Molecular characteristics of serogroup B neisseria meningitidis, China / 中华预防医学杂志

Objective@#To investigate the molecular characteristics of serogroup B neisseria meningitidis in China.@*Methods@#Total of 485 (100 strains isolated from cerebrospinal fluid or blood samples of encephalomyelitis cases, and 385 strains isolated from nasopharynx of healthy carriers) Meningococcal serogroup B (MenB) strains, isolated from 29 provinces of China between 1968 and 2016, were analyzed by multilocus sequence typing (MLST) and PorA typing methods. Further, the genetic diversity of three MenB vaccine proteins, FHbp, NadA and NHBA, were analyzed.@*Results@#The 485 study strains belonged to 270 sequence types (STs), 107 of which (representing 211 strains) could be grouped into ten clonal complexes (CC). CC4821 has been the predominant lineage in China since 2005 (28.7%, n=139). The most common PorA types of MenB strains from invasive meningococcal cases were P1.5-2,2-2 (10.0%, n=10), P1.5-1,2-2 (9.0%, n=9) and P1.5-1,10-4 (9.0%, n=9). Four hundred and twenty one strains had intact fhbp gene; variant 1, 2 and 3 accounted for 12.8% (54 strains), 85.0% (358 strains) and 2.2% (9 strains) respevtively. Ten out of 432 strains (2.3%) contained complete nadA gene. All the 172 strains for which the nhba gene was sequenced had intact gene sequence which corresponded to 68 peptide types.@*Conclusion@#CC4821 was the predominant CC of MenB strains in China; the vaccine proteins were diverse about the sequences. The vaccine proteins should be carefully selected when developing MenB vaccines in China.

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.

Characterization of Oropharyngeal Carriage Isolates of Neisseria meningitidis in Healthy Korean Adolescents in 2015

The meningococcus carriage rate is age-dependent, with a high prevalence in adolescents and young adults. This cross-sectional study aimed to estimate the oropharyngeal carriage rate of meningococcus among healthy Korean adolescents and its relationship with several population characteristics. The survey was conducted from April to May 2015 among 1,460 first-year high-school students in 9 high schools located in Gyeonggi province, Korea. Each student answered a short questionnaire assessing risk factors for carriage, and posterior pharyngeal wall swab samples were obtained. These samples were cultured on meningococcus-selective media, with colonies resembling meningococci identified using the Vitek® MS system (bioMérieux, Marcy l'Etoile, France). All isolates were characterized by molecular serogrouping and multilocus sequence typing (MLST). Meningococci were identified from 3.4% (49/1,460) swabs. Current smokers had significantly higher carriage rates than non-smokers (8.2% vs. 2.9%, P = 0.002), and boys had significantly higher carriage rates than girls (4.4% vs. 1.6%, P = 0.004). Serogroup B was the most common serogroup, followed by serogroup C, then 29E and Y. Twenty-seven different sequence types (STs) were identified; the most common were ST-3091, ST-11278, and ST-44. These belonged to clonal complexes (CCs) 269, 32, and 41/44, respectively, known as the hypervirulent clones. Evaluating meningococcal carriage is important to understand the epidemiology of meningococcal disease; however, little data exist in Korea. Similar to western countries, meningococcal serogroup B has emerged in Korea, and hypervirulent clones were identified. It is necessary to monitor the genetic and serologic characteristics of circulating meningococci and to assess the potential strain coverage of meningococcal vaccines.

Immune effects of different forms of vaccines of meningococcus serogroup B outer membrane protein 0315 / 中国免疫学杂志

