| 1. |
- Laabei, M., et al.
(författare)
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Predicting the virulence of MRSA from its genome sequence
- 2014
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051. ; 24:5, s. 839-849
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Tidskriftsartikel (refereegranskat)abstract
- Microbial virulence is a complex and often multifactorial phenotype, intricately linked to a pathogen's evolutionary trajectory. Toxicity, the ability to destroy host cell membranes, and adhesion, the ability to adhere to human tissues, are the major virulence factors of many bacterial pathogens, including Staphylococcus aureus. Here, we assayed the toxicity and adhesiveness of 90 MRSA (methicillin resistant S. aureus) isolates and found that while there was remarkably little variation in adhesion, toxicity varied by over an order of magnitude between isolates, suggesting different evolutionary selection pressures acting on these two traits. We performed a genome-wide association study (GWAS) and identified a large number of loci, as well as a putative network of epistatically interacting loci, that significantly associated with toxicity. Despite this apparent complexity in toxicity regulation, a predictive model based on a set of significant single nucleotide polymorphisms (SNPs) and insertion and deletions events (indels) showed a high degree of accuracy in predicting an isolate's toxicity solely from the genetic signature at these sites. Our results thus highlight the potential of using sequence data to determine clinically relevant parameters and have further implications for understanding the microbial virulence of this opportunistic pathogen.
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| 2. |
- Bertilsson, Stefan, et al.
(författare)
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The under-ice microbiome of seasonally frozen lakes
- 2013
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Ingår i: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 58:6, s. 1998-2012
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Forskningsöversikt (refereegranskat)abstract
- Compared to the well-studied open water of the ‘‘growing’’ season, under-ice conditions in lakes are characterized by low and rather constant temperature, slow water movements, limited light availability, and reduced exchange with the surrounding landscape. These conditions interact with ice-cover duration to shape microbial processes in temperate lakes and ultimately influence the phenology of community and ecosystem processes. We review the current knowledge on microorganisms in seasonally frozen lakes. Specifically, we highlight how under-ice conditions alter lake physics and the ways that this can affect the distribution and metabolism of auto- and heterotrophic microorganisms. We identify functional traits that we hypothesize are important for understanding under-ice dynamics and discuss how these traits influence species interactions. As ice coverage duration has already been seen to reduce as air temperatures have warmed, the dynamics of the under- ice microbiome are important for understanding and predicting the dynamics and functioning of seasonally frozen lakes in the near future.
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