• Pediatric Infection and Vaccine
• /
• 제23권3호
• /
• pp.229-235
• /
• 2016

최근 전 세계적으로 메티실린내성 황색포도알균(methicillin-resistant Staphylococcus aureus [MRSA])에 의한 감염성 심내막염의 빈도가 증가하는 추세이다. 저자들은 12세 여아가 침습적 치과 치료 이후에 발생한 MRSA에 의한 감염성 심내막염 1예를 경험하였기에 보고하는 바이다. 환아가 경부강직을 나타내어 시행한 뇌척수액 검사상 세포 증가증 소견이 보였고 세균성 수막염을 의심하여 항생제 치료를 시작하였으며, 입원 3병일째 혈액 배양검사에서 MRSA가 검출되었다. 심장 초음파상 승모판막의 전엽에 붙어있는 증식조직이 증명되어 항생제 치료 후 호전되어 퇴원하였다. 개정된 심내막염 예방을 위한 가이드라인에서는 오직 고위험군에서만 치과 처치 전에 예방적 항생제 요법을 권장하고 있다. 본 증례는 승모판 탈출증 이외에 고위험군이 없었던 환아에서 잇몸의 출혈을 유발하는 치과 치료를 받은 이후에 발병한 감염성 심내막염의 경우로서, 이후 12개월간 감염성 심내막염의 재발은 없었다.

• 생명과학회지
• /
• 제17권3호통권83호
• /
• pp.412-419
• /
• 2007

본 연구는 병원 내 감염의 주된 원인균으로 알려진 황색 포도상구균(Staphylococcus aureus : S. aureus)와 항생제 내성구균 (Methicillin-Resistant Staphylococcus aureus : MRSA)에 대해 항균활성이 우수한 천연 항균성 물질을 검색하기 위해 예로부터 민간과 한방에서 널리 이용되어 온 38종의 약용식물을 메탄올에 추출하여 항균활성을 조사해 보았다. MRSA에 대해 항균력 검색을 한 결과 세신, 황련, 호장근, 미역취씨 순으로 높은 항균활성이 나타났다. MRSA로 선별된 4종의 약용식물에 대해 농도와 배지를 다르게 하여 항균력을 측정한 결과 완전 배지인 TSA 배지에서 항균력을 측정한 결과 세신이 고농도인 5 mg/disc에서 S. aureus, MRSA 에 대해각각 21 mm, 19 mm로 우수한 항균력을 보였고, 미역취씨를제외한 3종의 약용식물은 S. aureus에서 MRSA보다 높은 항균력을 보였으며 미역취씨의 경우 두 균주 모두에서 효과가 나타나지 않았다. MSA 배지에서는 4종의 약용식물 모두 TSA 배지보다 높은 저해율을 보였고 특히 세신이 5 mg/disc 농도에서 S. aureus을 30 mm에 가까운 아주 우수한 항균력을 보였으며, 낮은 농도에서도 20 mm이상의 저해를 보였다. 미역취씨의 경우 TSA 배지에서는 항균력을 나타내지 않았으나 MSA배지의 경우 2.5 mg/disc의 낮은 농도에서도 두 균주 모두에서 10 mm이상을 저해하는 항균력을 보였다. 또한 4종의 약용식물을 서로 혼합하였을 경우 항균효과를 측정한 결과 TSA배지의 경우 두 균주 모두에서 세신과 황련을 혼합하였을 경우 세신, 황련의 각각 2.5 mg/disc의 항균력 보다 높게 나타났으며, MSA 배지의 경우 두 균주 모두에서 세신과 혼합한 3종의 약용식물에서 모두 항균력이 상승했고, 특히 호장근과 미역취씨는 20 mm의 높은 항균력을 보였다.