Objective:To evaluate preliminarily immunocompetence and immunoprotection of a NMB0315 nucleic acid vaccine,a recombinant protein vaccine and a nucleic acid vaccine plus a recombinant protein vaccine against Neisseria meningitidis serogroup B in mice, and to provide reliable experimental basis for further exploration of the effective immunization methods and pathways of NMB0315 vaccine. Methods:The NMB0315 nucleic acid vaccine [ pcDNA3. 1 (+)/NMB0315 ] and recombinant protein vaccine(pET-30a/NMB0315)were prepared. Female BALB/c mice were inoculated with a NMB0315 DNA vaccine followed by boosting with recombinant protein NMB0315 through intramuscular and intraperitoneal immunization respectively. Next, humoral immunologic response and cellullar immunologic response were detected in female BALB/c mice by ELISA. The survival rate of BALB/c mice was used to evaluate immunoprotection of the vaccines in mice. Results:Specific IgG,IgG1,IgG2a,and sIgA,induced by the NMB0315 DNA vaccine(pNMB0315-CpG),protein NMB0315 vaccine(rNMB0315-FA),NMB0315 DNA vaccine prime-protein boost at week 8, were detected by indirect ELISA,the A450 values were up to(0. 505±0. 042,0. 513±0. 022,0. 342±0. 017,0. 250±0. 015),(0. 823± 0. 061,0. 807±0. 045,0. 596±0. 027,0. 450±0. 028)and(0. 694±0. 053,0. 711±0. 032,0. 455±0. 021,0. 386±0. 024)respectively, which was significantly higher than the PBS control(P<0. 05). The antibody level of protein vaccine was significantly higher than the nucleic acid vaccine group and combined immunization group ( P<0. 05 ) . The stimulation index and IFN-γ level of combined immunization group were significantly higher than the protein vaccine group and nucleic acid vaccine group(P<0. 05). The bactericidal titer of nucleic acid vaccine group, protein vaccine group and combined immunization group reached 1 :64, 1 :128 and 1 :128 respectively,and the protection rates were 70%,95% and 80% respectively. The IgG2a/IgG1 ratios of the nucleic acid vaccine group, the recombinant protein vaccine group and the combined immunization vaccine group were all less than 1 at week 2, 4, 6, 8. Conclusion:The humoral immunity effects( including mucosal immune) induced by the NMB0315 vaccines form high to low were as follows:the recombinant protein vaccine group, the combined immunization vaccine group, the nucleic acid vaccine;and the cellular immune effects from high to low were as follows:the combined immunization vaccine group, the nucleic acid vaccine group, the recombinant protein vaccine group;The protection effects induced by the NMB0315 vaccines in BALB/c mice within 72 hours from high to low were as follows:the recombinant protein vaccine group, the combined immunization vaccine group, the nucleic acid vaccine group.

Immune effects of different forms of vaccines of meningococcus serogroup B outer membrane protein 0315 / 中国免疫学杂志

Objective:To evaluate preliminarily immunocompetence and immunoprotection of a NMB0315 nucleic acid vaccine,a recombinant protein vaccine and a nucleic acid vaccine plus a recombinant protein vaccine against Neisseria meningitidis serogroup B in mice, and to provide reliable experimental basis for further exploration of the effective immunization methods and pathways of NMB0315 vaccine. Methods:The NMB0315 nucleic acid vaccine [ pcDNA3. 1 (+)/NMB0315 ] and recombinant protein vaccine(pET-30a/NMB0315)were prepared. Female BALB/c mice were inoculated with a NMB0315 DNA vaccine followed by boosting with recombinant protein NMB0315 through intramuscular and intraperitoneal immunization respectively. Next, humoral immunologic response and cellullar immunologic response were detected in female BALB/c mice by ELISA. The survival rate of BALB/c mice was used to evaluate immunoprotection of the vaccines in mice. Results:Specific IgG,IgG1,IgG2a,and sIgA,induced by the NMB0315 DNA vaccine(pNMB0315-CpG),protein NMB0315 vaccine(rNMB0315-FA),NMB0315 DNA vaccine prime-protein boost at week 8, were detected by indirect ELISA,the A450 values were up to(0. 505±0. 042,0. 513±0. 022,0. 342±0. 017,0. 250±0. 015),(0. 823± 0. 061,0. 807±0. 045,0. 596±0. 027,0. 450±0. 028)and(0. 694±0. 053,0. 711±0. 032,0. 455±0. 021,0. 386±0. 024)respectively, which was significantly higher than the PBS control(P<0. 05). The antibody level of protein vaccine was significantly higher than the nucleic acid vaccine group and combined immunization group ( P<0. 05 ) . The stimulation index and IFN-γ level of combined immunization group were significantly higher than the protein vaccine group and nucleic acid vaccine group(P<0. 05). The bactericidal titer of nucleic acid vaccine group, protein vaccine group and combined immunization group reached 1 :64, 1 :128 and 1 :128 respectively,and the protection rates were 70%,95% and 80% respectively. The IgG2a/IgG1 ratios of the nucleic acid vaccine group, the recombinant protein vaccine group and the combined immunization vaccine group were all less than 1 at week 2, 4, 6, 8. Conclusion:The humoral immunity effects( including mucosal immune) induced by the NMB0315 vaccines form high to low were as follows:the recombinant protein vaccine group, the combined immunization vaccine group, the nucleic acid vaccine;and the cellular immune effects from high to low were as follows:the combined immunization vaccine group, the nucleic acid vaccine group, the recombinant protein vaccine group;The protection effects induced by the NMB0315 vaccines in BALB/c mice within 72 hours from high to low were as follows:the recombinant protein vaccine group, the combined immunization vaccine group, the nucleic acid vaccine group.

