• International Journal of Oral Biology
• /
• 제33권4호
• /
• pp.197-203
• /
• 2008

It has been reported that the antimicrobial susceptibility patterns of viridans streptococci vary according to geographical region. Although several studies on the antibiotic resistance of viridans streptococci in foreign countries have been reported, little is known about the distribution of resistance among viridans streptococci in Korea. In this study, 88 isolates of viridans streptococci from Korean students' dental plaque were identified as 12 different species. The susceptibility of these isolates to 8 antibiotics was investigated. The in vitro antibiotic activity of penicillin G, ampicillin, vancomycin, streptomycin, gentamicin, erythromycin, amoxicillin, and tetracycline was measured by the broth microdilution method. The range of the minimum inhibitory concentrations (MIC), MIC50, MIC90, and the percentage of the susceptible isolates were determined. Streptococcus mutans and Streptococcus salivarius were susceptible to the 8 antibiotics. Isolates with resistance to vancomycin, streptomycin, and amoxicillin were not found. The overall resistance rates of the 88 isolates to penicillin G, ampicillin, gentamicin, erythromycin, and tetracycline were 12.5%, 62.5%, 62.5%, 26.1%, and 26.1%, respectively.

• International Journal of Oral Biology
• /
• 제36권4호
• /
• pp.163-166
• /
• 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.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제22권3호
• /
• pp.330-336
• /
• 2000

A large number of streptococci that do not fit readily into any of the established classification schemes have been relegated to a large heterogeneous group called the Streptococcus viridans, which are members of the normal flora of the mucous membranes of the body, including the oral cavity, the nasopharynx, and genitourinary tract. This group includes S. mitis, S. oralis, S. sanguis, S. salivarius, S. milleri, etc. Surveying on the literature, it has been reported that infective endocarditis, meningitis, rhabdomyolysis, cholangitis, appendicitis caused by Streptococcus viridans, which were the most important pathogen in children with malignant hematologic disease. Various antibiotics has been chosen for treatment or prophylaxis for these infections, but were generally lower antimicrobial susceptibilities because of an abuse of antibiotics and advent of resistant group. Therefore, surveillant culture must be performed to evaluate personal antimicrobial susceptibilities of intraoral microbes for proper antimicrobial choice for dental procedures. This study examined sampling from subgingival plaque of 60 chidren's microbes. The cultured bacterial isolates, Streptococcus viridans were examined 10 antimicrobial drugs with the Kirby-Bauer agar disk diffusion method. The used drugs were Penicillin, Ampicillin, Oxacillin, Cephalothin, Imipenem, Gentamicin, Erythromycin, Vancomycin, Ciprofloxacin, Clindamycin. The results were as follows : 1. Sampling Streptococcus viridans were S. mitis(65%), S. oralis(22%), S. sanguis(5%), S. intermedius(3%), S. salivarius(2%), S acidominimus(2%), Unidentified streptococcus(2%). 2. The antimicrobial susceptibility of total Streptococcus viridans : Oxacillin< Erythromycin< Pencillin=Ciprofloxacin< Cephalothin< Ampicillin< Clindamycin< Gentamicin< Imipenem=Vancomycin. 3. The antimicrobial susceptibility of S. mitis : Oxacillin=Erythromycin< Ciprofloxacin< Cephalothin< Penicillin=Ampicillin< Gentamicin< Clidamycin< Imipenem=Vancomycin. 4. The antimicrobial susceptibility of S. oralis : Oxacillin< Erythromycin< Penicillin=Ciprofloxacin=Clindamycin< Cephalothin=Gentamicin< Ampicillin< Imipenem=Vancomycin. 5. There was no significant difference in the antimicrobial susceptibility among each Streptococcus viridans group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제49권4호
• /
• pp.198-207
• /
• 2023

