Effect of intrapartum antibiotic prophylaxis of group B streptococcus infection on the incidence and bacteriological profile of early-onset neonatal sepsis / 中国当代儿科杂志

OBJECTIVES@#To study the effect of intrapartum antibiotic prophylaxis (IAP) of group B streptococcus (GBS) infection on the incidence and bacteriological profile of early-onset neonatal sepsis (EONS).@*METHODS@#A retrospective analysis was performed on the medical data of 494 pregnant women with positive GBS screening results and 526 neonates born by these women. According to whether the pregnant woman received IAP, the neonates were divided into two groups: IAP (n=304) and control (n=222). The two groups were compared in terms of clinical indices, incidence rate of EONS, and distribution of pathogenic bacteria in blood culture.@*RESULTS@#Compared with the control group, the IAP group had a significantly lower proportion of children with abnormal clinical manifestations (P<0.001) and a significantly lower incidence rate of EONS (P=0.022). In the IAP group, Escherichia coli (2.3%) was the most common type of pathogenic bacteria in blood culture of the neonates with EONS, while GBS (3.2%) was the most common type of pathogenic bacteria in the control group. The IAP group had a significantly higher detection rate of ampicillin-resistant Escherichia coli than the control group (P=0.029).@*CONCLUSIONS@#Although IAP can significantly reduce the incidence rate of EONS in neonates born to pregnant women with positive GBS screening results, the infection rate of ampicillin-resistant Escherichia coli may increase after IAP treatment. Therefore, it is needed to enhance the monitoring of blood culture results of neonates with EONS and timely adjust treatment plan according to drug susceptibility test results.

Priorización de nuevas vacunas e innovación al servicio de estrategias de vacunación / New vaccines prioritization and immunization-related innovation

La vacunación es el medio más efectivo para controlar la morbilidad y mortalidad relacionadas con enfermedades infecciosas. Para lograr esto, necesitamos vacunas inmunogénicas y seguras que faciliten y mejoren sus condiciones de transporte, almacenamiento y administración. Gracias a los avances en inmunología y bioinformática, es posible impulsar el descubrimiento de nuevas vacunas para enfrentar la tuberculosis, el virus respiratorio sincicial, el Streptococcus agalactiae, la enfermedad meningocócica invasora, entre otros. Así también, nuevas tecnologías, como la producción de vacunas utilizando plantas transgénicas y parches de microagujas, los cuales podrían facilitar la producción, disminuir los costos y efectos adversos. Sin embargo, no solo necesitamos las vacunas, sino que debemos conocer la epidemiología de las enfermedades prevenibles con vacuna para tomar decisiones fundadas, con el objetivo de planificar estrategias sanitarias, medir su impacto y evaluar la seguridad de su utilización, para alcanzar las metas de salud pública y la confianza de la población.

Vaccination is the most effective strategy to avoid morbidity and mortality related to infectious diseases. To achieve this, we need immunogenic and safe vaccines that facilitate and improve its transport, storage and administration conditions. Thanks to current advances in immunology and bioinformatics, it is possible to boost the discovery of new vaccines to deal with tuberculosis, the respiratory syncytial virus, Streptococcus agalactiae, meningococcal invasive disease, among others. In addition to new technologies such as the production of plant-based vaccines, and microneedles patches, which can facilitate its production, reducing costs and adverse effects. However, vaccines is not the only thing that we need, because we must know the epidemiology and burden of disease to take informed decisions to design optimal strategies, measuring their impact and assessing the safety of their use in order to achieve the goals health and population confidence.

Assessment of conventional PCR and real-time PCR compared to the gold standard method for screening Streptococcus agalactiae in pregnant women

ABSTRACT Group B Streptococcus is a causative agent of invasive neonatal infections. Maternal colonization by Streptococcus agalactiae is a necessary condition for vertical transmission, with efficient screening of pregnant women playing an essential role in the prevention of neonatal infections. In this study, we aimed to compare the performance of conventional polymerase chain reaction and real-time PCR assays as screening methods for S. agalactiae in pregnant women against the microbiological culture method considered as the gold-standard. A total of 130 samples from pregnant women were analyzed for sensitivity, specificity, positive predictive value, and negative predictive value. Statistical analysis was performed using the SPSS software, version 20.0. The verified colonization rate was 3.8% with the gold-standard, 17.7% with conventional PCR assay, and 29.2% with the real-time PCR test. The trials with conventional PCR and real-time PCR had a sensitivity of 100% and a specificity of 85.6% and 73.6%, respectively. The real-time PCR assay had a better performance compared to the gold-standard and a greater detection rate of colonization by S. agalactiae compared to conventional PCR assay. With its quick results, it would be suitable for using in routine screenings, contributing to the optimization of preventive approaches to neonatal S. agalactiae infection.