Enfermedad meningocóccica invasora por serogrupo B en dos niños chilenos vacunados contra serogrupos ACWY / Meningococcal invasive disease caused by serogroup B in two Chilean children vaccinated against ACWY serogroups

Invasive meningococcal disease (IMD) by serogroup W has become predominant in Chile since 2012, prompting vaccination with conjugate ACWY. We reported two pediatric cases in patients already vaccinated, which evolved with IMD by serogroup B. This should remind us to keep the alertness with this pathology, despite the current vaccination system in Chile, emphasizing in improve our epidemiological case definition and its diagnosis.

La Enfermedad Meningocóccica Invasora (EMI) por serogrupo W ha llegado a ser predominante en Chile desde el 2012, motivando estrategias de inmunización con vacunas conjugadas contra los serogrupos ACWY. Presentamos dos casos pediátricos de pacientes vacunados contra meningococo ACWY que evolucionaron con EMI por serogrupo B, lo que debe recordarnos la alerta y sospecha de esta patología, inclusive con el esquema de vacunación actual chileno, poniendo énfasis en mejorar nuestra definición epidemiológica de caso sospechoso para optimizar su diagnóstico.

Enfermedad Meningocóccica Invasora: 15 años de Experiencia en un Centro de Referencia

Introducción: La enfermedad meningocóccica ha sido y sigue siendo una causa importante de morbilidad y mortalidad a nivel mundial. Objetivo General: Analizar las características clínicas y epidemiológicas de pacientes con infección meningocóccica invasora hospitalizados en un centro hospitalario de referencia. Materiales y método: Estudio descriptivo, observacional y retrospectivo de revisión de historias clínicas de los pacientes de edad ≤ 15 años ingresados en el Servicio de Pediatría del Instituto de Medicina Tropical con aislamiento o detección de N. meningitidis en sangre, LCR u otro fluido estéril, durante el periodo de enero de 1998 a diciembre de 2013. Resultados: Fueron captados 22 pacientes con enfermedad meningocóccica invasora durante el periodo estudiado (1-2 casos/año), con distribución similar para ambos sexos, predominio de <5 años (73%). 12 pacientes (54%) presentaron meningitis y 10 (45%) meningococcemia. Los síntomas predominantes fueron fiebre (100%) y vómitos (90%). Los signos predominantes fueron signos meníngeos (+) (45%), choque (36%) y púrpura (36%). (32%) requirieron ingreso a Unidad de Cuidados Intensivos. Se halló una letalidad del 13% (3 pacientes), todos con meningococcemia. El B fue el serogrupo predominante, (63%), seguido de los serogrupos C y Y/W135. Durante los últimos 5 años el serogrupo B totalizó las muestras remitidas. La meningococcemia (p=0.09), edad < 5 años (p=0.04), presencia de choque (p ≤ 0.01), síndrome purpúrico (p≤0.01) y Glasgow ≤12 (p=0.02) se asociaron con mayor ingreso a UCI. La plaquetopenia < 100.000 se asoció significativamente a ingreso a UCI (p=0.02). El serogrupo B, el más frecuente en toda la población estudiada, tuvo cierta preponderancia en el grupo de ingreso a UCI (p=0.2). Conclusión: La enfermedad meningocóccica presenta un patrón estable de endemicidad en nuestro país. En nuestro estudio el serogrupo B fue el predominante, y hegemónico en los últimos 5 años. La meningococcemia, edad < 5 años, presencia de choque, síndrome purpúrico y Glasgow ≤12 (p=0.02) se asociaron con mayor gravedad. La vigilancia continua es crucial para guiar las estrategias de prevención y control de la enfermedad meningocóccica

