• 동의생리병리학회지
• /
• 제20권3호
• /
• pp.617-622
• /
• 2006

In the present study, we investigated the anticariogenic compounds from Aralia continertalis (A. continnentalis) has been isolated and identified by MS, $^1H-NMR$ and $^{13}C-NMR$. The MeOH extract was suspended in $H_2O$ and sequentially Partitioned with $CHCl_3$, EtOAc, and n-BuOH. The $CHCl_3$ fraction showed remarkable antibacterial activity against S. mutans. The antibacterial activity compounds against 5. mutans by MIC was isolated successively through the screening system and various chromatography methods. From this active chloroform subfraction, isolation and identification finally gave continentalic acid by spectroscopic methods (MS, $^1H-NMR$ and $^{13}C-NMR$) as an active principle. The compound, continentalic acid, showed significant growth, acid production, adhesion and water-insoluble glucan synthesis inhibitory effect against 5. mutars. These results suggest that continentalic acid from A. continentalis may inhibit cariogenic properties of S. mutans and these properties may provide some scientific rationales that the local inhabitants used the extracts for treatment of dental diseases.

• 동의생리병리학회지
• /
• 제19권5호
• /
• pp.1233-1237
• /
• 2005

Catechin products in green tea extract was prepared to investigate antibacterial activity on the pathogenic bacteria. Survival of pathogenic bacteria (MASA - methicillin resistant Staphylocouus aureus, E.coli O157 and S. typhimurium Sal-13) in tryptic soy agar(TSA) containing Catechin products powder incubated at various concentration was evaluated. TSA containing $0{\sim}2%(w/v)$ of Catechin products was inoculated approximately $10^4\;CFU/ml$ of pathogenic bacteria and incubated at $37^{\circ}C$ for 24 hours. The plate counting technique and clear zoon test were used to test survival effect of the Catechin products. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was derived from the survival curves of pathogenic bacteria. S. typhimurium Sal-13 was the most sensitive strain to Catechin products. This result suggested that Catechin products can be used as an effective natural antibacterial agent.

• 한국동물위생학회지
• /
• 제40권3호
• /
• pp.219-225
• /
• 2017

This study was investigated the synergistic effects from the combination of cefalexin and gentamicin (CCG) against Staphylococcus spp. isolated from bovine milk. Minimum inhibitory concentrations (MICs) and fractional inhibitory concentration (FIC) index were determined for 16 bacteria from 13 bovine farms in Gyeongsangnam province by the National Committee for Clinical Laboratory Standards broth microdilution procedure. Antimicrobial agents tested included cefalexin, gentamicin and CCG. Against Staphylococcus spp. tested, the MIC ranges of cefalexin, gentamicin and CCG were 0.25~1.0, 0.5~0.125 and $0.06{\sim}0.125{\mu}g/mL$, respectively. In addition, the FIC index ranges of CCG against most of the isolates was 0.28~0.43 and the FIC index of CCG against 2 strains of Staphylococcus haemolyticus (S. haemolyticus) was 0.59. In conclusion, CCG has a high antibacterial activity against Staphylococcus isolates, then the combination may be applied for the treatment of bovine mastitis caused by Staphylococcus spp.

• 대한수의학회지
• /
• 제60권3호
• /
• pp.173-177
• /
• 2020

Edible offal is easily contaminated by Escherichia coli (E. coli) and fluoroquinolone (FQ)-resistant E. coli is considered a serious public health problem, thus, this study investigated the genetic characteristics of FQ-resistant E. coli from edible offal. A total of 22 FQ-resistant E. coli isolates were tested. A double mutation in each gyrA and parC led the highest MIC. Four (18.2%) isolates carried plasmid-mediated quinolone resistance genes. The fimH, eaeA, escV, astA, and iucC genes were confirmed. Seventeen isolates (77.3%) were positive for plasmid replicons. The isolates showed high genetic heterogeneity based on pulsed-field gel electrophoresis patterns.

