No abstract

Peptidoglycan hydrolase activities in Lactobacillus delbrueckii subsp. bulgaricus were detected by analysis of bacterial extracts on denaturing polyacrylamide gel electrophoresis containing lyophilized Micrococcus lysodeikticus cells as substrate. A hydrolase with an estimated molecular mass of 80 kDa was found to cross-react on Western blot with monoclonal antibodies raised against muramidase-2 of Enterococcus hirae. These antibodies were also used to demonstrate that the method of cell sample preparation affected protein detection. Slot and Western blots indicate that the peptidoglycan hydrolase from L. bulgaricus is bound to the cell wall. Immuno-labeling followed by optical and electron microscopic observations suggest that this hydrolase is intracellular and restricted mainly to the space between the membrane and the cell wall.

Objectives : Hwangheuk-san is a complex prescription composed of oriental traditional medicine and has been reported for antioxidant, antimicrobial and anticancer effects in the recent study. Methicillin-resistant Staphylococcus aureus (MRSA) is one of important causes of fatal infectious diseases such as septicemia, endocarditis, toxic shock syndrome, pneumonia, skin and soft tissue infections (SSTIs). S. aureus is reported as being for a variety of human diseases and its epidemiological relevance is mainly due to their ability of becoming highly resistant to common antimicrobials such as tetracycline, penicillin, cphalosporin and aminoglycoside. The objective of this study is to determine *

Objectives : Camellia sinensis (Theaceae) possesses a various beneficial effects such as free radical-scavenging, inactivation of urokinase in cancer cell proliferation, antibacterial, and hypotensive. Dental caries is one of the most common oral infectious disease in a human. Oral microorganisms play a significant role in the etiology of dental caries. An aberration to this ecology due to dietary habits, improper oral hygiene or systemic factors lead to an increase in cariogenic microorganisms. Cariogenic microorganisms like Streptococcus mutans and Streptococcus sobrinus encourage the accumulation and adherence of plaque biofilm by metabolizing sucrose into glucans. The purpose of this study was to investigate the antimicrobial activity of phenolic compounds of Camellia sinensis and R-carvone, monoterpenes, is can be found naturally in numerous essential oils, on Streptococcus mutans and Streptococcus sobrinus. Methods : The antimicrobial activity of these compounds was determined by the broth microdilution method and checkerboard dilution assay to investigate the potential synergistic effects of each five compounds of Camellia sinensis (C. sinensis) and R-carvone. Results : C. sinensis-isolated compounds and R-carvone were determined with MIC of more than 1,000 ㎍/mL. However, the combination test showed significant synergism against S. mutans and S. sobrinus, implicated in the lowered MICs. Conclusions : These results suggest that combinatory application of phenolic five compounds (theophyllin, l-theanine, epicatechin, epicatechin gallate, and caffeine) from C. sinensis and R-carvone has a potential synergistic effect and thus may be useful as a mouthrinse in helping control cariogenic microorganism.