• Natural Product Sciences
• /
• v.17 no.4
• /
• pp.267-272
• /
• 2011

In our search for bioactive phenolics from plants, the culms of Phyllostachys bambusoides has been selected for investigation of anti-cariogenic and 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging agents based on the initial screening results. Fractionation process of n-hexane and $CHCl_3$ extracts afforded four phenolic constituents, ferulic acid (1), vanillin (2), coniferaldehyde (3), and coniferyl alcohol (4) as guided by their DPPH free radical scavenging activities. Additionally, activity-guided fractionation of EtOAc extract with anti-cariogenic activity has resulted in the isolation of coniferaldehyde (3), 2,6-dimethoxy-p-benzoquinone (5), p-methoxycinnamic acid (6), (${\pm}$)-balanophonin (7), and 6-methoxychromanone (8). The structures of 1 - 8 were determined by spectroscopic data interpretation, and also by comparison of their data with the published values. Phenolic compounds 1 - 4 exhibited similar DPPH radical scavenging activities compared with the synthetic antioxidant, butylated hydroxytoluene (BHT), and compounds 3 and 5 - 8 showed significant antibacterial activity against cariogenic oral streptococci, Streptococcus mutans and S. sobrinus.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.6
• /
• pp.957-963
• /
• 2001

Bacillus subtilis YL-1004 was isolated from soil for the development of agents to control dental caries. This strain produced an extracellular lytic enzyme that hydrolyzed the Streptococcus mutans cell wall. The lytic enzyme was purified to homogeneity by affinity chromatography and gel permeation chromatography to give a single band on SDS-PAGE and non-denaturing polyacrylamide gel electrophoresis. The molecular weight of the enzyme was deduced from SDS-PAGE and gel chromatography to be 38 kDa and the PI to be 4.3 from isoelectric focusing. Sirty $\%$ of its lytic activity remained after incubation at $50^{\circ}C$ for 30 min, and its optimal temperature was $37^{\circ}C$ . The enzyme showed its highest activity at pH 8.0 and was stable at pHs ranging from 4.0 to 9.0. Treatment with several modifiers showed that a cysteine residue was involved in the active site of the enzyme. This lytic enzyme from Bacillus subtilis YL-1004 exhibited specificity towards Streptococci and also showed autolytic activity on Bacillus subtilis YL-1004.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.11
• /
• pp.1758-1764
• /
• 2007

Synthesis of oligosaccharides during milk fermentation was attempted by inoculating Leuconostoc citreum with Lactobacillus casei, Lb. delbrueckii subsp. bulgaricus, and Streptococcus thermophilus as starters. Dextransucrase of Ln. citreum worked as a catalyst for the transglycosylation reaction of sugars; sucrose was added as the glucose donor, and lactose or maltose acted as the acceptor compound for the reaction. When 4% sucrose was added in milk, glucosyl-lactose was synthesized (about 1%, w/v) after 1-2 days of fermentation at 15 or $25^{\circ}C$. Alternatively, when sucrose and maltose (2% each, w/v) were added, panose (about 1 %, w/v) and other isomaltooligosaccharides were made in a day at $15-35^{\circ}C$. Growth patterns of lactobacilli and streptococci starters were not affected by the coculture of leuconostoc starter, but the rate of acid synthesis was slightly slowed at every temperature. Addition of sugars in milk did not give any adverse effect on the lactate fermentation. Accordingly, the use of leuconostoc starter and addition of sugars in milk allowed the production of oligosaccharides-containing fermented milk, and application of this method will facilitate the extensive development of synbiotic lactate foods.

• Korean Journal of Microbiology
• /
• v.53 no.3
• /
• pp.225-226
• /
• 2017

Streptococcus mitis is a Gram-positive, facultative anaerobic, alpha-hemolytic, and nonmotile cocci. S. mitis is a viridans streptococci and a normal commensal of throat, nasopharynx, and mouse and is associated with infective endocarditis, septicemia, and meningitis. S. mitis KCOM 1350 (= ChDC B183) was isolated from a human mandibular osteomyelitis lesion. Here, we present the complete genome sequence of S. mitis KCOM 1350.

