• Journal of Yeungnam Medical Science
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• 제28권2호
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• pp.133-144
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• 2011

Background: Tigecycline (TIG), a new broad-spectrum glycylcycline with anti-multidrug-resistant-(MDR)-pathogen activity, was launched in March 2009 in South Korea, but there are insufficient clinical studies on its use in the country. As such, this study was performed to analyze cases of severe MDR-pathogen-caused infections treated with TIG. Methods: Patients treated with TIG within the period from May 2009 to June 2010 were enrolled in this study. Their clinical and microbiologic data were reviewed retrospectively. Results: Twenty-one patients were treated with TIG for complicated skin and soft-tissue infections (cSSTIs) (42.9%), complicated intra-abdominal infections (cIAIs) (38.1%), or pneumonia (19.1%) caused by MDR pathogens like carbapenem-resistant $Acinetobacter$ $baumannii$ (76.2%), methicillin-resistant $Staphylococcus$ $aureus$ (61.9%), extended-spectrum beta-lactamase-producing $Escherichia$ $coli$ and $Klebsiella$ $pneumoniae$ (38.1%), and penicillin-resistant $Enterococcus$ species (33.3%). Thirteen patients (61.9%) had successful clinical outcomes while five (23.8%) died within 30 days. The rate of clinical success was highest in cSSTI (77.8%), followed by cIAI (50%) and pneumonia (50%), and the mortality rate was highest in pneumonia (50%), followed by cIAI (25%) and cSSTI (11.1%), Conclusion: Tigecycline therapy can be an option for the treatment of severe MDR-pathogen-caused infections in South Korea, Due to its high risk of failure and mortality, however, prudence is required in its clinical use for the treatment of severe infections like nosocomial pneumonia.

• Journal of Dairy Science and Biotechnology
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• 제31권2호
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• pp.143-152
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• 2013

본 연구는 김치로부터 GABA 생성능이 우수한 젖산균을 분리 및 동정하고, 이 균주의 생리적 특성을 규명하여 상업적으로의 이용가능성을 검토하고자 실시하였다. 이를 위해 MSG 2%가 첨가된 MRS broth에 $37^{\circ}C$에서 18시간 배양한 후 GABA 함량이 $50{\mu}g/mL$ 이상 생산하는 75개의 균주를 1차로 선별하였으며, $90{\mu}g/mL$ 이상 생산하는 5 균주를 2차로 선별하였고, 선발된 5 균주를 MSG 1%, 2% 및 3% 함유된 MRS 배지에 각각 배양한 결과, K74 균주가 최종 선발되었다. K74 균주는 MSG 1%가 첨가된 MRS broth에서 GABA 함량이 $134.52{\mu}g/mL$이었고, MSG 2%와 3%가 첨가된 MRS broth에서GABA 함량이 각각 $212.27{\mu}g/mL$와 $234.63{\mu}g/mL$이었으며, 동정 결과 L. plantarum K74라고 명명되었다. L. plantarum K74의 최적 생장 온도는 $34^{\circ}C$이었으며, pH 4.4에 도달하기까지 18시간이 소요되었다. L. plantarum K74는 또한 답즙산과 산성의 pH에서 모두 우수한 생존력을 나타냈으며, 발암효소인 ${\beta}$-glucuronidase를 생성하지 않고 유당분해효소인 ${\beta}$-galactosidase를 약간 생성하는 것으로 나타났다. 항생제 내성 실험 결과 Kanamycin, Polymyxin B, Streptomycin에 내성을 Novobiocin, Bacitracin, Penicillin-G, Methicillin에감수성을나타냈으며, Escherichia coli와Salmonella typhimurium에 각각 54.9%와 46.3%의 억제 효과를 지니고 있고, Staphyloccous aureus에 대해서는 거의 억제 효과가 없는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1249-1256
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• 2017

In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as $cyclo-({\text\tiny{L}}-Val-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Leu-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Phe-{\text\tiny{L}}-Pro)$, $cyclo-({\text\tiny{L}}-Val-{\text\tiny{L}}-Phe)$, and N-(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus, with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.