Vigilancia de las enfermedades invasivas por streptococcus pyogenes / Surveillance of invasive streptococcus pyogenes diseases

Situación nacional de este tipo de infecciones, del que se observa un incremento global en las últimas décadas, en Europa y Norte América, sin que la causa haya sido determinada. En Argentina, los serotipos prevalentes, en base a datos aportados por el Laboratorio Nacional de Referencia- por él identificados en infección invasiva por Streptococcus pyogenes en población general durante el período 2000- 2016- fueron M12, M1, y M. A partir del año 2017 se observa un incremento del aislamiento de serotipo M3 principalmente en población pediátrica y no se registraron resistencias antimicrobianas específicas.Se describe la situación en la Ciudad Autónoma de Buenos Aires, la normativa a cumplir para la vigilancia de estas infecciones, y se incluyen recomendaciones para el personal de salud, la comunidad, y la comunidad educativa

Incidencia de sepsis precoz por Streptococcus agalactiae en recién nacidos del Centro Hospitalario Pereira Rossell en el período 2007-2015 / Incidence of group B streptococcal early-onset sepsis in infants born at Centro Hospitalario Pereira Rossell between 2007-2015

Resumen Introducción La infección por Streptococcus agalactiae (β-hemolítico del grupo B (SGB) continúa siendo una de las principales causas de sepsis precoz en países desarrollados a pesar de la implementación de profilaxis efectiva. Objetivos Describir la incidencia, características clínicas y mortalidad de sepsis precoz por SGB en recién nacidos del Centro Hospitalario Pereira Rossell (CHPR), y analizar las fallas de adherencia a las estrategias de prevención. Métodos Estudio retrospectivo de descripción de casos entre los años 2007 a 2015 identificados a partir de la base de datos del laboratorio de bacteriología. Resultados Se identificaron 15 casos de sepsis neonatal precoz a SGB con una incidencia en el período de estudio de 0,23‰. La quimioprofilaxis intraparto no fue realizada en caso alguno. Todos los recién nacidos se presentaron sintomáticos en las primeras 15 h de vida. La dificultad respiratoria fue el signo más frecuente (80%). En un caso se aisló SGB de líquido cefalorraquídeo. La mortalidad fue de 20%. Todas las muertes ocurrieron en las primeras 24 h de vida, siendo dos tercios prematuros. Conclusión La incidencia de sepsis precoz por SGB en el CHPR fue similar a la incidencia en centros donde se realiza quimioprofilaxis. Una mejor adherencia a las estrategias de prevención podría disminuir la incidencia.

Background: Group B Streptococcus (GBS) disease remains the leading cause of early-onset sepsis (EOS) in developed countries despite effective prophylaxis strategies. Aims: To describe the incidence, clinical features and mortality of GBS EOS in infants born at Centro Hospitalario Pereira Rossell (CHPR) and analyse failure of adherence to prevention strategies. Methods: Retrospective review of EOS cases between 2007 and 2015 collected from the bacteriology laboratory database. Results: Fifteen cases of GBS EOS were identified, with an incidence of 0.23% during the study period. Intrapartum antibiotic prophylaxis (IAP) was not administered in any of the cases. All infants were symptomatic within the first 15 hours of life, mainly due to respiratory signs (80%). In one case, GBS was isolated from spinal fluid. Mortality rate was 20%. All deaths occurred in the first 24 hours of life, corresponding two thirds to preterm infants. Conclusion: The incidence of GBS EOS at CHPR was similar to other centers where IAP is implemented. Better adherence to prophylaxis strategies could reduce the incidence.

Early-onset neonatal sepsis and the implementation of group B streptococcus prophylaxis in a Brazilian maternity hospital: a descriptive study

