Infecciones por estreptococos del grupo S. anginosus en pediatría / S. anginosus group streptococcal infections in children

Los estreptococos del grupo Streptococcus anginosus (EGA), también llamados "Streptococcus milleri", fueron reconocidos como parte de los estreptococos del grupo viridans (EGV) desde principios del siglo XX. Su rol como patógenos humanos, sin embargo comenzó a destacarse recién en la década de 1970. En esta actualización se describen aspectos microbiológicos y clínicos de los EGA. Los métodos fenotípicos de identificacón e incluso algunos genotípicos carecen de precisión para reconocer las tres especies del grupo (Streptococcus anginosus, Streptococcus constellatus y Streptococcus intermedius) e incluso pueden fallar en su clasificación a nivel de grupo. La mayoría de ellos son sensibles a los antibióticos beta-lactámicos pero son considerables los porcentajes de resistencia a macrólidos, lincosamidas y tetraciclinas. Los EGA son colonizantes habituales de las mucosas orofaríngea, intestinal y genitourinaria, pero, cada vez más frecuentemente, son reconocidos como patógenos humanos. Es ampliamente conocida su capacidad de formar abscesos en órganos sólidos, especialmente abscesos cerebrales, pulmonares y hepáticos. También producen sinusitis, empiemas y colecciones en piel y tejidos blandos, hueso, articulaciones, etc. Se han encontrado asociados con exacerbaciones pulmonares en pacientes con fibrosis quística y con enfermedad pulmonar obstructiva crónica. Producen también infecciones posteriores a mordeduras humanas, infecciones diseminadas, bacteriemia sin foco aparente y, en menor medida, endocarditis infecciosa (AU)

Streptococci from the Streptococcus anginosus group (SAG), also termed "Streptococcus milleri", were recognized as members of the viridans group streptococci (VGS) in the early 20th century. Nevertheless, their role as human pathogens only became evident in the 1970s. In this update, microbiological and clinical aspects of the SAG are described. Phenotypic and even some genotypic identification methods lack accuracy in recognizing the three species of the group (Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius) and may fail to classify them at the group level. Most of them are sensitive to beta-lactam antibiotics but rates of resistance to macrolides, lincosamides, and tetracyclines are significant. SAGs are common colonizers of the oropharyngeal, intestinal, and genitourinary mucosa, but are increasingly recognized as human pathogens. Their ability to form abscesses in solid organs, especially brain, lung and liver, is widely known. They may produce sinusitis, empyemas, and collections in skin and soft tissues, bone, joints, etc. They have also been associated with pulmonary exacerbations in patients with cystic fibrosis and chronic obstructive pulmonary disease. In addition, they may cause infections following human bites, disseminated infections, bacteremia without apparent focus, and, to a lesser extent, infective endocarditis (AU)

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.

Resistencia a antibióticos ß-lactámicos y eritromicina en bacterias de la cavidad oral / Resistance to ß-lactam Antibiotics and Erythromycin in Bacteria of the Oral Cavity

Resumen Introducción. La microbiota humana como fuente de bacterias y genes de resistencia constituyen un problema de salud pública. En este estudio se investigó la prevalencia de bacilos entéricos Gram negativos resistentes a β-lactámicos y de los Streptococcus del grupo viridans (EGV) con resistencia a eritromicina en la cavidad oral. Métodos. Se realizó un estudio descriptivo de corte transversal con 193 aislamientos de la cavidad oral sana de 178 adultos que asistieron a una Clínica Odontológica de la ciudad de Cali durante el 2018. La evaluación de la sensibilidad antimicrobiana se realizó en 59 bacilos entéricos y 134 EGV y se identificó por PCR los genes que confieren resistencia a β-lactámicos y eritromicina. El análisis estadístico se realizó mediante el empleo del paquete SPSS vs 23. Resultados. El 84,7% de los bacilos entéricos fueron multirresistentes y presentaron genes bla, siendo blaTEM-1 (49,2%) y blaVIM-2 (30,5%,) los más prevalentes. Los EGV fueron resistentes a eritromicina (38,8%) y clindamicina (28,4%). El 18,7% presentaron el fenotipo cMLSβ, 4,5% el iMLSβ y el 14,9% fueron M. El gen ermB se detectó en los cMLSβ, (13,4%) y el gen mef en los M (9,7%). Conclusión. En este estudio se demostró la presencia de EGV y bacilos entéricos resistentes a los antibióticos y portadores de genes de resistencia a eritromicina y genes bla en la cavidad oral sana. La presencia de estas bacterias representa un riesgo para la salud de los individuos portadores y contribuyen a la creciente epidemia de resistencia bacteriana.