Objectives: This study investigated causative strains and their antibiotic sensitivity in patients who were hospitalized for maxillofacial odontogenic infections at a tertiary center in South Korea over the past 10 years with the aim of providing guidelines for the selection of appropriate empirical antibiotics. Materials and Methods: Patients with head and neck fascial space abscesses due to odontogenic infections who underwent incision and drainage surgery with pus culture tests between 2013 and 2022 at the Department of Oral and Maxillofacial Surgery, Dankook University Hospital were included. The bacterial isolates and antibiotic sensitivity of each strain were analyzed for 2013-2022, 2013-2017, and 2018-2022. The affected fascial spaces were classified into primary, secondary, and deep neck spaces. Results: In the 192 patients included in this study, 302 strains were detected. Viridans streptococcus had the highest frequency (51.7%), followed by Prevotella spp. (16.9%), Staphylococcus spp. (5.6%), and Klebsiella pneumoniae (4.6%). The identification rate of viridans streptococcus significantly increased from 41.8% in 2013-2017 to 60.9% in 2018-2022. Viridans streptococcus showed an antibiotic sensitivity of 80.5% to ampicillin; the sensitivity to penicillin antibiotics decreased over the study period. Antibiotic susceptibility was approximately 94% for third-generation cephalosporins. K. pneumoniae, which was identified at a high percentage in patients with deep neck space infection, showed increasing antibiotic resistance to most antibiotics over the study period. Conclusion: Viridans streptococcus was identified in head and neck fascial space abscesses with the highest frequency. Empirical antibiotics should be effective against this strain; penicillin antibiotics are considered inappropriate. For effective treatment of deep neck space abscesses, bacterial culture and antibiotic sensitivity tests performed as soon as possible are essential.

• Clinical and Experimental Pediatrics
• /
• 제50권1호
• /
• pp.56-64
• /
• 2007

목 적 : 소아 종양 환자에서 발열이 있는 경우, 즉각적인 경험적 항생제 치료가 필요하기 때문에, 지역이나 병원 내에서 발생한 균혈증의 흔한 원인균과 항생제 감수성에 대한 최근 경향에 대한 정보가 필요하다. 본 연구에서는 4년간 소아 종양 환자에서 분리된 균혈증의 원인균 분포와 이들의 항생제 감수성에 대하여 분석하고자 하였다. 방 법 : 2002년 1월부터 2005년 12월까지 서울대학교 어린이병원 소아 종양 환자 128명 환아에서 발생한 197례의 균혈증과 이들에서 분리된 214균주에 대하여 분석하였다. 결 과 : 총 214균주 중 그람음성균이 64.0%, 그람양성균이 31.3%였으며 진균은 4.7%이었다. 균혈증을 일으킨 가장 흔한 균은 Klebsiella species(21%)와 E. coli(16.8%)였으며, CNS와 viridans streptococci도 7.9%와 7.5%로 분리율이 높았다. 호중구 감소증이 있는 환자군에서 그람음성균이 차지하는 비율이 감소증이 없는 환자군에 비해 높았고(67.5% vs. 51.1%, P=0.018), 균혈증 발생 당시 중심 정맥관을 가진 경우에 CNS(12.7% vs. 2.1%, P=0.004)와 viridans streptococci(11.0% vs. 3.1%, P=0.036)가 차지하는 비율이 더 높았다. 항생제 감수성 검사에서 그람양성균에서는 penicillin, oxacillin 및 vancomycin 내성률이 각각 83.3%, 48.5% 및 0.5%였으며, 그람음성균에서는 cefotaxime, piperacillin/tazobactam, imipenem, gentamicin 및 amikacin 내성률이 24.1%, 17.2%. 6.6%, 21.6% 및 14.2%이었다. 균혈증의 경과를 알 수 있었던 179례 중 42례(23.5%)가 중환자실 치료를 받았으며, 20례(11.2%)가 사망하였으며, 그람 음성균 감염의 경우 그람 양성균 감염에 비해 중환자실 치료율이 높았으며(26.5% vs. 10.3%, P=0.016), 중심 정맥관을 가진 경우에 중환자실 치료 빈도(34.4% vs. 10.8%, P<0.001)와 사망률(16.7 % vs. 4.8%, P=0.012)이 높았다. 결 론 : 최근 4년간 소아 종양 환자에서의 균혈증 분석 결과, 아직 그람음성균이 차지하는 빈도가 높으며 특히 호중구 감소증이 동반되었을 때 그람음성균에 대한 적절한 치료가 우선 시행되어야 하겠다. 하지만 그람양성균이 차지하는 비율이 증가하고 있는 것도 경험적 항생제 결정시 고려하여야 할 것으로 판단된다.

