Coinfección por astrovirus y Neisseria meningitidis serogrupo B en una niña / Coinfection by astrovirus and Neisseria B meningitidis in a girl

La infección meningocócica tiene una elevada morbimortalidad. Las coinfecciones virales han sido descritas, fundamentalmente, por virus herpes y respiratorios. Se presenta una paciente que ingresó al Servicio de Emergencia con convulsión tónico-clónica, hipotensión, taquicardia y escala de Glasgow posterior baja. En la Unidad de Cuidados Intensivos mantuvo alteración del nivel de conciencia y requirió estabilización hemodinámica. Se inició antibioterapia de amplio espectro. La paciente mostró deposiciones líquidas malolientes, sin sangre, que fueron cultivadas y estudiadas mediante reacción en cadena de la polimerasa. El líquido cefalorraquídeo fue normal. Las deposiciones resultaron positivas para astrovirus. Se confirmó, mediante reacción en cadena de la polimerasa en sangre, la presencia de Neisseria meningitidis serogrupo B. Se presenta el primer caso pediátrico de coinfección por astrovirus y Neisseria meningitidis. Este virus debería incluirse entre las causas de coinfección para descartar en caso de clínica abdominal predominante, vómitos o deposiciones líquidas.

Meningococcal infection associates high morbidity and mortality. Viral coinfection has been described mainly with herpes and respiratory virus. We describe a child who suffered a tonic-clonic seizure with hypotension, tachycardia and low Glasgow Coma Scale. She maintained an altered mental status and required hemodynamic stabilization in the Pediatric Intensive Care Unit. Wide spectrum antibiotherapy was initiated. She suffered large and foul-smelling liquid not bloody stools which were cultured and studied by polymerase chain reaction. The cerebrospinal fluid was normal. Later the polymerase chain reaction stools were positive to astrovirus, and the blood polymerase chain reaction was positive to Neisseria meningitidis group B. As far as we know, this is the first case of astrovirus and Neisseria meningitidis coinfection described in children. This virus should be considered as new cause of viral coinfection to discard if unexplained abdominal pain or vomits and liquid stools are observed.

Development of a DNA aptamer for screening neisseria meningitidis serogroup B by cell SELEX

Background: Artificial oligonucleotides like DNA or RNA aptamers can be used as biodiagnostic alternatives for antibodies to detect pathogens. Comparing to antibodies, artificial oligonucleotides are produced easily at lower costs and are more stable. Neisseria meningitidis, the causative agent of meningitis, is responsible for about 1% of infections in an epidemic period. Specific DNA aptamers that bind to N. meningitidis serogroup B were identified by whole-cell Systemic Evolution of Ligands by EXponential Enrichment [SELEX]

Methods: The SELEX begins with a library of labeled ssDNA molecules. After six rounds of selection and two rounds of counter-selection, 60 clones were obtained, of which the binding efficiency of 21 aptamers to the aforementioned bacterium was tested by flow cytometry

Results: The aptamers K3 and K4 showed the highest affinity to N. meningitidis serogroup B and no affinity to N. meningitidis serogroups Y, A, and C, or to other meningitis causing bacteria. The dissociation constant [Kd value] for K3 and K4 were calculated as 28.3 +/- 8.9 pM and 39.1 +/- 8.6 pM, respectively. K3 aptamer with the lowest Kd was chosen as the main aptamer. K3 could detect N. meningitidis in patients' cerebrospinal fluid [CSF] samples and in CSF from healthy volunteers inoculated with N. meningitidis serogroup B [ATCC 13090] at 200 and 100 CFU ml[-1], respectively

Conclusion: The findings suggest the application of the developed aptamer in specific detection of N. meningitidis serogroup B amongst a group of meningitis causing bacteria

Seroprevalence of bactericidal antibodies against serogroup B and C Meningococci in a University Hospital

