• 한국식품영양과학회지
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• 제41권5호
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• pp.714-720
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• 2012

콩 발효식품인 청국장과 된장에서 분리한 $Enterococcus$의 항생제 내성을 평가하고자 31개의 청국장과 17개의 된장으로부터 $Enterococcus$를 분리, 동정한 후 항생제 내성특성을 분석하였다. 모든 청국장 시료에서 119균주, 된장시료에서 4균주, 총 123개의 $Enterococcus$를 분리하였고 가장 많이 분리된 종은 청국장에서는 $E.$ $faecium$ 69균주, $E.$ $faecalis$ 20균주 등이며 된장시료에서 분리한 4균주는 모두 $E.$ $faecium$으로 동정되었다. 총 123개의 $Enterococcus$는 ampicillin, chloramphenicol, penicillin, tetracycline에 내성이 낮게 나타났다. 그리고 erythromycin, ripampin, streptomycin 등에게는 내성이 높은 것으로부터 민감성이 있는 것까지 다양하게 분포하였다. 청국장에서 분리된 $Enterococcus$의 vancomycin MiC 범위는 0.25~8 ${\mu}g/mL$로 나타났으며, MiC 8 ${\mu}g/mL$ 정도의 낮은 내성균 17균주가 $E.$ $faecalis$, $E.$ $faecium$, $E.$ $gallinarum$, $E.$ $casselifalvus$ 등에 고르게 분포되어 있음을 알 수가 있었다. 모든 분리균주에서 고농도 vancomycin 내성유전자인 $van$A, $van$B는 검출되지 않았다. 본 연구의 결과 $Enterococcus$는 자연환경에 널리 분포하고 있는 만큼 가공식품에는 항생제 내성균주와 vancomycin-resistant $Enterococcus$가 존재할 수 있으나 이들 청국장, 된장 등의 콩 발효식품 $Enterococcus$에는 주요 항생제에 내성정도가 높지 않아 항생제 안전성이 있는 것으로 보인다.

• 한국축산식품학회지
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• 제33권1호
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• pp.133-138
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• 2013

본 연구에서는 서울시내 256곳의 판매점에서 구입한 축산물 및 수산물에서 Enterococcus faecalis 와 Enterococcus facium을 분리하였으며 분리된 균주의 항생제 내성양상과 vancomycin 내성 유전자 보유여부를 검증하였다. 총 256개 시료 중 117개에서 E. faecalis(40.6%)와 E. faecium(5.1%)가 검출되어 45.7%의 분리율을 나타내었다. 축산물은 192개 중 105개 균주가 분리되어 54.7%의 분리율을 나타내었는데 닭고기에서 가장 높은 68.8%의 분리율을, 돼지고기에서 50.0%의 분리율을, 쇠고기에서 45.3%의 분리율을 나타내었다. 횟감어류에서는 18.8%의 분리율을 나타내었다. 분리된 균주에 대한 항생제 내성 양상은 10종의 항생제 디스크를 이용하여 검증하였다. Tetracycline의 내성률이 52.1%로 가장 높았으며, erythromycin의 내성률이 27.4%로 두 번째로 높게 나타났다. Ampicillin과 penicillin는 1개의 균주를 제외하고는 모두 감수성을 보였으며, amoxicillin & clavulanic acid에는 모든 균주가 감수성을 보였다. Vancomycin에는 모든 균주가 감수성을 보여 VRE는 검출되지 않았다. 분리된 균주의 vancomycin 내성유전자의 검출은 multiplex PCR을 이용하여 vanA gene과 vanB gene 보유여부를 확인하였다. vanA gene이 검출된 균주는 없었으나, vancomycin에 감수성을 나타내던 9개의 균주에서 vanB gene이 검출되어 VRE균 출현의 잠재적인 가능성을 보여주었다.