• Tuberculosis and Respiratory Diseases
• /
• 제78권3호
• /
• pp.196-202
• /
• 2015

Background: Viridans streptococci (VS) are a large group of streptococcal bacteria that are causative agents of community-acquired respiratory tract infection. However, data regarding their clinical characteristics are limited. The purpose of the present study was to investigate the clinical and radiologic features of community-acquired pneumonia (CAP) with or without parapneumonic effusion caused by VS. Methods: Of 455 consecutive CAP patients with or without parapneumonic effusion, VS were isolated from the blood or pleural fluid in 27 (VS group, 5.9%) patients. Streptococcus pneumoniae was identified as a single etiologic agent in 70 (control group) patients. We compared various clinical parameters between the VS group and the control group. Results: In univariate analysis, the VS group was characterized by more frequent complicated parapneumonic effusion or empyema and bed-ridden status, lower incidences of productive cough, elevated procalcitonin (>0.5 ng/mL), lower age-adjusted Charlson comorbidity index score, and more frequent ground glass opacity (GGO) or consolidation on computed tomography (CT) scans. Multivariate analysis demonstrated that complicated parapneumonic effusion or empyema, productive cough, bed-ridden status, and GGO or consolidation on CT scans were independent predictors of community-acquired respiratory tract infection caused by VS. Conclusion: CAP caused by VS commonly presents as complicated parapneumonic effusion or empyema. It is characterized by less frequent productive cough, more frequent bed-ridden status, and less common CT pulmonary parenchymal lesions. However, its treatment outcome and clinical course are similar to those of pneumococcal pneumonia.

• 미생물학회지
• /
• 제53권3호
• /
• pp.225-226
• /
• 2017

Streptococcus mitis는 그람 양성이면서, 통성 혐기성, 알파-용혈성 및 비운동성 구균이다. S. mitis는 인후, 비인두 및 구강내 정상세균총의 하나이고, 감염성 심내막염, 폐혈증 및 뇌수막염과 연관이 있다. KCOM 1350 (= ChDC B183) 균주가 사람 하악골 골수염 병소에서 분리되었다. S. mitis KCOM 1350 균주 유전체 염기서열을 해독하여 보고한다.

• International Journal of Oral Biology
• /
• 제37권4호
• /
• pp.197-201
• /
• 2012

LIVE/DEAD$^{(R)}$ BacLight$^{TM}$ and alamarBlue$^{(R)}$ are fluorescent materials used for the enumeration of live and dead bacteria. LIVE/DEAD$^{(R)}$ BacLight$^{TM}$ is generally used for confocal microscopy applications to differentiate live from dead bacteria in a biofilm or planktonic state. AlamarBlue$^{(R)}$ has also been used widely to assay live and dead bacteria in a planktonic state. Whilst these materials are successfully utilized in experiments to discriminate live from dead bacteria for several species of bacteria, the application of these techniques to oral bacteria is limited to the use of LIVE/DEAD$^{(R)}$ BacLight$^{TM}$ in biofilm studies. In our present study, we assessed whether these two methods could enumerate live and dead oral bacterial species in a planktonic state. We tested the reagents on Streptococcus mutans, Streptococcus sobrinus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Enterococcus faecalis and found that only LIVE/DEAD$^{(R)}$ BacLight$^{TM}$ could differentiate live from dead cells for all five of these oral strains. AlamarBlue$^{(R)}$ was not effective in this regard for P. gingivalis or A. actinomycetemcomitans. In addition, the differentiation of live and dead bacterial cells by alamarBlue$^{(R)}$ could not be performed for concentrations lower than $2{\times}10^6$ cells/ml. Our data thus indicate that LIVE/DEAD$^{(R)}$ BacLight$^{TM}$ is a more effective reagent for this analysis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권4호
• /
• pp.322-328
• /
• 2005