Meningococcus serogroup B (MenB), clonal complex 32 (cc 32), was the Brazilian epidemic strain of meningococcal disease (MD) in the 1990’s. Currently, meningococcus serogroup C (MenC), cc 103, is responsible for most of the cases of the disease in Brazil. The aim of this study was to investigate the seroprevalence of bactericidal antibody (SBA) against representative epidemic strains of MenC, (N753/00 strain, C:23:P1.22,14-6, cc103) and MenB, (Cu385/83 strain, B:4,7:P1.15,19, cc32) in students and employees of a university hospital in the State of Rio Grande do Sul (RS, Brazil). A second MenC strain (N79/96, C:2b:P1.5-2,10, cc 8) was used as a prototype strain of Rio de Janeiro’s outbreak that occurred in the 1990’s. Our previous study showed a 9% rate of asymptomatic carriers in these same individuals. A second goal was to compare the SBA prevalence in meningococcal carriers and non-carriers. Fifty-nine percent of the studied population showed protective levels of SBA titers (log2≥2) against at least one of the three strains. About 40% of the individuals had protective levels of SBA against N753/00 and Cu385/83 strains. Nonetheless, only 22% of the individuals showed protective levels against N79/96 strain. Significantly higher antibody levels were seen in carriers compared to non-carriers (P≤0.009). This study showed that, similar to other States in Brazil, a MenC (23:P1.22,14-6, cc103) strain with epidemic potential is circulating in this hospital. Close control by the Epidemiological Surveillance Agency of RS of the number of cases of MD caused by MenC strains in the State is recommended to prevent a new disease outbreak.

Neisseria meningitidis presenting as acute abdomen and recurrent reactive pericarditis

ABSTRACT Meningococcal meningitis is a well established potential fatal infection characterized by fever, headache, petechial rash, and vomiting in the majority of cases. However, protean manifestations including abdominal pain, sore throat, diarrhea and cough, even though rare, should not be overlooked. Similarly, although disseminated infection could potentially involve various organ-targets, secondary immune related complications including joints or pericardium should be dealt with caution, since they remain unresponsive to appropriate antibiotic regimens. We hereby report the rare case of an otherwise healthy adult female, presenting with acute abdominal pain masking Neisseria meningitidis serotype B meningitis, later complicated with recurrent reactive pericarditis despite appropriate antibiotic treatment. There follows a review of current literature.

Meningitis neonatal por Neisseria meningitidis serogrupo B / Neonatal meningitis caused by serogroup B Neisseria meningitides

La meningitis meningocóccica es una infección poco frecuente en el período neonatal internacionalmente, y solo hay una publicación previa en la literatura médica cubana hace 25 años atrás, de recién nacidos con meningitis bacteriana causada por Neisseria meningitidis. Se presenta el caso de un recién nacido febril, con manifestaciones de toxicidad, fontanela abombada, y cuando se realizó punción lumbar, se encontró pleocitosis del líquido cefalorraquídeo y se aisló N. meningitidis serogrupo B, por lo que se diagnostica meningitis meningocóccica neonatal. Tuvo evolución favorable. Se describen algunas características de la infección meningocócica, y se destaca el diagnóstico y tratamiento recomendado para este tipo de infección, así como se hace referencia a reportes de casos publicados en la literatura internacional.

Meningoccocal meningitis is a rare infection in the neonatal period worldwide and there is just one publication in the Cuban medical literature dated 25 years ago, which presented some neonates with bacterial meningitis caused by Neisseria meningitides. This is a febrile neonate with toxicity manifestations and bulging fontanelle; he was performed a lumbar puncture to find spinal fluid pleocytosis and the serogroup B N. meningitides was then isolated, so he was diagnosed with neonatal meningococcal meningitis with favorable progression. Some characteristics of the meningococcal infection, the diagnosis and recommended treatment were described in addition to making reference to case reports published in the international literature.

