Transcriptome Adaptation of Group B Streptococcus to Growth in Human Amniotic Fluid

Sitkiewicz, Izabela; Green, Nicole M.; Guo, Nina; Bongiovanni, Ann Marie; Witkin, Steven S.; Musser, James M.

doi:10.1371/journal.pone.0006114

Cited by 36 publications

(37 citation statements)

References 44 publications

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“…Similar observations were made for S. agalactiae grown in human amniotic fluid containing low concentrations of free amino acids. Here, genes encoding for amino acid transporter systems were found to be strongly expressed [23,24]. Accordingly, a Streptococcus pneumoniae mutant library used in a rabbit meningitis model revealed an important role of genes required for the uptake of amino acids, especially branched-chain and polar amino acids, during experimental meningitis [25].…”

Section: Resultsmentioning

confidence: 99%

Transcriptomic Analysis Reveals Selective Metabolic Adaptation of Streptococcus suis to Porcine Blood and Cerebrospinal Fluid

et al. 2017

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Streptococcus suis is a zoonotic pathogen that can cause severe pathologies such as septicemia and meningitis in its natural porcine host as well as in humans. Establishment of disease requires not only virulence of the infecting strain but also an appropriate metabolic activity of the pathogen in its host environment. However, it is yet largely unknown how the streptococcal metabolism adapts to the different host niches encountered during infection. Our previous isotopologue profiling studies on S. suis grown in porcine blood and cerebrospinal fluid (CSF) revealed conserved activities of central carbon metabolism in both body fluids. On the other hand, they suggested differences in the de novo amino acid biosynthesis. This prompted us to further dissect S. suis adaptation to porcine blood and CSF by RNA deep sequencing (RNA-seq). In blood, the majority of differentially expressed genes were associated with transport of alternative carbohydrate sources and the carbohydrate metabolism (pentose phosphate pathway, glycogen metabolism). In CSF, predominantly genes involved in the biosynthesis of branched-chain and aromatic amino acids were differentially expressed. Especially, isoleucine biosynthesis seems to be of major importance for S. suis in CSF because several related biosynthetic genes were more highly expressed. In conclusion, our data revealed niche-specific metabolic gene activity which emphasizes a selective adaptation of S. suis to host environments.

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Section: Resultsmentioning

confidence: 99%

Transcriptomic Analysis Reveals Selective Metabolic Adaptation of Streptococcus suis to Porcine Blood and Cerebrospinal Fluid

et al. 2017

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“…This is achieved by controlling at a transcriptional level the production of proteins involved in adhesion, nutrient acquisition, and survival against host immune system [12], [13]. In particular, global gene expression analysis of GBS grown in amniotic fluid, blood and pH stress conditions [14], [15], [16] has recently revealed a number of mechanisms used by GBS to adapt to the host [13], [14], [15]. However the transcriptional network underlying the GBS response to glucose availability has been so far only marginally investigated.…”

Section: Introductionmentioning

confidence: 99%

Adaptive Response of Group B Streptococcus to High Glucose Conditions: New Insights on the CovRS Regulation Network

et al. 2013

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Although the contribution of carbohydrate catabolism to bacterial colonization and infection is well recognized, the transcriptional changes during these processes are still unknown. In this study, we have performed comparative global gene expression analysis of GBS in sugar-free versus high glucose milieu. The analysis revealed a differential expression of genes involved in metabolism, transport and host-pathogen interaction. Many of them appeared to be among the genes previously reported to be controlled by the CovRS two-component system. Indeed, the transcription profile of a ΔcovRS strain grown in high-glucose conditions was profoundly affected. In particular, of the total genes described to be regulated by glucose, ∼27% were under CovRS control with a functional role in protein synthesis, transport, energy metabolism and regulation. Among the CovRS dependent genes, we found bibA, a recently characterized adhesin involved in bacterial serum resistance and here reported to be down-regulated by glucose. ChIP analysis revealed that in the presence of glucose, CovR binds bibA promoter in vivo, suggesting that CovR may act as a negative regulator or a repressor. We also demonstrated that, as for other target promoters, chemical phosphorylation of CovR in aspartic acid increases its affinity for the bibA promoter region. The data reported in this study contribute to the understanding of the molecular mechanisms modulating the adaptation of GBS to glucose.

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“…C5A peptidase has been also shown to facilitate fibronectin-independent invasion of epithelial cells [30]. Similar down regulation of adhesins and capsule was observed in GBS when grown in AF [19].…”

Section: Resultsmentioning

confidence: 65%

“…The majority of these genes in ML and LL phases were up regulated rather than down regulated. This differs from the response of GBS grown in AF [19], in which the majority of genes are down regulated when compared to laboratory conditions and the bulk of changes are observed during the transition from logarithmic to stationary phase [19]. The complete list of transcriptional changes in GAS is shown in Table S1 and comparison of gene expression between GAS and GBS in Table S2.…”

Section: Resultsmentioning

confidence: 86%

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Adaptation of Group A Streptococcus to Human Amniotic Fluid

et al. 2010

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BackgroundFor more than 100 years, group A Streptococcus has been identified as a cause of severe and, in many cases, fatal infections of the female urogenital tract. Due to advances in hospital hygiene and the advent of antibiotics, this type of infection has been virtually eradicated. However, within the last three decades there has been an increase in severe intra- and post-partum infections attributed to GAS.MethodologyWe hypothesized that GAS alters its transcriptome to survive in human amniotic fluid (AF) and cause disease. To identify genes that were up or down regulated in response to growth in AF, GAS was grown in human AF or standard laboratory media (THY) and samples for expression microarray analysis were collected during mid-logarithmic, late-logarithmic, and stationary growth phases. Microarray analysis was performed using a custom Affymetrix chip and normalized hybridization values derived from three biological replicates were collected at each growth point. Ratios of AF/THY above a 2-fold change and P-value <0.05 were considered significant.Principal FindingsThe majority of changes in the GAS transcriptome involved down regulation of multiple adhesins and virulence factors and activation of the stress response. We observed significant changes in genes involved in the arginine deiminase pathway and in the nucleotide de novo synthesis pathway.Conclusions/SignificanceOur work provides new insight into how pathogenic bacteria respond to their environment to establish infection and cause disease.

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Transcriptome Adaptation of Group B Streptococcus to Growth in Human Amniotic Fluid

Cited by 36 publications

References 44 publications

Transcriptomic Analysis Reveals Selective Metabolic Adaptation of Streptococcus suis to Porcine Blood and Cerebrospinal Fluid

Transcriptomic Analysis Reveals Selective Metabolic Adaptation of Streptococcus suis to Porcine Blood and Cerebrospinal Fluid

Adaptive Response of Group B Streptococcus to High Glucose Conditions: New Insights on the CovRS Regulation Network

Adaptation of Group A Streptococcus to Human Amniotic Fluid

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