본 시험은 무궁화과에 속하는 초본 식물인 Kenaf (Hibiscus cannabinus L.)를 경상대학교 시험농장 에서 2010년 6월 1일 파종하여 같은 해 11월 18일 수확하여 건조 한 후, 꽃 (HCME-F)과 잎 (HCME-L)에서 추출한 메탄올 추출물을 이용하여, 세포 독성 시험 및 주요 병원균에 대한 항균효과를 규명하였다. 항균효과에 사용된 균주는 가축에서 피부 질환, 유방염 및 소화기질병을 유발하는 그람양성 균인 St. aureus 와 Str. epidermidis, 그람음성균인 S. typhimurium 과 E. coli 균을 공시균주로 사용하였다. 추출물의 안전성을 평가하기 위해 두 추출물 HCME-F과 HCME-L을 0, 25, 50, 100 및 200 ㎍/ml 농도로 첨가한 배지에서 RAW 264.7 세포와 24시간 반응 후 세포 독성을 측정해 본 결과, 세포 독성이 인정되지 않았으며, 항균효과 시험결과 그람양성균인 St. aureus와 Str. epidermidis 균에 대하여 1, 50 및 100 ㎍/ml의 추출물 농도 및 반응시간 경과에 따라 항균 효과가 증가되었으나, 그람음 성균인 S. typhimurium 과 E. coli 에서는 항균효과가 인정되지 않았다. 종합적으로 Kenaf의 꽃과 잎 에서 추출한 메탄올 추출물이 세포에 대한 안전성이 입증되었고, 가축과 사람의 피부 질환 및 유방염의 대표적 그람양성균인 St. aureus와 Str. epidermidis 균에 대한 항균효과를 보여, Kenaf의 꽃과 잎을 이용한 선택적 그람양성균 치료제 및 사료첨가제 개발이 가능할 것으로 판단된다.

Salmonellosis is the commonest zoonosis worldwide that generally causes enterocolitis and foodborne poisoning which represents a considerable public health burden. Salmonella spp. are potential enteric pathogens and intracellularly replicates in host cells resulting in chronic infections. The medical treatments for salmonellosis have been difficult yet and had a serious problem including the increasing emergence of antibiotic resistance. The present report was designated to investigate the antibacterial effects of Saururus chinensis Baill ethanol extract (SCEE) on pure culture and infection with Salmonella enterica serovar Typhimurium (S. typhimurium) in murine derived macrophage RAW 264.7 cells. In determination of antibacterial activity of SCEE against S. typhimurium, bacterial viability was markedly decreased compared to the control. Also, SCEE significantly induced morphological change (p<0.05) of RAW 264.7 cells. In infection assay of S. typhimurium in RAW 264.7 cells pretreated with 100㎍/㎖ of SCEE, which is a non-cytotoxic concentration, bacterial uptake ability of macrophage was increased corresponding with morphological change, whereas bacterial survival rates within macrophage were markedly reduced compared with untreated control. Furthermore, nitric oxide (NO) production in SCEE-treated cells was slightly increased until 2 h but showed a tendency of decrease after 4 h until 24 h post infection compared with untreated control with S. typhimurium infection. Taken together, these findings demonstrated that SCEE has the antibacterial activity for S. typhimurium and the protective effects against S. typhimurium infection through activating murine macrophage independent on NO, suggesting that SCEE may be beneficial on the disease caused by intracellularly replicating pathogens as a safe alternatives of conventional chemotherapies.