Pericarditis como presentación inicial de enfermedad meningocócica diseminada / Pericarditis as initial presentation of disseminated meningococcal disease

La pericarditis es una complicación conocida pero poco frecuente de la infección meningocócica. La incidencia es de 3% a 19% en todos los grupos etarios, con pocos casos informados en la edad pediátrica. La enfermedad meningocócica diseminada con pericarditis es defnida como pericarditis purulenta con evidencia clínica de meningococemia y meningitis. Se presenta el caso de un lactante de 4 meses con diagnóstico de enfermedad meningocócica diseminada con pericarditis causada por Neisseria meningitidis serogrupo B. Tras el tratamiento antibiótico adecuado, se logró controlar el cuadro séptico y cardiológico. Se resalta el hecho de que la infección meningocócica puede presentar formas clínicas poco frecuentes, lo que puede llevar a difcultades diagnósticas y terapéuticas.

Pericarditis is a well-recognized but uncommon complication of meningococcal infection. The incidence of pericarditis complicating meningococcal disease in all age groups is reported to be 3-19%. There are few cases reported in the paediatric age group. Disseminated meningococcal disease with pericarditis, defned as purulent pericarditis with clinical evidence of disseminated meningococcemia and meningitis. We report the case of a 4-month-old male infant who presented disseminated meningococcal disease with pericarditis caused by Neisseria meningitidis serogroup B. The patient was treated with antibiotic with excellent response. It is important to point out that meningococcal disease may present in unusual forms which may lead to diagnostic and therapeutic diffculties.

Identificación In Silico del mimetismo molecular entre Epitopes T de Neisseria meningitidis B y el proteoma humano / In Silico identification of molecular mimicry between T-Cell Epitopes of Neisseria meningitidis B and the human proteome

El objetivo del estudio fue determinar los epítopes T de cuatro de las proteínas antigénicas más frecuentes de la membrana externa de Neisseria meningitidis B e identificar los sitios más relevantes donde existe mimetismo molecular para estos epítopes en seres humanos. Para ello se realizó un estudio in silico (estudios que usan herramientas bioinformáticas) usando las bases de datos SWISS-PROT/TrEMBL SYFPEITHI y FASTA, las cuales se emplearon para la determinación de las secuencias proteicas, la predicción de los epítopes T CD4 y CD8, y la determinación del mimetismo molecular en humanos, respectivamente. Se encontró similitud molecular en varias proteínas humanas presentes en diferentes órganos y tejidos, entre ellos: hígado, piel y epitelios, cerebro, sistema linfático y testículos, destacando las encontradas en estos últimos, ya que ellas mostraron la frecuencia más alta de secuencias miméticas. Este hallazgo ayuda a comprender el éxito de N. meningitidis B para colonizar tejidos humanos, el fracaso de ciertas vacunas contra esta bacteria e incluso ayuda a explicar posibles reacciones autoimmunes asociadas a la infección o vacunación.

The objective of the study was to determine the T-cell epitopes of four of the most frequent antigenic proteins of the outer membrane of Neisseria meningitidis B, and to identify the most relevant sites for molecular mimicry with T-cell epitopes in humans. In order to do so, an in silico study -a type of study that uses bioinformatic tools- was carried out using SWISS-PROT/TrEMBL, SYFPEITHI and FASTA databases, which helped to determine the protein sequences, CD4 and CD8 T-cell epitope prediction, as well as the molecular mimicry with humans, respectively. Molecular similarity was found in several human proteins present in different organs and tissues such as: liver, skin and epithelial tissues, brain, lymphatic system and testicles. Of these, those found in testicles were more similar, showing the highest frequency of mimetic sequences. This finding shed light on the success of N. meningitidis B to colonize human tissues and the failure of certain vaccines against this bacterium, and it even helps to explain possible autoimmune reactions associated with the infection or vaccination.

