Recent research on the epidemiology and preventive strategies of neonatal group B Streptococcus infection in the latest decade / 中国当代儿科杂志

Currently, the main strategy for preventing neonatal group B Streptococcus (GBS) infection is prenatal screening combined with intrapartum antibiotic prophylaxis, which has effectively reduced the incidence of neonatal GBS early-onset disease. However, the burden of GBS infection is still significant. The intrapartum antibiotic prophylaxis strategy has limitations such as inducing antibiotic resistance and inability to effectively prevent GBS late-onset disease. It is crucial to develop and evaluate other prevention strategies, while paying close attention to assessing penicillin allergy in pregnant women and how to prevent GBS infection in neonates with negative maternal GBS screening. In recent years, there has been some progress in GBS vaccines and related immunological research, and the use of specific vaccines is expected to significantly reduce GBS infection in neonates.

Sepsis precoz, osteoartritis y meningitis: a propósito de un caso clínico / Early sepsis, osteoarthritis and meningitis: a clinical case / Sepse precoce, osteoartrite e meningite: relato de caso

Se expone el caso de un recién nacido que desarrolló sepsis connatal precoz a Streptococcus agalactiae, con meningitis aguda supurada y osteoartritis de rodilla izquierda. Como factor de riesgo la madre no tenía realizado el exudado rectovaginal, pesquisa que detecta la colonización por estreptococo del grupo B (EGB). Se aisló el germen en hemocultivo y en líquido de punción articular. Recibió tratamiento antibiótico adecuado a la sensibilidad del microorganismo y según pauta de sepsis con meningitis, evolucionando favorablemente. En este trabajo se describe la epidemiología de la sepsis neonatal y los cambios ocurridos luego de la implementación de la profilaxis antibiótica en el preparto.

We hereby present the case of a newborn with early connatal sepsis due to Streptococcus agalactiae, with acute suppurative meningitis and left knee osteoarthritis. As a risk factor, the mother had not performed the rectus vaginal exudate screening that detects colonization by Group B Streptococcus (GBS). The germ was isolated in blood culture and in joint puncture fluid. The patient received germ-sensitive antibiotic treatment for meningitis sepsis and evolved favorably. This paper describes the epidemiology of neonatal sepsis and the changes that have occurred after the administration of the antibiotic prophylaxis during pregnancy.

Apresentamos o caso de um recém-nascido com sepse neonatal precoce por Streptococcus agalactiae, com meningite supurativa aguda e osteoartrite de joelho esquerdo. Como fator de risco, a mãe não realizou teste de exsudato vaginal do reto que detecta a colonização por estreptococos do grupo B (SGB). O germe foi isolado em hemocultura e líquido de punção articular. A paciente recebeu tratamento com antibióticos germinativos para padrão meningite sepse e evoluiu favoravelmente. Este artigo descreve a epidemiologia da sepse neonatal e as mudanças ocorridas após a administração da profilaxia antibiótica durante a gravidez.

Multiple Brain Abscesses by an Air Gun Shot: A Case Report

Introduction Low-velocity penetrating brain injury is not prevalent. In some conditions such as childhood, and with the penetration of a pellet in weak spots of skull, low-velocity penetrating brain injury is expected; however, high-velocity projectiles have also been reported as the cause of severe brain injuries. One of the complications of penetrating brain injury is infection, in which different types ofmicroorganisms play a role. The Streptococcus genus is the leading cause of abscess formation in nontraumatic patients. Multiple brain abscesses are not common. Case Presentation A 10-year-old boy with penetrating brain injury caused by an air gun pellet, who developed signs and symptoms of high intracranial pressure 18 days after the trauma. After the imaging scans and the detection of multiple brain abscesses and severe brain edema, prompt surgical intervention was performed for all three lesions in a single operation. The culture of a pus specimen was positive for Streptococcus species, and, with adequate antibiotic therapy, the patient was discharged from the hospital in good condition. Conclusion Brain injurywith air gun shot is not prevalent. The penetration of a low-velocity air gun pellet in weak points of the skull (such as the orbit, the squamous portion of the temporal bone, and the cranial suture), specially in children, can cause significant brain injuries.

