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Sequenciação do genoma completo como ferramenta da epidemiologia molecular: caracterização de estirpes de Neisseria meningitidis do serogrupo W isoladas em Portugal
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Advisor(s)
Abstract(s)
Neisseria meningitidis é um comensal da nasofaringe que ocasionalmente
causa doença invasiva. Os serogrupos são definidos com base nos
antigénios capsulares e a similaridade genética, avaliada por Multilocus
Sequence Typing (MLST), permite agrupar as estirpes em complexos clonais
(cc). Na Europa, os serogrupos B e C têm sido os mais prevalentes.
Desde a epidemia com origem no Hajj em 2000, obser va-se uma incidência
crescente de doença invasiva meningocócica (DIM) por estirpes W
(MenW), maioritariamente as designadas como a linhagem Hajj. Per tencendo
ao cc11, estas estirpes dispersaram-se e evoluíram para várias
sublinhagens, nomeadamente a sul-americana, à qual está associada
DIM com apresentação clinica atípica e letalidade elevada. É objetivo
deste estudo conhecer as características genómicas das estirpes MenW
isoladas em Por tugal e compreender a sua relação evolutiva entre estirpes
cc11 do mesmo serogrupo, com uma distribuição geográfica e temporal
diversa. Caracterizaram-se as estirpes invasivas MenW isoladas
em Por tugal entre 2012 e 2018, por MLST e por sequenciação do genoma
completo (WGS). Para comparação genómica selecionaram-se os genomas
MenWcc11 disponíveis na base de dados Neisseria PubMLST. A
análise bioinformática foi realizada com o sof tware chewBBACA e a possível
relação evolutiva foi analisada aplicando o algoritmo GoeBURST
na plataforma PHYLOViZ Online. No período em análise registaram-se 9
casos de DIM por MenW em Por tugal, agrupadas apenas em dois genótipos
cc22 e cc11. As estirpes MenW cc11 incluídas no estudo (4 invasivas
e 2 de por tadores) distribuíram-se nas sublinhagens Original UK e Novel
UK, emergidas sequencialmente a par tir das estirpes sul-americanas, e
numa linhagem da região distal. Tal poder de diferenciação nunca teria
sido possível utilizando a metodologia tradicional de caracterização do
genótipo (sequenciação de Sanger). O cenário em Por tugal é semelhante
ao obser vado noutros países europeus, o que reforça a impor tância
da vigilância da DIM, potencialmente com um quadro clínico atípico e letalidade
elevada. A metodologia de WGS é uma ferramenta fundamental
nesta vigilância e no estudo de sur tos pelo seu poder de diferenciação.
Neisseria meningitidis is a commensal that colonises the nasophar ynx and occasionally causes invasive disease. Capsular polysaccharides define the meningococci serogroups and Multilocus Sequence Typing (MLST) identifies genetic similarities gathering strains into clonal complexes (cc). Serogroups B and C have been the most prevalent in Europe however, since the Haj j epidemics, in 2000, invasive meningococcal disease (IMD) due to W strains (MenW), mostly the referred as the Haj j lineage, are been increasing. Belonging to cc11, these strains spread and evolved into dif ferent sublineage, namely the South American that is associated to an at ypical clinical presentation and high fatalit y rate. This study aims to characterize genetically Por tuguese MenW strains and understand the evolutionar y relationship with MenWcc11 with diverse geographic and temporal distribution. Invasive MenW strains isolated in Por tugal from 2012 to 2018 were characterized by MLST and whole genome sequencing (WGS). For genomic comparison, MenWcc11 available genomes were selected from Neisseria PubMLST database. The sof tware chewBBACA was used for bioinformatics analysis and the algorithm GoeBURST from the PHYLOViZ Online plat form was used for analysis of evolutionar y relationship between strains. Nine cases of IMD due to MenW were obser ved in Por tugal in this 7 years study. Just two genot ypes were identified belonging to cc22 and cc11. The MenWcc11 isolates included in this study (4 invasive and 2 from carriers) were clustered into the sublineages Original UK and Novel UK, that successively emerged from South American strains, and into a distal region lineage. Such dif ferentiation power would never been possible using the traditional genot ype characterization methodology (Sanger sequencing). The scenario in Por tugal is quite similar to other European countries, which reinforces the impor tance of sur veillance of IMD, potentially with an at ypical clinical presentation and high fatalit y rate. WGS is an impor tant tool in this sur veillance and for outbreaks study due to its power to dif ferentiate strains.
Neisseria meningitidis is a commensal that colonises the nasophar ynx and occasionally causes invasive disease. Capsular polysaccharides define the meningococci serogroups and Multilocus Sequence Typing (MLST) identifies genetic similarities gathering strains into clonal complexes (cc). Serogroups B and C have been the most prevalent in Europe however, since the Haj j epidemics, in 2000, invasive meningococcal disease (IMD) due to W strains (MenW), mostly the referred as the Haj j lineage, are been increasing. Belonging to cc11, these strains spread and evolved into dif ferent sublineage, namely the South American that is associated to an at ypical clinical presentation and high fatalit y rate. This study aims to characterize genetically Por tuguese MenW strains and understand the evolutionar y relationship with MenWcc11 with diverse geographic and temporal distribution. Invasive MenW strains isolated in Por tugal from 2012 to 2018 were characterized by MLST and whole genome sequencing (WGS). For genomic comparison, MenWcc11 available genomes were selected from Neisseria PubMLST database. The sof tware chewBBACA was used for bioinformatics analysis and the algorithm GoeBURST from the PHYLOViZ Online plat form was used for analysis of evolutionar y relationship between strains. Nine cases of IMD due to MenW were obser ved in Por tugal in this 7 years study. Just two genot ypes were identified belonging to cc22 and cc11. The MenWcc11 isolates included in this study (4 invasive and 2 from carriers) were clustered into the sublineages Original UK and Novel UK, that successively emerged from South American strains, and into a distal region lineage. Such dif ferentiation power would never been possible using the traditional genot ype characterization methodology (Sanger sequencing). The scenario in Por tugal is quite similar to other European countries, which reinforces the impor tance of sur veillance of IMD, potentially with an at ypical clinical presentation and high fatalit y rate. WGS is an impor tant tool in this sur veillance and for outbreaks study due to its power to dif ferentiate strains.
Description
Keywords
Neisseria meningitidis Serogrupo W Vigilância Laboratorial Infecções Respiratórias Doenças Infecciosas Sequenciação de Nova Geração Sequenciação do Genoma Completo Saúde Pública Portugal
Pedagogical Context
Citation
Boletim Epidemiológico Observações. 2018;7(Supl 10):29-33
Publisher
Instituto Nacional de Saúde Doutor Ricardo Jorge, IP