살모넬라증은 대표적인 인수공통전염병의 하나로서 세포내 기생하며 질병을 유발하며 장염과 식중독 등을 유발하여 공중보건학적으로 심각한 문제를 야기하고 있다. 본 연구는 삼백초의 수용성 추출물을 (SCWE) 이용하여 숙주세포에 대한 안전성, S. typhimurium 균에 대한 항균효과 및 대식세포 내 균 증 식억제 기능을 규명하였다. 본 실험을 통하여 SCWE 1, 10 및 100 μg/ml 농도로 첨가한 배지에서 RAW 264.7 체포와 24 시간 반응 후 평가해본 결과 세포독성이 인정되지 않았으며, S. typhimurium 균에 대하여 시간 경과에 따라 항균효과가 증가되는 것을 확인하였고, SCWE 처리에 의해 대식세포의 형태적 변화가 증가되는 것으로 나타났으며 (p<0.05), 살모넬라균의 탐식능력 및 대식세포 내 균 증식 억제 능 력이 비 처리군에 비해 현저히 증가되는 것이 확인되었다. 또한 SCWE 처리 한 대식세포에 살모넬라균 감염을 수행하였을 때 대식세포의 nitric oxide (NO) 산생능력이 비 처리 군에 비해 저하되는 것으로 나타나, 살모넬라균에 의한 대식세포의 세포독성을 억제하는 것으로 나타났다. 종합적으로 SCWE의 숙 주세포에 대한 안전성, 살모넬라균에 대한 항균효과 및 대식세포 내 균 증식 억제 효과가 있는 것으로 나타나 SCWE를 이용한 세포내 기생세균의 치료제 개발이 가능할 것으로 판단된다.

Thrombin-induced platelet microbicidal protein (tPMP) is a small cationic peptide that exerts potent in vitro microbicidal activity against a broad spectrum of human pathogens, including Staphylococcus aureus and Streptococcus rattus BHT. Earlier evidence has suggested that tPMP targets and disrupts the bacterial membrane. However, it is not yet clear whether membrane disruption itself is sufficient to kill the bacteria or whether subsequent, presumably intracellular, events are also involved in this process. In this study, we investigated the microbicidal activity of rabbit tPMP toward S. rattus BHT cells in the presence or absence of a pretreatment with antibiotics that differ in their mechanisms of action. The streptocidal effects of tPMP on control cells (no antibiotic pretreatment) were rapid and concentration-dependent. Pretreatment of S. rattus BHT cells with either penicillin or amoxicillin (inhibitors of bacterial cell wall synthesis) significantly enhanced the anti-S. rattus BHT effects of tPMP compared with the effects against the respective control cells over most tPMP concentration ranges tested. On the other hand, pretreatment of S. rattus BHT cells with tetracycline or doxycycline (30S ribosomal subunit inhibitors) significantly decreased the streptocidal effects of tPMP over a wide peptide concentration range. Furthermore, pretreatment with rifampin (an inhibitor of DNA-dependent RNA polymerase) essentially blocked the killing of S. rattus BHT by tPMP at most concentrations compared with the respective control cells. These results suggest that tPMP exerts anti-S. rattus BHT activity through mechanisms involving both the cell membrane and intracellular targets.

To develop a lactic starter to produce antimicrobial substance for inhibiting the growth of a variety of foodborne spoilage bacteria in fermented foods, we investigated the antibacterial effect of the antibacterial substance, produced by Lactobacillus amylovorus IMC-1, against foodborne spoilage strains, and its sensitivity on the treatment of proteolytic enzymes. L. amylovorus IMC-1, which was isolated from a traditional cheese in Inner Mongolia, produced a maximum amount of antibacterial substance in the skim milk medium after 72 h incubation at 37℃, and further incubation resulted in the same activity. The substance obtained from gel filtration inhibited all strains used such as Bacillus subtilis IFO 3025, Staphylococcus aureus IAM 1011, Listeria monocytogenes VTU 206, Escherichia coli RB, and Pseudomonas fragi IFO 3458 at the concentration of 20 units/ml. This substance was found to show bactericidal action against B. subtilis, E. coli, and Ps. fragi, and bacteriostatic activity against both Staph. aureus and L. monocytogenes. The bactericidal action was due to cellular lysis. The substance is not organic acid, hydrogen peroxide and proteinaceous compound.

본 연구의 목적은 L. monooytogenes에 대한 LP system의 항균효과를 측정하기 위하여 수행되었다 초기 접종수준(10², 10⁴, 10^(7) CFU/ml), LP의 농도는(10, 20, 30 ppm), 그리고 저장온도(5, 10, 15℃), 배지종류(TSB-YE, UHT milk)에 따라 L. monocytogenes에 대한 항균효과를 측정 비교한 결과 초기접종수준을 10²cfu/ml로 하였을 때와 LP농도는 10 ppm 및 5℃로 배양에서 항균력이 높게 나타났다. UHT milk를 이용한 LP system의 항균효과는 Tryptic soy agar를 이용한 시험결과와 비슷하게 나타났다.