Abstract Introduction. The human microbiota as a source of bacteria and resistance genes is a public health problem. This study researched the prevalence of Gram-negative enteric bacilli resistant to β-lactams and erythromycin resistance in the oral cavity. Methods. A descriptive cross-sectional study was carried out with 193 isolates obtained from the oral cavity of 178 healthy adults who were treated at a Dental Clinic in the city of Cali during 2018. The evaluation of antimicrobial sensitivity was performed in 59 enteric bacilli and 134 EGV and the genes that confer resistance to β-lactam and erythromycin were identified by PCR. Statistical analysis was performed using the SPSS statistical package vs. 25.0. Results. 84.7% of the enteric bacilli presented the MDR phenotype and all presented the bla genes, blaTEM-1 (49.2%) and blaVIM-2 (30.5%) being the most prevalent. EGVs were resistant to erythromycin (38.8%) and clindamycin (28.4%). 18.7% presented the cMLSβ phenotype, 4.5% the iMLSβ and 14.9% were M. The ermB gene was detected more frequently in the cMLSβ, (13.4%) and the mef gene in the M (9.7%). Conclusion. This study demonstrated the presence of antibiotics and Gram-negative enteric bacilli resistant to antibiotics and carriers of erythromycin resistance genes and bla genes, respectively in the healthy oral cavity. The presence of these bacteria represents a risk to the health of carrier individuals and contributes to the growing epidemic of bacterial resistance.

Brain Abscess and Esophageal Dilatation: Where is the Link? ­ Case Report

Introduction Caustic substance ingestion is a common cause of esophageal stricture in children. The primary treatment is esophageal dilatation. Although it is known that endoscopic esophageal dilatation is a procedure associated with a high rate of bacteremia, current guidelines do not recommend routine throat swab cultures or antibiotic prophylaxis for the general children population. Case Report We describe a case of a 7-year-old boy presenting with refractory headaches who was diagnosed with cranial abscess after multiple esophageal dilatations due to stenosis caused by caustic soda ingestion. The patient was subjected to neurosurgical intervention and intravenous antibiotic treatment for 6 weeks. Streptococcus viridans culture was positive in purulent abscess content. Conclusion We highlight this condition that, although rare, needs immediate diagnosis and proper treatment. We also recommend routine testing of throat swabs and antibiotics prophylaxis to children undergoing esophageal dilatation.

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.

Influencia del estrés académico percibido, sobre la calidad de la microbiota oral y el pH salival / Influence of academic stress perceived, on the quality of oral microbiota and salivary pH

OBJETIVO: determinar la influencia del estrés académico percibido sobre la microbiota oral y el pH salival en los estudiantes de quinto año de la Facultad de Odontología - UMSS en la segunda rotación de la gestión 2018. MÉTODOS: estudio descriptivo y prospectivo longitudinal. Se trabajó con 26 estudiantes, se les realizaron pruebas al inicio y al final de la segunda rotación: Cuestionario de Estrés Percibido (CPE), hisopado bucal (identificación microbiota) y toma de muestra salival (determinación pH). RESULTADOS: test psicológico, inicio de rotación: 69,2% de los estudiantes nivel 2 medianamente estresado, 23,0% nivel 3 estresado y 7,6% nivel 1 poco estresado. Final de rotación: 46,1% nivel 3 estresado, 30,7% nivel 2 medianamente estresado, 19,2% nivel 4 muy estresado y 3,8% nivel 1 poco estresado. Análisis del pH salival, primera toma: valor promedio 6,79. Segunda toma: valor promedio 6,20. Prueba microbiológica, primera toma: en los 26 cultivos se desarrolló Streptococcus viridans, en 3 Staphylococcus spp, en 3 Cándida albicans, en 2 Escherichia coli y en 1 Staphylococcus aureus. Segunda toma: en los 26 cultivos se desarrolló Streptococcus viridans, en 6 Cándida albicans, en 1 Klebsiella spp, en 3 Escherichia coli y en 1 Staphylococcus aureus; en esta última toma hubo incremento significativo del desarrollo microbiano en todos los casos. CONCLUSIÓN: los niveles de estrés académico percibidos por los estudiantes de la Facultad de Odontología - UMSS son elevados al finalizar la segunda rotación de la gestión 2018, concordantes con el incremento del desarrollo de Streptococcus viridans y Cándida albicans, acompañados por un descenso marcado en el pH salival.(AU)