Abstract Objectives: To describe early-onset neonatal sepsis (EOS) epidemiology in a public maternity hospital in Brasilia, Brazil. Methods: We defined EOS as a positive blood culture result obtained from infants aged ≤72 hours of life plus treatment with antibiotic therapy for ≥5 days. Incidence was calculated based on the number of cases and total live births (LB). This is a descriptive study comparing the period of 2012-2013 with the period of 2014-September 2015, before and after implementation of antibiotic prophylaxis during labor for group B streptococcus (GBS) prevention, respectively. Results: Overall, 36 infants developed EOS among 21,219 LB (1.7 cases per 1000 LB) and 16 died (case fatality rate of 44%). From 2014, 305 vaginal-rectal swabs were collected from high-risk women and 74 (24%) turned out positive for GBS. After implementation of GBS prevention guidelines, no new cases of GBS were detected, and the EOS incidence was reduced from 1.9 (95% CI 1.3-2.8) to 1.3 (95% CI 0.7-2.3) cases per 1000 LB from 2012-2013 to 2014-September 2015 (p = 0.32). Conclusions: Although the reduction of EOS incidence was not significant, GBS colonization among pregnant women was high, no cases of neonatal GBS have occurred after implementation of prevention guidelines.

Antimicrobial susceptibility patterns, emm type distribution and genetic diversity of Streptococcus pyogenes recovered in Brazil

Streptococcus pyogenes is responsible for a variety of infectious diseases and immunological complications. In this study, 91 isolates of S. pyogenes recovered from oropharynx secretions were submitted to antimicrobial susceptibility testing, emm typing and pulsed-field gel electrophoresis (PFGE) analysis. All isolates were susceptible to ceftriaxone, levofloxacin, penicillin G and vancomycin. Resistance to erythromycin and clindamycin was 15.4%, which is higher than previous reports from this area, while 20.9% of the isolates were not susceptible to tetracycline. The macrolide resistance phenotypes were cMLSB (10) and iMLSB (4). The ermB gene was predominant, followed by the ermA gene. Thirty-two emm types and subtypes were found, but five (emm1, emm4, emm12, emm22, emm81) were detected in 48% of the isolates. Three new emm subtypes were identified (emm1.74, emm58.14, emm76.7). There was a strong association between emm type and PFGE clustering. A variety of PFGE profiles as well as emm types were found among tetracycline and erythromycin-resistant isolates, demonstrating that antimicrobial resistant strains do not result from the expansion of one or a few clones. This study provides epidemiological data that contribute to the development of suitable strategies for the prevention and treatment of such infections in a poorly studied area.

Interferon-γ inhibits group B Streptococcus survival within human endothelial cells

Endothelial dysfunction is a major component of the pathophysiology of septicaemic group B Streptococcus (GBS) infections. Although cytokines have been shown to activate human umbilical vein endothelial cells (HUVECs), the capacity of interferon (IFN)-γ to enhance the microbicidal activity of HUVECs against GBS has not been studied. We report that the viability of intracellular bacteria was reduced in HUVECs activated by IFN-γ. Enhanced fusion of lysosomes with bacteria-containing vacuoles was observed by acid phosphatase and the colocalisation of Rab-5, Rab-7 and lysosomal-associated membrane protein-1 with GBS in IFN-γ-activated HUVECs. IFN-γ resulted in an enhancement of the phagosome maturation process in HUVECs, improving the capacity to control the intracellular survival of GBS.

Aumento de resistencia de Streptococcus agalactiae vaginal-anal en el tercer trimestre de gestación a eritromicina y clindamicina al cabo de una década de tamizaje universal / Streptococcus agalactiae increase in resistance to erythromycin and clindamycin in vaginal-anal colonization in third quarter of pregnancy in one decade of universal screening

Introduction: Streptococcus agalactiae (GBS) is the main causative agent of early perinatal sepsis. The acquisition of prevention policies has led to frequent use of intrapartum antibiotics. Surveillance of antimicrobial resistance is indispensable for defining drugs of choice and alternatives for such prophylaxis. Objectives: To determine the evolution of antimicrobial resistance of GBS from maternal colonization to drugs used in the prevention of neonatal sepsis, between 2002 and 2008. Methods: We studied 100 GBS positive vaginal and anal samples from pregnant women. Disc diffussion susceptibility method was performed for penicillin, ampicillin, cefazolin, erythromycin and clindamycin according to the Clinical and Laboratory Standards Institute (CLSI). Results: We analyzed the susceptibility of 99 strains. Seventeen were resistant to erythromycin (17.1 percent) and 13 were resistant to clindamycin (13.1 percent). Thirteen of the 17 strains resistant to erythromycin had the MLS phenotype (resistance to erythromycin and clindamycin) and 4 had the M phenotype (resistance to erythromycin only). Within the MLS phenotype, resistance was constitutive in 9 strains, and induced in 4 strains (positive D test). Compared with 2002 there was a significant increase in resistance to clindamycin (from 3.27 percent to 13.1 percent p < 0.002) and erythromycin (1.09 percent to 17 percent p < 0.001). 100 percent GSB remained sensitive to penicillin and ampicillin. Conclusions: GBS remains highly susceptible to drugs of choice for prevention of perinatal sepsis. There is a significant increase in antimicrobial resistance to clindamycin and erythromycin. Therefore, it is necessary to request susceptibility testing in GBS from third trimester of pregnancy screening in patients allergic to penicillin.