Adenitis cervical con anaerobios sin causa aparente en lactante / Cervical adenitis with anaerobes without apparent cause in infant

Las adenopatías cervicales benignas en lactantes son relativamente frecuentes, se definen como el aumento de volumen ganglionar de más de 1 cm, sin síntomas sistémicos y cuando están presentes, el término correcto es adenitis. Para su estudio, las adenitis se dividen en: locales, sistémicas, unilaterales, bilaterales, agudas, crónicas, y por edad, con diferentes etiologías. Se presenta el caso clínico de un lactante de 11 meses de edad con diagnóstico de adenitis cervical abscedada unilateral aguda, con cuadro de 72 h de evolución, con crecimiento constante a nivel cervical derecho, compromiso del estado general, fiebre y anorexia, por lo que se inician antibióticos de primera línea para los agentes bacterianos más frecuentes (Staphylococcus aureus y Streptococcus pyogenes), con evolución tórpida a las 48 h, por lo que se solicita ultrasonido cervical, ya que la familia no contaba con recursos para solicitar cultivo o tomografía, reportando el ultrasonido ganglio cervical de 3,5 cm de diámetro abscedado, por lo que se agrega cobertura para anaerobios, con respuesta muy favorable a las 24 h. Queda la duda del origen de los anaerobios en la paciente, sin antecedentes de importancia y en grupo etario diferente al afectado por esos gérmenes. Consideramos este caso interesante por su comportamiento atípico, para el enriquecimiento del ejercicio de la otorrinolaringología, recalcando el invaluable apoyo de la clínica y solo con un ultrasonido, ya que no siempre se tendrán todos los recursos disponibles, pero siguiendo las pautas de lo reportado en la literatura, se tuvo una resolución exitosa.

Benign cervical lymphadenopathies in infants are relatively frequent, they are defined as an increase in lymph node volume of more than 1 cm, without systemic symptoms, and when they are present, the correct term is adenitis. For its study, adenitis is divided into: local, systemic, unilateral, bilateral, acute, chronic, and by age, with different etiologies. An 11-month-old infant with a diagnosis of acute unilateral abscessed cervical adenitis, with a 72 h evolution, with constant growth at the right cervical level, fever and anorexia, for which first-line antibiotics were started to the most frequent bacterial agents (Staphylococcus aureus and Streptococcus pyogenes), with torpid evolution at 48 h, for which only cervical ultrasound is requested, since the family did not have the resources to request culture or tomography, reporting the cervical ganglion ultrasound of 3.5 cm of abscessed diameter, so coverage for anaerobes is added, with a very favorable response at 24 hrs. There remains the doubt of the origin of the anaerobes in the patient, without important antecedents and in an age group different from that affected by these germs. We consider this case interesting due to its atypical behavior, for the enrichment of the otolaryngology exercise, emphasizing the invaluable support of the clinic, and only with an ultrasound, since other clinical tools were not available, but following the guidelines of what is reported in literature, there was a successful resolution.

Bacteriemia por Streptococcus equi subespecie zooepidemicus en un binomio madre hijo / Streptococcus equi subspecies zooepidemicus bacteremia in a mother-child binomial

Resumen Streptococcus equi subespecie zooepidemicus es una cocácea grampositiva, p-hemolítica, considerada parte de la microbiota de los equinos y un patógeno oportunista en otros animales. La infección en humanos es poco frecuente, pero suele manifestarse como cuadros graves. Se ha asociado al contacto con animales, especialmente caballos, y al consumo de productos lácteos no pasteurizados. Presentamos el caso de una bacteriemia en un binomio madre-hijo por este agente, asociado al consumo de quesos artesanales. Pese a que la penicilina es el tratamiento de elección, la recién nacida fue tratada en forma exitosa con ampicilina y la madre con ceftriaxona. Ninguna de ellas presentó complicaciones asociadas a la bacteriemia. A nuestro conocimiento, este es el primer reporte de infección connatal por este agente.

Abstract Streptococcus equi subspecies zooepidemicus is a Gram-positive, P-hemolytic coccus considered part of the commensal flora in horses and an opportunistic pathogen in other animals. Infection in humans is rare, but it usually manifests as serious symptoms, it has been associated with contact with animals, especially horses, and the consumption of unpasteurized dairy products. In this report we describe a case of bacteremia of the mother-child binomial by this agent, associated with the consumption of artisan cheeses. Although penicillin is the treatment of choice, the newborn was successfully treated with ampicillin and the mother with ceftriaxone, none of them presented complications associated with bacteremia. To our knowledge, this is the first report of connatal infection by this agent.