Patentes e registro sanitário de vacinas antimeningocócicas sorogrupo B no Brasil: aspectos importantes para a regulação e o controle / Patents and sanitary registration of serogroup B meningococcal vaccine in Brazil: basic aspects for biological products regulation and control from rice bran

As vacinas são um dos instrumentos mais importantes para a saúde pública. O registro sanitário é uma das ferramentas que a vigilância sanitária dispõe para controlar a entrada de todos os medicamentos e constitui a base das informações sobre eles para o Sistema de Vigilância Sanitária. No caso da meningite meningocócica, doença causada pela bactéria Neisseria meningitidis (Nm), várias vacinas foram desenvolvidas inicialmente contra os sorogrupos A, C, W135 e Y, utilizando-se os polissacarídeos capsulares. Pelo fato de o antígeno polissacarídico do sorogrupo B não induzir boa resposta imunológica em seres humanos, outras estratégias vacinais foram testadas. O objetivo deste trabalho foi mapear as patentes de produtos vacinais contra o sorogrupo B, depositadas no período de 1990 a 2005, e comparar esses pedidos com vacinas registradas. O levantamento dos pedidos de patentes foi realizado utilizando-se as bases de dados eletrônicos do Instituto Nacional de Propriedade Industrial (INPI) e do Escritório de Patentes Europeu (EPO), a partir de janeiro de 1995. Várias patentes solicitam proteção dos antígenos presentes em vacina já registrada, o que não caracteriza inovação. Os maiores depositantes de patentes são as multinacionais, o que mostra a necessidade de incremento dessa pesquisa aplicada por instituições brasileiras.

Aislamiento de cepas invasivas de Neisseria meningitidis serogrupos B y Y en la ciudad de Cumaná, años 2009-2010 / Isolation of invasive strains of neisseria meningitides, serogroups B and Y, in Cumana, 2009-2010

Neisseria meningitidis es agente causal de meningitis y meningococcemia. Se realizó la presente investigación a fin de analizar fenotípicamente las cepas invasivas de N. meningitidis aisladas en Cumaná, estado Sucre. Se incluyó el total de cepas identificadas como N. meningitidis en el laboratorio de bacteriología del Hospital Universitario “Antonio Patricio de Alcalá”, durante los años 2009-2010; provenientes de muestras de líquido cefalorraquídeo (LCR) y sangre (hemocultivos). A cada aislamiento se le determinó la susceptibilidad antimicrobiana y el serogrupo respectivo. Durante el período en estudio se analizaron 10 cepas, de las cuales 5 provenían de LCR. El ensayo de susceptibilidad antimicrobiana reveló que las cepas presentaban sensibilidad a penicilina, cefotaxima, meropenem, rifampicina, ciprofloxacina y cloranfenicol siendo sólo resistentes al trimetoprim/ sulfametoxazol. El serogrupo más frecuente fue el B (8 cepas), aislándose un caso de serogrupo Y. Respecto al grupo etario de los pacientes, de las 10 cepas, 8 provenían de pacientes pediátricos. Este es el primer estudio con cepas de N. meningitidis aisladas en Cumaná, por lo que se hace imprescindible el análisis permanente de las cepas aisladas en la zona, con fines de monitoreo, principalmente, de la susceptibilidad antimicrobiana y los serogrupos circulantes.

Neisseria meningitidis is the causal agent for meningitis and meningococcemia. This research was performed to phenotypically analyze invasive strains of N. meningitidis isolated in Cumana, State of Sucre. The study included all strains identified as N. meningitidis isolated in the bacteriology laboratory at the University Hospital “Antonio Patricio de Alcalá,” during the years 2009-2010, coming from cerebrospinal fluid (CSF) samples and blood cultures. For each isolate, the antimicrobial susceptibility and respective serogroup were determined. During the period of study, 10 strains were analyzed, of which 5 came from CSF. The antimicrobial susceptibility test revealed that the strains showed sensitivity to penicillin, cefotaxime, meropenem, rifampicin, ciprofloxacin and chloramphenicol; they were resistant only to trimethoprim/ sulfamethoxazole. Serogroup B was the most frequent (8 strains); one case of serogroup Y was isolated. Regarding the patient’s ages, of the 10 strains, 8 were found in pediatric patients. This is the first study about strains of N. meningitidis isolated in Cumaná, so it is essential that permanent research regarding the strains isolated in the area is carried out for monitoring purposes, mainly in terms of antimicrobial susceptibility and the circulating serogroups.

