• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.189-196
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• 2021

Periplanetasin-2 from cockroach exhibits broad-spectrum antimicrobial activity. The underlying antibacterial mechanisms rely on the stimulation of reactive oxygen species overproduction to induce apoptotic cell death. A promising strategy to increase the bioavailability of periplanetasin-2 involves reducing the dose through combination therapy with other antibacterials that show synergistic effects. Thus, the synergistic antibacterial activity of periplanetasin-2 with conventional antibacterial agents and its mechanisms was examined against Escherichia coli in this study. Among the agents tested, the combinations of periplanetasin-2 with vancomycin and chloramphenicol exhibited synergistic effects. Periplanetasin-2 in combination with vancomycin and chloramphenicol demonstrated antibacterial activity through the intracellular oxidative stress response. The combination with vancomycin resulted in the enhancement of bacterial apoptosis-like death, whereas the combination with chloramphenicol enhanced oxidative stress damage. These synergistic interactions of periplanetasin-2 can help broaden the spectrum of conventional antibiotics. The combination of antimicrobial peptides and conventional antibiotics is proposed as a novel perspective on treatments to combat severe bacterial infection.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권1호
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• pp.104-111
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• 1994

Necrotizing fascitis is a severe soft tissue infection characterized by extensive necrosis of superficial fascia, suppurative fascitis, vascular thrombosis, widespread undermining of surrounding tissues. Associated systemic problems are widespread undermining of surrounding tissues, Associated systemic problems are common, with chronic alcoholism and diabetes being most prominent. Most commonly this disease presents in the extremities, trunk, and perineum. Necrotizing fascitis of dental origing is rare and its fulminating clinical course is not well documented in the dental literature. The present report is a case of necrotizing fascitis following vital extirpation of the pulp in a patient with uncontrolled diabetes mellitus and liver cirrhosis. Originally throught to be caused by hemolytic streptococcus organism or stphylococcus aureus, advances in anaerobic culturing have shown it to be a synergistic bacterial infection involving aerobic and ovligate anaerobes. it is relatively rare in relatively rare in haea and neck regions. If it was not diagnosed and treated in early stages, necrotizing fascitis can be potentially fetal, with a mortality rate approaching 40%. It's treatment requires early recognition, prompt and aggressive surgical debriment and proper supportive cares, such as, antibiotic therapy, fluid resuscitation and correction of metabolic and electrolyte disorder, resolving of the underlying systemic disease. Recently, we experienced two cases of necrotizing fascitis in cervicofacial region, One patient was 60 years old male with uncontrolled Diabetes Mellitus and other patient was 48 years old with steroid therapy during 30 years. Local surgical wound healing was successful but, patients were died after admission, because of lung abscess, gastrointestinal bleeding, septic shock and respiration hold.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.953-958
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• 2016

Chitosan-based film-forming gel is regarded as a promising vehicle for topical delivery of antimicrobial agents to skin wounds, since it protects from microbial infection and the cationic polymer itself possesses antibacterial activity. In this study, possible synergistic interaction against common skin pathogens between the cationic polymer and tyrothricin (TRC), a cyclic polypeptide antibiotic, was investigated, by determining the concentration to inhibit 90% of bacterial isolates (MIC). The addition of the polysaccharide to TRC dramatically reduced the MIC values of TRC by 1/33 and 1/4 against both methicillin-resistant and methicillin-susceptible Staphylococcus aureus, respectively. The synergism of TRC and chitosan combination against both strains was demonstrated by the checkerboard method, with a fractional inhibitory concentration index below 0.5. Moreover, co-treatment of TRC and chitosan exhibited antibacterial activity against Pseudomonas aeruginosa, due to the antibacterial activity of chitosan, whereas TRC itself did not inhibit the gram-negative bacterial growth. These findings suggested that the use of chitosan-based film for topical delivery of TRC could be an alternative to improve TRC antimicrobial activity against strains that are abundant in skin wounds.

• 대한약침학회지
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• 제22권1호
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• pp.49-54
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• 2019

Objective: Antibiotic resistance is a global health problem and threatens health of societies. These problems have led to a search for alternative approaches such as combination therapy. The aim of the present study was to investigate the effect of caffeine and omeprazole in combination with gentamicin or ciprofloxacin against standard and clinically resistant isolates of Staphylococcus aureus and Escherichia coli. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interaction of non- antibiotic drugs with gentamicin and ciprofloxacin was studied in vitro using a checkerboard method and calculating fraction inhibitory concentration index (FICI). Verapamil as efflux pump inhibitor was used to evaluate the possible mechanism of bacterial resistance to antibiotics. Results: The MIC and MBC values of gentamicin against bacterial strains were in the range of $20-80{\mu}g/ml$ and $40-200{\mu}g/ml$, respectively. Caffeine and omeprazole had no intrinsic inhibitory activity against tested microorganisms. However, upon combination of caffeine with antibiotics, the synergistic effects were observed. Verapamil was able to reduce the MIC values of gentamicin (4 folds) only in some bacterial strains. Conclusion: These findings indicated that caffeine was effective in removing bacterial infection caused by S. aureus and E. coli. The relevant mechanisms of antibiotic resistance were not related to the drug efflux.

