Spectrophotometric Analysis of Streptococcus mutans Growth and Biofilm Formation in Saliva and Histatin-5 Relate to pH and Viscosity

ABSTRACT Objective: To analyze the ability of saliva in controlling the growth and the biofilm formation of Streptococcus mutans (S. mutans) as well as the effect of histatin-5 anti-biofilm relate to pH and saliva viscosity. Material and Methods: The S. mutans biofilm assayed by crystal violet 1% and its growth measured by spectrophotometer. The saliva viscosity was analyzed by viscometer, and pH of saliva was measured by pH meter. Results: Based on the optical density values, growth of S. mutans in saliva ranged <300 CFU/mL (0.1 nm) at concentrations of 25%, 12.5% and 6.25% for 24 hours. Whereas at the 48 h and 72 h period of incubation shown an increase in growth of S. mutans ranged 300-600 CFU/mL (0.2-0.36 nm). The inhibitory biofilm formation of S. mutans in saliva was significantly higher at concentrations of 12.5% and 6.25% at 24 h incubation times on a moderate scale, whereas the histatin-5 was effective to inhibit S. mutans biofilm on the 50 and 25 ppm. The saliva possessed a higher inhibitory of biofilm S. mutans than histatin-5 and good level viscosity (0.91-0.92 cP). Conclusion: The saliva was able to control the growth of S. mutans, and histatin-5 can inhibit the biofilm formation S. mutans. Furthermore, the saliva was also able to respond to the pH change with good viscosity of saliva.

Characterization and distribution of viridans group streptococci isolated from infectious endophthalmitis and keratitis / Caracterização e distribuição de estreptococos do grupo viridans isolados de endoftalmite infecciosa e ceratite

ABSTRACT Purpose: The aims of this study were to characterize alpha-hemolytic streptococci among isolates from cases of infectious endophthalmitis and keratitis and to determine their distributions. Methods: The sample included 27 and 35 nonduplicated isolates of alpha-hemolytic streptococci recovered from patients with infectious endophthalmitis (2002-2013) and keratitis (2008-2013), respectively. Isolates were identified by the optochin susceptibility and bile solubility tests, using a biochemical identification system. The minimum inhibitory concentration was determined by the broth microdilution method. Molecular identification was performed by analyses of three constitutive genes and the complementary multilocus sequence. The molecular epidemiology of Streptococcus pneumoniae was investigated using multilocus sequence typing, and the presence of the capsular polysaccharide-encoding gene was assessed using conventional polymerase chain reaction. Outcomes were evaluated using the patients' medical records. Results: Phenotypic tests differentiated S. pneumoniae from other alpha-hemolytic streptococci, consistent with later molecular identifications. Streptococcus oralis was significantly prevalent among the endophthalmitis isolates, as was S. pneumoniae in the keratitis isolates. High levels of susceptibility to antibiotics were observed, including vancomycin, cephalosporins, and fluoroquinolones. High genetic variability was detected among the 19 S. pneumoniae strains, with 15 predicted to be encapsulated. The medical records of patients with infectious endophthalmitis were reviewed (n=15/27; 56%), and final visual acuity was assessed in 12 cases (44%). Many patients progressed to a final visual acuity state of "no light perception" (6/12; 50%), "light perception" (3/12; 25%), or "hand motion" (1/12; 8%). The medical records of patients with infectious keratitis were also reviewed (n=24/35; 69%), and final visual acuity was assessed in 18 cases (51%). Similarly, most patients progressed to a final visual acuity state of "no light perception" (6/18; 33%), "light perception" (1/18; 6%), or "hand motion" (6/18; 33%). Overall, the majority of patients progressed to a final visual acuity state of "no light perception" (12/30), "light perception" (4/30), or "hand motion" (7/30). Conclusions: The distribution of alpha-hemolytic streptococci in ocular infections suggested the presence of a species-specific tissue tropism. The prognoses of patients with ocular streptococcal infections were highly unfavorable, and antibiotic resistance did not contribute to the unfavorable clinical progressions and poor outcomes.