• 생명과학회지
• /
• 제20권6호
• /
• pp.964-967
• /
• 2010

본 연구는 동물유래 E. coli에서 plasmid-mediated quinolone resistance (PMQR) 유전자의 분포도를 조사하였다. 55주의 E. coli를 대상으로 PCR을 수행한 결과, PMQR 양성균은 11주이었으며 그 중 2주는 두 개의 PMQR 유전자를 동시에 가지고 있었다. PMQR 유전자의 염기서열 분석 결과, qnrS, aac(6')-Ib-cr, qepA로 확인되었고 qnrS (1.8%)와 aac(6')-Ib-cr (7.3%) 보다는 qepA (14.5%)가 높은 분포도를 나타내었으며, qnrA와 qnrB는 검출되지 않았다. 11주의 PMQR 양성균의 MIC를 측정한 결과, 대부분의 PMQR 양성균이 검사한 항생제에 내성을 보였지만 일부에서 감수성 균주도 확인되었다. 또한, aac(6')-Ib-cr 유전자는 단독으로 존재할 때 보다 qnrS 또는 qepA와 함께 존재할 때 내성이 더욱 증가함을 알 수 있었다. 내성유전자 전달능 실험에서 11주 모두 PMQR 유전자를 전달하였으며, PMQR 유전자를 전달받은 수용체에서 공여체와 동일한 내성 phenotype 및 PMQR 유전자를 확인 할 수 있었다.

• 약학회지
• /
• 제40권1호
• /
• pp.102-111
• /
• 1996

LB10522 is a new parenteral broad spectrum cephalosporin with a catechol moiety at C-7 position of beta-lactam ring. This compound can utilize tonB-dependent iron transp ort system in addition to porin proteins to enter bacterial periplasmic space and access to penicillin-binding proteins (PBPs) which are the lethal targets of ${\beta}$-lactam antibiotics. The chelating activity of LB10522 to metal iron was measured by spectrophotometrically scanning the absorbance from 200 to 900nm. When $FeCl_3$ was added, optical density was increased between 450 and 800nm. LB10522 was more active against gram-negative strains in iron-depleted media than in iron-replete media. This is due to the increased expression of iron transport channels in iron-depleted condition. LB10522 showed a similar activity against E. coli DC2 (permeability mutant) and E. coli DCO (wild type strain) in both iron-depleted and iron-replete media, indicating a minimal permeaility barrier for LB10522 uptake. LB10522 had high affinities to PBP 3 and PBP 1A, 1B of E. coli. By blocking these proteins, LB10522 caused inhibition of cell division and the eventual death of cells. This result was correlated well with the morphological changes in E. coli exposed to LB10522. Although the in vitro MIC of LB10522 against P. aeruginosa 1912E mutant (tonB) was 8-times higher than that of the P. aeruginosa 1912E parent strain, LB10522 showed a similar in vivo protection efficacy against both strains in the mouse systemic infection model. This result suggested that tonB mutant, which requires a high level of iron for normal growth, might have a difficulty in surviving in their host with an iron-limited environment.

• 사상체질의학회지
• /
• 제16권3호
• /
• pp.85-95
• /
• 2004

1. Objectives Although the incidence of allergic rhinitis is increasing continually, Sasang Constitutional Medicine is showing favorable treatment outcomes. This study was aimed to test the antimicrobial effects of Bojungikgi-tang, Gwakhyangjeonggi-san, and Gunggwihyangso-san which are being applied to allergic rhinitis of Soeumin. 2. Methods Klebsiella pneumoniae 289 was extracted from allergic rhinitis patients. Bojungikgi-tang, Gwakhyangjeonggi-san, and Gunggwihyangso-san were boiled down and concentrated, and the substances obtained were tested for the effects on stability to temperature and pH and on antimicrobial activity 3. Results When measured the level of antimicrobial activity, the inhibition zones of Bojungikgi-tang, Gwakhyangjeonggi-san, and Gunggwihyangso-san were found 11.42, 11.07, and 10.63mm, respectively. The levels of MIC were $15{\mu}{\ell}$, $20{\mu}{\ell}$, and $10{\mu}{\ell}$ in that order. The antimicrobial activities were increased 13.88% in Bojungikgi-tang, 16.63% in Gwakhyangjeonggi-san, and 10.72% in Gunggwihyangso-san. There was no influence of pH to antimicrobial activity of all three substances. 4. Conclusions Bojungikgi-tang, Gwakhyangjeonggi-san, and Gunggwihyangso-san had a high level of antimicrobial activity to Klebsiella pneumoniae 289 even at a low concentration.

