0000000000803814

AUTHOR

Johannes Cairns

0000-0003-1329-2025

showing 9 related works from this author

Genomic evolution of bacterial populations under co-selection by antibiotics and phage

2017

Bacteria live in dynamic systems where selection pressures can alter rapidly, forcing adaptation to the prevailing conditions. In particular, bacteriophages and antibiotics of anthropogenic origin are major bacterial stressors in many environments. We previously observed that populations of the bacterium Pseudomonas fluorescens SBW25 exposed to the lytic bacteriophage SBW25Φ2 and a noninhibitive concentration of the antibiotic streptomycin (coselection) achieved higher levels of phage resistance compared to populations exposed to the phage alone. In addition, the phage became extinct under coselection while remaining present in the phage alone environment. Further, phenotypic tests indicate…

phage resistancephage phi-2experimental evolutionPseudomonas fluorescenssublethal antibiotic concentrationsantibioottiresistenssi
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Sublethal streptomycin concentrations and lytic bacteriophage together promote resistance evolution.

2017

Sub-minimum inhibiting concentrations (sub-MICs) of antibiotics frequently occur in natural environments owing to wide-spread antibiotic leakage by human action. Even though the concentrations are very low, these sub-MICs have recently been shown to alter bacterial populations by selecting for antibiotic resistance and increasing the rate of adaptive evolution. However, studies are lacking on how these effects reverberate into key ecological interactions, such as bacteria-phage interactions. Previously, co-selection of bacteria by phages and antibiotic concentrations exceeding MICs has been hypothesized to decrease the rate of resistance evolution because of fitness costs associated with re…

0301 basic medicineantibiotic resistancemedicine.drug_classAntibioticsPseudomonas fluorescensGeneral Biochemistry Genetics and Molecular BiologyMicrobiologyBacteriophageEvolution Molecular03 medical and health sciencesAntibiotic resistancephage Φ2medicineexperimental evolution2. Zero hungerExperimental evolutionbiologyResistance (ecology)ta1182Articlesbiology.organism_classificationBiological Evolutionsublethal antibiotic concentrationsAnti-Bacterial Agents030104 developmental biologyLytic cyclephage resistanceStreptomycinStreptomycinGeneral Agricultural and Biological SciencesPseudomonas PhagesBacteriamedicine.drugPhilosophical transactions of the Royal Society of London. Series B, Biological sciences
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Genomic evolution of bacterial populations under coselection by antibiotics and phage

2017

Bacteria live in dynamic systems where selection pressures can alter rapidly, forcing adaptation to the prevailing conditions. In particular, bacteriophages and antibiotics of anthropogenic origin are major bacterial stressors in many environments. We previously observed that populations of the bacterium Pseudomonas fluorescens SBW25 exposed to the lytic bacteriophage SBW25Φ2 and a noninhibitive concentration of the antibiotic streptomycin (coselection) achieved higher levels of phage resistance compared to populations exposed to the phage alone. In addition, the phage became extinct under coselection while remaining present in the phage alone environment. Further, phenotypic tests indicate…

0301 basic medicineMutation rateantibiotic resistancemedicine.drug_class030106 microbiologyAntibioticsBiologyPseudomonas fluorescensmedicine.disease_causeMicrobiologyEvolution MolecularBacteriophage03 medical and health sciencesAntibiotic resistanceMutation RateDrug Resistance BacterialGeneticsmedicineBacteriophagesexperimental evolutionSelection GeneticEscherichia coliEcology Evolution Behavior and Systematics2. Zero hungerExperimental evolutionta1182biology.organism_classificationsublethal antibiotic concentrationsAnti-Bacterial AgentsPhenotypeLytic cyclephage resistanceStreptomycinta1181phage phi-2Genome BacterialBacteria
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Conjugation is necessary for a bacterial plasmid to survive under protozoan predation

2016

Horizontal gene transfer by conjugative plasmids plays a critical role in the evolution of antibiotic resistance. Interactions between bacteria and other organisms can affect the persistence and spread of conjugative plasmids. Here we show that protozoan predation increased the persistence and spread of the antibiotic resistance plasmid RP4 in populations of the opportunist bacterial pathogenSerratia marcescens. A conjugation-defective mutant plasmid was unable to survive under predation, suggesting that conjugative transfer is required for plasmid persistence under the realistic condition of predation. These results indicate that multi-trophic interactions can affect the maintenance of con…