RESUMO Objetivo: O objetivo deste estudo foi caracterizar os estreptococos alfa-hemolíticos isolados de endoftalmite infecciosa e ceratite e determinar sua distribuição. Métodos: A amostra incluiu 27 e 35 isolados não-duplicados de estreptococos alfa-hemolíticos recuperados de pacientes com endoftalmite infecciosa (2002-2013) e ceratite (2008-2013), respectivamente. Os isolados foram identificados pelos testes de suscetibilidade à optoquina e bile solubilidade, utilizando um sistema de identificação bioquímica. A concentração inibitória mínima foi determinada pelo método de microdiluição em caldo. A identificação molecular foi realizada pela análise de três genes constitutivos e análise complementar de sequências multilocus. A epidemiologia molecular do Streptococcus pneumoniae foi investigada por tipagem de sequência multilocus, e a presença do gene codificador do polissacarídeo capsular foi avaliada por reação em cadeia da polymerase convencional. Os resultados foram avaliados utilizando os prontuários médicos dos pacientes. Resultados: Os testes fenotípicos diferenciaram S. pneumoniae dos outros estreptococos alpha-hemolíticos, consistentes com identificações moleculares posteriores. S. oralis foi significativamente prevalente entre os isolados de endoftalmite, assim como S. pneumoniae nos isolados de ceratite. Foram observados altos níveis de suscetibilidade a antibióticos, incluindo vancomicina, cefalosporinas e fluoroquinolonas. Alta variabilidade genética foi detectada entre as 19 cepas de S. pneumoniae, com 15 previstas para serem encapsuladas. Os prontuários médicos dos pacientes com endoftalmite infecciosa foram revisados (n=15/27; 56%), e a acuidade visual final foi avaliada em 12 casos (44%). Muitos pacientes evoluiram para um estado final de acuidade visual de "sem percepção luminosa" (6/12; 50%), "percepção luminosa" (3/12; 25%) ou "movimentos de mãos" (1/12; 8%). Também foram revisados os prontuários médicos dos pacientes com ceratite infecciosa (n=24/35; 69%), e a acuidade visual final foi avaliada em 18 casos (51%). Da mesma foram, a maioria dos pacientes evoluiu para um estado final de acuidade visual de "sem percepção luminosa" (6/18; 33%), "percepção luminosa" (1/18; 6%) ou "movimentos de mãos" (6/18; 33%). No geral, a maioria dos pacientes evoluiu para um estado final de acuidade visual de "sem percepção luminosa" (12/30), "percepção luminosa" (4/30) ou "movimentos de mãos" (7/30). Conclusões: A distribuição de estreptococos alfa-hemolíticos nas infecções oculares sugeriu a presença de um tropismo de tecido específico da espécie. Os prognósticos dos pacientes com infeções oculares por estreptococos foram altamente desfavoráveis e a resistência a antibióticos contribuiu não para as progressões clínicas des­favoráveis e os maus resultados.

jptsd123 / 口腔疾病防治

@#Esophageal cancer is one of the most lethal digestive system cancers, and its pathogenic factors have always been the focus of research. Recently, it has been found that microorganisms and their metabolites in the esophagus may also represent one of the pathogenic factors. Because of their continuity in anatomical structure, the oral cavity and esophagus have a certain correlation in terms of the composition of flora. In recent years, many scholars have studied the relationship between oral microorganisms and esophageal cancer to monitor changes in oral microorganisms as well as to diagnose and treat esophageal cancer more effectively. In this paper, the research status of oral microorganisms and esophageal cancer was reviewed. The Results of the literature review show that the diversity of bacteria in the esophagus is affected by oral flora in terms of the occurrence and development of esophageal cancer. Among these bacteria, the periodontal red complex, which includes Porphyromonas gingivalis, forsythia and Treponema dentata, as well as common oral microorganisms, such as Streptococcus viridis and Fusobacterium nucleatum, are all related to the occurrence and development of esophageal cancer to a certain extent. At present, there are few studies on the mechanism of microorganisms and esophageal cancer, but scholars have found that lipopolysaccharides and endotoxins, the products of Gram-negative bacteria in the esophagus, may participate in the innate immune response of the host, and the relevant mechanism of action needs further study in order to find new targets for monitoring and treatment.