OBJECTIVE: to determine the influence of perceived academic stress on the oral microbiota and salivary pH in the fifth year students of the Faculty of Dentistry - UMSS in the second rotation of the 2018 term. METHODS: longitudinal descrptive and prospective study. We worked with 26 students, the following were made at the beginning and at the end of the term: Questionnaire of Stress Perceived (CPE), buccal swab (to identify microbiota) and sample taking of saliva (to determine pH). RESULTS: psychological test, at the beginning: 69,2% level 2 stressed and 23,0% level 3moderately stressed , 7,6% of students level 1 little stressed. At the end: 46,1% level 3moderately stressed, 30,7% level 2 stressed, and 19,2% level 4 very stressed, 3,8% level 1 little stressed. Salivary pH levels, fist shot: average level was 6,9. Second shot: average level was 6,20. Microbiological test, first shot: Streptococcus viridans were developed in 26 cultures, in 3 Staphylococcus spp, in 3 Candida albicans, in 2 Escherichia coli and in 1 Staphylococcus aureus. In the second shot there was a significant increase in bacterial development in all cases. Salivary pH analysis, first intake: average value 6,79. Second shot: average value 6,20. CONCLUSIONS: the levels of academic stress perceived by the students of the Faculty of Dentistry - UMSS are high at the end of the second rotation of the 2018 management, consistent with the increased development of Streptococcus viridans and Candida albicans, accompanied by a marked decrease in salivary pH.(AU)

Endocarditis infecciosa nativa en pediatría: enfoque clínico cardiológico / Native valve infective endocarditis in children: From the focus of clinical cardiology

Objetivos: Analizar las características demográficas, clínicas, microbiológicas, evolución y factores de riesgo de morbimortalidad asociados a la endocarditis de válvula nativa (EIN) en pacientes (p) pediátricos. Población y métodos: Se evaluaron 176 p con EIN, divididos en grupo I: <3meses (27p) y grupo II: >3meses (149p). Resultados: Grupo I: el 66% tenía corazón sano. El microorganismo más frecuente fue Staphylococcus aureus (44,4%). Afectación derecha (77,8%-p<0,0001). Evento principal: infección no controlada (INC) (52%, p=0,0009) y asociada a Candida (p<0,00001). Se indicó tratamiento quirúrgico a 10 p (37%). Mortalidad 29,6%(8p). Grupo II: el 57% presentaba cardiopatía previa. Microorganismos prevalentes: S.aureus (49,1%) y estreptococos del grupo viridans (22,5%). Hubo compromiso predominantemente izquierdo (p=0,001). Eventos: embolias sistémicas (36,2%-p=0,01), perforación valvular (51%-p=0,0005), insuficiencia cardíaca (26%-p=0,03) e INC (21,5%). La embolia sistémica se asoció a S.aureus (p=0,01). El 36,2% requirió cirugía. Mortalidad 6,7% (10p). En el análisis univariado la mortalidad se asoció a edad <3meses (p=0,0003), INC (p=0,002) y S.aureus (p=0,03). En el multivariado la mortalidad se relacionó a edad < 3meses (OR:7,50 ­IC95%:1,77­31,69) y a INC (OR:4,2-IC95%:1,16­15,29). Conclusiones: La EN se presentó en pacientes con corazón sano en el 50% de los casos. El microorganismo más frecuente fue S.aureus. En los <3 meses la infección no controlada fue la complicación más frecuente asociada a Candida, con afectación predominante de cavidades derechas. Los >3meses tuvieron mayor prevalencia de perforación valvular izquierda asociada a embolias sistémicas e insuficiencia cardíaca. El 35% de los p requirió cirugía. Los predictores de mortalidad fueron la edad <3meses y la INC.