Introducción: Streptococcus agalactiae es el principal agente causal de sepsis perinatal precoz. La adquisición de políticas de prevención ha traído consigo la utilización frecuente de antimicrobianos intra-parto. La vigilancia de resistencia antimicrobiana se hace indispensable para definir el fármaco de elección y alternativas en dicha profilaxis. Nuestro centro realiza tamizaje universal desde hace 10 años. Objetivos: Determinar la evolución de la resistencia antimicrobiana de S. agalactiae de colonización materna, a los antimicrobianos utilizados en la prevención de sepsis neonatal, entre 2002 y 2008. Métodos: Se estudiaron 100 muestras vaginales-anales positivas para S. agalactiae de mujeres embarazadas, con edad gestacional de 35 a 37 semanas. Se realizó estudio de susceptibilidad in vitro por discos a penicilina, ampicilina, cefazolina, eritromicina y clindamicina, según método estandarizado por Clinical and Laboratory Standards Institute (CLSI). Resultados: Se analiza la susceptibilidad de 99 cepas. Diecisiete fueron resistentes a eritromicina (17,1 por ciento) y 13 eran resistentes a clindamicina (13,1 por ciento). De las 17 cepas resistentes a eritromicina, 13 eran fenotipo MLS y 4 del fenotipo M. Dentro del fenotipo MLS, la resistencia fue constitutiva en nueve cepas e inducible en cuatro cepas (test D positivo). En comparación con el año 2002, hubo un aumento significativo de resistencia a clindamicina (de 3,2 a 13,1 por ciento p < 0,002) y a eritromicina (de 1,09 a 17 por ciento p < 0,001). Streptococcus agalactiae se mantuvo 100 por ciento sensible a penicilina y ampicilina. Conclusiones: S. agalactiae mantiene alta sensibilidad a los antimicrobianos de elección para la prevención de sepsis neonatal y a un antimicrobiano alternativo: cefazolina. Se observó un aumento significativo de resistencia antimicrobiana a clindamicina y eritromicina. Se hace necesario, entonces, solicitar antibiograma en el tamizaje del tercer trimestre del embarazo, en pacientes alérgicas a penicilina.

Prevenção da doença perinatal pelo estreptococo do grupo B: atualização baseada em algoritmos / Prevention of perinatal group B streptococcal disease: algorithm-based update

A infecção pelo estreptococo β-hemolítico do grupo B (EGB) ou Streptococcus agalactiae persiste como uma causa líder de morbimortalidade perinatal. A antibioticoprofilaxia da infecção pelo EGB, baseada no rastreio universal em gestações de 35 a 37 semanas, é mais efetiva do que a estratégia baseada em fatores de risco. A seleção do antibiótico deve se basear na suscetibilidade da cepa do EGB e na história materna de alergia ao medicamento. A penicilina G, administrada por via endovenosa (≥4 horas), continua sendo a droga de escolha para a profilaxia intraparto, enquanto a ampicilina é uma alternativa aceitável. A cefazolina é recomendada para gestantes alérgicas à penicilina, as quais apresentam baixo risco de anafilaxia, enquanto a clindamicina e a eritromicina são indicadas para os casos com alto risco de anafilaxia. A vancomicina deve ser utilizada nas gestantes alérgicas à penicilina, quando houver resistência à clindamicina e à eritromicina ou quando a sensibilidade a essas drogas for desconhecida. No entanto, devido à persistência da morbimortalidade perinatal e ao surgimento de novos dados relevantes nas áreas de epidemiologia, obstetrícia, neonatologia, microbiologia, biologia molecular e farmacologia, em 2010, o Centers of Disease Control and Prevention (CDC) publicou uma terceira revisão das suas diretrizes sobre a doença causada pelo EGB. Este artigo de atualização propõe-se a divulgar de forma comentada e sintética, baseada prioritariamente em algoritmos, as recentes diretrizes do CDC sobre o tema