[Computer-aided vaccine design: a brief report]

Although the conventional vaccines have been instrumented in the incidence of many infectious diseases, the advances in genetic engineering and bioinformatics have provided the opportunity for developing improved and new vaccines. Reverse vaccinology was pioneered by a group of researchers investigating development of a vaccine against serogroup B Neisseria meningitidis. Reverse vaccinology analyzes the entire genome of a pathogen with the aid of computational programs to identify potentially antigenic extracellular proteins. Using this method for Neisseria meningitidis genome analysis, 600 secretory or surface-exposed proteins were identified and, subsequently, 350 proteins were expressed and purified. Finally, seven proteins capable of activating the immune system against a range of strains were identified. Improved computational techniques are now able to provide researchers with high-confidence predictions for complex biological characteristics. This will herald a move to computer-aided biotechnology in which time-consuming and expensive large-scale experimental approaches are progressively replaced by functional bioinformatic investigations

Desenvolvimento e manutenção de memória imunológica após imunização contra Neisseria meningitidis B com a vacina VA-MENGOC-BC / Development and maintenance of immunological memory after immunization against Neisseria meningitidis B with vaccine VA-MENGOC-BC

Neisseria meningitidis é uma das principais causas de meningite bacteriana e septicemia em todo o mundo, acometendo principalmente crianças menores de 4 anos. Atualmente, não existe uma vacina universal contra o meningococo B (MenB). A imunidade protetora contra o meningococo caracteriza-se pela presença e persistência de anticorpos bactericidas, porém pouco se sabe sobre os mecanismos de desenvolvimento desta memória sorológica. Avaliamos em modelo animal e em humanos, a geração e manutenção das células secretoras de anticorpos (ASC) e dos linfócitos B de memória (LBm) após vacinação contra MenB. Utilizamos como referência a vacina diftérica (dt ou DTP), considerada ter ótima eficácia em humanos. Para o estudo em modelo animal, grupos de 6 a 8 camundongos suíços, fêmeas, de 5 a 6 semanas, foram imunizados com 3 doses da vacina VA-MENGOC-BC ou DTP, via intramuscular, com intervalo de 2 semanas entre as doses. Aproximadamente 2, 4 ou 6 meses após a última dose, os animais receberam a dose reforço. A vacina anti-MenB induziu uma resposta primária de ASC maior que a resposta à dose reforço. Ao contrário, a resposta de ASC à vacina dT foi maior após o booster. A resposta de LBm anti-MenB permaneceu constante (média de 1%) ao longo de todo o estudo, mas a resposta ao toxóide diftérico (TD) foi maior após o booster (média de 1,9%) que após a imunização primária. A concentração de IgC, anticorpos bactericidas e opsonizantes contra MenB foi dose-dependente e foi reativada após a administração das doses reforços. Esses resultados sugerem que os LBm presentes no baço foram responsáveis pela forte resposta de anticorpos observada após a dose reforço. Para o TD, ambas ASC e LBm foram importantes na manutenção da memória sorológica. Para o estudo em humanos, seis voluntários foram imunizados com 3 doses da vacina VA-MENGOC-BC, via intramuscular, com intervalo de 6 a 7 semanas entre as doses. Seis meses após a imunização primária, os indivíduos receberam uma dose...