• Journal of Microbiology and Biotechnology
• /
• 제32권2호
• /
• pp.220-227
• /
• 2022

The spread of antibiotic-resistant strains of Staphylococcus aureus, a gram-positive opportunistic pathogen, has increased due to the frequent use of antibiotics. Inhibition of the quorum-sensing systems of biofilm-producing strains using plant extracts represents an efficient approach for controlling infections. Torilis japonica is a medicinal herb showing various bioactivities; however, no studies have reported the anti-biofilm effects of T. japonica extracts against drug-resistant S. aureus. In this study, we evaluated the inhibitory effects of T. japonica ethanol extract (TJE) on biofilm production in methicillin-sensitive S. aureus (MSSA) KCTC 1927, methicillin-resistant S. aureus (MRSA) KCCM 40510, and MRSA KCCM 40511. Biofilm assays showed that TJE could inhibit biofilm formation in all strains. Furthermore, the hemolysis of sheep blood was found to be reduced when the strains were treated with TJE. The mRNA expression of agrA, sarA, icaA, hla, and RNAIII was evaluated using reverse transcription-polymerase chain reaction to determine the effect of TJE on the regulation of genes encoding quorum sensing-related virulence factors in MSSA and MRSA. The expression of hla reduced in a concentration-dependent manner upon treatment with TJE. Moreover, the expression levels of other genes were significantly reduced compared to those in the control group. In conclusion, TJE can suppress biofilm formation and virulence factor-related gene expression in MSSA and MRSA strains. The extract may therefore be used to develop treatments for infections caused by antibiotic-resistant S. aureus.

• Journal of Microbiology and Biotechnology
• /
• 제15권5호
• /
• pp.1039-1046
• /
• 2005

The salt resistance of antibacterial activity and synergistic effect with clinically used antibiotic agents are critical factors in developing effective peptide antibiotic drugs. For this reason, we investigated the resistance of antibacterial activity to antagonism induced by NaCl and $MgCl_2$ and the synergistic effect of P20 with cefotaxime. P20 is a 20-residue synthetic peptide derived from a cecropin A (CA)-melittin(ME) hybrid peptide. In this study, P20 was found to have potent antibacterial activity against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) strains without hemolytic activity against human erythrocytes. The combination study revealed that P20 in combination with cefotaxime showed synergistic antibacterial activity in an energy-dependent manner. We also confirmed the synergism between P20 and cefotaxime by fluorescence-activated flow cytometric analysis by staining bacterial cells with propidium iodide (PI) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (BOX). This study suggests that P20 may be useful as a therapeutic antibiotic peptide with synergistic effect in combination with conventional antibiotic agents.

• Clinical and Experimental Pediatrics
• /
• 제59권2호
• /
• pp.96-99
• /
• 2016

Survival rates of preterm infants have improved in the past few decades, and central venous catheters play an important role in the intensive medical treatment of these neonates. Unfortunately, these indwelling catheters increase the risk of intracardiac thrombosis, and they provide a nidus for microorganisms during the course of septicemia. Herein, we report a case of persistent bacteremia due to methicillin-resistant Staphylococcus aureus in an extremely low birth weight (ELBW) infant, along with vegetation observed on an echocardiogram, the findings which are compatible with a diagnosis of endocarditis. The endocarditis was successfully treated with antibiotic therapy, and the patient recovered without major complications. We suggest a surveillance echocardiogram for ELBW infants within a few days of birth, with regular follow-up studies when clinical signs of sepsis are observed.