Caracterización clínica y microbiológica de episodios de bacteriemia por Streptococcus grupo viridans en niños con cáncer y neutropenia febril de alto riesgo / Clinical characteristics and microbiological profile of viridans group streptococci bacteremia in children with cancer and high-risk febrile neutropenia

Resumen Introducción: Streptococcus grupo viridans (SGV) ha adquirido relevancia como microorganismo causante de neutropenia febril, asociándose a morbilidad significativa. Objetivo: Caracterizar episodios de bacteriemia causados por SGV en niños con cáncer que desarrollaron neutropenia febril de alto riesgo (NFAR) desde abril de 2004 a junio de 2018 en seis hospitales pediátricos de Santiago, Chile. Pacientes y Métodos: Análisis retrospectivo de bases de datos de cuatro proyectos FONDECYT sucesivos, prospectivos y multicéntricos, registrando características clínicas y de laboratorio de los pacientes, además de patrón de resistencia antimicrobiana de las cepas aisladas. Resultados: Se registraron 95 episodios de bacteriemia asociada a SGV en 91 niños con NFAR. Destacan: leucemia mieloide aguda como enfermedad de base, neutropenia profunda, hospitalización prolongada (15 días), uso extendido de antimicrobianos (14 días), uso de citarabina en esquemas de quimioterapia (86% episodios). Las manifestaciones clínicas más frecuentes fueron respiratoria y gastrointestinal, asociándose en 26% a síndrome de shock por Streptococcus grupo viridans. Hubo elevada resistencia a β lactámicos, sin cepas no susceptibles a vancomicina. Discusión: SGV es un patógeno relevante en niños con cáncer, fiebre y neutropenia en nuestro medio, asociado a casos de sepsis. La resistencia a β lactámicos es un aspecto que requiere vigilancia epidemiológica estricta en esta población.

Abstract Background: Viridans group streptococci (VGS) has acquired relevance as a microorganism causing febrile neutropenia, associated with significant morbidity. Aim: To characterize episodes of bacteremia caused by VGS in children with cancer who developed high-risk febrile neutropenia (HRFN) during the period from April 2004 to June 2018 in six pediatric hospitals of Santiago, Chile. Method: Database analysis of 4 successive, prospective and multicentric studies recording clinical and laboratory characteristics of patients, as well as antimicrobial susceptibility pattern of isolated strains. Results: 95 episodes of VGS bacteremia in 91 children with HRFN were analyzed. It emphasizes acute myeloid leukemia as cancer type, deep neutropenia, prolonged hospitalization (15 days), with extended use of antimicrobials (14 days) and use of cytarabine in chemotherapy schemes (86% episodes). The most frequent clinical manifestations were respiratory and gastrointestinal, associating up to 26% viridans group shock syndrome. There was high resistance to β lactams. As expected, there were not non-susceptible strains to vancomycin. Discussion: VGS is a relevant microorganism in children with cancer, fever and neutropenia, with a high percentage of sepsis. Resistance to β lactams is an issue that requires strict epidemiological surveillance in this population.

Síndrome celulitis-adenitis, una forma infrecuente de presentación de la sepsis neonatal tardía: A propósito de dos casos / Adenitis-cellulitis syndrome, an infrequent form of presentation of the late-onset neonatal septicemia: Report of two cases

La sepsis es la principal causa de mortalidad neonatal. La forma precoz, habitualmente, está relacionada con la colonización recto-vaginal u otros factores de riesgo materno. En la forma tardía, es difícil establecer su origen; por lo general, es nosocomial o de la comunidad. El Streptococcus agalactiae (Streptococcus beta-hemolítico del grupo B) es el germen implicado con más frecuencia en la sepsis neonatal en países desarrollados. La forma tardía, generalmente, se presenta con septicemia y meningitis, y, en ocasiones, pueden detectarse infecciones osteoarticulares o de piel y tejidos blandos. El síndrome celulitis-adenitis en la región cervical, forma poco frecuente de presentación, es causado por Staphylococcus aureus y, ocasionalmente, por Streptococcus agalactiae. Se reportan 2 casos de sepsis neonatal tardía con clínica de celulitis-adenitis cervical causados por Streptococcus beta-hemolítico del grupo B, con una evolución satisfactoria con terapia antibiótica de amplio espectro.