Neisseria meningitides is one of the leading causes of bacterial meningitis and septicemia worldwide, particularly in children less than four years old. Currently, there is no universal vaccine agoinst serogroup B meningococcus (MenB). Protective immunity against meningococcus is characterized by the presence and persistence of bactericidal antibody, but little is known about the mechanisms of development of the serological memory. In this study, we evaluated in animal model and in humans the generation and maintenance of antibody secreting cells (ASC) and memory B cell after vaccination against MenB. We used the diphtheria vaccine (dT or DTP) as a reference for efficacy in humans. Five to six-week old female Swiss mice in groups of 6 to 8 were immunized with three intramuscular injections of VA-MENGOC-BC or DTP vaccine 2 weeks apart. Approximately 2, 4 or 6 months after the last dose, mice received a booster injection of the vaccine. Vaccination against MenB induced a higher ASC primary response compared with the booster response. In contrast, ASC response to dT was higher after booster than after primary immuinization. Memory B-cell to MenB remained at constant levels (mean of 1%) during the whole study, but the response to diphtheria toxoid (TD) was higher after boosting (mean of 1.9%) when compared with the primary response. IgG, bactericidal and opsonic antibody concentrations to MenB was dose-dependent and was reactivated after booster doses. These data suggest that spleen memory B-cells were responsible for the strong boosting antibody response to MenB. For TD, both ASC and memory B-cell were important for maintenance of the serological memory. For the human study, six volunteers were immunized with three intramuscular injections of VA-MENGOC-BC 6 to 8 weeks apart. Six months after the last dose, subjects received a booster dose. Another group of volunteers (n=5) were immunized with a booster dose of dT vaccine. Three doses of vaccine...

Abdomen agudo como manifestación inicial de meningococemia / Acute abdomen as initial manifestation of menincococcemia

El abdomen agudo como síntoma inicial de meningococemia es una entidad muy poco frecuente y raramente descripta en la bibliografía. Presentamos el caso de un paciente de 4 años de edad, sexo masculino, previamente sano, que consulta por síndrome febril y dolor abdominal de 24 h de evolución. Seinterna en unidad clínico-quirúrgica con diagnóstico de abdomen agudo quirúrgico. El paciente evoluciona desfavorablemente y súbitamente presenta signos compatibles con sepsis grave. Se realiza laparotomía de urgencia; se observa escasa cantidad de líquido citrino libre en cavidad con adenitis mesentérica. Desarrolla luego lesiones purpúricas palpables de rápida progresión en miembros inferiores y evolución al shock séptico. Se aísla en hemocultivos periféricos Neisseria meningitidis serogrupo B. El objetivo de esta publicación es exponer y alertar sobre una modalidad de presentación clínica poco frecuente de la meningococemia, pues el retraso en su diagnóstico y tratamiento impactan sobre la morbimortalidad en la población pediátrica.

Abdominal pain as an initial symptom of meningococcemia is an infrequent entity, rarely described in literature. We present a case of a 4 year-old, male, previously healthy child with a 24 hour history of fever and abdominal pain. He is admitted in a surgical unit with a diagnosis of acute abdomen for surgical resolution. The clinical course turns unfavorably, and patient presents signs of severe sepsis. Urgent laparotomy is performed, observing little brownish fluid and mesenteric adenitis. He then exhibits palpable purpuric rapidly progressive lesions in lower extremities, progressing to septic shock. Later, Neisseria meningitidis serogroup B is isolated from blood cultures.The aim of this article is drawing attention to a nontypical form of manifestation of meningococcemia, as a delayeddiagnosis and treatment has an impact on morbidity and mortality among the pediatric population.

[Neonatal meningitis by Neisseria meningitidis B]

Neisseria meningitidis is one of the major causes of meningitis in children and adolescents, but it is uncommonly found in neonatal meningitis. To report a rare case of meningitis by Neisseria meningitides B. We report the case of neonatal meningitis in a 20 day-old girl without shock or purpura. The symptoms were fever and seizures. The culture of cerebrospinal fluid showed to be positive for Neisseria meningitidis B. culture blood was negative. Antibiotic therapy was started at admission and maintained for 3 weeks. The outcome was favourable without neurological sequelae. Early diagnosis and treatment are mandatory for life saving

Production of outer membrane vesicles (OMV) in batch cultivation of Neisseria meningitidis serogroup B