Objectives: To analyze demographic, clinical, and microbiological, outcome, and morbidity and mortality risk factors associated with native valve endocarditis (NVE) in pediatric patients (p). Population and methods: 176 p with NVE were evaluated and divided into group I: <3 months (27p) and group II: >3 months (149p). Results: Group I: 66% had a healthy heart. The most common microorganism was Staphylococcus aureus (44.4%). Right-sided involvement (77.8%-p<0.0001). Main event: Uncontrolled infection (UCI) (52%, p-0.0009) and association with Candida (p<0.00001). Surgical treatment was indicated in 10 p (37%). Mortality was 29.6% (8p). Group II: 57% had previous heart disease. Prevalent microorganisms: S. aureus (49.1%) and viridans group streptococci ( (22.5%). Left-sided involvement predominated (p-0.001). Events: systemic embolism (36.2%-p-0.01), valve perforation (51%-p-0.0005), heart failure (26%-p-0.03), and UCI (21.5%). Systemic embolism was associated with S. aureus infection (p-0.01). 36.2% required surgery. Mortality was 6.7% (10p). In univariate analysis, mortality was associated with age <3 months (p-0.0003), UCI (p-0.002), and S. aureus infection (p-0.03). In multivariate analysis, mortality was related to age <3 months (OR:7.50 ­ 95% CI:1.77­31.69) and UCI (OR:4.2 -95% CI:1.16­15.29). Conclusions: NVE was observed in patients with a healthy heart in 50% of cases. The most common microorganism found was S. aureus. In the <3 months group, uncontrolled infection was the most common complication associated with Candida, predominantly affecting the right side. The >3 months group had a higher prevalence of left-valve perforation associated with systemic embolism and heart failure. 35% of p required surgery. Predictors of mortality were age <3 months and UC (AU)

Identificación y sensibilidad a los antimicrobianos de aislados de estreptococos del grupo viridans provenientes de pacientes internados en un hospital universitario de la ciudad de Buenos Aires / Identification and antibiotic susceptibility of viridans group streptococci isolates recovered from patients hospitalized at a teaching hospital in Buenos Aires City

Los estreptococos del grupo viridans (EGV) son agentes causales de infecciones localizadas e invasivas. Dada la gravedad de las infecciones producidas por EGV sumada a las escasas comunicaciones actuales en nuestro país, los objetivos de este trabajo fueron la identificación y el estudio de la sensibilidad a los antibióticos de aislados caracterizados como EGV, recuperados de pacientes internados, para actualizar el conocimiento sobre el perfil de resistencia y la epidemiología de las infecciones ocasionadas por EGV. Se recuperaron 132 aislados de EGV en el Hospital de Clínicas «José de San Martín¼ en el período 2011-2015. La identificación se realizó mediante pruebas convencionales y espectrometría de masas (Matrix Assisted Laser Desorption Ionization - Time of Flight Mass Spectrometry). El grupo Streptococcus anginosus fue el más frecuente (42%) seguido por el grupo Streptococcus mitis (33%). Dentro del grupo S. mitis se excluyó a Streptococcus pneumoniae. El 100% de los aislados fue sensible a ertapenem, linezolid y vancomicina; el 96,9% a cef-triaxona y cefepima. Se encontró un 25,8% de resistencia a penicilina (I+R) fundamentalmente en aislados de grupo S. mitis. La resistencia a tetraciclina fue del 27,2% y solo 2/132 aislados fueron resistentes a levofloxacina. Los valores de CIM de gentamicina oscilaron entre 0,5 y 32 -og/ml. El 17,4% de los aislados presentó resistencia a eritromicina sin diferencia significativa en la distribución de fenotipos M y MLS. Los resultados muestran la importancia de la vigilancia continua de las infecciones producidas por estos microorganismos con el fin de generar aportes para la elección de la terapia antibiótica adecuada.