Septicemia is the main cause of neonatal mortality. The early-onset neonatal sepsis is usually related to maternal factor risks including recto-vaginal colonization. In the late-onset neonatal septicemia it is more difficult to establish the etiology because the majority of the cases are nosocomial or community related. The Streptococcus agalactiae (beta-hemolytic Streptococcus) is the most frequent germ associated with neonatal sepsis in developed countries. The late-onset form usually occurs with septic symptoms and meningitis and, in a few cases, with osteoarticular, skin and soft tissue infection. Adenitis-cellulitis syndrome is rarely seen, and its main cause is Staphylococcus aureus, followed by Streptococcus agalactiae. We report two cases of group B Streptococcus late-onset neonatal septicemia, both of them with adenitis-cellulitis syndrome. Patients recovered uneventfully after an adequate antibiotic therapy.

Sensibilidad a los antimicrobianos de aislamientos de Streptococcus equi subsp. equi de la provincia de Buenos Aires, Argentina / Antimicrobial susceptibility in isolates of Streptococcus equi subsp. equi from Buenos Aires province, Argentina

Streptococcus equi subsp. equi es el agente etiológico de la adenitis equina, una enfermedad infecciosa que afecta al tracto respiratorio superior y linfonódulos de cabeza y cuello de equinos. La terapia antimicrobiana tradicional incluye como antibiótico de primera elección a la penicilina G (PEN), a la que los estreptococos suelen ser sensibles. El objetivo de este trabajo fue estudiar el perfil de sensibilidad a distintos antimicrobianos de cepas de S. equi que circulan en la provincia de Buenos Aires, Argentina. Se estudiaron 92 aislamientos mediante el método de difusión con discos; los antimicrobianos evaluados fueron PEN, cefotaxima, eritromicina, tetraciclina, enrofloxacina (ENR), trimetroprima-sulfametoxazol (TMS), ciprofloxacina, clindamicina (CLI), estreptomicina (STR) y florfenicol. Se determinó la concentración inhibitoria mínima (CIM) de la PEN y de aquellos antimicrobianos frente a los cuales S. equi mostró resistencia o sensibilidad intermedia. Se obtuvieron altos porcentajes de sensibilidad a todos los antimicrobianos por el método de difusión y valores de CIM por debajo de los puntos de corte para PEN, TMS y CLI. Se identificaron cepas resistentes a ENR y STR, con CIM50, CIM9o y rangos de CIM por encima de los puntos de corte. Los resultados confirman que la PEN podría utilizarse empíricamente, ya que las cepas circulantes en Buenos Aires no mostraron resistencia a este antimicrobiano. Se enfatiza en la relevancia del uso racional de los antibióticos para lograr éxito terapéutico, evitar la cronicidad, la recidiva de infecciones y la aparición de resistencia.

Streptococcus equi subsp. equi is the etiologic agent of strangles, an infectious disease affecting the upper respiratory tract and head and neck lymph nodes of equines. Routine antimicrobial therapy includes penicillin (PEN) as antibiotic of first choice. Streptococci are usually susceptible to PEN and only a few antimicrobial studies had been performed. The aim of this work was to study the antimicrobial susceptibility profile of S. equi from Buenos Aires, Argentina. Ninety-two isolates were studied by the single disk method to PEN, cefotaxime, erythromycin (ERY), tetracycline, enrofloxacin (ENR), trimethoprim sulfamethoxazole (TMS), ciprofloxacin, clindamycin (CLI), streptomycin (STR) and florfenicol. Minimum inhibitory concentration (MIC) to PEN and antibiotics with resistance and intermediate susceptibility were tested. High percentages of susceptibility were obtained by the disk diffusion method and MIC values of PEN, TMS and CLI were found to be under the breakpoint values. Resistant strains of ENR and STR with MIC50, MIC90 and MIC ranges above breakpoints were identified. These findings confirm that PEN may be used empirically because resistant strains were not found in Buenos Aires. Emphasis is placed on the rational use of antibiotics to achieve therapeutic success, to prevent chronicity, recurrence of infections and the emergence of resistance.

