• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.579-586
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• 2004

The objective of the present prospective trial was to compare the efficacy of chlorhexidine(Cervitec), Fluoride (Fluorprotector) and combination of chlorhexdine and fluoride varnishes in decreasing the level of salivary mutans streptococci. Forty healthy students of school of dentistry, Chonbuk national university were investigated to evaluate mutans streptococci(MS) counts and randomized into four groups to treat with the experimental varnishes; A) untreated group(n=10), B) chlorhexidine group(n=10), C) fluoride group(n=10), D) chlorhexidine and fluoride group(n=10). Dentocult $SM^{(R)}$ (Orion Diagnostica) strip method was used for measurement of the level of mutans streptococci in saliva. Stimulated saliva were collected at baseline for mutans streptococci counts evaluation (ms1), 12 weeks later the completion of each varnish treatment, mutans streptococci counts were re-evaluated. In varnish group with chlorhexidine, fluoride and combination of chlorhexidine and fluoride, the level of mutans streptococci was lower after 12 weeks than at baseline, but there were no significant differences in saliva(p>0.05), when compared with baseline. After 12 weeks, a remarkable reduction was still found in the subjects with high level of mutans streptococci at baseline, but not different in the low and moderate level of mutans streptococci(p>0.05).

• Korean Journal of Microbiology
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• v.18 no.2
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• pp.67-72
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• 1980

this paper presents the findings of a study in which throat cultures was ontained from all grade of primary school surrounding Seoul area. The number and percentages of children with positive throat cultures of streptococci were 181 cases (9.4%) among 1914 cases. Group A streptococci composed 4.3% (83 cases) of betahemolytic streptococci recovered. A total of 181 strains of group A streptococci were tested for susceptibility to 21 anibiotics in vitro. The strains were almost equally sensitive to most of the individual antibiotics : all of the group A strains were uniformly susceptible to bacitracin ; 93.6% to ampicillin ; 82.3% to erythromycin. The susceptibility to colymycin to colymycin and kanamycin were not found.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.1
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• pp.34-37
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• 2006

Beta-hemolytic streptococci (BHS) are frequently isolated pathogens in clinical microbiology laboratories. Among them, Group C, G and F streptococci infrequently cause respiratory infections, but they often invade other sites. Patients with underlying diseases are prone to be infected by the organisms and some of them can be fatal. Therefore, combination tests of serological and biochemical tests are needed to correct the identification of non-A, B streptococci because to various species belong to this species. The aim of this study was to investigate the isolation rates of strains and distribution of serogroup C, G and F streptococci at Wonju Hospital during the period of 2003-2004. 133 clinical isolates of group C, G and F streptococci were examined. Of them, 13 (9.8%) were group C, 41 (31.8%) were group F, 79 (59.4%) were group G. The prevalent isolation of the strains by serogroup were: group C, Streptococcus constellatus (38.5%); group F, Streptococcus anginosus (56.1%), Streptococcus constellatus (26.9%); group G, Streptococcus anginosus (54.4%), Streptococcus dysgalatiae subsp. equisimilis (26.5%). Overall, the most frequently isolated BHS was Streptococcus anginosus (51.2%).

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.51-59
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• 2005

The aim of this study was to compare the species and biotypes of mutans streptococci isolated from dental plaques sampled from the interfaces between the bracket aid tooth surface and smooth tooth surfaces In orthodontic patients. Dental plaque was collected from the interfaces between brackets aid teeth (test group), and from smooth tooth surfaces distant from brackets by more that 2mm (control group). The dental plaque collected by a sterilized curette was transferred into a vial of 1 X PBS. The sample in the vial was vigorously vortexed for 1 min and plated ou mitis-salivarius bacitracin (MSB) agar plate using cotton tips. The agar plates were incubated at $37^[\circ}C$ in a candle jar for 2 days, and again incubated for 1 more day at anambient temperature Individual colonies were cultured in TH broth at $37^[\circ}C\;CO_2$ incubator. The PCR-RFLP based on dextranase gene was performed for the identification of mutans streptococci at the species-level For biotyping of mutans streptococci, biochemical tests were performed There was no significant difference of the species of mutans streptococci isolated from both test and control groups However, the biotypes of the mutans streptococci isolated from test and control groups were different. These results may offer the basic data to verify the relationship between the mutans streptococci biotype and enamel decalcification or dental caries in orthodontic patients with fixed appliances.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.632-638
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• 2007

The purpose of this study was to investigate the effect of xylitol chewing gums on mutans streptococci (MS) counts in saliva. Sixty two children 6 to 11 years old were randomly assigned into one of three groups. Stimulated saliva specimens were plated in duplicate on conventional selective culture (mitis salivarius kanamycin bacitracin agar) for mutans streptococci. Polymerase chain reaction (PCR) amplication was performed to identify MS. After the 4-month period a significant decrease of the MS counts occurred in the group B (two gum 3 times a day; P < 0.05) but not in group A (one gum 3 times a day) and control group (didn't receive xylitol gum). According to qualitative evaluations, xylitol use did reduce the levels of MS in mixed dentition children. It has been suggested that a daily intake of 2 tablet for 3 times a day (about 10g) is needed in order to obtain a clinical anticariogenic effect.

• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.69-73
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• 1975

A Total of 173 streptococci isolated from 536 dairy cattle in Gyeonggi Province identified by Lancefield serological reaction and other biological properties. Antibiotics sensitivity test was also examined and the results obtained were as follows: 1. A total of 173 isolates of 167 strains (96.5%) were reacted with group A,B,C,D,E and G antisera. 2. Of the 167 positive strains, 75 strains were identified to Streptooccus uberis, 56 to Streptococcus agalactiage and 26 to Streptococcus dysgactiae, respectively. Also, Sreptococcus pyogenes, group D and group G streptococci were rarely isolated. 3. In results of antibiotic sensitivity tests, the most isolates were sensitive to leucomycin and erythromycin but less sensitive to streptomycin. and kanamycin.

• International Journal of Oral Biology
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• v.36 no.4
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• pp.163-166
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• 2011

Oral viridans streptococci are recognized as one of the etiological agents of a variety of infectious diseases such as dental caries and infective endocarditis. Although antimicrobial susceptibility tests for these fastidious bacterial species are now established and standardized, a comparison between the broth microdilution and broth macrodilution tests has not previously been performed. This comparison was performed in the present study using the tests adopted by the Clinical and Laboratory Standards Institute (CLSI) and seven clinical isolates of oral viridans streptococcal strains. A modified broth macrodilution susceptibility test method was also included in this analysis, in which the media was not supplemented with horse blood. The susceptibility interpretation category agreements were measured at 83% (broth microdilution versus broth macrodilution) and 71% (broth microdilution versus modified broth macrodilution). The interpretation category agreement between the broth macrodilution and modified broth macrodilution tests was also 83%. These data indicate that the interpretation of antibiotic susceptibility test results for oral viridans streptococci are influenced by the methods used.

• Clinical and Experimental Pediatrics
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• v.45 no.11
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• pp.1368-1372
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• 2002

Purpose : Group A streptococci have a cell wall which consists of M protein and T protein. T protein is known to be helpful in the understanding of the epidemiology of group A streptococci. To study the epidemiologic characteristics, we serotyped T protein of group A streptococci obtained from patients admitted to hospitals, or who visited OPD in five districts of Seoul the during last three years. Methods : Group A streptococci were obtained in five districts in north, northeast, central, northwest and south Seoul from 1998 through 2000. All isolated group A streptococci were serotyped with T protein antisera(Institute of Sera and Vaccine, Prague, Czech Republic). Results : In 1998, analysis of obtained total number of 92 strains revealed that T12, T4, and NT acounted for 72.2%. Among seven cases of scarlet fever, T12 was isolated in four cases and T4 was found in three cases. Two cases of tonsilar abscess produced T8 and NT. One case of cervical lymphadenitis showed T12. In 1999, 41 cases were studied showing that T12, T4, and T1 contributed 68%. Among five cases of scarlet fever, T12 and T4 make up three case. There were two cases of pneumonia(T4 and T1) and one case of cervical lymphadenitis(T8/25). In 2000, the study was performed in four districts except the central area. Among 83 isolates, T12, T4 and T1 accounted for 63.9%. There were three cases of scarlet fever(T12, T4, T5), one case of tonsillar abscess(T12), one case of pneumonia(NT) and one case of sepsis(T1). Conclusion : Serological analysis of T protein of group A streptococci shows no endemic specificity. The yearly pattern reveals that T12 had been decreasing but T1 had shown the opposite trend.

• International Journal of Oral Biology
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• v.38 no.1
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• pp.29-36
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• 2013

Mitis group streptococci (MGS) were classified based on the nucleotide sequences 16S rRNA gene (16S rDNA) and comprised 13 Streptococcus species. However, 16S rDNA homogeneity among MGS was too high to discriminate between clinical strains at the species level, notably between Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, and Streptococcus pseudopneumoniae. The purpose of this study was to discriminate between 37 strains of MGS isolated from Korean oral cavities using phylogenetic analysis of the DNA-dependant RNA polymerase beta-subunit gene (rpoB). 16S rDNA and rpoB from clinical strains of MGS were sequenced using the dideoxy chain termination method and analyzed using MEGA version 5 software. The resulting phylogenetic data showed that the rpoB sequences could delineate clinical strains of MGS at the species level. Phylogenetic analysis of rpoB is therefore a useful approach for identifying MGS at the species level.

• Pediatric Infection and Vaccine
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• v.13 no.1
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• pp.85-88
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• 2006

Perianal streptococcal dermatitis is a bright red, sharply demarcated, perianal rash that is caused by group A beta-hemolytic streptococci. It primarily occurs in children between six months and 10 years of age and is often misdiagnosed and treated inappropriately. We report a case of Perianal streptococcal dermatitis in a 13-months-old female patient. A culture of the perianal area grew group A beta-hemolytic streptococcus. The patient was given systemic antibiotics and topical applications of mupirocin, and a dramatic improvement was noted.