• 대한수의학회지
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• 제43권1호
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• pp.103-112
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• 2003

A multiplex PCR assay, which allows simultaneous detection of vancomycin resistant genotypes and Enterococcus species-specific genes, was developed. Vancomycin resistant enterococci (VRE) from chickens and humans could be detected for vanA, vanB, vanC-1, vanC-2, $ddl_{E.faecium}$ and $ddl_{E.faecalis}$ by multiplex PCR. Eight isolates of VRE from humans (n=11) had $ddl_{E.faecium}$ and vanA, and 3 isolates of the VRE had $ddl_{E.faecium}$ and vanB. One isolate of VRE from chickens (n=6) had $ddl_{E.faecium}$ and vanA, and 5 isolates of the VRE had only vanA. E. faecium, E. faecalis, E. gallinarum and E. casseliflavus were also confirmed for the species-specific gene by multiplex PCR. This multiplex PCR could detect E. faecium, E. faecalis, E. gallinarum, E. casseliflavus, vanA, vanB, vanC-1 and vanC-2, simultaneously. The PCR assay established in the present study can be an alternative to time-consuming biochemical tests and antibiotic susceptibility tests of Enterococcus spp.

• Molecules and Cells
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• 제44권3호
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• pp.179-185
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• 2021

Vancomycin response regulator (VncR) is a pneumococcal response regulator of the VncRS two-component signal transduction system (TCS) of Streptococcus pneumoniae. VncRS regulates bacterial autolysis and vancomycin resistance. VncR contains two different functional domains, the N-terminal receiver domain and C-terminal effector domain. Here, we investigated VncR C-terminal DNA binding domain (VncRc) structure using a crystallization approach. Crystallization was performed using the micro-batch method. The crystals diffracted to a 1.964 Å resolution and belonged to space group P212121. The crystal unit-cell parameters were a = 25.71 Å, b = 52.97 Å, and c = 60.61 Å. The structure of VncRc had a helix-turn-helix motif highly similar to the response regulator PhoB of Escherichia coli. In isothermal titration calorimetry and size exclusion chromatography results, VncR formed a complex with VncS, a sensor histidine kinase of pneumococcal TCS. Determination of VncR structure will provide insight into the mechanism by how VncR binds to target genes.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권3호
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• pp.153-158
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• 2000

Vancomycin belongs to the vancomycin-risocetin family of glycopeptides, and is a subclass of linear sugar containg peptides composed of seven amino acids. Its strochemical configuration forms the basic of a peptidoglycon monomer. The glycosylated hexapeptide chainconsists of chloro-$\beta$-hydroxytyrosines, p-hytidoglycines, N-anthylleucine and aspartic acid forms a rigid molecular frame work and gives the difficulty in the analysis. Voncomycin in the serum samples is usually estimated by liquid chromatography and the bacterial sensitivity was genereally tested by the microbiological assay. The pressent review deals with the qualitative, quantutative, microbioligical and immunological assays and the comparison of the quantitative methods. Clinical implications of vancomycin have also been cited in the review.

• 대한수의학회지
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• 제39권2호
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• pp.343-352
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• 1999

Vancomycin resistant enterococci (VRE) have emerged as an important nosocomial pathogen. Since 1989 the Center for Disease Control, United States, has reported a rapid increase in the incidence of enterococcal bacteremia and endocarditis infection by VRE. It was suggested that the use of avoparcin was associated with the appearance of VRE in animal husbandry. To date, several detection methods have been used based on conventional methods of culture and gene detection. However, these methods have some limitations such as time-consuming, laborious and additional differential needs. Therefore, In this study a multiplex PCR method was established to detect and differentiate resistance types of enterococci which specifically amplify the four van genes encoding vancomycin resistance elements. Using the method, we investigated the incidence rates and types of VRE from farms using or not using avoparcin. A total of 1091 animal fecal samples were collected from 70 pig and 32 poultry farms. A total of 425 of enterococci were isolated from samples. Of the 425 isolates, 11 of the them showed a pattern of high-level vancomycin resistance (MIC : $64{\sim}256{\mu}g/ml$) which was associated with the presence of the vanA or vanB gene. Fifty-seven isolates showed a pattern of low-level vancomycin resistance (MIC : $3{\sim}8{\mu}g/ml$) associated with the vanC-1 or vanC-2 gene. Interestingly, all isolates with high-level vancomycin resistance were from farms that have never used avoparcin. Moreover, the high-level VRE isolation rate in Korea (2.58%) was much lower than that of other countries (50% in England, 7% in Belgium) where avoparcin have been used. In conclusion, the multiplex PCR method established in this study could be applied for detection of VRE.