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.

Celulitis orbitaria complicada por absceso subperióstico debido a infección por Streptococcus pyogenes / Orbital cellulitis complicated by subperiosteal abscess due to Streptococcus pyogenes infection

Resumen: Introducción: La celulitis orbitaria es una enfermedad infecciosa muy frecuente en la edad pediátrica que puede provocar el desarrollo de severas complicaciones. Los principales microorganismos involucrados son Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae y Moraxella catarrhalis, que juntos corresponden al 95% de los casos. También se pueden presentar Streptococcus beta hemolíticos y microorganismos anaerobios, que corresponden a menos del 5% de los casos. Se presenta un caso poco frecuente de celulitis orbitaria complicada por absceso subperióstico ocasionado por Streptococcus pyogenes (estreptococo beta hemolítico del grupo A). Caso clínico: Paciente masculino de 9 años de edad con antecedente de trastorno por déficit de atención e hiperactividad desde los 5 años de edad. Inició su padecimiento actual por presentar eritema en canto externo del ojo derecho; posteriormente, aumento de volumen periorbicular con limitación de apertura palpebral, progresión a proptosis, dolor a los movimientos oculares y secreción conjuntival purulenta. Los estudios de imagen subperióstico reportaron absceso y preseptal derecho con celulitis extraocular. Se inició manejo empírico con antibióticos, drenaje quirúrgico y cultivo del material purulento. De este, se aisló Streptococcus pyogenes. Conclusiones: Debido a la implementación de los esquemas de vacunación desde la década de los 90 contra H. influenza y S. pneumoniae, los casos por estos patógenos han disminuido, provocando que nuevas bacterias tomen su lugar como causantes de la infección. La importancia de considerar a S. pyogenes como etiología de celulitis orbitaria radica en la rápida progresión para la formación de abscesos, así como los pocos casos descritos en la literatura.

Abstract: Background: Orbital cellulitis is an infectious disease that is very common in pediatric patients, in which severe complications may develop. Etiological agents related to this disease are Haemophilus influenzae B, Staphylococcus aureus, Streptococcus pneumoniae and Moraxella catarrhalis, which correspond to 95% of cases. Moreover, Streptococcus beta hemolytic and anaerobic microorganisms may also be present corresponding to < 5% of the cases. We present an uncommon case of cellulitis complicated by sub-periosteal abscess caused by Streptococcus pyogenes (Group A beta hemolytic streptococcus). Case report: A 9-year-old male patient with a history of deficit disorder and hyperactivity since 5 years of age. His current condition started with erythema in the external edge of the right eye, increase in peri-orbicular volume with limitation of eyelid opening, progression to proptosis, pain with eye movements and conjunctival purulent discharge. Image studies reported subperiosteal abscess and preseptal right with extraocular cellulitis. The patient started with empirical antibiotic treatment, surgical drainage and culture of purulent material from which Streptococcus pyogenes was isolated. Conclusions: Due to the implementation of vaccination schemes against H. influenza and S. pneumoniae since the 90s, the cases by these pathogens have decreased, causing new bacteria to take place as the cause of the infection. The importance of considering S. pyogenes as an etiology of orbital cellulitis is the rapid progression to abscess formation, and the few cases described in the literature.

Epidemiological Study of Erythromycin-Resistant Streptococcus pyogenes From Korea and Japan by emm Genotyping and Multilocus Sequence Typing