Group B streptococcus (GBS) or Streptococcus agalactiae remains as a leading cause of perinatal morbidity and mortality. The antibiotic prophylaxis of GBS infection, based on universal screening in pregnancies from 35 to 37 weeks, is more effective than a strategy based on risk factors. The choice of antibiotic should be based on the susceptibility of the strain of GBS and on the maternal history of allergy to the medicine. Penicillin G, administered intravenously (≥4 hours), remains the drug of choice for intrapartum prophylaxis, while ampicillin is an acceptable alternative. Cefazolin is recommended for pregnant women allergic to penicillin, who present low risk of anaphylaxis, while clindamycin and erythromycin are recommended for cases with high risk of anaphylaxis. Vancomycin should be used in pregnant women allergic to penicillin when there is resistance to erythromycin and clindamycin, or the sensitivity to these drugs is unknown. However, due to the persistence of perinatal morbidity and mortality and the emergence of new relevant data in the s of epidemiology, obstetrics, neonatology, microbiology, molecular biology and pharmacology, in 2010, the Centers for Disease Control and Prevention (CDC) published a third revision of the guidelines disease caused by GBS. This update article aims at disseminating the synthetic form - primarily based on algorithms - and commenting on these recent CDC guidelines

Optimización de metodologías de cribaje para la búsqueda de Streptococcus agalactiae en embarazadas / Optimization of screening methodologies for the detection of Streptococcus agalactiae in pregnant women

Streptococcus agalactiae es una causa importante de morbimortalidad en mujeres embarazadas y neonatos en todo el mundo. El objetivo del presente trabajo fue determinar la utilidad del medio cromogénico chromID Strepto B de bioMérieux para detectar S. agalactiae en embarazadas cuando la muestra es sembrada directamente en dicho medio o después del enriquecimiento en caldo de Todd Hewitt selectivo, opciones que se compararon con la metodología propuesta por el CDC . Se analizaron 1924 hisopados, 962 de introito vaginal y 962 rectales, correspondientes a 962 embarazadas entre la semana 35 y 37 de gestación, asistidas en distintos hospitales. Los hisopados se sembraron directamente en el medio chromID Strepto B (CR) y luego se colocaron en un caldo de Todd Hewitt selectivo, suplementado con 15 µg/ml de ácido nalidíxico y 10 µg/ml de colistina (CTH-sel). Luego de 24 h de incubación, se realizaron subcultivos en el medio CR y en agar con 5% de sangre de carnero (ASO). La prevalencia global de S. agalactiae fue de 17,4%. La sensibilidad, la especificidad y los valores predictivos positivo y negativo del subcultivo en CR del material desarrollado en el CTH -sel fueron 98,8%, 100%, 100% y 99,7% respectivamente, con una incubación de 48 h. Los valores correspondientes de la siembra directa fueron 57,8%, 100%, 100% y 90%. La sensibilidad del subcultivo en ASO del material desarrollado en el CTH -sel fue del 85%. Se destaca el excelente rendimiento del subcultivo en CR luego del enriquecimiento en caldo de Todd Hewitt selectivo en comparación con el método propuesto por el CDC.

Streptococcus agalactiae is a significant worldwide cause of morbidity and mortality in pregnant women and their newborn infants. The objective of this work was to determine the usefulness of bioMrieux chromogenic medium chromID Strepto B (CR) for detecting S. agalactiae in pregnant women from the selective Todd-Hewitt broth (sel-THB ) against the methods proposed by the CDC . A total of 1924 swabs were analyzed, 962 from vaginal introitus and 962 rectal, belonging to 962 women in weeks 35-37 of pregnancy. The swabs were directly seeded in CR. Both swabs were later placed in sel-THB with 15 µg/ml supplement of nalidixic acid and 10 µg/ml colistin. After 24 h of incubation, subcultures in CR medium and agar containing 5% sheep blood (SBA) were performed. The prevalence found was 17.4%. Sensitivity, specificity, positive and negative predictive values of sel-THB subcultures with CR supplement and 48 h incubation were: 98.8, 100, 100 and 99.7%, respectively. The corresponding values of direct harvest of the sample were 57.8, 100, 100, and 90%, respectively. Sensitivity of sel-THB in SBA was 85%. Sel-THB subculture performance in CR was outstanding in comparison with the method proposed by the CDC.

Solicitar ou não cultura para estreptococo do grupo B no final da gestação? / Request or not culture for group B streptococcal in the end of pregnancy?