• The korean journal of orthodontics
• /
• v.23 no.3 s.42
• /
• pp.311-318
• /
• 1993

This study was done to evaluate the effect of fixed orthodontic patients on the level of oral streptococci, Streptococcus mutans, lactobacilli, yeasts in saliva. 35 patients wearing bands were compared with age-matched 35 non-banded control group by conlony counting method on the specially designed culture medium. The following results were obtained ; 1. The colony forming unit(CFU) of total streptocci per militer of saliva in subjects with or without orthodontic treatment showed no significant statistical difference between them(p>0.05). 2. The colony forming unit(CFU) of total Streptococcus mutans per mililiter of saliva in subjects with orthodontic treatment showed significantly higher than those without orthodontic treatment(p<0.05). 3. The colony forming unit(CFU) of total lactobacilli per mililiter of saliva in sujects with or without orthodontic treatment showed no significant statistical difference between them but higher tendency in those with orthodontic treatment(p=0.052). 4. The colony forming unit(CFU) of total yeasts per mililiter of saliva in subjects with or without orthodontic treatment showed no significant statistical difference between them(p>0.05).

• Korean journal of food and cookery science
• /
• v.20 no.6 s.84
• /
• pp.658-666
• /
• 2004

In order to develop and commercialize high quality frozen soy yogurt, the effects of industrial proteases and commercial mixed cultures were examined on the functional properties and the sensory attributes of frozen soy yogurt. For quality improvement, soy protein isolates were primarily hydrolyzed by either Flavourzyme or Neurtrase, industrial Proteases, to reduce the beany flavor and increase the functional properties of the protein. The viable cell count of lactic acid bacteria was higher in the soy protein hydrolysates than whenuntreated. ABT-5 (L. acidophilus, Bifidobacterium lactis, and S. thermophilus) resulted in higher acid tolerance, bile acid tolerance and melt-down percent values than those with YC-X11 (Lactobacillus bulgaricus and Streptococci thermophilus). The overrun of frozen soy yogurt was improved by both Flavourzyme $(193.3\%)$ and Neurtrase $(156.7\%)$ treatments. With regard to thesensory characteristics, Flavourzyme improved the beany flavor, astringency taste, mouth feel and overall quality of frozen soy yogurts fermented with ABT-5. Further studies onproduct formulation will be needed to commercialize the frozen soy yogurt for the market.

• International Journal of Oral Biology
• /
• v.40 no.4
• /
• pp.189-196
• /
• 2015

Minimal inhibitory concentration (MIC) is the lowest antibiotic concentration that inhibits the visible growth of bacteria. Sub-minimal inhibitory concentration (Sub-MIC) is defined as the concentration of an antimicrobial agent that does not have an effect on bacterial growth but can alter bacterial biochemistry, thus reducing bacterial virulence. Many studies have confirmed that sub-MICs of antibiotics can inhibit bacterial virulence factors. However, most studies were focused on Gram-negative bacteria, while few studies on the effect of sub-MICs of antibiotics on Gram-positive bacteria. In this study, we examined the influence of sub-MICs of doxycycline, tetracycline, penicillin and amoxicillin on biofilm formation and coaggregation of Streptococcus gordonii, Streptococcus mutans, Actinomyces naeslundii, and Actinomyces odontolyticus. In this study, incubation with sub-MIC of antibiotics had no effect on the biofilm formation of S. gordonii and A. naeslundii. However, S. mutans showed increased biofilm formation after incubation with sub-MIC amoxicillin and penicillin. Also, the biofilm formation of A. odontolyticus was increased after incubating with sub-MIC penicillin. Coaggregation of A. naeslundii with S. gordonii and A. odontolyticus was diminished by sub-MIC amoxicillin. These observations indicated that sub-MICs of antibiotics could affect variable virulence properties such as biofilm formation and coaggregation in Gram-positive oral bacteria.