Members of the viridans group streptococci (VGS) are the cause of local and invasive infections. Due to the severity of these infections and taking into account that reports regarding epidemiological aspects are scarce, the aims of this work were the identification and the study of the antibiotic susceptibility profiles of the isolates recovered from patients that were hospitalized in order to find out about the resistance level and the epidemiology of infections in which VGS are involved. A hundred and thirty two isolates identified as VGS were isolated at Hospital de Clínicas «José de San Martín¼ during the period 2011-2015. The identification was performed by biochemical test and mass spectrometry by Matrix Assisted Laser Desorption Ionization -Time of Flight Mass Spectrometry. Streptococcus anginosus group was prevalent (42%) followed by Streptococcus mitis group (33%). In the latter, isolates of Streptococcus pneumoniae were excluded. All the VGS isolates were susceptible to ertapenem, meropenem, linezolid and vancomycin; 25.8% were resistant (I+R) to penicillin, being prevalent in the S. mitis group. Regarding ceftriaxone and cefepime 96.9% of the isolates were susceptible. Only two isolates were resistant to levofloxacin, 27.2% to tetracycline and it was not found high level resistance to gentamycin (MIC range 0.5-32 µg/ml). Resistance to erythromycin was 17.4% with no significant difference between M and MLS phenotypes. The most active antibiotics were in addition to ceftriaxone and cefepime, vancomycin, ertapenem, meropenem and linezolid. These results highlight the importance of the continuous surveillance of the infections caused by VGS in order to predict a correct antibiotic therapy.

Antibacterial effect of lidocaine in various clinical conditions

BACKGROUND: Infection, one of the complications associated with procedures, can cause fatal outcomes for patients. Although the local anesthetic agent we use is less susceptible to infection due to its antibacterial action, we performed this study to check the change in the antibacterial effect of lidocaine in various clinical conditions. METHODS: After exposing lidocaine to five contaminated environments, we checked on whether the bacteria could be cultured in blood agar plate (BAP) media. In each contaminated environment, lidocaine was exposed for 4 h (n = 9) and 8 h (n = 9), and the results were compared. Lidocaine was swabbed with chlorhexidine (group A), brought into contact with saliva (group B), skin (group C), an operating room floor and an outpatient room floor (group D), operating room air for 24 h (group A-a), and outpatient room air for 24 h (group A-b). After exposure, the culture was initiated. RESULTS: In 2 of 9 BAP media where lidocaine was exposed to saliva (group B) for 8 h, growth of a colony was observed. In gram staining, it was found to be Streptococcus viridans. No bacteria were found in any other groups. CONCLUSIONS: Though lidocaine has strong antibacterial activity, it has been found that long-term exposure to a contaminated environment reduces its antibacterial activity and that drug contamination can be heavily affected not only by environmental but also human effects. Therefore, the use of aseptic drugs is necessary, and stopping the reuse of the drug is a way to prevent complications, including infection.

Diagnostic value of pediatric blood culture bottles for acute postoperative endophthalmitis

OBJECTIVE: To report our experience using conventional culture methods (CM) and pediatric blood culture bottles (PBCBs) for vitreous sample culture of acute postoperative endophthalmitis. METHODS: A retrospective study was conducted at the Department of Ophthalmology, Hospital das Clinicas, HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, BR, from January 2010 to December 2015, and it included 54 patients with clinically suspected acute postoperative endophthalmitis. Vitreous samples were obtained by vitreous tap or vitrectomy. Samples from January 2010 to December 2011 were cultivated in CM, whereas samples from January 2012 to December 2015 were inoculated in PBCBs. The measured outcome was the yield of positive cultures. RESULTS: Twenty cases were included in the CM group, and 34 cases were included in the PBCB group. The yield of positive cultures in PBCBs (64.7%) was significantly higher than that in conventional CM (35%, p=0.034). Staphylococcus epidermidis and Streptococcus viridans were the two most commonly found agents. CONCLUSION: PBCBs can be used successfully in clinically suspected endophthalmitis. The method showed a higher yield of positive cultures than the conventional method. This technique appears to have several advantages over the traditional method: it saves time, as only one medium needs to be inoculated; transportation to a laboratory is easier than in the traditional method, and there is no need to maintain a supply of fresh agar media. The use of PBCBs may be recommended as the primary method for microbiological diagnosis and is especially suitable for office settings and remote clinics.