Embora a cultura reto-vaginal para estreptococo do grupo B (EGB), ou Streptococcus agalactiae, entre 35 e 37 semanas pareça ser o método mais sensível e específico para detecção das gestantes colonizadas na hora do parto, a decisão de solicitar esse exame rotineiramente, como uma medida de prevenção para infecção neonatal, é controversa. A prevalência mundial de gestantes colonizadas por EGB encontra-se em torno de 20 porcento. A transmissão vertical ocorre na metade dos casos. No entanto, estima-se que a incidência de infecção neonatal por EGB seja de 1 a 2 casos por 1.000 nascidos vivos. O objetivo desta revisão é identificar e sintetizar evidências relevantes sobre EGB durante a gravidez, fatores de risco, etiologia, incidência e complicações da infecção neonatal, limitações da cultura para EGB, indicações da profilaxia antibiótica intraparto (PAI), antibióticos preconizados e seus efeitos adversos. As bases de dados Medline, Lilacs/Scielo e Biblioteca Cochrane foram consultadas por meio de pesquisa com os termos gravidez, estreptococo do Grupo B e infecção neonatal.

Although the cultures of the vagina and rectum for streptotoccus group B (GBS) or streptococcus agalactiae between 35 e 37 weeks of gestation appears to achieve the best sensitivity and specificity for detection of colonized women at the time of delivery, the decision of requesting streptotoccus group B (GBS) cultures for all pregnant women to prevent neonatal infection is controversial. The worldwide prevalence of pregnant women colonized by GBS is nearly 20 percent. Vertical transmission occurs in health cases. However, it is estimated that incidence of neonatal infection for GBS is 1 to 2 cases per 1.000 birth lives. The objective of this review is to identify and to synthesize relevant evidence about screening for GBS during pregnancy, the risk factors associated with early neonatal infection, etyology, incidence and neonatal infection complications, culture limitations, indications of intrapartum antibiotics prophylactic (IAP) for group B streptococcus colonisation, indicated antibiotics and their adverse effects. Medline, Lilacs/Scielo and Cochrane Library were consulted by mean of a search with the keywords pregnancy, streptococcus group B and neonatal infection.

Revisão de literatura: utilização do xilitol para a prevenção de otite média aguda / Literature review: use of xylitol for prevention of acute otitis media

Introdução: O xilitol é um carboidrato naturalmente encontrado em diversas frutas e vegetais. Estudos têm demonstrado o uso do xilitol como uma estratégia inovadora na prevenção de otite média aguda (OMA). Objetivo: Esclarecer os possíveis mecanismos de ação do xilitol sobre a inibição do crescimento de bactérias otopatogênicas e descrever estudos que contribuem para a discussão sobre a viabilidade deste carboidrato na prevenção de OMA. Método: Revisão de literatura baseado em artigos científicos selecionados por meio das bases médicas MEDLINE, Cochrane, PubMed (MeSH) e Web of Science. Resultados: Trabalhos demonstraram que o xilitol é eficaz na prevenção de OMA quando administrado em gomas de mascar cinco vezes ao dia. Porém, o carboidrato não é tão efetivo quando administrado durante infecções de vias aéreas superiores. Comentários Finais: O xilitol parece ser uma estratégia eficaz na prevenção de otite média aguda. No entanto, novos estudos são necessários para estabelecer doses, frequências e veículos ideais para a correta administração do açúcar, possibilitando sua utilização no sistema público de saúde.

Introduction: Xylitol is a sugar naturally found in various vegetables and fruits. Studies have demonstrated that the xylitol can be used as new preventive method for acute otitis media (AOM). Objective: To clarify the possible mechanisms of xylitol actions to inhibit the growth of otopathogenic bacteria and to describe researches that contribute for the discussion about the feasibility of the use of this sugar in the prevention of AOM. Method: Literature review based on scientific articles selected by means of the medical databases: MEDLINE, Cochrane, PubMed (MeSH) and Web of Science. Results: Studies have demonstrated the efficacy of xylitol to prevent the AOM, when it is administered five times a day in chewing gum. However, this sugar is not so effective in the prevention of AOM during upper airways infections. Final Comments: Xylitol seems to be an effective strategy in prevention of acute otitis media. However, new studies are necessary to establish ideal doses, frequencies and vehicles for the correct administration of the sugar, which allows for its utilization in the public health system.

