| 1. |
- Stenmark, Bianca, 1987-, et al.
(författare)
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Complete genome and methylome analysis of Neisseria meningitidis associated with increased serogroup Y disease
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Invasive meningococcal disease (IMD) due to serogroup Y Neisseria meningitidis emerged in Europe during the 2000s. Draft genomes of serogroup Y isolates in Sweden revealed that although the population structure of these isolates was similar to other serogroup Y isolates internationally, a distinct strain (YI) and more specifically a sublineage (1) of this strain was responsible for the increase of serogroup Y IMD in Sweden. We performed single molecule real-time (SMRT) sequencing on eight serogroup Y isolates from different sublineages to unravel the genetic and epigenetic factors delineating them, in order to understand the serogroup Y emergence. Extensive comparisons between the serogroup Y sublineages of all coding sequences, complex genomic regions, intergenic regions, and methylation motifs revealed small point mutations in genes mainly encoding hypothetical and metabolic proteins, and non-synonymous variants in genes involved in adhesion, iron acquisition, and endotoxin production. The methylation motif CACNNNNNTAC was only found in isolates of sublineage 2. Only seven genes were putatively differentially expressed, and another two genes encoding hypothetical proteins were only present in sublineage 2. These data suggest that the serogroup Y IMD increase in Sweden was most probably due to small changes in genes important for colonization and transmission.
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| 2. |
- Törös, Bianca, 1987-, et al.
(författare)
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Genome-based characterization of emergent invasive Neisseria meningitidis serogroup Y isolates in Sweden from 1995 to 2012
- 2015
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 53:7, s. 2154-2162
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Tidskriftsartikel (refereegranskat)abstract
- Invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup Y has increased in Europe, especially in Scandinavia. In Sweden, serogroup Y is now the dominating serogroup, and in 2012, the serogroup Y disease incidence was 0.46/100,000 population. We previously showed that a strain type belonging to sequence type 23 was responsible for the increased prevalence of this serogroup in Sweden. The objective of this study was to investigate the serogroup Y emergence by whole-genome sequencing and compare the meningococcal population structure of Swedish invasive serogroup Y strains to those of other countries with different IMD incidence. Whole-genome sequencing was performed on invasive serogroup Y isolates from 1995 to 2012 in Sweden (n = 186). These isolates were compared to a collection of serogroup Y isolates from England, Wales, and Northern Ireland from 2010 to 2012 (n = 143), which had relatively low serogroup Y incidence, and two isolates obtained in 1999 in the United States, where serogroup Y remains one of the major causes of IMD. The meningococcal population structures were similar in the investigated regions; however, different strain types were prevalent in each geographic region. A number of genes known or hypothesized to have an impact on meningococcal virulence were shown to be associated with different strain types and subtypes. The reasons for the IMD increase are multifactorial and are influenced by increased virulence, host adaptive immunity, and transmission. Future genome-wide association studies are needed to reveal additional genes associated with serogroup Y meningococcal disease, and this work would benefit from a complete serogroup Y meningococcal reference genome.
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| 3. |
- Törös, Bianca, et al.
(författare)
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Whole-genome characterization of emergent invasive Neisseria meningitidis serogroup Y in Sweden from the two recent decades
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background and Objective: Invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup Y has increased in Europe, especially in Scandinavia. In Sweden, serogroup Y is the dominating serogroup and in 2012 the serogroup Y disease incidence was 0.46/100,000 population. We have previously shown that a strain type belonging to ST-23 is responsible for the emergence of this serogroup in Sweden. The objective of this study was to compare the meningococcal population structure and phylogeography of Swedish invasive serogroup Y strains to other countries with different disease incidence.Materials and Methods: Whole-genome sequencing was performed on invasive serogroup Y isolates from 1995 to 2012 in Sweden (n=186). A comparison of serogroup Y isolates was performed using a collection of isolates from England, Wales and Northern Ireland (n=143), which has relatively low incidence, and two isolates from the USA, where serogroup Y remains one of the major causes of IMD.Results: The meningococcal population structures were similar in the investigated regions; however, different strain types were dominating in each geographic region. A number of genes, known or hypothesized to have an impact on meningococcal virulence, were shown to be associated with different strain types and subtypes.Conclusions: The emergence of serogroup Y is most likely not associated with a previously described strain type that has been introduced into the Swedish meningococcal population. The reasons for the disease increase are most probably multifactorial; both increased virulence and host adaptive immunity influence infection and transmission. Future genomewide association studies could reveal additional genes associated with serogroup Y meningococcal disease.
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