chloroform, clean-up by Sep-Pak $C_{18}$ and Bakerbond SPE carboxylic acid column. The chloroform layer is used for the analysis of sulfa agents. macrolides antibiotics and antibacterial agents, Adsorbed materials in the Sep-Pak $C_{18}$ were also employed for th analysis of penicillins and tetracyclines. Effluents from the Sep-Pak $C_{18}$ were cleaned-up one more by Bakerbond 10 SPE COOH column and employed for the analysis of aminoglycosides. In the instrumental analysis by using the GC/MSD, residual antibiotics and antibacterial agent were quantitated by selected ion monitoring (SIM) mode after derivatization. A simultaneous analysis of six residual antibiotic and antibacterial agent such as oxytetracycline, penicillin, ampicillin, choliraphenicol and thiamphenicol was developed with simple cleanup procedures revealing good recovery and reproducibility. Also, simultaneous detection of macrolides antibiotics such as erythromycin, spiramycin, and oleandomycin was developed after acid hydrolysis due to their large molecular structures. Because of the high reproducibility and selectivity of these two methods, it is very desirable that the combination of the two methods be used in the bioassay for the screening of residual antibiotics and antibacterial agent and that GC/MSD analysis be used for the confirmation and quantitation.

• 한국동물위생학회지
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• 제19권3호
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• pp.213-219
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• 1996

Seventy-nine strains of Enterobacteriaceae isolated from 117 slaughtered pigs (bile, urine, small intestine, cecum and rectum) in 1995 were examined for biotypes and susceptibility to 19 antibiotics with MicroScan WalkAway 40/96. The obtained results were as follows : 1. Among the twenty-two species isolated from the samples, Proteus mirabilis, E. coli and Enterobacter cloacae were commonly encountered. 2. The distribution frequency of isolates from cecum, small intestine, rectum, bile, and urine was 31(38.8%), 25(31.3%), 18(22.8%), 3(3.7% ), and 2(2.5% ), respectively. 3. A majority of isolates were sensitive to 16 antibiotics, singly or in combination. And these isolates were commonly susceptible to various antibiotics such as Cp, Ts, Azt, Caz, To, Gm, Cfz, Crm, Am and Cfx, in order. Whereas the Salmonella spp was susceptible to Cf, Ti and Pi, and Proteus mirabilis to Imp, Tim, Cft and Cz. Meanwhile, no effect was found to Cf, Ak and Cax. 4. Among the antibiotic resistant strains, a total of 17 reistant patterns was noted End of these Ak Tim 45(57.0%), Ak Am Cf Cfx Cfz Tim 8(10.1%) and Ak Ti Tim 6(7.6% ) were frequently encountered.