BACKGROUND: We determined the epidemiological characteristics of erythromycin (EM)-resistant Streptococcus pyogenes (group A streptococci, GAS) strains isolated from Korea and Japan, using emm genotyping and multilocus sequence typing (MLST). METHODS: Clinical isolates of GAS had been collected from 1992 to 2012 in Korea and from 2004 to 2009 in Japan. EM resistance was determined by the microdilution method, and resistance genotypes were assessed by PCR. The emm genotyping and MLST were performed by DNA sequencing. RESULTS: The emm genotypes and sequence types (STs) were concordant in 143 (85.1%) of 168 EM-resistant GAS strains from Korea. ST36/emm12 (35.1%), ST52/emm28 (22.6%), and ST49/emm75 (16.1%) were the most common types. Most of the ST36 (93.9%) and ST52 (95.8%) strains harbored erm(B), whereas strains ST49, ST42, and ST15 contained mef(A). The concordance between emm genotypes and STs was 41 (93.2%) among 44 EM-resistant GAS strains from Japan. ST36/emm12 (34.1%), ST49/emm75 (18.2%), and ST28/emm1 (15.9%) were the major types. ST36 isolates harbored either erm(B) (56.3%) or mef(A) (37.5%), whereas isolates ST28, ST49, and ST38 carried only mef(A). The proportion of erm(B) and mef(A) was 66.1% and 33.3% in Korea and 22.7% and 68.2% in Japan, respectively. CONCLUSIONS: The common STs in Korea and Japan were ST36 and ST49, whereas ST52 was present only in Korea and ST28 only in Japan. Genotype erm(B) was predominant in Korea, whereas mef(A) was frequent in Japan. There were differences between Korea and Japan regarding the frequencies of emm genotypes, STs, and EM resistance genes among the EM-resistant GAS.

Etiología y patrones de resistencia antimicrobiana en sepsis neonatal temprana y tardía, en una Unidad de Terapia Intensiva Neonatal / Etiology and antimicrobial resistance patterns in early and late neonatal sepsis in a Neonatal Intensive Care Unit

Introducción. La sepsis neonatal es una de las principales causas de muerte en recién nacidos. El tratamiento antimicrobiano empírico se sustenta en información epidemiológica y pruebas de susceptibilidad antimicrobiana. El objetivo del estudio fue describir los agentes etiológicos y su sensibilidad antimicrobiana enreciénnacidos con sepsis temprana (SNTe) o tardía (SNTa) de una Unidad de Terapia Intensiva Neonatal. Métodos. Estudio transversal realizado en un hospital de concentración del occidente de México. Se determinó la resistencia antimicrobiana de los gérmenes aislados en sangre o líquido cefalorraquídeo de pacientes con SNTe o SNTa nosocomial. Resultados. Se aislaron bacterias o levaduras en 235 cultivos de 67 eventos de SNTe y 166 eventos de SNTa. Del total de aislamientos, las bacterias más frecuentes fueron enterobacterias (51,5%), seguidas de Streptococcus spp. en SNTe y Staphylococcus spp. en SNTa. En cuanto a las enterobacterias de adquisición nosocomial, el 40% fueron productoras de betalactamasas de espectro extendido. En especies de Staphylococcus, la resistencia a oxacilina se registró en el 65,5%. En las enterobacterias (n: 121), la frecuencia de resistencia a amikacina, piperacilina-tazobactam y meropenem fue menor del 3%. En bacterias no fermentadoras, no se observó resistencia a amikacina, ciprofloxacino y cefepime; sin embargo, el número de aislamientos fue escaso. Conclusiones. Las bacterias identificadas con mayor frecuencia en SNTe fueron enterobacterias (67,6%) y Streptococcus spp. (17,6%), mientras que, en SNTa, fueron enterobacterias (44,9%) y Staphylococcus spp. (34,7%). El 40% de las enterobacterias de adquisición nosocomial fueron productoras de betalactamasas de espectro extendido y el 65,5% de Staphylococcus spp. mostraron resistencia a oxacilina.

Introduction. Neonatal sepsis is one of the main causes of death among newborn infants. Empirical antimicrobial treatment is based on epidemiological information and antimicrobial susceptibility tests. The objective of this study was to describe etiologic agents and their antimicrobial susceptibility among newborn infants with early-onset neonatal sepsis (EONS) or late-onset neonatal sepsis (LONS) at a Neonatal Intensive Care Unit. Methods. Cross-sectional study conducted at a tertiary referral hospital in Western Mexico. Determination of antimicrobial resistance of microorganisms isolated in blood or cerebrospinal fluid of patients with EONS or nosocomial LONS. Results. Yeasts and bacteria were isolated from 235 cultures corresponding to 67 events of EONS and 166 events of LONS. Of all isolates, the most common bacteria were Enterobacteriaceae (51.5%), followed by Streptococcus spp. in EONS, and by Staphylococcus spp. in LONS. Of all nosocomial Enterobacteriaceae, 40% were extended spectrum beta-lactamase producing bacteria. Among Staphylococcus species, resistance to oxacillin was recorded in 65.5%. Among Enterobacteriaceae (n: 121), resistance to amikacin, piperacillin-tazobactam, and meropenem was below 3%. Non-fermenting bacteria did not show resistance to amikacin, ciprofloxacin or cefepime; however, the number of isolates was scarce. Conclusions.The most commonly identified bacteria in EONS were Enterobacteriaceae (67.6%) and Streptococcus spp. (17.6%), and Enterobacteriaceae (44.9%) and Staphylococcus spp. (34.7%) in LONS. Forty percent ofnosocomial Enterobacteriaceae were extended spectrum beta-lactamase producing bacteria, and 65.5% of Staphylococcus spp. showed resistance to oxacillin.