Oral and maxillofacial infections are most commonly odontogenic in origin. The present study was implemented for patients with oral and maxillofacial infections in order to determine what differences were present in cultured bacteria, depending upon the different types of infection. For the present study, the epidemiological characteristics, the state of infection, and the results of the pus culture and antibiotic susceptibility tests were analyzed for the 159 cases where pus culture tests were performed. The patients were treated at the Oral and Maxillofacial Surgical Department of Chonnam National University Hospital during an 18-months period from March 2003 to August 2004. Among the total 159 pus culture specimens, bacteria were cultured in 111 cases (69.8%). In the 111 pus culture specimens, Streptococcus species, Neisseria species, and Staphylococcus species were cultured from 69 cases (51.1%), 21 cases (15.6%), and 15 cases (11.1%), respectively and were determined to be bacterial strains the predominant bacteria responsible for oral and maxillofacial infectious diseases. Twenty four cases (15.1%) among the 159 specimens showed mixed infections. The mostly isolated bacteria from each of the space abscess, dentoalveolar abscess, inflammatory cyst, and pericoronitis cases were the Viridans streptococci. There was little relevance between the type of infection and the type of cultured bacteria. Antibiotic susceptibility tests showed a high level of susceptibility to teicoplanin(100%), vancomycin(100%), chloramphenicol(96.4%), ofloxacin(88.3%), imipenem(83.3%), erythromycin(82.5%) and a low susceptibility to cefazolin(40.0%), oxacillin(44.7%), ampicillin(49.4%), penicillin(51.1%). These results indicate that there was no significant difference among the cultured bacteria depending on the type of infections and their susceptibility to cephalosporin and penicillin G was low.

• Pediatric Infection and Vaccine
• /
• 제24권2호
• /
• pp.71-78
• /
• 2017

목적: 2011년부터 2015년까지 최근 5년간 서울대학교 어린이병원 소아 혈액종양 환자에게 발생한 균혈증의 원인균 분포와 이들의 항생제감수성을 분석하여 경험적 항생제 선택에 실제적인 도움을 얻고자 하였으며 원인균의 분포와 항생제감수성에서 이전 연구와 경향성을 비교하고자 하였다. 방법: 2011년부터 2015년 12월까지 서울대학교 어린이병원에서 입원 치료를 받은 소아 혈액종양 환자들에게 발생한 균혈증에 대하여 의무기록을 후향적으로 분석하였다. 결과: 총 167명의 소아 종양 환자에게 221예의 균혈증이 발생하였고, 229 균주가 분리되었다. 이 중 그람음성균, 그람양성균, 진균이 각각 69.0% (2002-2005년 64.0%, 2006-2010년 63.4%), 28.8%(2002-2005년 31.3%, 2006-2010년 34.6%), 2.2% (2002-2005년 4.7%, 2006-2010년 2.0%)의 분포를 보였다. 그람음성균 중에는 Klebsiella species (53.2%, 84/158), Escherichia coli (19.6%, 31/158), 그람양성균 중에는 Staphylococcus aureus (48.5%, 32/66), viridans streptococci (21.2%, 14/66)가 높은 비율로 분리되었다. 그람양성균의 페니실린, 옥사실린, 반코마이신 감수성률은 각각 13.8%, 54.8%, 96.9% (2002-2005년 16.7%, 51.5%, 95.5%; 2006-2010년 14.3%, 34.1%, 90.5%)이었고, 그람음성균의 세포탁심(cefotaxime), 피페라실린/타조박탐(piperacillin/tazobactam), 이미페넴(imipenem), 겐타마이신(gentamicin), 아미카신(amikacin) 감수성률은 각각 73.2%, 77.2%, 92.6%, 71.0%, 95.2% (2002-2005년 75.9%, 82.8%, 93.4%, 78.4%, 85.8%; 2006-2010년 62.8%, 82.9%, 93.8%, 67.8%, 86.3%)이었다. 본 연구의 원인균 분포 및 항생제감수성률은 과거 연구와 비교하여 차이가 없었다. 전체 환자에서 치사율은 13.1%이었다. 결론: 그람음성균은 소아 혈액종양 환자의 균혈증의 가장 흔한 원인균이다. 균혈증의 원인균과 항생제감수성은 이전 연구들과 다르지 않았다. 연구 결과에 따라 본 연구 기관에서는 예년과 같이 발열을 동반하는 소아 혈액종양 환자에서의 경험적 항생제를 피페라실린/타조박탐으로 투여할 수 있을 것이다.