• 한국어병학회지
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• 제13권1호
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• pp.45-51
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• 2000

최근 육상의 넙치 양식장에서는 두 가지의 서로 다른 특성을 가지는 세균성질병이 같이 감염되는 혼합감염증이 빈번하게 발생하고 있는데, 혼합감염증은 서로 다른 원인균의 특성 때문에 단일 종류의 약제만으로는 치료효과를 거두기가 어려운 실정이다. 그러므로 본 연구는 약제의 병용 투여에 의해 이들의 상승작용을 이용함으로써 합병증에 대한 치료효과를 높이기 위한 기초자료를 얻고자 실시하였다. 어류 세균성질병의 원인세균인 Vibrio anguillarum, Edwardsiella tarda, Streptococcus sp., Staphylococcus epidermidis을 선정하여 병용 항균제의 시험관내 활성을 평가하는 대표적 방법인 Checkerboard법을 적용하여 fractional inhibitory concentration (FIC)지수를 구하여 상승효과를 나타내는 병용 항균제를 찾아내었다. (OTC+LM), (TC+FF), (OTC+FF)의 병용 항균제는 V. anguillarum에 대하여, (SNF+FF), (TC+FF), (SNF+OXA), (OTC+FF)의 병용 항균제는 E. tarda에 대하여, (CFX+OL), (OTC+OL), (TC+OL), (OTC+LM), (OTC+SPM), (OTC+EM), (DOXY+OL), (TC+SPM)의 병용 항균제는 Streptococcus sp.에 대하여, (CFX+EM), (FF+EM), (DOXY+OL), (CFX+OL)의 병용 항균제는 S. epidermidis에 대하여 시험관내 상승적 상호작용을 나타내었다.

• 한국축산식품학회지
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• 제43권5호
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• pp.751-766
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• 2023

Helicobacter pylori is a bacterium that naturally thrives in acidic environments and has the potential to induce various gastrointestinal disorders in humans. The antibiotic therapy utilized for treating H. pylori can lead to undesired side effects, such as dysbiosis in the gut microbiota. The objective of our study was to explore the potential antibacterial effects of nisin and lactic acid (LA) in yogurt against H. pylori. Additionally, we investigated the anti-inflammatory effects of nisin and LA in human gastric (AGS) cells infected with H. pylori. Nisin and LA combination showed the strongest inhibitory activity, with confirmed synergy at 0.375 fractional inhibitory concentration index. Also, post-fermented yogurt with incorporation of nisin exhibited antibacterial effect against H. pylori. The combination of nisin and LA resulted in a significant reduction of mRNA levels of bacterial toxins of H. pylori and pro-inflammatory cytokines in AGS cells infected with H. pylori. Furthermore, this also increased bacterial membrane damage, which led to DNA and protein leakage in H. pylori. Overall, the combination of nisin and LA shows promise as an alternative therapy for H. pylori infection. Additionally, the incorporation of nisin into foods containing LA presents a potential application. Further studies, including animal research, are needed to validate these findings and explore clinical applications.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2018년도 춘계학술대회 및 임시총회
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• pp.44-44
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• 2018

Fusarium head blight (FHB) caused by infection with Fusarium graminearum leads to enormous losses to crop growers, and may contaminate grains with a number of Fusarium mycotoxins that pose serious risks to human and animal health. Antagonistic bacteria that are used to prevent FHB offer attractive alternatives or supplements to synthetic fungicides for controlling FHB without the negative effects of chemical management. Out of 500 bacterial strains isolated from soil, Bacillus amyloliquefaciens JCK-12 showed strong antifungal activity and was considered a potential source for control strategies to reduce FHB. B. amyloliquefaciens JCK-12 produces several cyclic lipopeptides (CLPs) including iturin A, fengycin, and surfactin. Iturin A inhibits spore germination of F. graminearum. Fengycin or surfactin alone did not display any inhibitory activity against spore germination at concentrations less than 30 ug/ml, but a mixture of iturin A, fengycin, and surfactin showed a remarkable synergistic inhibitory effect on F. graminearum spore germination. The fermentation broth and formulation of B. amyloliquefaciens JCK-12 strain reduced the disease incidence of FHB in wheat. Furthermore, co-application of B. amyloliquefaciens JCK-12 and chemical fungicides resulted in synergistic in vitro antifungal effects and significant disease control efficacy against FHB under greenhouse and field conditions, suggesting that B. amyloliquefaciens JCK-12 has a strong chemosensitizing effect. The synergistic antifungal effect of B. amyloliquefaciens JCK-12 and chemical fungicides in combination may result from the cell wall damage and altered cell membrane permeability in the phytopathogenic fungi caused by the CLP mixtures and subsequent increased sensitivity of F. graminearum to fungicides. In addition, B. amyloliquefaciens JCK-12 showed the potential to reduce trichothecenes mycotoxin production. The results of this study indicate that B. amyloliquefaciens JCK-12 could be used as an available biocontrol agent or as a chemosensitizer to chemical fungicides for controlling FHB disease and as a strategy for preventing the contamination of harvested crops with mycotoxins.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.305-315
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• 2021