Sepsis neonatal por Streptococcus Grupo B / Group B Streptococcus neonatal sepsis: up-to-date

Group B Streptococcus is one of the leading bacterias causing early onset neonatal sepsis. It constitutes an important factor of neonatal morbidity and mortality and high costs in health. Many strategies have been formulated to avoid vertical transmission from the colonized mother to the newborn, in an attempt to prevent infection of the infant. The most used nowadays is antibiotic prophylaxis given to the mother during labor, depending on the results of recto-vaginal culture taken during 35 to 37 weeks of gestation. This strategy has importantly diminished the prevalence of early onset neonatal sepsis by this agent, although there is still concern about the potential generation of antibiotic resistance and drug-induced adverse reactions in the mother. New techniques for prevention are being developed, such as vaccines against Streptococcus. In the newborn, infection caused by Streptococcus has a broad spectrum of clinical manifestations, like sepsis and meningitis which are the most frequent and lethal. Neurological sequelae are common among the survivors, so an early suspicion of disease must lead to a prompt antibiotic treatment.

El Streptococcus grupo B (SGB) es uno de los principales agentes causales de sepsis neonatal precoz, siendo un importante factor de morbimortalidad neonatal y de costos en salud pública. Se han implementado múltiples estrategias para evitar la transmisión vertical desde la madre colonizada a su recién nacido, de modo de prevenir la infección de éste último. La más usada en la actualidad es la profilaxis antibiótica administrada a la madre en el momento del parto dependiendo del resultado de un cultivo perineal realizado entre las semanas 35 y 37 de gestación. Mediante esta estrategia se ha logrado disminuir de manera importante la incidencia de la sepsis neonatal por este agente, pero existen aprehensiones acerca de la posible generación de resistencia antibiótica o reacciones adversas a fármacos por parte de la madre. Por esto último, nuevas técnicas de prevención se encuentran en estudio, como las vacunas contra el SGB. En los recién nacidos la infección por Streptococcus agalactiae puede manifestarse de diversas maneras, siendo la sepsis y la meningitis las más frecuentes y mortales. El porcentaje de secuelas entre los sobrevivientes es elevado, por lo que ante la sospecha precoz de infección debe iniciarse tratamiento antibiótico a la brevedad.

Antibiotic susceptibility patterns and prevalence of group B Streptococcus isolated from pregnant women in Misiones, Argentina / Sensibilidade a antibióticos e prevalência de Streptococcus do grupo B em mulheres grávidas em Missiones, Argentina

This study was performed to determine the susceptibility patterns and the colonization rate of Group B Streptococcus (GBS) in a population of pregnant women. From January 2004 to December 2006, vaginal-rectal swabs were obtained from 1105 women attending Dr. Ramón Madariaga Hospital, in Posadas, Misiones, Argentina. The carriage rate of GBS among pregnant women was 7.6 percent. A total of 62 GBS strains were randomly selected for in vitro susceptibility testing to penicillin G, ampicillin, tetracycline, levofloxacin, gatifloxacin, ciprofloxacin, quinupristin-dalfopristin, linezolid, vancomycin, rifampicin, trimethoprim-sulfametoxazol, nitrofurantoin, gentamicin, clindamycin and erythromycin, and determination of resistance phenotypes. No resistance to penicillin, ampicillin, quinupristin-dalfopristin, linezolid, and vancomycin was found. Of the isolates examined 96.8 percent, 98.3 percent, 46.8 percent, and 29.0 percent were susceptible to rifampicin, nitrofurantoin, trimethoprim-sulfametoxazol and tetracycline, respectively. Rank order of susceptibility for the quinolones was: gatifloxacin (98.4 percent) > levofloxacin (93.5 percent) > ciprofloxacin (64.5 percent). The rate of resistance to erythromycin (9.7 percent) was higher than that of other reports from Argentina. High-level resistance to gentamicin was not detected in any of the isolates. Based on our finding of 50 percent of GBS isolates with MIC to gentamicin equal o lower than 8 µg/ml, a concentration used in one of the selective media recommended for GBS isolation, we suggested, at least in our population, the use of nalidixic acid and colistin in selective media with the aim to improve the sensitivity of screening cultures for GBS carriage in women.