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.

Streptococcal acute pharyngitis

Acute pharyngitis/tonsillitis, which is characterized by inflammation of the posterior pharynx and tonsils, is a common disease. Several viruses and bacteria can cause acute pharyngitis; however, Streptococcus pyogenes (also known as Lancefield group A β-hemolytic streptococci) is the only agent that requires an etiologic diagnosis and specific treatment. S. pyogenes is of major clinical importance because it can trigger post-infection systemic complications, acute rheumatic fever, and post-streptococcal glomerulonephritis. Symptom onset in streptococcal infection is usually abrupt and includes intense sore throat, fever, chills, malaise, headache, tender enlarged anterior cervical lymph nodes, and pharyngeal or tonsillar exudate. Cough, coryza, conjunctivitis, and diarrhea are uncommon, and their presence suggests a viral cause. A diagnosis of pharyngitis is supported by the patient's history and by the physical examination. Throat culture is the gold standard for diagnosing streptococcus pharyngitis. However, it has been underused in public health services because of its low availability and because of the 1- to 2-day delay in obtaining results. Rapid antigen detection tests have been used to detect S. pyogenes directly from throat swabs within minutes. Clinical scoring systems have been developed to predict the risk of S. pyogenes infection. The most commonly used scoring system is the modified Centor score. Acute S. pyogenes pharyngitis is often a self-limiting disease. Penicillins are the first-choice treatment. For patients with penicillin allergy, cephalosporins can be an acceptable alternative, although primary hypersensitivity to cephalosporins can occur. Another drug option is the macrolides. Future perspectives to prevent streptococcal pharyngitis and post-infection systemic complications include the development of an anti-Streptococcus pyogenes vaccine.

Bacteriostatic effect of copaiba oil (Copaifera officinalis) against Streptococcus mutans

This study evaluated the inhibitory activity of copaiba oil (Copaifera officinalis against the cariogenic microorganism, Streptococcus mutans. For such purpose, a minimum inhibition concentration test of copaiba oil against S. mutans was performed, using the serial dilution in broth technique, with a negative control, a positive control (0.12 percent chlorhexidine) and a 10 percent copaíba oil solution as a test. A minimum bactericidal concentration test with tubes presenting microbial inhibition was also conduced. In the minimum inhibitory concentration test, copaiba oil showed inhibition of bacterial growth at all concentrations tested up to 0.78 µL/mL of the 10 percent copaiba oil solution in the broth. In addition, the negative control had no inhibition, and the 0.12 percent chlorhexidine solution was effective up to 6.25 µL/mL in the broth. Copaiba oil showed a bacteriostatic activity against S. mutans at low concentrations, and could be a an option of phytotherapic agent to be used against cariogenic bacteria in the prevention of caries disease.

Este estudo avaliou a atividade inibitória do óleo de copaíba (Copaifera officinalis contra o microrganismo cariogênico, Streptococcus mutans. Para isso, foi realizado um teste de concentração mínima inibitória do óleo de copaíba contra S. mutans, utilizando a técnica de diluição seriada em caldo, com um controle negativo, um controle positivo (clorexidina a 0,12 por cento) e uma solução de óleo de copaíba 10 por cento como teste. Também foi conduzido um teste de concentração mínima bactericida com os tubos que apresentaram inibição microbiana. No teste de concentração inibitória mínima, o óleo de copaíba mostrou inibição do crescimento bacteriano em todas as concentrações testadas até 0,78 µL/mL da solução a 10 por cento do óleo de copaíba no caldo. Além disso, o controle negativo não teve nenhuma inibição, e a solução de clorexidina 0,12 por cento foi eficaz até 6,25 µL/mL no caldo. O óleo de copaíba mostrou uma atividade bacteriostática contra S. mutans em baixas concentrações, apresentando-se assim como uma opção de fitoterápico a ser utilizado contra bactérias cariogênicas na prevenção de cáries.