Meningococcal disease is an important cause of death and morbidity throughout the world. Nearly 330,000 cases and 35,000 deaths occur yearly. Neisseria meningitidis, serogroup B strain N.44/89, is prevalent in Brazil. Its outer membrane vesicles (OMV) with iron regulated proteins (IRP) are released to the culture medium and are used as antigen for vaccine production. In order to have knowledge about the kinetic parameters, especially the final OMV concentration values, 20-h batch cultivations were carried out in Catlin medium with iron restriction. Process conditions comprised: 7 L bioreactor, 36°C, 0.5 atm, overlay air flowrate of 1 L/min, agitation varying from 250 rpm to 850 rpm and dissolved oxygen control set at 10 percent of saturation condition. Biomass was determined by optical density at 540 nm and dry weight. Glycerol, lactate, pH and dissolved oxygen were measured from samples taken during cultivation. Outer membrane vesicle (OMV) concentration was determined by Lowry's method after ultracentrifugation. IRP presence was verified by SDS-PAGE. Highest biomass value, corresponding to the highest initial lactate concentration (7.84 g/L) was achieved at the 9th hour process time corresponding to 1.0 g/L dry biomass and 2.3 optical density at 540 nm. Lactate consumption was directly related to cell growth (yield factor: 0.24 g dry biomass / g lactate). Glycerol concentration in the medium did not change significantly during the process. OMV concentration reached the highest value of 80 mg/L at end cultivation time. The obtained results suggest that lactate is a main limiting growth factor and the maximum amount of antigen is obtained during stationary growth and cell death phases.

A doença meningocócica é uma causa importante de morte a nível mundial. Aproximadamente 330.000 casos e 35.000 mortes ocorrem anualmente. A cepa N.44/89 do sorogrupo B de Neisseria meningitidis é prevalente no Brasil. Suas vesículas de membrana externa (OMV - "outer membrane vesicles"), com proteínas reguladoras de ferro (IRP - "iron regulated proteins") liberadas no meio de cultura, são empregadas como antígeno para a produção da vacina. A fim ter o conhecimento sobre os parâmetros cinéticos, especialmente os valores finais da concentração de OMV, cultivos batelada de 20 hs foram realizados no meio de Catlin com limitação do ferro. As condições de processo compreenderam: biorreator de 7 litros, 36°C, 0,5 atm, vazão de ar de 1 L/min, agitação variando entre 250 a 850 rpm, controle do oxigênio dissolvido em 10 por cento da condição de saturação. A biomassa foi determinada pela densidade ótica em 540 nm e peso seco. Glicerol, lactato, pH e oxigênio dissolvido foram medidos das amostras retiradas durante o cultivo. A concentração de OMV foi determinada pelo método de Lowry após ultracentrifugação. A presença de IRP foi verificada por SDS-PAGE. O valor mais elevado de biomassa, correspondendo à concentração inicial mais elevada de lactato (7,84 g/L) foi obtido no tempo de processo de 9 horas, o qual corresponde a biomassa seca de 1,0 g/L e a densidade ótica de 2,3 em 540 nm. O consumo de lactato. foi relacionado diretamente ao crescimento celular (fator de conversão de 0,24 biomassa por lactato g/g). A concentração do glicerol no meio não se alterou significativamente ao longo do processo. A concentração de OMV alcançou o valor mais elevado de 80 mg/L no tempo final de cultivo. Os resultados obtidos sugerem que o lactato é o principal fator limitante do crescimento e o máximo do antígeno é obtido durante a fase estacionária de crescimento e de morte celular.

