Serotype 4 pneumococcus
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ABSTRACT:
PROVIDER: PRJEB42817 | ENA |
REPOSITORIES: ENA
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Project description:We were interested in determining if the LuxS signaling system contributed to the regulation of pneumococcal genes. To accomplish this, we compared the in vitro transcriptional profiles over time of S. pneumoniae D39, a serotype 2 strain of pneumococcus, with that of an isogenic deletion mutant, (delta)luxS, using a spotted S. pneumoniae- specific DNA microarray. For in vitro time course experiments, broth cultures of D39 and (delta)luxS were grown to low density (optical densities between ~0.01- 0.02), the cells were collected by centrifugation, washed 1x with sterile PBS, back diluted to ~3x105CFU/ ml into fresh broth, and immediately incubated at 37oC in a 5% CO2 chamber for 45 minutes. At this point, the first sample was collected. Subsequently, growth was monitored for approximately 8 generations by measuring both the optical density (OD600) and determining viable counts every 30 to 45 minutes. At these points samples were also harvested by centrifugation for RNA isolation and stored at -80oC until processing. For microarray probe synthesis, experimental samples were generated using 0.5ug total bacterial RNA isolated from either D39 or (delta)luxS strains at the various time points throughout the growth curve. These RNAs were used as templates for reverse transcription, and the resulting cDNAs were labelled with Cy5. The reference sample for each time course was generated from the D39 time zero RNA. Subsequent to reverse transcription, the resulting cDNAs were labelled with Cy3. The probes were mixed in hybridization buffer, heated to 99oC for at least 2 minutes, centrifuged briefly, and applied to the microarray. Hybridizations were carried out at 60oC for at least 24 hours.
2005-07-21 | E-SMDB-2173 | biostudies-arrayexpress
Project description:Non-vaccine type penicillin nonsusceptible pneumococcus
| PRJEB13827 | ENA
Project description:To investigate the mechanistic role of NanA and Siglec-5 in this excessive inflammation, we systemically analyzed genes and signaling pathways differentially regulated in macrophages infected with wild type and NanA-deficient pneumococcus.
2020-11-12 | GSE161269 | GEO
Project description:Streptococcus pneumoniae is a frequent coloniser of the human nasopharynx and a major cause of life-threating invasive infections such as pneumonia, meningitis and sepsis. Over 1 million people die every year due to invasive pneumococcal disease (IPD), mainly in developing countries. Serotype 1 is a common cause of IPD; however, unlike other serotypes, it is rarely found in the carrier state in the nasopharynx, which is often considered a prerequisite for disease. The aim of this study was to understand this dichotomy. We used murine models of carriage and IPD to characterise the pathogenesis of African serotype 1 (Sequence Type 217) pneumococcal strains obtained from the Queen Elizabeth Central Hospital in Blantyre, Malawi. We found that ST217 pneumococcal strains were highly virulent in a mouse model of invasive pneumonia, but in contrast to the generally accepted assumption, can also successfully establish nasopharyngeal carriage. Interestingly, we found that co-colonising serotypes may proliferate in the presence of serotype 1, suggesting that acquisition of serotype 1 carriage could increase the risk of developing IPD by other serotypes. RNAseq analysis confirmed that key virulence genes associated with inflammation and tissue invasiveness were upregulated in serotype 1. These data reveal important new insights into serotype 1 pathogenesis, with implications for carriage potential and risk of invasive disease through interactions with other co-colonising serotypes; an often overlooked factor in transmission and disease progression.
2020-11-12 | GSE159305 | GEO
Project description:BackgroundPneumococcus is a diverse pathogen, with >90 serotypes, each of which has a distinct polysaccharide capsule. Pneumococci can switch capsules, evading vaccine pressure. Certain serotype pairs are more likely to occur on the same genetic background as a results of serotype switching, but the drivers of these patterns are not well understood.MethodsWe used the PubMLST and Global Pneumococcal Sequencing Project databases to quantify the number of genetic lineages on which different serotype pairs occur together. We also quantified the genetic diversity of each serotype. Regression model were used to evaluate the relationship between shared polysaccharide components and the frequency of serotype co-occurrence and diversity.ResultsA number of serotype pairs occurred together on the same genetic lineage more commonly than expected. Co-occurrence of between-serogroup pairs was more common when both serotypes had glucose as a component of the capsule (and, potentially, glucuronic acid, any-N-acetylated sugar, or ribitol). Diversity also varied markedly by serotype and was associated with the presence of specific sugars in the capsule.ConclusionsCertain pairs of serotypes are more likely to co-occur on the same genetic background. These patterns were correlated with shared polysaccharide components. This might reflect adaptation of strains to produce capsules with specific characteristics.
| S-EPMC7184915 | biostudies-literature
Project description:We used RNA-Seq to compare gene expression between representative serotype M1 and M3 GAS isolates
2017-11-24 | GSE97935 | GEO
Project description:Streptococcus pneumoniae (the pneumococcus) account for significant morbidity and mortality worldwide, causing life-threatening diseases such as pneumonia, bacteremia and meningitis. In this study, we used microarray analysis to compare gene expression patterns of either serotype 4 or serotype 6A pneumococci in the nasopharynx and blood of mice, as a model to identify genes involved in invasion of blood in the context of occult bacteremia in humans.
2015-09-19 | GSE73217 | GEO
Project description:RNA-seq experiments of a wild-type and isogenic rocA deletion mutant serotype M28 group A streptococcus strain at two time points
2018-08-27 | GSE118609 | GEO