Abstrac Introduction: Meningococcal disease has been and remains an important cause of morbidity and mortality worldwide. Objective: To analyze the clinical and epidemiological characteristics of patients with invasive meningococcal infection hospitalized in a hospital of reference. Materials and Methods: A descriptive, observational and retrospective study of review of medical records of patients of age ≤15 years admitted to the Pediatrics Institute of Tropical Medicine in isolation or detection of N. meningitidis in blood, CSF or other sterile fluid, during the period January 1998 to December 2013. Results: 22 patients were captured with invasive meningococcal disease during the period studied (1-2 cases / year), with similar distribution for both sexes, prevalence of <5 years (73%) of 12 patients (54%) had meningitis and 10. (45%) meningococcemia. The predominant symptoms were fever (100%) and vomiting (90%). The predominant signs were meningeal signs (+) (45%), shock (36%) and purple (36%). (32%) required admission to intensive care unit. A fatality rate of 13% (3 patients), all with meningococcemia was found. The serogroup B was the predominant (63%), followed by serogroups C and Y / W135.Durante the last 5 years serogroup B samples totaled forwarded. Meningococcemia (p = 0.09), age < 5 years (p = 0.04), presence of shock (p ≤ 0.01), purpuric syndrome (p ≤ 0.01) and Glasgow ≤ 12 (p = 0.02) were associated with increased ICU admission. Thrombocytopenia < 100,000 was significantly associated with ICU admission (p = 0.02). Serogroup B, the most common in the entire study population, had some preponderance in the ICU income group (p = 0.2). Conclusion: Meningococcal disease presents a stable pattern of endemic in our country. In our study serogroup B was the predominant and hegemonic in the last 5 years. Meningococcemia, age < 5 years, presence of shock, and Glasgow ≤1 2 purpuric syndrome (p = 0.02) were associated with greater severity. Continued vigilance is crucial to guide prevention strategies and control of meningococcal disease

New versus old meningococcal Group B vaccines: How the new ones may benefit infants & toddlers.

Invasive disease caused by Neisseria meningitidis is associated with high mortality and high disability rates and mainly affects children under one year of age. Vaccination is the best way to prevent meningococcal disease, especially in infants and toddlers. The introduction of massive meningococcal serogroup C vaccination has drastically reduced the incidence of disease caused by this serogroup, and serogroup B has now become the main causative agent in several industrialized countries. The first serogroup B vaccines, which were used for more than two decades, were based on outer membrane vesicles and proved to be protective only against specific epidemic strains in Cuba, Norway, Brazil and New Zealand. Moreover, these often elicited a scant immune response in young children. Innovative genomics-based reverse vaccinology subsequently enabled researchers to identify genes encoding for surface proteins that are able to elicit a strong immune response against several B strains. This important discovery led to the development and recent approval in Europe of the four-component meningococcal serogroup B (4CMenB) vaccine. Large clinical trials have shown high immunogenicity and tolerability and acceptable safety levels of 4CMenB in infants and toddlers. This vaccine is expected to cover a large number of circulating invasive strains and may also be efficacious against other serogroups. Young children are particularly vulnerable to the devastating consequences of meningococcal disease. Given the high performance of 4CMenB and its non-interference with routine vaccinations, this age-group will be the first to benefit from the introduction of this vaccine.

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.

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.

Study Progress on Serogroup B Meningococcal Vaccine / 中国疫苗和免疫

Meningococcal disease,caused by Neisseria meningitidis (Nm),is still one serious threatening infectious disease with high mortality.Vaccination is available for prevention and control of such disease.Based on the chemical structure of capsule polysaccharide,Nm strains were classified into 13 serogroups.Meningococcal polysaccharide vaccines and polysaccharide conjugated protein vaccine against serogroup A,C,W 135 and Y were efficacious and have been widely used.Because of poor immunogenicity and the structurally homologous with neural cell,capsule polysaccharide of serogroup B Nm can not be used as vaccine candidate.In last several decades,B group vaccines develoment focused on the proteins research.Based on the out membrane protein and reverse vaccinology technology,progress of B group vaccine were accelerated.Several meningococcal B vaccine showed favorable immunogenicity and efficacity.Some B vaccines have been licensed and widely used.

Meningococcal Disease in the Republic of Korea Army: Incidence and Serogroups Determined by PCR

This study was performed to determine the incidence and serogroups of meningococcal disease in the Korean Army. From August 2000 to July 2001, we identified prospective cases in the Korean Army. Meningococcal disease was confirmed by isolation of Neisseria meningitidis or detection of its antigen by latex agglutination from cerebrospinal fluid (CSF) or blood. Polymerase chain reactions (PCRs) were performed in the crgA gene to identify N. meningitidis regardless of its serogroup, and then in orf-2 (serogroup A) and siaD (serogroups B, C, Y, and W135) respectively for serogroup prediction. During the study period, twelve patients (four meningitis and eight septicaemia) were identified. The annual incidence was 2.2 per 100,000 (95% confidence interval, 1.3-3.8) among 550,000 private soldiers. Latex agglutinations were positive to A/C/Y/W135 polyvalent latex, but not to B latex in all patients. PCRs of crgA gene were positive in ten patients, whose samples (2 isolates from CSF, 2 CSFs, and 6 sera) were stored. In PCRs for serogroup prediction, one isolate was serogroup A, and one isolate and two sera were serogroup C. The need for meningococcal vaccination would be considered in the Korean Army through the cost-benefit analysis based on the result of this study.