• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.247-254
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• 2007

Mutans streptococci have been reported to be implicated in dental caries. Of these streptococcal species, Streptcoccus mutans and Streptococcus sobrinus are most commonly found in human dental caries. Prevalence of these bacterial species in dental caries is found to be varied in different races and countries. Therefore, importance of these bacteria in dental caries remains to be determined The present study was performed to find out correlation S. mutans and S. sobrinus with dental caries in 125 Korean children with mixed dentition between 6 to 11 years of age. They were classified as group A(6-8 years) and group B(9-11 years) by age. For the study, stimulated saliva samples were collected from each subject. The vials containing saliva specimens were serially diluted (1:10) in saline and plated in duplicate on tryptone-yeast extract-cysteine with sucrose and bacitracin (TYCSB) for S. mutans and S. sobrinus. After genomic DNA was extracted from the samples, polymerase chain reaction (PCR) amplification was performed for identification using universal primers and specific primers to S. mutans and S. sobrinus. Data of microbial variables were compared to caries status of the subjects. According to this study, the result were as follows : 1. S. mutans versus S. sobrinus were moderate positive linear correlated in both group A(r=0.70) and group B(r=0.50). 2. Between S. mutans and dental caries there were weak positive linear correlation in both group A(r= 0.25) and group B(r=0.34). 3. S. sobrinus versus dental caries were not correlated in group A but slightly correlated in group B(r=0.21). 4. Between S. mutans and age, there were not correlation in both group. 5. S. sobrinus versus age were weak correlated in group A(r=0.32) but not correlated in group B.

• 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%).

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.531-538
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• 2009

Xylitol has the ability to reduce the adherence of Streptococcus mutans(S. mutans), which can make it easier to remove plaque, decrease acid production and inhibit dental caries. There are few reports on the effects of xylitol on the expression of the virulence related genes in S. mutans. This study examined the inhibitory effect of chewing gum containing xylitol on glucan synthesis related gene expression of S. mutans. Participants were voluntarily recruited for a women's oral health prevention program, classified into two groups(a control and a xylitol group), and then followed for 2 years. Twenty salivary samples were randomly selected from each group. Colony count and real-time reverse transcription polymerase chain reaction were used to analyze the characteristics of S. mutans. The following results were obtained: The S. mutans counts decreased steadily in the xylitol group over the study period(p<0.05). The expression of the virulence related genes (gtfB, gtfC and gtfD) was significantly lower in the xylitol group than in the control groups (p<0.05). In conclusion, these results suggest that chewing xylitol gum for a long period of time may reduce the expression of the genes associated with S. mutans virulence, which can result in a decrease growth of S. mutans colonies as a result.

• Pediatric Infection and Vaccine
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• v.19 no.2
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• pp.43-54
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• 2012

Group B streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis in developed countries. This article reviews the neonatal invasive GBS disease, maternal GBS colonization, and prevention strategies in the context of recent epidemiological changes in Korea. Although Korean neonates had been supposed to have low incidence of invasive GBS disease, GBS has been recently reported to be the most common cause of invasive neonatal infection after 1990s. Among Korean pregnant women, GBS carriage rate in the vagina and rectum has been reported to be much lower than that in Western countries. However, it has increased in recent studies. For decision making about preventive strategy for neonatal GBS disease in Korea, further studies are required in terms of the incidence of neonatal GBS infection and serotype distribution. In addition, studies about maternal carriage rate and serotype distribution have to be continued.

• Childhood Kidney Diseases
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• v.24 no.1
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• pp.53-57
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• 2020

Streptococcus agalactiae or group B streptococcus (GBS) is associated with infections in neonates and pregnant women. Herein, we describe a rare case of GBS renal abscess with peritonitis and pleural effusion in a 17-year-old girl with type 1 diabetes mellitus. The girl was admitted due to fever and right flank pain. Laboratory findings included leukocytosis and increased C-reactive protein level and erythrocyte sedimentation rate. Her serum glucose level was 484 mg/dL. Urinalysis showed no pyuria. Renal sonography revealed parenchymal swelling in the right kidney. The patient was administered intravenous cefotaxime. Urine and blood cultures were negative. Fever seemed to improve, but the following day, she complained of abdominal pain and fever. Antibiotic was switched to imipenem, and abdominal and pelvic CT revealed a ruptured right renal abscess, peritonitis, and bilateral pleural effusion with atelectasis. Pigtail catheter drainage of the abscess was performed. Culture from the abscess was positive for GBS, and fever subsided 2 days after the drainage. She was discharged with oral cefixime. The clinical course of urinary tract infections (UTIs) can be atypical in patients with diabetes, and GBS can be a cause of UTIs. Prompt diagnosis and management are necessary to prevent complications in patients showing atypical courses.