Queratopatía cristalina: diagnóstico clínico y microbiológico de una infección corneal infrecuente causada por el grupo Streptococcus mitis

El objetivo del presente informe es describir un caso de queratopatía cristalina causada por microorganismos pertenecientes al grupo Streptococcus mitis en una paciente que concurrió a la consulta oftalmológica por molestias en su ojo derecho. Al examen oftalmológico presentó un punto de sutura interrumpida de nylon 10-0 sin tensión y con secreciones mucosas adheridas. El punto flojo fue retirado bajo normas de asepsia. Se indicó colirio de moxifloxacina al 0,5 %; el ojo tuvo una evolución adecuada, con una correcta epitelización. Sin embargo, luego de 15 días desarrolló un infiltrado blanquecino arboriforme. Se tomó una muestra en el quirófano, enhebrando el trayecto intraestromal de la sutura retirada con sutura de vicryl 7-0. Se indicaron colirios de vancomicina con 50 mg/ml. El infiltrado se mantuvo estable durante 45 días, luego se incrementó el tamaño y se produjo necrosis tisular con peligro de perforación corneal. Se realizó un recubrimiento conjuntival bipediculado. La paciente evolucionó favorablemente y luego de la retracción espontánea del recubrimiento, se observó leucoma cicatrizal y neovasos corneales.

Crystalline keratopathy: an infrequent corneal infection produced by the Streptococcus mitis group. The objective of this report is to describe a case of crystalline keratopathy caused by the Streptococcus mitis group corresponding to a patient who attended hospital for discomfort in his right eye. The ophthalmological examination showed an interrupted stitch of 10-0 nylon suture without tension and with attached mucus secretions. The loose suture was removed under aseptic conditions. Moxifloxacin 0.5 % eye drops were topically indicated. The treated eye successfully epithelialized and evolved favorably. However, after 15 days, a white tree-shaped infiltrate developed. A corneal sample was taken in the operating room, threading the intrastromal path of the removed stitch with a 7-0 vicryl suture. Vancomycin 50 mg/ml drops were indicated. The infiltrate, which was stable for 45 days, later increased its size and tissue necrosis occurred with danger of corneal perforation. A bipedicle conjunctival flap was performed in the affected corneal area, which evolved favorably. After spontaneous conjunctival flap retraction, only corneal scarring and neovascularization outside the visual axis were observed.

Análisis de los fenotipos y genotipos de resistencia a eritromicina y clindamicina en cepas de Streptococcus pyogenes aisladas en Chile en un período de 10 años / Resistance phenotypes and genotypes of Streptococcus pyogenes clinical isolates in Chile over a 10-year period

Background: Macrolide and lincosamide resistance in Streptococcus pyogenes is due to the acquisition of mef, ermB and ermA genes, which confer different resistance phenotypes, namely M, MLSBconstitutive and MLSBinducible respectively. The last report of resistance in Chile was done in the period 1990-1998, in which resistance to macrolides was 5.4 percent, with M phenotype as the predominant one. Aim: To characterize the evolution of erythromycin and clindamycin resistance and their associated genes in S. pyogenes strains isolated from patients with invasive and non-invasive infections in the period 1996 to 2005. Material and Methods: Resistance to erythromycin and clindamycin was determined in 1,282 clinical isolates using the disk diffusion test. Resistant isolates were analyzed by polymerase chain reaction (PCR) for the presence of the above mentioned resistance genes. Results: Global resistance to erythromycin and clindamycin was 3.5 and 0.7 percent respectively. Eighty percent of the resistant strains possessed the M. phenotype. Conclusions: Resistance levels of S. pyogenes have decreased in Chile in the last years. Most resistant strains have M phenotype in contrast to many countries in which the MLSB constitutive phenotype is the predominant one.