본 연구 E. coli O157:H7에 대한 LP system(lactoperoxidae/thiocyanate/hydrogen peroxide)의 항균효과를 측정하기 위해 수행되었다. 초기 접종수준(10^2, 10^4, 10^7 cfu/ml), LP의 농도(10 ppm, 20 ppm, 30 ppm), 배지종류 (TSB, UHT milk, raw milk), 배양온도(5℃, 10℃, 15℃) 등에 따라 E. coli O157:H7에 대한 항균효과를 측정, 비교한 결과, 초기 접종수준을 10^2/ml으로 하였을 때와 LP의 농도를 10 ppm 및 5℃ 배양에서 항균력이 가장 높게 나타났다.

Background : Panos extract is a mixture of four Panax plant extracts namely Dendropanax morbifera, Panax ginseng, Acanthopanax senticosus and Kalopanax septemlobus. We intended to use Panos extract for ZnO nanoparticles(NPs) synthesis and application for waste water treatment. Methods and Results : In the present study, we have synthesized Panos ZnO nanoparticles via co precipitation method. Characterization of the NPs has been done using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and UV-Visible spectroscopy. An average of 75% efficacy in degrading the methylene blue dye has been observed. The nanoparticles showed antibacterial activity against E. coli and S. aureus. Conclusion : The results shows that Panos ZnO NPs can be a potential eco-friendly and economical tool for waste water management in the current scenario where there an intense urge to remediate the polluted environment through novel approaches such as Nanobiotechnology.

Background: The objective of this study were to determine the antibacterial activity and antibiotic activity-enhancing effect of 70% ethanol extract of the root of Rumex japonicus Houtt. and its fractions when used in combination with gentamicin against aerobic skin flora. Methods and Results: The antibacterial activity and antibiotic (gentamicin) activity enhancing effect against aerobic skin flora were determined using the disc diffusion assay. Chloroform fraction (CF) and ethyl acetate fraction (EF) showed higher activities against Staphylococcus aureus and Staphylococcus epidermidis than those shown by other fractions. Regarding the antibiotic (gentamicin) activity-enhancing effect against aerobic skin flora, the n-hexane fraction (HF) and CF showed strong activity. The combination of HF and CF with gentamicin was evaluated using the broth dilution assay to determine the inhibitory effect on the growth of aerobic skin flora. The combination of CF with gentamicin exhibited the highest inhibitory effect on the growth of S. aureus and S. epdermidis. MTT assay performed to determine the viability of L929 cells revealed that EF treatment resulted in viability of 33.96 - 116.76% at the tested concentration. The combination of 70% ethanol extract and its other fractions with gentamicin showed low cell toxicity. Conclusions: Appropriate use of antimicrobial agents is important prior to the development of new antibiotics. The 70% ethanol extract of the root of R. japonicus Houtt. and its fractions showed significant synergism with gentamicin when used in combination against S. aureus and S. epdermidis. Thus, R. japonicus Houtt. could be used as a functional materials in antimicrobial-related fields.

Methicillin-resistant Staphylococcus aureus (MRSA) is a substantial contributor to morbidity and mortality. In search of a natural products capable of inhibiting this multidrug resistant bacteria, we have investigated the antimicrobial activity of brazilein (BRZ) isolated from Caesalpinia sappan L. (Leguminosae) against 8 different strains of Staphylococcus aureus (S. aureus). New antimicrobial activity was found using the minimum inhibitory concentrations (MICs), broth dilution as well as checkerboard method. Against the 8 strains, the minimum inhibitory concentrations of BRZ were in the range of 62.5-500μg/mL. From those results we performed the checkerboard test to determine the synergism of BRZ in combination with Hygromycin-b (HgB) against 4 strains. The combined activity of BRZ and HgB against 4 strains resulted in a fractional inhibitory concentrations index (FICI) ranging from 0.18-0.5. The effect of BRZ with HgB was found to be synergistic. We found that BRZ reduced the MICs of HgB. BRZ and HgB could lead to the development of new combination antibiotics against MRSA infection.