Childhood meningitis in Kuwait: epidemiology of etiologic agents and the need for pneumococcal disease prevention

To investigate the epidemiology of the etiologic agents causing bacterial meningitis in Kuwait. This is a retrospective analysis of the medical records of children 1 month to 12 years old who had cerebrospinal fluid [CSF] findings consistent with meningitis. Patients were identified from the records of the Departments of Microbiology and Communicable Diseases in six regional hospitals during 2001. They were divided into bacterial and viral infective groups. Ninety children had CSF findings consistent with meningitis, 44 bacterial [23 culture proven, 21 probable] and 46 viral. Streptococcus pneumoniae and Neisseria meningitidis were the most frequently isolated organisms [44 and 30%, respectively]. A 2-month-old child had Haemophilus influenzae and was the only mortality of this series. S. pneumoniae is the leading bacterial agent causing meningitis in children under the age of 1 year; 61% had bacterial meningitis compared to 37% with viral meningitis. Sequelae were encountered in 23% of bacterial cases. The results indicate that S. pneumoniae is the leading bacterial agent causing meningitis, indicating a need for the introduction of polyvalent pneumococcal vaccine

Estudo da imunogenicidade da proteína de classe 5C de Neisseria meningitidis B em camundongos imunizados pela via nasal

Neisseria meningitidis ‚ um patógeno humano para o qual não existe uma vacina totalmente eficaz. As vacinas antimeningocócicas, produzidas a partir dos polissacarides capsulares do meningococo são efetivas contra os sorogrupos A e C, embora nos Estados Unidos, uma vacina quadrivalente contendo meningococos dos sorogrupos A, C, Y e W- 135 seja eficaz para indivíduos acima de dois anos de idade. No entanto, vacinas polissacarídicas apresentam limitações, pois não são imunogênicas em crianças abaixo de dois anos de idade e nas outras faixas etárias, a resposta imune‚ de curta duração. O desenvolvimento de uma vacina contra o sorogrupo B enfrenta um problema ainda maior devido à similaridade entre a estrutura capsular do polissacaride B e o cidopolisilico contendo glicopeptídeos que faz parte do tecido cerebral humano, podendo levar à autoimunidade. Por isso, os estudos atuais estão se voltando para a pesquisa de antígenos vacinais derivados da membrana externa do meningococo. Estudos promissores têm sido conduzidos para o desenvolvimento de uma vacina baseada nas proteínas de membrana externa (OMPs) de N. meningitidis B. As principais OMPs de N. meningitidis são designadas de classe 1 a classe 5. No entando, vacinas baseadas em OMP são antígenos fracos em crianças, sendo necessário o uso de adjuvantes. O objetivo deste estudo foi investigar as propriedadades adjuvantes da Bordetella pertussis, da toxina colérica e do LPS (imunotipos L8 e L379) em diferentes esquemas de imunização com a proteína de membrana externa de classe 5C purificada da cepa de referência 44/76 de N. meningitidis B e verificar a modulação da resposta imune contra esta proteína administrada pela via intranasal e intramuscular em camundongos BALB/c adultos e neonatos/ jovens. As amostras de soros de camundongos imunizados foram avaliadas quanto à presença de anticorpos específicos de isótipos IgG, IgM, IgA por meio de ELISA e Immunoblotting. Foram ainda, avaliados...

Peptide Mimotopes of Neisseria meningitidis Group B Capsular Polysaccharide

The antigenic similarity between Neisseria meningitidis group B (NMGB) capsular polysaccharide (PS) and human polysialic acid (PSA) has hampered the development of a NMGB PS-based vaccine. But the possibility of a safe vaccine based on NMGB PS has been demonstrated by the existence of the NMGB PS-associated nonautoreactive epitope, which is distinct from those present on human PSA. To obtain peptide mimotopes of NMGB PS, we used HmenB3, a protective and nonautoreactive monoclonal antibody, to screen a phage library with 12 amino acids. We obtained 23 phage clones that bound to HmenB3 but not in the presence of E. coli K1 PS [which is alpha (2-8) -linked PSA like NMGB PS]. The clones contained 3 mimotopes and differed from previously described NMGB PS mimotopes. Immunization with a synthetic peptide of one mimotope elicited anti-NMGB antibodies in BALB/c mice. These mimotopes may be useful in the development of group B meningococcal vaccines.