• YAKHAK HOEJI
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• v.50 no.2
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• pp.78-83
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• 2006

VISA and VRE are the main causes of surgical infection, urinary tract infections and bacteremia in hospitals. In this study; we selected VISA (Vancomycin Intermediate resistant Staphylococcus aureus) and VRE (Vancomycin Resistant Enterococcus) isolated from the clinical isolates. One of the isolated strains indicated the high resistance to severel anti-biotics (Vancomycin, Teicoplanin, Mupirocin, Synercid, Ciprofloxacin, Gentamicin, Lincomycin, Cefotaxim, Meropenem). Antimicrobial activity of Bifidobacterium spp. against VISA and VRE were measured. About $10^4$ cells of VISA or VRE were mixed with 1,5 and 9 ml of Bifidobacterium and the final volume was adjusted to 10 ml with brain heart infusion (BHI) broth. The cell suspension was incubated for 3, 6, 9, and 24 hr, serially diluted and then plated on BHI agar plate. As numbers of Bifidobacterium were increased viable cell count of VISA and VRE decreased. The strongest antimicrobial activity of the Bifidobacterium was observed after 9hr incubation in any mixture, almost completely inhibiting the growth of VISA and VRE.

• Archives of Pharmacal Research
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• v.28 no.6
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• pp.660-666
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• 2005

The intestinal microbiota are important to the host with regard to resistance they impart against bacterial infections and their involvement in mediating metabolic functions. Lactic acid producing bacteria such as Lactobacillus play an important physiological role in these matters. The aim of the present study was to isolate Lactobacillus sp. that inhibits enteric pathogens. Initially, 17 isolates from healthy Koreans were collected on Lactobacillus selective medium. Resistance of the isolates to antibiotics including rifampicin, streptomycin, clindamycin and vancomycin was measured. One of the isolate was identified as Lactobacillus ruminus on the basis of bacterial cell morphology, cultural characteristic and biochemical characteristics, 16S rRNA sequence analysis and PCR-RAPD. Antimicrobial activity of the bacterium against Vancomycin Intermediate Resistant Staphylococcus aureus (VISA) and Vancomycin-Resistant Enterococci (VRE) was measured. About $10^4$ cells of VISA or VRE were mixed with 1, 5, and 9 mL of L. ruminus SPM 0211 and the final volume was adjusted to 10 mL with brain heart infusion (BHI) broth. The cell suspension was incubated for 3, 6, 9, and 24 h, serially diluted and then plated on BHI agar plates. As numbers of L. ruminus SPM 0211 were increased, viable cell count of VISA and VRE decreased. The strongest antimicrobial activity of SPM 0211 was observed after 9 h incubation in any mixture, almost completely inhibiting the growth of these two bacteria. The results suggest that the freshly isolated L. ruminus SPM 0211 may be used as a pro-biotic microbe that prevents the colonization of enteric pathogens and can thereby promote good gastrointestinal health.

• YAKHAK HOEJI
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• v.51 no.4
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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.