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.

Microbiology and clinical characteristics of viridans group streptococci in patients with cancer

ABSTRACT This study assessed the microbiology, clinical syndromes, and outcomes of oncologic patients with viridans group streptococci isolated from blood cultures between January 1st, 2013 and December 31st, 2016 in a referral hospital in Mexico using the Bruker MALDI Biotyper. Antimicrobial sensitivity was determined using BD Phoenix 100 according to CLSI M100 standards. Clinical information was obtained from medical records and descriptive analysis was performed.Forty-three patients were included, 22 females and 21 males, aged 42 ± 17 years. Twenty (46.5%) patients had hematological cancer and 23 (53.5%) a solid malignancy. The viridans group streptococci isolated were Streptococcus mitis, 20 (46.5%); Streptococcus anginosus, 14 (32.6%); Streptococcus sanguinis, 7 (16.3%); and Streptococcus salivarius, 2 (4.7%). The main risk factors were pyrimidine antagonist chemotherapy in 22 (51.2%) and neutropenia in 19 (44.2%) cases, respectively. Central line associated bloodstream infection was diagnosed in 18 (41.9%) cases. Septic shock occurred in 20.9% of patients, with an overall mortality of 18.6%. Only four S. mitis revealed penicillin-resistance.Our results are similar to those of other series, identifying these bacteria as emerging pathogens with significant morbidity and mortality in oncologic patients. The MALDI-TOF system increased the rate of viridans group streptococci isolation in this population.

Globicatella sanguinis Bacteremia in a Korean Patient / 대한임상미생물학회지

Globicatella sanguinis is an unusual pathogen causing bacteremia, meningitis, and urinary tract infection, and can be misidentified as Streptococcus pneumoniae or viridans streptococci due to its colonial morphology. A 76-year-old female patient with hypertension and degenerative arthritis was admitted to the hospital complaining of knee joint pain. Blood culture revealed the presence of Gram-positive cocci, and the isolated organism was equally identified as S. pneumoniae using the MicroScan identification system (Beckman Coulter, USA) and Vitek 2 identification system (bioMérieux, USA). However, the isolate showed optochin resistance based on the optochin disk susceptibility test. The organism was finally confirmed to be G. sanguinis based on 16S rRNA sequencing and hydrogen sulfide production testing. Accurate identification of G. sanguinis isolated from aseptic body fluids including blood is important for appropriate antibiotic selection based on accurate application of interpretative criteria of antimicrobial susceptibility test.

Molecular Characterization of Group B Streptococcus Serotypes By Multiplex Polymerase Chain Reaction / Caracterização molecular dos sorotipos de estreptococos do grupo b por reação multiplex pcr

OBJECTIVE: Group B Streptococcus (GBS) serotypes (Ia, Ib and II to IX) are classified based on variations in their capsular polysaccharide; their prevalence differs between different geographic areas. We examined the prevalence of all GBS serotypes in rectal and vaginal swab samples obtained from 363 pregnant women followed at a Brazilian referral center (Hospital da Mulher Professor Doutor José Aristodemo Pinotti); bacterial susceptibility to antibiotics was further determined. METHOD: Prevalence of positive GBS was evaluated by latex agglutination and by multiplex PCR analysis; bacterial susceptibility to antibiotics, such as clindamycin, erythromycin, levofloxacin, linezolid, penicillin and tetracycline was determined by the disk diffusion method. RESULTS: (a) standard GBS culture and the multiplex PCR analysis tested positive for 83 swabs, collected from 72 women (prevalence of GBS colonization: 72/363; 20%); the most prevalent Serotype was Ia (n=43/83; 52%), followed by serotype V (n=14/83; 17%); according to anatomical origin, serotype Ia accounted for 27/59 (46%) and 16/24 (67%) of the vaginal and rectal samples, respectively; PCR also identified serotypes Ib, II, III and VI. Serotype VI is rarely described and had not been previously reported in Brazil or in Latin America. (b) The latex agglutination test only identified 44 positive samples, all of which were serotyped: 34 of these samples (77%) had serotypes matching those identified by multiplex PCR. (c) Only one sample (serotype Ia) showed resistance to erythromycin and clindamycin. CONCLUSION: Regional studies on GBS serotypes prevalence are essential to guide immunoprophylactic interventions (vaccines) and the implementation of adequate antibiotic prophylaxis or treatment. In this study, the incidence of the serotype VI, a new and rare serotype of GBS was described for the first time in a Brazilian population.

