• 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%).

• International Journal of Oral Biology
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• v.38 no.1
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• pp.21-27
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• 2013

Anginosus group streptococci (AGS) were classified based on the nucleotide sequences of the 16S rRNA gene (16S rDNA) and comprised Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus. It is known that AGS is a causative factor of oral and systematic diseases. The purpose of this study was to discriminate the 56 clinical strains of AGS isolated from Korean oral cavities using phylogenetic analysis of 16S rDNA and species-specific PCR at the species-level. The 16S rDNA of clinical strains of AGS was sequenced using the dideoxy chain termination method and analyzed using MEGA version 5 software. PCR was performed to identify the clinical strains using species-specific primers described in previous studies and S. intermedius-specific PCR primers developed in our laboratory. The resulting phylogenetic data showed that the 16S rDNA sequences can delineate the S. anginosus, S. intermedius, and S. constellatus strains even though the 16S rDNA sequence similarity between S. intermedius and S. constellatus is above 98%. The PCR data showed that each species-specific PCR primer pair could discriminate between clinical strains at the species-level through phylogenetic analysis of 16S rDNA nucleotide sequences. These results suggest that phylogenetic analysis of 16S rDNA and PCR are useful tools for discriminating between AGS strains at the species-level.

• Pediatric Infection and Vaccine
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• v.19 no.3
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• pp.157-161
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• 2012

Streptococcus anginosus is a member of Streptococcus milleri group, and is found in the oral mucosa, respiratory tract, and gastrointestinal tract as normal flora. It can develop into a disease in patients with deteriorating clinical condition or with clinical risk factors. A previously healthy 15-year-old boy was admitted due to fever, abdominal discomfort and vomiting which lasted for 7 days. He had a history of dental procedure 1 day before the development of fever. He was diagnosed with acute acalculous cholecystitis based on the clinical, laboratory, and imaging finding, and S. anginosus was isolated from the blood culture. The patient was successfully treated with antibiotic therapy.

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

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.1-8
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• 2019

Due to the major role played by several species of Streptococcus in the etiology of periodontitis, it is important to assess the pattern of Streptococcus pathogenic pathways within the infected subgingival pockets using a bacterial specific 16S rRNA fragment. From the total of 50 patients with periodontitis included in the study, only 23 Streptococcal isolates were considered for further analyses, in which their 16S rRNA fragments were amplified and sequenced. Then, a comprehensive phylogenetic tree was constructed and in silico prediction was performed for the observed Streptococcal species. The phylogenetic analysis of the subgingival Streptococcal species revealed a high discrimination power of the 16S rRNA fragment to accurately identify three groups of Streptococcus on the species level, including S. salivarius (14 isolates), S. anginosus (5 isolates), and S. gordonii (4 isolates). The employment of state-of-art in silico tools indicated that each Streptococcal species group was characterized with particular transcription factors that bound exclusively with a different 16S rRNA-based secondary structure. In conclusion, the observed data of the present study provided in-depth insights into the mechanism of each Streptococcal species in its pathogenesis, which differ in each observed group, according to the differences in the 16S rRNA secondary structure it takes, and the consequent binding with its corresponding transcription factors. This study paves the way for further interventions of the in silico prediction, with the main conventional in vitro microbiota identification to present an interesting insight in terms of the gene expression pattern and the signaling pathway that each pathogenic species follows in the infected subgingival site.

• Tuberculosis and Respiratory Diseases
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• v.71 no.6
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• pp.476-479
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• 2011

The Streptococcus milleri group, which also includes S. anginosus, S. intermedius and S. constellatus, is found in the oropharynx, upper respiratory tract, gastrointestinal tract, and urogenital tract mucosa. Bacteria in the Streptococcus milleri group are associated with bacteremia and abscess formation. Most of the reports of of Streptococcus milleri group (SMG) infection occur in patients with underlying medical conditions. Predisposing factors that have been associated with S. milleri group empyema include mucosal disturbances (sinusitis, periodontal disease, enteric disease), preceding to pneumonia, thoracic surgery, malignancy, neurological disease, alcohol abuse, and also diabetes mellitus. We report on a 42-year-old man with mental retardation. He who suffered from dyspnea and a fever that he had developed for over 14 days. S. constellatus and anaerobic bacterias (Prevotella buccae and Micromonas micros) were cultured. The patient was treated with the drainage of pleural effusion and clindamycin and levofloxacin.

• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.100-103
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• 2002

Streptococcus milleri Goup Bacteria(SMG) comprise three species, Streptococcus anginosus, Streptococcus intermedius, Streptococcus constellatus. Although they are commensal organism, they can be pathogenic. SMG can be aggressive pathogen in the head and neck with a propensity for abscess formation and local extension of the infection. SMG is culturally and biochemically variable, which makes it hard for the clinicians to recognize it. Hence, it seems that this organism has been relatively neglected. Most of the Lancefield F streptococci are SMG. We report one patient who had Group F streptococcal bacteremia and subdural abscess. According to his medical history, he was diagnosed as membranoproliperative glomerulonephritis three years ago. He complained headache although he was treated by appropiate antibiotics. Brain CT was used as a tool to identify the brain abscess. He had surgical drainage and was treated with IV antibiotics postoperatively.