An author has been known that A-type zeolite supported with silver ions has excellent antibacterial activity. However, it is no research of concern in the antibacterial activity of eluted silver ions. This study tested the elution of silver ions from A-type zeolite silver ions in deionized distilled water and NaNO3 aqueous solution. In NaNO3 aqueous solution of 74mM to 588mM, it was found that the concentration of silver ions and electric conductivity increased with the increasing concentration of sodium ions, and equilibrated at 15 min, and the ion exchange equilibrium coefficient, k, is 1.3×10-3. However, deionized distilled water is not equilibrated to pass 6 months. A-type zeolite sodium ions showed no antibacterial activity. It was found that antibacterial activity was exhibited even at the concentration of 10 nM of eluted silver ions, and E-coli died with the incorporation of 2.43×108 Ag ion/cell. antibacterial activity of A-type zeolite silver ions were mainly attributed to hydroxyl radical.

The antibiotic and antioxidant effect of botanical antimicrobial agent-citrus product(BAAC) prepared from citrus fruits were investigated by using fishmeats made from pollack and ascidian fillet. We inoculated Salmonella typhi into fishmeats that were aferwards treated with BAAC varying the concentration level (50-500ppm) including the control not-treated with BAAC. While specimens were stored at 5 for designated period, we measured changes of total number of bacteria, peroxide level and textural properties. In addition, we performed organoleptic examination, focusing on appearance, texture and odor for fishmeats treated with BAAC and stored for designated period. For pollack and ascidian fishmeats, the initial total number of bacteria were 3.7l0CFU/g and 7.5l0CFU/g, respectively. After they were treated with 250 ppm of BAAC solution and stored for 5 days at 5, the figures reduced to 2.5l0CFU/g and 8.410CFU/g. No bacteria were found in fishmeats treated with above 500 ppm of BAAC, which remarkably proved antibiotic effect of BAAC solution. Furthermore, all the BAAC-treated specimens exhibited notable antioxidant effect. Fishmeats which were previously treated with 500 ppm of BAAC solution and stored for 30 days at 5, showed the lower peroxide level of 16.5 meq/kg than 68.9 meq/kg in the control of pollack and 21.2 meq/kg than 80.7 meq/kg in the control of ascidian. In the results of texture and organoleptic evaluation we could also observe good effects of BAAC on maintaining the freshness of fisher products.

쇠뜨기에 다른식물의 생장을 저해하는 물질이 생성되는지를 알아보기 위하여, 수용추출액으로 몇가지 식물의 캘러스 생장, 종자발아, 유묘생장 및 항균활성에 미치는 영향을 조사하였다. 수용 추출액의 첨가농도가 높은 배지에서 벼와 배추의 캘러스 유기 및 발달을 억제하였으며, 80℃ 추출액이 25℃ 추출액보다 유의하게 캘러스 유기 및 생장을 억제하였다. 20%추출액 첨가배지에서 공시식물의 캘러스 생장은 추출온도에 관계없이 도라지, 참깨, 배추, 벼 순으로 억제되었다. 냉동건조한 수용추출액 고형물은 저농도에서는 영향이 적었으나, 처리농도에 비례하여 벼, 참깨, 배추의 종자발아를 억제하였고, 특히 배추는 2,000μg/mι농도에서 대조구의 28.3%로 급격한 발아억제를 보였다. 유식물 생장은 500μg/mι의 저농도에서는 대조구보다 초장이 약간 촉진되는 경향을 보였으나, 처리농도가 증가함에 따라 심하게 억제되었으며, 특히 근장이 유의하게 억제되었다. 추출액 고형물의 항균활성은 500μg에서 E. carotovora에서만 약간의 억제대를 형성하였으며, X. oryzae pv. oryzae와 E. coli에 대해서 는 항균활성을 보이지 않았다.