Prevalence of rectovaginal colonization by group B Streptococcus in pregnant women seen at prenatal care program of a health organization / Prevalência de colonização retovaginal por estreptococo do grupo B em gestantes de programa de atendimento pré-natal de instituição de saúde

ABSTRACT Objective To evaluate the prevalence of group B Streptococci in pregnant women of a corporate health program, as well as the epidemiological correlations. Methods This retrospective study used medical records of patients who participated of the prenatal care program at a private hospital in the city of São Paulo (SP), Brazil, from 2015 to 2016. Those who abandoned the program or had incomplete data in their medical records were excluded. Quantitative variables were described by means, standard deviations, median, minimal and maximal values. Parity and socioeconomic status were described by absolute frequency and percentages. We used logistic regression models in the software (SPSS) to analyze correlations of variables according to vaginal-rectal culture, considering a 95%CI and p-values. Variables were age, number of pregnancies, weight gain in pregnancy and gestational age at delivery. Results A total of 347 medical records were included, and after applying the exclusion criteria, 287 medical records composed the final sample. Patients' age ranged between 17 and 44 years. Mean age was 30.6 years, 67 patients had positive result for group B Streptococcus (prevalence of 23.3%; 95%CI: 18.7-28.5). Conclusion Considering the high prevalence of group B Streptococcus in our service, the antibiotic prophylaxis strategy based on rectovaginal culture screening approach seems to be cost-effective.

RESUMO Objetivo Identificar a prevalência de estreptococo do grupo B entre gestantes que frequentaram um programa de saúde corporativa, bem como as correlações com a colonização positiva. Métodos Estudo retrospectivo dos prontuários do pré-natal de um hospital privado em São Paulo, no período de 2015 a 2016. Foram excluídas as mulheres que abandonaram o programa ou apresentavam dados incompletos nos prontuários. As variáveis quantitativas foram descritas por média, desvios padrão, mediana, valores mínimos e máximos. A paridade e a condição socioeconômica foram descritos por frequência absoluta e percentagens. Utilizamos modelos de regressão logística no programa (SPSS) para analisar as correlações de variáveis de acordo com a cultura retovaginal, considerando IC95% e valores de p. As variáveis foram idade, número de gestações, peso ganho na gestação e idade gestacional no parto. Resultados Foram incluídos 347 prontuários e, após a aplicação dos critérios de exclusão, 287 prontuários compuseram a amostra final. A idade dos pacientes variou entre 17 e 44 anos. A média de idade foi de 30,6 anos, e 67 pacientes tiveram resultado positivo para o estreptococo do grupo B (prevalência de 23,3%; IC95%: 18,7-28,5). Conclusão Considerando a alta prevalência de estreptococos do grupo B em nosso serviço, existem evidências de que a estratégia de antibiótico profilaxia baseada na cultura retovaginal é custo-efetiva.

Modeling the Growth of Bacteria Streptococcus sobrinus Using Exponential Regression

Abstract Objective: To build an exponential regression model based on parameter estimation. Material and Methods: We developed a simple mathematical model to simulate the growth of bacteria and the exponential growth is often used to model population growth as such cell growth while the exponential decay is portraying a declining or decreases in the size of the population. An exponential regression method was used to fit the data and estimate growth parameter values Streptococcus sobrinus using statistical software SPSS version 20. Results: Based on the results of the parameter estimates, which is constant are 83.039 and b1 is 0.005 while R-square is 0.952. According to the R-Square results obtained, the model is good and appropriate. Conclusion: The model can be used to find the potential biological parameters, which may be able to predict the treatment outcome. This study helps researchers to understand the specific growth rate(s), which can be used to best grow the organism.

Microbial species associated with dental caries found in saliva and in situ after use of self-ligating and conventional brackets

Abstract Objectives Enamel demineralization is among the main topics of interest in the orthodontic field. Self-ligating brackets have been regarded as advantageous in this aspect. The aim of this study was to evaluate the break homeostasis in the oral environment and the levels of microorganisms associated with dental caries among the different types of brackets. Material and Methods Twenty patients received two self-ligating brackets: In-Ovation®R, SmartClipTM, and one conventional GeminiTM. Saliva was collected before bonding (S0), 30 (S1) and 60 (S2) days after bonding. One sample of each bracket was removed at 30 and 60 days for the in situ analysis. Checkerboard DNA-DNA Hybridization was employed to evaluate the levels of microbial species as-sociated with dental caries. Data were evaluated by nonparametric Friedman and Wilcoxon tests at 5% significance level. Results The salivary levels of L. casei (p=0.033), S. sobrinus (p=0.011), and S. sanguinis (p=0.004) increased in S1. The in situ analyses showed alteration in S. mutans (p=0.047), whose highest levels were observed to the In-Ovation®R. Conclusions The orthodontic appliances break the salivary homeostasis of microorganisms involved in dental caries. The contamination pattern was different between self-ligating and conventional brackets. The In-Ovation®R presented worse performance considering the levels of cariogenic bacterial species.