0106 biological sciences0301 basic medicineFood ChainMutant010603 evolutionary biology01 natural sciencesRP4 plasmidPredationMicrobiologyTetrahymena thermophila03 medical and health sciencesPlasmidAntibiotic resistanceevolution of antibiotic resistance/dk/atira/pure/subjectarea/asjc/1100PathogenSerratia marcescens/dk/atira/pure/subjectarea/asjc/1100/1101Evolutionary BiologybiologyAgricultural and Biological Sciences(all)Conjugationta1183ta1182biology.organism_classificationAgricultural and Biological Sciences (miscellaneous)Protozoan predation030104 developmental biologyprotozoan predationConjugation GeneticSerratia marcescensHorizontal gene transferta1181Evolution of antibiotic resistanceGeneral Agricultural and Biological SciencesBacteriaconjugationPlasmids
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Supplementary methods and results from Sublethal streptomycin concentrations and lytic bacteriophage together promote resistance evolution

2016

i) Estimating minimal inhibiting streptomycin concentration at the end of the 66-day experiment; ii) Testing for potential pleiotropy between streptomycin and phage resistance

biochemical phenomena metabolism and nutrition
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Data from: Genomic evolution of bacterial populations under co-selection by antibiotics and phage

2016

Bacteria live in dynamic systems where selection pressures can alter rapidly, forcing adaptation to the prevailing conditions. In particular, bacteriophages and antibiotics of anthropogenic origin are major bacterial stressors in many environments. We previously observed that populations of the bacterium Pseudomonas fluorescens SBW25 exposed to the lytic bacteriophage SBW25Φ2 and a non-inhibitive concentration of the antibiotic streptomycin (co-selection) achieved higher levels of phage resistance compared to populations exposed to the phage alone. In addition, the phage became extinct under co-selection while remaining present in the phage alone environment. Further, phenotypic tests indic…

medicine and health carephage Φ2Life SciencesMedicinePseudomonas fluorescenssublethal antibiotic concentrations
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Data from: Black Queen evolution and trophic interactions determine plasmid survival after the disruption of conjugation network

2019

Mobile genetic elements such as conjugative plasmids are responsible for antibiotic resistant phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. race to the bottom) was a more significant factor over an…

medicine and health careMedicineblack queen evolutionLife sciencesconjugationTetrahymena thermophila
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Data from: Sublethal streptomycin concentrations and lytic bacteriophage together promote resistance evolution

2017

Sub-minimum inhibiting concentrations (sub-MICs) of antibiotics frequently occur in natural environments owing to wide-spread antibiotic leakage by human action. Even though the concentrations are very low, these sub-MICs have recently been shown to alter bacterial populations by selecting for antibiotic resistance and increasing the rate of adaptive evolution. However, studies are lacking on how these effects reverberate into key ecological interactions, such as bacteria–phage interactions. Previously, co-selection of bacteria by phages and antibiotic concentrations exceeding MICs has been hypothesized to decrease the rate of resistance evolution because of fitness costs associated with re…

medicine and health carephage Φ2MedicinePseudomonas fluorescensLife sciencessublethal antibiotic concentrations
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Data from: Conjugation is necessary for a bacterial plasmid to survive under protozoan predation

2016

Horizontal gene transfer by conjugative plasmids plays a critical role in the evolution of antibiotic resistance. Interactions between bacteria and other organisms can affect the persistence and spread of conjugative plasmids. Here we show that protozoan predation increased the persistence and spread of the antibiotic resistance plasmid RP4 in populations of the opportunist bacterial pathogen Serratia marcescens. A conjugation-defective mutant plasmid was unable to survive under predation, suggesting that conjugative transfer is required for plasmid persistence under the realistic condition of predation. These results indicate that multi-trophic interactions can affect the maintenance of co…

medicine and health careprotozoan predationevolution of antibiotic resistanceLife SciencesMedicineRP4 plasmidSerratia marcescensconjugationTetrahymena thermophila
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