• Tuberculosis and Respiratory Diseases
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• v.41 no.2
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• pp.165-170
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• 1994

B군 연쇄상구균(group B streptococcus or Streptococcus agalactiae)은 신생아 뇌막염과 균혈증의 원인균으로 알려져 있고, 우리나라에서는 현재까지 23예의 신생아 B군 연쇄상구균 감염 임상 증례가 보고되었다. 그러나 성인에서의 B군 연쇄상구균 분리 동정에 대한 분석은 보고되었으나, 폐렴 증례는 아직 보고된 바 없고, S. agalactiae의 penicillin에 대한 최소억제농도가 대표적 연쇄상구균인 S. pyogenes 보다 높고 동물실험 및 시험관검사에서 penicillin과 aminoglycoside을 병합사용할 경우 상승작용이 관찰되었기 때문에, 치료제로 penicillin 또는 cephalosporin 을 aminoglycoside와 병합투여하여야 하는 특정을 지니고 있다. 저자들은 74세 남자 당뇨 환자에서 B군 연쇄상구균에 의한 폐렴과 패혈증이 발생한 증례를 치험하여 보고하고자 한다.

• 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.

• Perinatology
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• v.29 no.4
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• pp.147-152
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• 2018

Objective: This study examines whether maternal group B Streptococcus (Streptococcus agalactiae, GBS) infection was associated with preterm births and premature neonatal outcomes. Methods: Maternal and neonatal outcomes were examined among singleton pregnant women with preterm birth (from $24^{+0}weeks$ to $36^{+6}weeks$) who were tested for GBS (n=203) during the pregnancy. Data were collected retrospectively from the medical records of women who delivered at our hospital from January 2015 to February 2017. We compared obstetrical factors (causes of preterm birth) and neonatal (gestational age at delivery, birth weight, Apgar score 1 min/5 min, hospitalization period, duration of mechanical ventilation, neonatal C-reactive protein within three days, and other complication [respiratory distress syndrome, neonatal deaths]) outcomes between GBS-infected and non-infected pregnant women. Results: There were 203 singleton pregnant women included in the study, 25 of whom were confirmed to have a GBS infection during the pregnancy. There was no difference in neonatal outcomes by GBS status. Preterm premature rupture of membranes (pPROM), as an obstetric factor, was associated with GBS infection (P=0.022). GBS infection raised the risk of pPROM by 3.6 times (odds ratio 3.648, 95% confidence interval 1.476-9.016, P=0.005). Conclusion: GBS infection in preterm birth was associated with pPROM but did not result in adverse neonatal outcomes. Continuous attention and evaluation of GBS infection, a major cause of neonatal sepsis and pneumonia, are needed.

• Restorative Dentistry and Endodontics
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• v.49 no.1
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• pp.4.1-4.9
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• 2024

Objectives: This study aims to correlate caries-causing microorganism load, lactic acid estimation, and blood groups to high caries risk in diabetic and non-diabetic individuals and low caries risk in healthy individuals. Materials and Methods: This study includes 30 participants divided into 3 groups: Group A, High-risk caries diabetic individuals; Group B, High-risk caries non-diabetic individuals; and Group C, Low-risk caries individuals. The medical condition, oral hygiene, and caries risk assessment (American Dental Association classification and International Caries Detection and Assessment System scoring) were documented. Each individual's 3 mL of saliva was analyzed for microbial load and lactic acid as follows: Part I: 2 mL for microbial quantity estimation using nutrient agar and blood agar medium, biochemical investigation, and carbohydrate fermentation tests; Part II: 0.5 mL for lactic acid estimation using spectrophotometric analysis. Among the selected individuals, blood group correlation was assessed. The χ² test, Kruskal-Wallis test, and post hoc analysis were done using Dunn's test (p < 0.05). Results: Group A had the highest microbial load and lactic acid concentration, followed by Groups B and C. The predominant bacteria were Lactobacilli (63.00 ± 15.49) and Streptococcus mutans (76.00 ± 13.90) in saliva. Blood Group B is prevalent in diabetic and non-diabetic high-risk caries patients but statistically insignificant. Conclusions: Diabetic individuals are more susceptible to dental caries due to high microbial loads and increased lactic acid production. These factors also lower the executing tendency of neutrophils, which accelerates microbial accumulation and increases the risk of caries in diabetic individuals.