Bacteriology of peritonsillar abscess: the changing trend and predisposing factors / Bacteriologia do abscesso peritonsilar: tendência de mudança e fatores predisponentes

Abstract Introduction: Peritonsillar abscess is the most common deep neck infection. The infectious microorganism may be different according to clinical factors. Objective: To identify the major causative pathogen of peritonsillar abscess and investigate the relationship between the causative pathogen, host clinical factors, and hospitalization duration. Methods: This retrospective study included 415 hospitalized patients diagnosed with peritonsillar abscess who were admitted to a tertiary medical center from June 1990 to June 2013. We collected data by chart review and analyzed variables such as demographic characteristics, underlying systemic disease, smoking, alcoholism, betel nut chewing, bacteriology, and hospitalization duration. Results: A total of 168 patients had positive results for pathogen isolation. Streptococcus viridans (28.57%) and Klebsiella pneumoniae (23.21%) were the most common microorganisms identified through pus culturing. The isolation rate of anaerobes increased to 49.35% in the recent 6 years (p = 0.048). Common anaerobes were Prevotella and Fusobacterium spp. The identification of K. pneumoniae increased among elderly patients (age > 65 years) with an odds ratio (OR) of 2.76 (p = 0.03), and decreased in the hot season (mean temperature > 26 °C) (OR = 0.49, p = 0.04). No specific microorganism was associated with prolonged hospital stay. Conclusion: The most common pathogen identified through pus culturing was S. viridans, followed by K. pneumoniae. The identification of anaerobes was shown to increase in recent years. The antibiotics initially selected should be effective against both aerobes and anaerobes. Bacterial identification may be associated with host clinical factors and environmental factors.

Resumo Introdução: O Abscesso Peritonsilar é a infecção cervical profunda mais comum. O microrganismo infeccioso pode ser diferente de acordo com os fatores clínicos. Objetivo: Identificar o principal agente causador do abscesso peritonsilar e investigar a relação entre o patógeno causador, os fatores clínicos do hospedeiro e a duração da hospitalização. Método: Este estudo retrospectivo incluiu 415 pacientes hospitalizados diagnosticados com abscesso peritonsilar que foram internados em um centro médico terciário de junho de 1990 a junho de 2013. Coletamos dados através da análise dos arquivos médicos dos pacientes e analisamos variáveis como características demográficas, doença sistêmica subjacente, tabagismo, alcoolismo, hábito de mascar noz de betel, bacteriologia e duração da hospitalização. Resultados: Um total de 168 pacientes apresentaram resultados positivos para isolamento de patógenos. Streptococcus viridans (28,57%) e Klebsiella pneumoniae (23,21%) foram os microrganismos mais comuns identificados pela cultura da secreção. A taxa de isolamento de anaeróbios aumentou para 49,35% nos últimos 6 anos (p = 0,048). Os anaeróbios comuns foram Prevotella e Fusobacterium spp. A identificação de K. pneumoniae aumentou em pacientes idosos (idade > 65 anos) com razão de chances (Odds Ratio - OR) de 2,76 (p = 0,03) e diminuiu na estação do calor (temperatura média > 26 °C) (OR = 0,49, p = 0,04). Nenhum microrganismo específico foi associado à hospitalização prolongada. Conclusão: O patógeno mais comumente identificado através da cultura de secreção foi S. viridans, seguido por K. pneumoniae. A identificação de anaeróbios mostrou ter aumentado nos últimos anos. Os antibióticos selecionados inicialmente devem ser efetivos contra aeróbios e anaeróbios. A identificação bacteriana pode estar associada a fatores clínicos e fatores ambientais do hospedeiro.