• Biomolecules & Therapeutics
• /
• v.4 no.4
• /
• pp.378-384
• /
• 1996

In vitro activities of LB20304a were compared with those of grepafloxacin (OPC-17116), Q-35, ciprofloxacin, and sparfloxacin against 380 clinical isolates collected from general hospitals in 1996. LB 20304a was the most active agent against gram-positive strains including staphylococci, streptococci and enterococci. LB20304a was also very active against gram-negative bacteria and its activity was comparable to that of ciprofloxacin but better than those of grepafloxacin, Q-35 and sparfloxacin. The therapeutic effect of LB20304a was superior to those of sparfloxacin and ciprofloxacin against systemic infection by methicillin-resistant Staphylococcus aureus K283 (MRSA) in neutropenic mice. Against urinary tract infection induced by Escherichia coli 851E in mice, LB20304a was more active than sparfloxacin and ciprofloxacin. However, LB 20304a was slightly less active than that of ciprofloxacin against urinary tract infection by Pseudomonas aeruginosa 1912E, but better than that of sparfloxacin.

• Pediatric Infection and Vaccine
• /
• v.2 no.2
• /
• pp.194-199
• /
• 1995

Most boys afflicted with panhypogammaglobulinemia, also known as X-linked agammaglobulinemia, remain healthy during the first 6 to 12 months of life because of protection by maternally transmitted IgG antibodies. Thereafter, they repeatedly acquire infections with high-grade pathogens, such as pneumococci, streptococci, and hemophilus unless given antibiotics or immunoglobulin replacement therapy. We experienced a case of panhypogammaglobulinemia in a 4 years old boy. He had been suffered from recurrent upper respiratory tract infection, otitis media and pneumonia since late infancy. He was admitted due to right pleural effusion with pneumonia, and streptococcus pneumoniae was isolated from pleural fluid and blood cultures. His immune status revealed panhypogammaglobulinemia and deficiency in mature B lymphocyte. He was treated with appropriate antibiotics therapy, but showed poor responses. He was transferred to department of thoracic surgery, and received minithoracotomy (decortication) operation. He was successfully treated with operation, antibiotics, and IV gammaglobulin infusions. Now he is being followed with periodic IV gammaglobulin replacement therapy.

• Korean Journal of Clinical Laboratory Science
• /
• v.40 no.1
• /
• pp.6-17
• /
• 2008

From the total 116,429 clinical specimens submitted to "C" hospital from January 2005 to December 2006, 2,195 strains of streptococci were isolated. Twenty four species of Streptococcus were identified with 0.1~19.8% isolation frequencies, of which S. pneumoniae was 19.8%, S. agalactiae 16.2%, S. anginosus 9.8%, S. constellatus 5.0%, S. oralis 3.9%, S. mitis 3.3%, S. pyogenes 2.7%, S. salivarius subsp. salivarius 2.2%, S. sanguinis 1.9%. For S. pneumoniae, clinical specimens showing over 9.0% isolation rate were 82.8% in sputum, 9.2% in blood, and for Streptococcus species other than S. pneumoniae, 18.0% in sputum, 16.0% in urine and 9.7% in blood. The antimicrobial agents that showed over 90.0% susceptibility were cefotaxime, gatilfloxacin, imipenem, levofloxacin, linezolid, moxifloxacin, rifampin and sporfloxacin in S. pneumoniae, ampicillin, cefotaxime, cetriaxone, levofloxacin, linezolid, penicillin, quinupristin/dalfopristin and vancomycin in S. agalactiae, chloramphenicol, clindamycin, levofloxacin and vancomycin in S. anginosus, levofloxacin, vancomycin in S. constellatus subsp. constellatus, vancomycin in S. oralis, vancomycin in S. mitis, chloramphenicol, clindamycin, levofloxacin, quinupristin/dalfopristin and vancomycin in S. pyogenes, chloramphenicol, levofloxacin and vancomycin in S. salivarius subsp. salivarius, chloramphenicol, levofloxacin and vancomycin in S. bovis II, chloramphenicol, levofloxacin, quinupristin/dalfopristin and vancomycin in S. dysgalactiae subsp. dysgalactiae, levofloxacin, chloramphenicol and vancomycin in the whole group of 10 Streptococcus spp. other than Streptococcus pneumoniae.