OBJETIVO: Os sorotipos (Ia, Ib e II ao IX) do estreptococo do grupo B (GBS) são classificados baseado nas variações em seus polissacarídeos capsulares; sua prevalência difere entre diferentes áreas geográficas. Nós examinamos a prevalência de todos os sorotipos do estreptococo do grupo B em amostras de swabs vaginal e retal obtidas de 363 mulheres seguidas em um centro de referência brasileiro, o Hospital da Mulher Professor Doutor José Aristodemo Pinotti; a susceptibilidade bacteriana a antibióticos foi também determinada. MÉTODO A prevalência de estreptococo do grupo B positivo foi avaliada por aglutinação em látex e através de análise por multiplex PCR; susceptibilidade bacteriana a antibióticos, tais como clindamicina, eritromicina, levofloxacin, linezolide, penicilina e tetraciclina foi determinada pelo método de disco difusão. RESULTADOS: (a) Tanto a cultura padrão para estreptococo do grupo B quanto a análise por multiplex PCR testaram positivos para 83 swabs. A prevalência para colonização por GBS foi 20%. O sorotipo Ia foi o mais prevalente (n= 43/83; 52%), seguido pelo sorotipo V (n= 14/83; 17%); De acordo com a origem anatômica, o sorotipo Ia positivou 27/59 (46%) e 16/24 (67%) das amostras vaginais e retais, respectivamente; o teste de PCR também identificou os sorotipos Ib, II, III, VI. O sorotipo VI é raramente descrito e não reportado no Brasil ou na América Latina até esta data. (b) O teste de aglutinação em látex somente identificou 44 amostras positivas, todas das quais foram sorotipadas: 34 destas amostras (77%) tiveram os sorotipos coincidindo com aqueles identificados pela multiplex PCR. (c) Somente uma amostra (sorotipo Ia) mostrou resistência a eritromicina e clindamicina. CONCLUSÃO: Estudos regionais sobre a prevalência dos sorotipos do estreptococo do grupo B são essenciais para guiar medidas imunoprofiláticas (vacinas) e a implementação de adequada antibiótico profilaxia. Neste estudo, a incidência do sorotipo VI foi descrita pela primeira vez na população Brasileira, um novo e raro sorotipo do estreptococo do grupo B.

Etiology of Bacteremia in Children with Hemato-oncologic Diseases from a Single Center from 2011 to 2015

PURPOSE: The aim of this study was to identify the pathogens of blood stream infection (BSI) in children with hemato-oncologic disorders, to analyze susceptibility patterns of microorganisms to guide empirical antimicrobial therapy, and to compare temporal trends of the pathogen and antimicrobial susceptibility with those of previous studies. METHODS: We retrospectively analyzed the medical records of children with hemato-oncologic disorders whose blood culture grew pathogens at the Seoul National University Children's Hospital between 2011 and 2015. RESULTS: A total of 167 patients developed 221 episodes of bacteremia. Among 229 pathogens, gram-negative bacteria (GNB) accounted for 69.0% (64.0% in 2002 to 2005, 63.4% in 2006 to 2010); gram-positive bacteria (GPB) accounted for 28.8% (31.3% in 2002 to 2005, 34.6% in 2006 to 2010); and fungus accounted for 2.2%. Among GNB, Klebsiella species (53.2%, 84/158) and Escherichia coli (19.6%, 31/158) were common. Staphylococcus aureus (48.5%, 32/66) and viridans streptococci (21.2%, 14/66) were frequently isolated among GPB. The susceptibilities of oxacillin and vancomycin in GPB were 54.8% and 96.9% (51.5% and 95.5% in 2002 to 2005; 34.1% and 90.5% in 2006 to 2010), respectively, whereas in GNB, the susceptibilities of cefotaxime, piperacillin/tazobactam, and imipenem were 73.2%, 77.2%, and 92.6% (75.9%, 82.8%, and 93.4% in 2002 to 2005; 62.8%, 82.9%, 93.8% and in 2006 to 2010), respectively. There were no significant differences in the proportion of etiologic agents or the antimicrobial susceptibilities between the current study and that of the previous two studies from 2002 to 2010. Overall fatality rate was 13.1%. CONCLUSIONS: GNB predominated in BSI among children with hemato-oncologic disorders. The etiology of bacteremia and antimicrobial susceptibility were comparable to those of the previous studies. Thus, piperacillin/tazobactam can be used as the initial empirical antimicrobial agent in febrile neutropenia.