Relevancia de profilaxis antibiótica ante procedimientos dentales generadores de bacteriemias transitorias / Antimicrobial prophylaxis for transient bacteremia during dental procedures

This review examines the evidence about the relationship between dental procedures and the incidence of transient bacteremia. One of the main obstacles was to define "invasive dental procedure" as an indication for antimicrobial prophylaxis for patients with high risk of bacteremia. A search in WorldWideScience and ScienceDirect was performed and 20 articles were selected for review. Two contradictions stood out. There is no concrete evidence that a transient bacteremia arising during a dental procedure may be a risk factor for the appearance of bacterial endocarditis. There is no certainty about the effectiveness of antimicrobial prophylaxis, due to the lack of clinical trials of good quality. There is a similitude between bacteremia resulting from invasive and non-invasive dental procedures. The importance of periodontal health as a preventive measure for bacterial endocarditis among high risk patients is highlighted.

Identification of viridans streptococci With Matrix-Assisted Laser Desorption & Ionization Time-of-flight Mass Spectrometry by an In-house Method and a Commercially Available System

Two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based methods were compared for their ability to identify viridans streptococci. One approach employed a reference database and software developed in-house. All inhouse measurements were performed using an Autoflex II Instrument (Bruker Daltonics GmbH, Germany). The other system, a VITEK-MS (BioMérieux, France) was operated on the commercially available V2.0 Knowledge Base for Clinical Use database. Clinical isolates of viridans streptococci (n=184) were examined. Discrepant results were resolved by 16S rDNA sequencing. Species-level identification percentages were compared by a chi-square test. The in-house method correctly identified 179 (97%) and 175 (95%) isolates to the group and species level respectively. In comparison, the VITEK-MS system correctly identified 145 (79%) isolates to the group and species level. The difference between the two methods was statistically significant at both group and species levels. Using the Autoflex II instrument combined with an extraction method instead of whole cell analysis resulted in more reliable viridans streptococci identification. Our results suggest that combining extraction with powerful analysis software and the careful choice of well-identified strains included into the database was useful for identifying viridans streptococci species.

Species-Specific Difference in Antimicrobial Susceptibility Among Viridans Group Streptococci

BACKGROUND: Viridans group streptococci (VGS) are both commensal microbes and potential pathogens. Increasing resistance to penicillin in VGS is an ongoing issue in the clinical environment. We investigated the difference in susceptibility and resistance to penicillin among various VGS species. METHODS: In total 1,448 VGS isolated from various clinical specimens were analyzed over a two-yr period. Identification and antimicrobial susceptibility test was performed by the automated VITEK 2 system (bioMerieux, France) or the MicroScan MICroSTREP system (Siemens, Germany). RESULTS: Among the 1,448 isolates, 412 were isolated from blood (28.4%). Streptococcus mitis group was the most frequently isolated (589 isolates, 40.7%), followed by the S. anginosus group (290 isolates, 20.0%), S. sanguinis group (179 isolates, 12.4%) and S. salivarius group (57 isolates, 3.9%). In total, 314 isolates could not be identified up to the species level. The overall non-susceptibility to penicillin was observed to be 40.0% (resistant, 11.2% and intermediately resistant, 28.8%) with uneven distribution among groups; 40.2% in S. sanguinis group (resistant, 5.0% and intermediately resistant, 35.2%), 60.3% in S. mitis group (resistant, 20.9% and intermediately resistant, 39.4%), 78.9% in S. salivarius group (resistant, 8.8% and intermediately resistant, 70.1%), and 6.2% in S. anginosus group (resistant, 1.7% and intermediately resistant, 4.5%). CONCLUSIONS: Antimicrobial resistance patterns towards penicillin show differences among various VGS; this should be considered while devising an effective antimicrobial treatment against VGS.

Clinical Characteristics of Community-Acquired Viridans Streptococcal Pneumonia / 결핵및호흡기질환

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.

Infective endocarditis:a review of 28 cases / 中华传染病杂志

Objective To investigate the clinical features,diagnostic examinations,treatment and clinical outcomes of patients with definite infective endocarditis (IE).Methods This retrospective study included 28 adults with IE who were admitted to Sir Run Run Shaw Hospital from January 1,2009 to June 30,2011.All the IE cases met the modified Duke criteria and the data were reviewed on clinical presentations,microbiological profiles,echocardiographic findings,in-hospital course and clinical outcomes.Results The mean age was (50.9± 17.4) years with a male preponderance.All patients had native valve IE.Mitral valve prolapse was the most common underlying heart disease.Fever was presented as the primary manifestation.Blood culture results were positive only in 36.4％ of the 11 cases.Streptococcus viridans represented the leading causative agent.Echocardiography was positive in 96.4％ of the cases.46.4％ of the cases underwent surgery for IE.Eighteen cases had at least one major complication.The in hospital mortality was 3.6％.Conclusions Typical clinical presentations of IE are rare.Comparing with previous studies,there are no changing trends in the microbiology.Advanced antibiotics are overused during the treatment,which is awaiting improvements.