Esse estudo objetivou determinar os padrões de sensibilidade a antibióticos e as taxas de colonização de Streptococcus do grupo B (GBS) em uma população de mulheres grávidas. Entre janeiro de 2004 e dezembro de 2006, foram obtidos swabs vaginais-retais de 1105 mulheres no Hospital Dr. Ramon Madariaga, em Posadas, Missiones, Argentina. A positividade para GBS nas mulheres grávidas foi 7,6 por cento. Um total de 62 cepas de GBS foi selecionado ao acaso para testes in vitro de sensibilidade a penicilina G, ampicilina, tetraciclina, levofloxacina, gatifloxacina, ciprofloxacina, quinupristina-dalfopristina, linezolida, vancomicina, rifampicina, trimetoprim-sulfametoxazol, nitrofurantoína, gentamicina, clindamicina e eritromicina, e determinação dos fenótipos de resistência. Não foi encontrada resistência à penicilina, ampicilina, quinupristina-dalfopristina, linezolida e vancomicina. Entre as cepas, 96,8 por cento, 98,3 por cento, 46,8 por cento e 29,0 por cento foram sensíveis à rifampicina, nitrofurantoína, trimetoprim-sulfametoxazol e tetraciclina, respectivamente. Para as quinolonas, a ordem de sensibilidade foi: gatifloxacina (98,4 por cento) > levofloxacina (93,8 por cento) > ciprofloxacina (64,5 por cento). A taxa de resistência à eritromicina (9,7 por cento) foi superior a de outros relatos na Argentina. Nenhuma das cepas apresentou alto nível de resistência à gentamicina. Devido a 50 por cento das cepas de GBS terem apresentado MIC para gentamicina igual ou inferior a 8 mg/ml, correspondente à concentração usada em um dos meios seletivos recomendados para GBS, sugeriu-se ao menos em nossa população, o emprego de ácido nalidíxico e colistina em meios seletivos para melhorar a sensibilidade da triagem de culturas para GBS em mulheres grávidas.

Doença perinatal associada aos estreptococos do Grupo B: aspectos clínico-microbiológicos e prevenção / Perinatal Group B streptococcal disease: clinical-microbiological aspects and prevention

Os cocos Gram-positivos Streptococcus agalactiae ou estreptococos do Grupo B de Lance (EGB) são bactérias que fazem parte da microbiota residente nas membranas mucosas de seres humanos, colonizando principalmente os tratos gastrintestinal e geniturinário. Sua importância é relacionada à contaminação vertical dos neonatos de parturientes colonizadas, que pode acontecer de forma ascendente ainda no útero ou durante o parto. Mundialmente, a prevalência da colonização pelos EGB nas gestantes varia de 3% a 41%. Entre as infecções neonatais associadas a estes microrganismos destacam-se, principalmente, a septicemia e a pneumonia e, em menor freqüência, meningite, celulite, osteomielite e artrite séptica. Em 1996, foi publicado o primeiro guia preventivo da doença estreptocócica perinatal, estabelecendo as diretrizes e critérios para a prevenção da transmissão vertical destes agentes. Em 2002, foi estabelecido o uso da profilaxia antimicrobiana intraparto e a investigação rotineira da colonização pelo S. agalactiae no final da gestação, através de cultura de material vaginal e retal em meio seletivo. Nos países que adotaram estas medidas profiláticas, registrou-se um decréscimo significativo na incidência da doença. No Brasil, a mortalidade neonatal é um grave problema de saúde pública e ainda não foram adotadas estratégias de prevenção e tratamento para reduzir a prevalência de infecção neonatal pelo EGB. Considerando o custo elevado e as graves conseqüências da doença estreptocócica perinatal, verifica-se a necessidade de elaboração de políticas de saúde, visando reduzir a transmissão vertical. Assim, percebe-se a necessidade de atualização literária, englobando aspectos microbiológicos e preventivos da doença estreptocócica perinatal, visando, sobretudo, a uma abordagem que facilite o entendimento e a aplicabilidade deste conhecimento dentro do cenário nacional.

Lance group B streptococci (GBS, or Streptococcus agalactiae) are Gram-positive bacterial components of the resident microbiota of human mucous membranes, mainly colonizing the gut and the urogenital tract. Vertical perinatal transmission of colonized women is known to occur as both, intrauterine infection or through contamination during labor. The worldwide prevalence of GBS-colonized pregnant women ranges from 3% to 41%. Neonatal infection may lead mainly to sepsis and pneumonia, with less frequent occurrences of meningitis, celullitis, osteomyelitis and septic arthritis. The first guidelines for prevention of the vertical transmission of perinatal streptococcal disease were issued in 1996. Routine investigation of the S. agalactiae colonization status, through selective medium culture of vaginal and rectal secretions at the term of pregnancy, and intrapartum antimicrobial prophylaxis, were established in 2002. A significant decrease in the incidence of perinatal infection was seen in the countries that adopted the prophylactic measures. Although neonatal mortality in Brazil is a serious public health issue, no preventive or treatment strategies targeting GBS-neonatal infection have been adopted. Due to the high costs and serious consequences of perinatal streptococcal disease, health policies aiming at reducing vertical transmission are clearly called for. In this regard, literary updates are needed, specially considering microbiology and prevention of GBS-neonatal infection, to give clearly understandable and applicable supportive arguments, in the national scenery.