• Advances in environmental research
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• 제7권3호
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• pp.213-223
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• 2018

Continuous input into the aquatic ecosystem and persistent structures have created concern of antibiotics, primarily due to the potential for the development of antimicrobial resistance. Degradation kinetics and mineralization of vancomycin B (VAN-B) by photocatalysis using $TiO_2$ and ZnO nanoparticles was monitored at natural pH conditions. Photocatalysis (PC) efficiency was followed by means of UV absorbance, total organic carbon (TOC), and HPLC results to better monitor degradation of VAN-B itself. Experiments were run for two initial VAN-B concentrations ($20-50mgL^{-1}$) and using two catalysts $TiO_2$ and ZnO at different concentrations (0.1 and $0.5gL^{-1}$) in a multi-lamp batch reactor system (200 mL water volume). Furthermore, a set of toxicity tests with Daphnia magna was performed to evaluate the potential toxicity of oxidation by-products of VAN-B. Formation of intermediates such as chlorides and nitrates were monitored. A rapid VAN-B degradation was observed in ZnO-PC system (85% to 70% at 10 min), while total mineralization was observed to be relatively slower than $TiO_2-PC$ system (59% to 73% at 90 min). Treatment efficiency and mechanism of degradation directly affected the rate of transformation and by-products formation that gave rise to toxicity in the treated samples.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제3권1호
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• pp.98-104
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• 2000

Pseudomembranous colitis, thought to be uncommon in children, is a bacterial, toxin-mediated inflammatory process resulting in acute or chronic diarrhea and is characterized by colonic pseudomembranes. It is mediated by toxins produced by Clostridium difficile and is increasingly recognized in pediatric population. Diagnosis is based on positive culture of C. difficile in selective media and positive test of C. difficile toxin. Oral metronidazole or vancomycin are the main treatment options but avoidance of further antibiotics should also be encouraged where possible. We have experienced a case of pseudomembranous colitis in a 4-year-old female presented with septic shock and colitis. This case was diagnosed with positive test of C. difficile toxin B and confirmed by isolation of the organism on cultire in selective media. Symptoms have been ameliorated by discontinuation of antibiotics and administration of metronidazole and oral vancomycin, and ICU care.

• 대한임상검사과학회지
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• 제43권3호
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• pp.124-132
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• 2011

The aim of this study was to evaluate the effects of the photosensitizer photogem with light-emitting diode (LED) on vancomycin-resistant enterococci (VRE). Two VRE strains isolated from the feces of patients. that was identificated Enterococcus faecium (vanA) and Enterococcus gallinarum (vanC1) using traditional biochemical tests and confirmed VRE genotyping from using polymerase chain reaction. In addition, three strains were used Enterococcus. faecalis CDC-286 (vanA), E. faecalis CDC-583 (vanB) and E. gallinarum CDC-42 (vanC1). To examine the antimicrobial effect of photogem mediated photodynamic therapy (PDT) against, CFU quantification and Disk diffusion antimicrobial susceptibility test were evaluated. The effects of Photodynamic therapy was not associated with genotype. Photogem mediated PDT perfectly inhibited the colony formation of E. faecalis CDC-286. The number of viable bacteria decreased greatly after PDT application with photogem $50{\mu}g/mL$ and energy density of $15J/cm^2$. The diameter of inhibition zone was increased to after PDT more than before PDT. The case of vancomycin disc on E. faecalis CDC-583 and E. galinanum-Patient were changed from resistant to intermediate resistant, from intermediate resistant to susceptable. These results demonstrate that lethal photosensitization of VRE can be achieved using photogem plus 630 nm LED irradiation.

• 약학회지
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• 제51권4호
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• pp.253-258
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• 2007

Bombycis corpus, a batryticated silkworm and white-stiff silkworm, is an oriental drug consisting of the dried larva of silkworm, dead and stiffened due to the infection of Beauveria. An peptidyl antimicrobial molecule was purified from B. corpus by reverse phase-column chromatography and HPLC. Its molecular weight was determined to be 2295.45 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Its antimicrobial activity was diminished by trypsin digestion. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram- positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin-resistant enterococci (VRE), methicillin-resistant S. arureus (MRSA), and vancomycin-intermediate resistant S. arureus (VISA). It may be a useful molecule for a new antibiotic development, especially against antibiotic resistant microbe. This substance may play a role in the defense system of this animal against Beauveria bassiana. This is the first report of a peptidyl antimicrobial substance from B. corpus.