Comparison of LIVE/DEAD(R) BacLight(TM) Bacterial Viability Test and alamarBlue(R) Method for Enumeration of Live and Dead Bacteria for Oral Bacterial Species

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 x 10(6) cells/ml. Our data thus indicate that LIVE/DEAD(R) BacLight(TM) is a more effective reagent for this analysis.

Factors Associated with Infective Endocarditis and Predictors of 3-month mortality of Patients with Viridans Streptococcal Bacteremia / 감염과화학요법

BACKGROUND: Viridans streptococci is a major pathogen of infective endocarditis. This study was conducted in order to investigate the factors associated with infective endocarditis and predictors for three-month mortality among patients with viridans streptococcal bacteremia (VSB). MATERIALS AND METHODS: In this study, among 261 eligible patients diagnosed as VSB from January 2000 through June 2011 in a university-affiliated hospital, a retrospective analysis of 197 patients was conducted. All patients with VSB were classified into two groups according to sites of bacteremia; infective endocarditis and other infections. Demographic and clinical characteristics were reviewed through electronic medical records factors associated with infective endocarditis and predictors of three-month mortality in VSB patients were evaluated. RESULTS: Of the 197 patients, 37 (18.8%) patients had viridans streptococcal infective endocarditis (VSIE) and 160 (81.2%) patients had VSB due to other infection. In logistic regression analysis, underlying valvular heart disease (odds ratio [OR], 48.43; 95% confidence interval [CI], 5.77-406.38) and persistent bacteremia (OR, 46.32; 95% CI, 7.18-299.01) showed an independent association with VSIE. Three-month mortality rate was 21.7% in patients with VSB. In logistic regression analysis, previous steroid use (OR, 9.31; 95% CI, 1.34-64.52), previous immunosuppressive therapy (OR, 9.50; 95% CI, 2.13-42.30), hypotension at onset of bacteremia (OR, 7.72, 95% CI, 2.45-24.33), and Charlson comorbidity score > or =3 (OR, 4.53, 95% CI, 1.55-13.28) showed an independent association with three-month mortality in patients with VSB. CONCLUSIONS: VSB patients who have valvular heart disease or persistent bacteremia routinely require echocardiography. Previous steroid use, immunosuppressive therapy, hypotension, and higher Charlson comorbidity score suggested poor prognosis in patients with VSB.

Clinical analysis of infective endocarditis: a report of 97 cases / 中华传染病杂志

Objective To analyse the clinical feature of infective endocarditis (IE) in recent years.Methods Clinical profiles including age of onset,predisposing factor,clinical manifestation,blood culture and ultrasonic cardio gram (UCG) of 97 cases from Huashan Hospital in the recent 10 years were collected and analyzed retrospectively. Descriptive data were represented as mean ±standard deviation form.Positive rate was represented as percentage form.Fisher's exact test were used to determine two groups' comparison.Results The mean age of the population was (49±17)years.Seventy-three patients (75.3％) had background heart disease,the top 3 of which was rheumatic heart disease in 27 patients (27.8％),congenital heart disease in 23 patients (23.7％) and idiopathic mitral valve prolapse in 18 patients (18.6 ％).The most common clinical manifestation were fever (99.0％),murmurs (95.9％) and anemia (84.5％).Sixty-six patients (68.0％) had positive result of blood cultures. Streptococcus viridans,which was found in 28 patients with native valve endocarditis (42.4 ％),was still the most common pathogen.Staphylococcus,which was found in 18patients (27.3％),had an elevated ratio.Staphylococcus aureus was found in 10 patients (15.2％)and 3 of which were MRSA.Coagulase-negative staphylococcus was found in 8 patients (12.1 ％ ) and 2 of which were MRCNS. Drug-resistant bacteria was increased and pathogens were varied.Vegetations were found in 79 patients (81.4％) by UCG.ConclusionsClinical manifestation,predisposing factor and pathogen have changed in IE patients. Attaching importance to physical examination,multiple-time blood culture and UCG helps the diagnose of IE.

