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.

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.

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.