• Journal of Microbiology and Biotechnology
• /
• 제26권2호
• /
• pp.408-420
• /
• 2016

This study proposes an alternative approach for the use of chitosan silver-based dressing for the control of foot infection with multidrug-resistant bacteria. Sixty-five bacterial isolates were isolated from 40 diabetic patients. Staphylococcus aureus (37%) and Pseudomonas aeruginosa (18.5%) were the predominant isolates in the ulcer samples. Ten antibiotics were in vitro tested against diabetic foot clinical bacterial isolates. The most resistant S. aureus and P. aeruginosa isolates were then selected for further study. Three chitosan sources were tested individually for chelating silver nanoparticles. Squilla chitosan silver nanoparticles (Sq. Cs-Ag⁰) showed the maximum activity against the resistant bacteria when mixed with amikacin that showed the maximum synergetic index. This, in turn, resulted in the reduction of the amikacin MIC value by 95%. For evaluation of the effectiveness of the prepared dressing using Artemia salina as the toxicity biomarker, the LC₅₀ was found to be 549.5, 18,000, and 10,000 μg/ml for amikacin, Sq. Cs-Ag⁰, and dressing matrix, respectively. Loading the formula onto chitosan hydrogel dressing showed promising antibacterial activities, with responsive healing properties for the wounds in normal rats of those diabetic rats (polymicrobial infection). It is quite interesting to note that no emergence of any side effect on either kidney or liver biomedical functions was noticed.

• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 2003년도 정기총회 및 학술발표회
• /
• pp.69-69
• /
• 2003

Human CD99 is a ubiquitous 32-kDa transmembrane protein encoded by the mic2 gene. The major cellular functions of CD99 protein are related to homotypic cell adhension, apoptosis, vesicular protein transport, and differentiation of thymocytes or T cells. Recently it has been reported that expression of a splice variant of CD99 transmembrane protein (Type I and Type II) increases invasive ability of human breast cancer cells. To understand structural basis for cellular functions of CD99 (Type I), we have initiated studies on hCD99$^{TMcytoI}$ and hCD99$^{cytoI}$ using circular dichroism (CD) and multi-dimensional NMR spectroscopy. CD spectrum of hCD99$^{TMcytoI}$ in the presence of 200mM DPC and CHAPS displayed an existence $\alpha$-helical conformation. The solution structure of hCD99$^{cytoI}$ determined by NMR is composed of one N-terminal $\alpha$-helix, $\alpha$A, two C-terminal short $\alpha$-helix segments, $\alpha$B and $\alpha$C. While $\alpha$A and $\alpha$B are connected by the long flexible loop, $\alpha$B and $\alpha$C connected by type III$\beta$-turn. Although it has been rarely figured out the correlation between structure and functional mechanism of hCD99$^{TMcytoI}$ and hCD99$^{cytoI}$, there is possibility of dimerization or oligomerization. In addition, the feasible mechanism of hCD99$^{cytoI}$ is that it could have intramolecular interaction between the N- and C- terminal domain through large flexible AB loop.

• 약학회지
• /
• 제39권3호
• /
• pp.276-282
• /
• 1995

Compared to the first and second-generation cephalosporins, the third-generation cephalosporins are remarkably stable against hydrolysis by the $\beta$-lactamases produced by aerobic gram-negative bacilli, such as Enterobacteriaceae. Among these bacteria, the most prevalent plasmid-encoded $\beta$-lactamase is TEM-1 $\beta$-lactamase belonging to class A or group 2b. This enzyme is produced constitutively and is principally active against peniciflins and old cephalosporins rather than third-generafion cephalosporins, carbapenems and mmobactams. However, new TEM type $\beta$-lactamases including TEM-9 and TEM-12 evolved through point mutations in a gene encoding $\beta$-lactamase have been discovered from patients during chemotherapy. These $\beta$-lactamases are known to be capable of hydrolyzing most of the third-generatim cephalosporins. To study the prevalence of $\beta$-lactamases from clinical isolates collected in Korea. the minimal inhibitory concentratims(MICs) of several third-generation cephalosporins against 628 clinical isolates were determined by agar dilution methods, and $\beta$-lactamas-producing bacteria were isolated by use of cefinase disc. By polymerase chain reaction (PCR) method, clinical isolates harboring a gene for TEM type $\beta$-lactamase were identified among the $\beta$-lactamase producing strains. Twentiy three percent of the clinical isolates was resistant to the thirdgeneration cephalosporins, and more than 90% of resistant cells produced various $\beta$-lactamases. TFM type $\beta$-lactamases were dominant in gram-negative bacilli, such as Escherichia coli, Klebsiella pneumoniae, Enterobacter species. These results suggest the necessity of the development of new cephalosporins which are stable against $\beta$-lactamases like TEM.