Clinical Significance of Bacteremia Caused by Viridans Streptococci / 감염과화학요법

BACKGROUND: Clinical significance of viridans streptococcal bacteremia may be variable from insignificant colonization to serious invasive diseases such as endocarditis. However, there have been no data on the clinical implications of viridans streptococcal bacteremia in Korea to date. MATERIALS AND METHODS: We have analyzed 95 cases of viridans streptococcal bacteremia diagnosed at the Samsung Medical Center from 1997 to 2003. All available clinical and microbiological data were analyzed. RESULTS: Of the total 95 cases, 76 (80%) had clinically significant infections, while 20% of cases were not associated with clinical diseases. Primary bacteremia was the most common disease (48%) followed by intra-abdominal infections (15%), and infective endocarditis (8%). Primary bacteremia was mostly observed in patients with neutropenia after anti-cancer chemotherapy. Infective endocarditis was unlikely if patients did not have underlying heart diseases. S. mitis, S. oralis, and S. intermedius were the most common etiologic agent in infective endocarditis, primary bacteremia, and intra-abdominal infection, respectively. Thirty-eight percent of isolates were not susceptible to penicillin. CONCLUSION: Viridans streptococcal bacteremia is likely to be associated with invasive clinical diseases, especially in patients with neutropenia, intra-abdominal diseases or underlying heart diseases. However, the presence of viridans streptococci in the blood cultures does not necessarily mean the possibility of infective endocarditis.

Clinical Significance of Bacteremia Caused by Viridans Streptococci / 감염과화학요법

BACKGROUND: Clinical significance of viridans streptococcal bacteremia may be variable from insignificant colonization to serious invasive diseases such as endocarditis. However, there have been no data on the clinical implications of viridans streptococcal bacteremia in Korea to date. MATERIALS AND METHODS: We have analyzed 95 cases of viridans streptococcal bacteremia diagnosed at the Samsung Medical Center from 1997 to 2003. All available clinical and microbiological data were analyzed. RESULTS: Of the total 95 cases, 76 (80%) had clinically significant infections, while 20% of cases were not associated with clinical diseases. Primary bacteremia was the most common disease (48%) followed by intra-abdominal infections (15%), and infective endocarditis (8%). Primary bacteremia was mostly observed in patients with neutropenia after anti-cancer chemotherapy. Infective endocarditis was unlikely if patients did not have underlying heart diseases. S. mitis, S. oralis, and S. intermedius were the most common etiologic agent in infective endocarditis, primary bacteremia, and intra-abdominal infection, respectively. Thirty-eight percent of isolates were not susceptible to penicillin. CONCLUSION: Viridans streptococcal bacteremia is likely to be associated with invasive clinical diseases, especially in patients with neutropenia, intra-abdominal diseases or underlying heart diseases. However, the presence of viridans streptococci in the blood cultures does not necessarily mean the possibility of infective endocarditis.

Neonatal Sepsis Caused by Multi-Resistant Streptococcus Mitis

PURPOSE: Streptococcus mitis, one of the Viridans streptococci, is a normal female genital tract flora. It is known as a common cause of chorioamnionitis and subsequent abortions in perinatal period. Although it has been suggested to be less virulent they can cause severe neonatal infections. In this study, we focused on the clinical presentations of neonatal septicemia and the antibiotic susceptibilities of Streptococcus mitis. METHODS: Nine newborns for whom Streptococcus mitis was isolated from normally sterile sites were seen in the NICU of Eulji University Hospital from Jan. 1 to Dec. 31 2005. Medical records were reviewed for the perinatal risk factors, maternal clinical manifestations, obstetric complications and the placental pathologic findings. We also observed the neonatal clinical courses and antibiotic susceptibilities of Streptococcus mitis. RESULTS: All nine infants were high-risk newborns because of prematurity, low birth weight and/or co-morbid diseases. Clinical manifestations varied from asymptomatic to severe neonatal sepsis. Six cases resistant to ampicillin were all sensitive to vancomycin. Five among them had clinical sepsis, and one infant was asymptomatic. Three cases were sensitive to ampicillin, two of them were asymptomatic and one infant with sepsis was successfully treated with ampicillin and aminoglycoside. CONCLUSION: Streptococci mitis should not be overlooked as a contaminant when isolated from normally sterile sites. If Streptococci mitis or Viridans streptococci are recovered from a high-risk newborn showing no clinical response to penicillin, it would be better to switch antibiotics to vancomycin until the susceptibility results available.