• 대한의생명과학회지
• /
• 제15권3호
• /
• pp.233-239
• /
• 2009

The aim of this study was to evaluate the photodynamic effect of various photosensitizing agents against methicillin-resistant Staphylococcus aureus (MRSA). MRSA was exposed to light from a 632 urn diode laser (15 J/$cm^2$) in the presence of various photosensitizer, such as photofrin, photogem, radachlorine and ALA. In vivo study was performed using ICR mice. Twenty eight mice had a standard wound ($100\;mm^2$) created on the dorsum, and MRSA was inoculated into the wound region. The four groups were classified as follows: (1) the untreated control group (bacteria alone), (2) the bacteria plus light group (15 J/$cm^2$), (3) the bacteria plus photofrin group (kept in the dark), and (4) the photodynamic therapy (PDT) group (bacteria, photofrin, and light). After photofrin (dose 1 mg/kg) injection, the experimental group was irradiated with 632 urn diode laser (15 J/$cm^2$) for 30 minutes after In vitro results of PDT showed the complete killing of MRSA at the photofrin, radachlorine, and photogem However, ALA-PDT was ineffective on MRSA viability. In vivo results showed that photofrin has therapeutic effect on the wound infection. These results demonstrate that selective lethal photosensitization of MRSA can be achieved using phofrin, photogem and radachlorin. Thus, PDT can inactivate MRSA survival.

• 대한수의학회지
• /
• 제39권2호
• /
• pp.383-389
• /
• 1999

A randomized experimental study was done to evaluate short course therapeutic efficacies of two types of mupirocin ointment (Bactroban Nasal and Bactroban) in the elimination of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization (16 dogs) and wound infection (3 dogs or 18 wound sites) in dogs. In each model, dogs being assigned to TR-1 treatment group was given ointment twice a day for two consecutive days, and those that assigned to TR-2 treatment group was given the same dose for three days. Neither TR-1 nor TR-2 regimen was effective to clear nasal carriage completely with a clearing rate of 62.5% and 87.5%, respectively. Whereas, for 2 days at least twice daily application of mupirocin for wound infection was quite enough to eliminate MRSA, with a clearing rate of 83.3~100% by 4 weeks follow-up. No apparent side effects were observed in each model, and in no case was it necessary to discontinue the treatment. Further controlled studies on the elimination of nasal colonization are required to establish cost-effective and efficient regimen on companion animals.

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

• Environmental Engineering Research
• /
• 제24권4호
• /
• pp.566-571
• /
• 2019

One-pot hydrothermal route was adopted to synthesize Al:BiVO₄, at 4 h and 8 h reaction durations, by adding 1% aluminiumoxide powder (w/v) to the precursors. The products were investigated using several characterization techniques that conform a significant morphological change and a decrease in bandgap energy of the materials upon Al modification of scheelite monoclinic bismuth vanadate matrix at both hydrothermal durations. Antibacterial experiments were performed against methicillin-resistant Staphylococcus aureus in visible light condition to harness the photoxidation property of Al-doped BiVO₄ and compare to that of unaltered BiVO₄. Minimum inhibitory concentration of the synthesized materials was identified. The results indicate that Al-doping on BiVO₄ has a significant effect on its photocatalytic antibacterial performance. Al:BiVO₄ synthesized at 8 h hydrothermal treatment parades excellent sunlight-driven photocatalysis compared to the one synthesized at 4 h.

• 기본간호학회지
• /
• 제12권3호
• /
• pp.395-403
• /
• 2005

Purpose: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen in the intensive care units (ICUS). The purpose of this case-control study is to identify risk factors for acquisition of MRSA during ICU stays in patients with and without MRSA. Method: The study was conducted in a 16 beds-neurosurgical intensive care unit of a 2200-bed tertiary care university hospital in Seoul, Korea. Medical record and Critical Classification Scoring System were reviewed retrospectively in patients who were admitted more than 3 days from August 1, 2003 to May 30, 2004. Cases and controls were matched for age and gender. The obtained specimens were nasal swab and sputum. Result: There were 950 patients' admissions during the period. Among them, MRSA was isolated from twenty-three patients who were considered as hospital acquired. Artificial airway (p=.045), frequency of suction (p=.002), nasogastric tube (p=.004), wound drain (p=.045), and vancomycin (p=.019) were risk factors for MRSA acquisition in univariate analysis. Frequency of suction (p=.012, OR 3.5) was revealed as the only risk factor in multivariate conditional logistic regression. Conclusion: Our findings give support to recent studies that suggest that frequent physical contact maγ increase the nosocomial acquisition of MRSA in a neurosurgical ICU.