The cotton leafworm, Spodoptera littoralis, is a major pest in Egypt and many countries worldwide, and causes heavy economic losses. As a result, management measures to control the spread of the worm are required. S. littoralis nucleopolyhedrovirus (SpliNPV) is one of the most promising bioagents for the efficient control of insect pests. In this study, a chitinase gene (chitA) of a 1.8 kb DNA fragment was cloned and fully characterized from SpliNPV-EG1, an Egyptian isolate. A sequence of 601 amino acids was deduced when the gene was completely sequenced with a predicted molecular mass of 67 kDa for the preprotein. Transcriptional analyses using reverse transcription polymerase chain reaction (RT-PCR) revealed that chitA transcripts were detected first at 12 h post infection (hpi) and remained detectable until 168 hpi, suggesting their transcriptional regulation from a putative late promoter motif. In addition, quantitative analysis using quantitative RT-PCR showed a steady increase of 7.86-fold at 12 hpi in chitA transcription levels, which increased up to 71.4-fold at 120 hpi. An approximately 50 kDa protein fragment with chitinolytic activity was purified from ChitA-induced bacterial culture and detected by western blotting with an anti-recombinant SpliNPV chitinase antibody. Moreover, purification of the expressed ChitA recombinant protein showed in vitro growth inhibition of two different fungi species, Fusarium solani and F. oxysporum, confirming that the enzyme assembly and activity was correct. The results supported the potential role and application of the SpliNPV-ChitA protein as a synergistic agent in agricultural fungal and pest control programs.

• Archives of Plastic Surgery
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• 제37권3호
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• pp.227-232
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• 2010

Purpose: Continuous irrigation method is an important step in managing wound infection. V.A.C. devices have been used in intractable wounds for reducing discharge, improving local blood flow, and promoting healthy granulation tissue. We expect synergistic effects of reduced infection and more satisfactory, accelerated wound healing when using both methods simultaneously. This study evaluated continuous irrigation combined with V.A.C. appliance for treatment of infected chronic wounds. Methods: We reviewed data from 17 patients with infected intractable chronic wounds. V.A.C. device (Group A) was used in 9 patients, and V.A.C. with antibiotics irrigation (Group B) was used in 8 patients. We placed Mepitel$^{(R)}$ on the surface of wound and placed an irrigation and aspiration tube on each side. A sponge was placed on the Mepitel$^{(R)}$ and covered with film dressing. The wound was irrigated continuously with mixed antibiotics solution at the speed of 200 cc/hr and aspirated through the wall suction at the pressure of -125 mmHg. V.A.C. applied time, wound culture and wound size were compared between the two groups. Results: No complication were seen in two groups. Compared with Group A, in the Group B, V.A.C. applied time was shortened from 32.7 days to 25.6 days and showed efficacy in the reduction rate of wound size. No statistical differences were shown in bacterial reversion. Conclusion: V.A.C. appliance with continuous irrigation is an effective new method of managing infected chronic wounds and useful to reduce treatment duration and decrease wound size. Moreover it could be applied more widely to infected wound.

• 생약학회지
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• 제47권2호
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• pp.122-127
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• 2016

Methicillin-Resistant Staphylococcus aureus(MRSA) is a multidrug-resistant(MDR) strain. (+)-Usnic acid(UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against 17 different strains of the bacterium. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid(EDTA) was used. In the other hand, Sodium azide($NaN_3$) was used as inhibitors of ATPase. Against the 17 strains, the minimum inhibitory concentrations(MICs) of UA were in the range of $7.81-31.25{\mu}g/ml$. EDTA or $NaN_3$ cooperation against MRSA showed synergistic activity on cell wall. UA and in combination with EDTA and $NaN_3$ could lead to the development of new combination antibiotics against MRSA infection.