Evolution of Pseudomonas aeruginosa toward higher fitness under standard laboratory conditions.
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ABSTRACT:
SUBMITTER: Grekov I
PROVIDER: S-EPMC8115180 | biostudies-literature | 2021 Apr
REPOSITORIES: biostudies-literature
Publications
Evolution of Pseudomonas aeruginosa toward higher fitness under standard laboratory conditions.
Grekov Igor I Thöming Janne Gesine JG Kordes Adrian A Häussler Susanne S
The ISME journal 20201203 4
Identifying genetic factors that contribute to the evolution of adaptive phenotypes in pathogenic bacteria is key to understanding the establishment of infectious diseases. In this study, we performed mutation accumulation experiments to record the frequency of mutations and their effect on fitness in hypermutator strains of the environmental bacterium Pseudomonas aeruginosa in comparison to the host-niche-adapted Salmonella enterica. We demonstrate that P. aeruginosa, but not S. enterica, hyper ...[more]
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Project description:We studied adaptation of the metabolically versatile bacterium Pseudomonas aeruginosa to standard laboratory conditions by propagating mismatch repair-deficient P. aeruginosa in exponential phase for 24 days in rich medium. In the selective environment of this large-bottleneck mutation accumulation experiment, the bacteria developed shorter lag phases, higher growth rates and higher maximum cell densities. Transcriptional profiling and phenotyping for growth in different media revealed that higher fitness under laboratory conditions evolved via different pathways. Although common adaptive mutations or mutations that define trade-offs were not identified, there was a convergent evolution of transcriptional profiles associated with a shift from biofilm-associated to planktonic lifestyles. Our results indicate that under constant planktonic conditions P. aeruginosa uses several genetic pathways in order to fine-tune adaptation towards faster growth. The selected mutations in the different genetic pathways show a great variety of biofilm, virulence and motility phenotypic trade-offs, thus implying that on the population level, the adaptation of P. aeruginosa to constant conditions does not compromise its versatility. Methods: mRNA profiles were generated for Pseudomonas aeruginosa samples derived from LB-cultures grown to an OD600 =0.4-0.6. The removal of ribosomal RNA was performed using the Ribo-Zero Bacteria Kit (Illumina) and cDNA libraries were generated with the ScriptSeq v2 Kit (Illumina). The samples were sequenced in single end mode on an Illumina HiSeq 2500 device and mRNA reads were trimmed and mapped to the NC_008463.1 (PA14) reference genome from NCBI using Stampy pipeline with default settings.
2020-11-26 | GSE146906 | GEO
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