Clinical Significance of Viridans Streptococcal Bacteremia / 대한진단검사의학회지

BACKGROUND: Viridans streptococci, a diverse group of streptococcal species is present in the oral flora of all humans, and clinical isolation of these organisms could be misinterpreted as contamination. The purposes of this study were to ascertain the clinical significance of viridans streptococcal bacteremia and to determine the epidemiological, clinical, and microbiological features. METHODS: All cases of viridans streptococcal bacteremia in the period from January 1998 to December 2002 were reviewed. Bacterial identification was done with the Vitek system, and antimicrobial susceptibility tests for penicillin, cefotaxime, chloramphenicol, clindamycin, and erythromycin by the disk diffusion method or E-test were carried out. RESULTS: Of 154 cases of viridans streptococcal bacteremia, 56 cases were identified to the species level such as S. salivarius (19), S. mitis (16), S. intermedius (7), S. sanguis (7), S. uberis (3), S. oralis (2), S. bovis (1), and S. mutans (1). The most frequent diagnostic category was infectious diseases (54), followed by solid organ tumors (45), hematologic malignancies (29), and liver diseases (8). Seven patients (4.5%) had subacute endocarditis and all of them had underlying heart disease. Seventy six (49.3%) patients showed positive blood culture from two or more blood samples. Thirty three (21.4%) patients had an absolute neutrophil count of less than 500 cells/ L. Thirty four cases of bacteremia were polymicrobial (22%). When the diagnosis of viridans streptococcal bacteremia was established by the presence of two or more positive blood cultures or presence of neutropenia or signs of sepsis, 29.9% was interpreted as contamination. Two patients died of septic shock caused by viridans streptococcal infection alone. Sixty-eight percent of isolates were susceptible to penicillin. CONCLUSIONS: About 70% of viridans streptococcal bacteremia was clinically significant. Most viridans streptococcal bacteremia was found in patients with cancer or neutropenia and these infections were associated with limited morbidity.

Antimicrobial Susceptibilities of Viridans Streptococci Isolated from Blood Cultures during Recent Period / 임상검사와정도관리

BACKGROUND: Viridans group streptococci (VGS) are being increasingly reported as pathogens causing septicemia in neutropenic and other immunocompromised patients since 1980s. In the past, VGS were nearly uniformly susceptible to beta-lactam antimicrobial agents, aminoglycosides, tetracyclines, and macrolides. Several recent published studies, however, indicate that antimicrobial resistance may be emerging as a problem with VGS. The purpose of this study was to determine the antimicrobial susceptibility of VGS strains isolated from blood cultures in recent period. METHODS: A total of 45 consecutive strains of VGS isolated from blood cultures between May 2001 and March 2002 at Wonju Christian Hospital were tested for antimicrobial susceptibility. Identification of VGS were performed by API Strep 32(bioMerieux sa, Marcy-l'Etoile, France) commercial kit. Antimicrobial susceptibility tests were done by NCCLS recommended disk diffusion method and penicillin MICs were determined by E test. RESULTS: Among the 45 VGS strains, frequently isolated organisms were Streptococcus mitis (31.1%), Streptococcus oralis (17.8%), Streptococcus constellatus (11.1%), and Streptococcus anginosus (8.9%). Overall intermediate-and resistant rates to antimicrobial agents of VGS were as follows: penicillin; 26.7% and 8.9%, erythromycin; 4.4% and 28.9%, clindamycin 2.2% and 22.2%, and ceftriaxone; 4.4% and 6.7%, respectively. Resistant rates of Streptococcus mitis and Streptococcus oralis were as follows: penicillin; 50% vs 50%, erythromycin 43% vs 37%, clindamycin 21% vs 37%, and ceftriaxone 7% vs 25%, respectively. CONCLUSIONS: These results indicate the species-related variability of susceptibility among VGS isolated from blood in recent period. In addition to S. mitis, S. oralis also displayed high rates of resistance to penicillin, macrolides, and ceftriaxone. The difference in susceptibilities between species of VGS indicates the importance of accurate identification and the need for continuing monitoring of antimicrobial resistance.