| 1. |
- Eriksson, Lorraine, 1990-, et al.
(författare)
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Difference in virulence between Neisseria meningitidis serogroups W and Y in transgenic mice
- 2020
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Ingår i: BMC Microbiology. - : BioMed Central. - 1471-2180. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neisseria meningitidis serogroups W and Y are the most common serogroups causing invasive meningococcal disease in Sweden. The majority of cases are caused by the serogroup W UK 2013 strain of clonal complex (cc) 11, and subtype 1 of the serogroup Y, YI strain of cc23. In this study, virulence factors of several lineages within cc11 and cc23 were investigated in transgenic BALB/c mice expressing human transferrin. Transgenic mice were infected intraperitoneally with serogroup W and Y isolates. Levels of bacteria and the proinflammatory cytokine CXCL1 were determined in blood collected 3 h and 24 h post-infection. Apoptosis was investigated in immune cells from peritoneal washes of infected mice. Adhesion and induction of apoptosis in human epithelial cells were also scored.RESULTS: The levels of bacteraemia, CXCL1, and apoptosis were higher in serogroup W infected mice than in serogroup Y infected mice. Serogroup W isolates also induced higher levels of apoptosis and adhesion in human epithelial cells. No significant differences were observed between different lineages within cc11 and cc23.CONCLUSIONS: N. meningitidis Serogroup W displayed a higher virulence in vivo in transgenic mice, compared to serogroup Y. This was reflected by higher bacteremia, proinflammatory activity, and ability to induce apoptosis in mouse immune cells and human epithelial cells.
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| 2. |
- 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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