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.

Increase in Antibiotic-Resistant Gram-Negative Bacterial Infections in Febrile Neutropenic Children

BACKGROUND: The incidence of bacteremia caused by Gram-negative bacteria has increased recently in febrile neutropenic patients with the increase of antibiotic-resistant Gram-negative bacterial infections. This study aimed to identify the distribution of causative bacteria and the proportion of antibiotic-resistant bacteria in bacteremia diagnosed in febrile neutropenic children. MATERIALS AND METHODS: The medical records of febrile neutropenic children diagnosed with bacteremia between 2010 and 2014 were retrospectively reviewed. The causative bacteria and proportion of antibiotic-resistant bacteria were investigated and compared yearly during the study period. The clinical impact of antibiotic-resistant bacterial infections was also determined. RESULTS: A total of 336 bacteremia episodes were identified. During the entire study period, 181 (53.9%) and 155 (46.1%) episodes were caused by Gram-negative and Gram-positive bacteria, respectively. Viridans streptococci (25.9%), Klebsiella spp. (16.7%), and Escherichia coli (16.4%) were the most frequent causative bacteria. The overall distribution of causative bacteria was not significantly different annually. Antibiotic-resistant bacteria were identified in 85 (25.3%) episodes, and the proportion of antibiotic-resistant bacteria was not significantly different annually. Extended-spectrum β-lactamase-producing E. coli and Klebsiella spp. were most common among antibiotic-resistant Gram-negative bacteria, and they accounted for 30.6% (n = 34) of the identified E. coli and K. pneumoniae. Methicillin-resistant coagulase-negative staphylococci were most common among antibiotic-resistant Gram-positive bacteria, and it accounted for 88.5% (n = 23) of the identified coagulase-negative staphylococci. Antibiotic-resistant bacterial infections, especially antibiotic-resistant Gram-negative bacterial infections, caused significantly higher mortality due to bacteremia compared with non-antibiotic-resistant bacterial infections (P <0.001). CONCLUSION: Recently, Gram-negative bacteria caused more bacteremia cases than Gram-positive bacteria in febrile neutropenic children, and antibiotic-resistant Gram-negative bacterial infections increased. Antibiotic-resistant bacterial infections caused poorer prognosis compared with non-antibiotic-resistant bacterial infections, and therefore, continuous surveillance for changing epidemiology of antibiotic-resistant bacterial infections and their clinical impact is necessary.

Rapid detection and identification of infectious pathogens based on high-throughput sequencing / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The dilemma of pathogens identification in patients with unidentified clinical symptoms such as fever of unknown origin exists, which not only poses a challenge to both the diagnostic and therapeutic process by itself, but also to expert physicians.</p><p><b>METHODS</b>In this report, we have attempted to increase the awareness of unidentified pathogens by developing a method to investigate hitherto unidentified infectious pathogens based on unbiased high-throughput sequencing.</p><p><b>RESULTS</b>Our observations show that this method supplements current diagnostic technology that predominantly relies on information derived five cases from the intensive care unit. This methodological approach detects viruses and corrects the incidence of false positive detection rates of pathogens in a much shorter period. Through our method is followed by polymerase chain reaction validation, we could identify infection with Epstein-Barr virus, and in another case, we could identify infection with Streptococcus viridians based on the culture, which was false positive.</p><p><b>CONCLUSIONS</b>This technology is a promising approach to revolutionize rapid diagnosis of infectious pathogens and to guide therapy that might result in the improvement of personalized medicine.</p>