The Effect of Environmental Heterogeniety on the Fitness of Antibiotic Resistant Escherichia Coli

Clarke, Leah

doi:10.22215/etd/2018-13257

Cited by 2 publications

(2 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…LB and M9-Glucose were prepared as described ( Sambrook and Russell 2001 ). Synthetic urine medium is a defined medium containing 416 mM urea and 10 mM creatinine and was modified from published recipes ( Laube et al 2001 ; Clarke 2018 ) by the addition of 0.001% Casamino acids to augment bacterial growth. Synthetic colon medium is a tryptone-based medium supplemented with 0.4% bile salts and was prepared as described ( Polzin et al 2013 ).…”

Section: Methodsmentioning

confidence: 99%

Unpredictability of the Fitness Effects of Antimicrobial Resistance Mutations Across Environments in Escherichia coli

Hinz,

Amado,

Kassen

et al. 2024

Molecular Biology and Evolution

View full text Add to dashboard Cite

The evolution of antimicrobial resistance (AMR) in bacteria is a major public health concern, and antibiotic restriction is often implemented to reduce the spread of resistance. These measures rely on the existence of deleterious fitness effects (i.e., costs) imposed by AMR mutations during growth in the absence of antibiotics. According to this assumption, resistant strains will be outcompeted by susceptible strains that do not pay the cost during the period of restriction. The fitness effects of AMR mutations are generally studied in laboratory reference strains grown in standard growth environments; however, the genetic and environmental context can influence the magnitude and direction of a mutation’s fitness effects. In this study, we measure how three sources of variation impact the fitness effects of Escherichia coli AMR mutations: the type of resistance mutation, the genetic background of the host, and the growth environment. We demonstrate that while AMR mutations are generally costly in antibiotic-free environments, their fitness effects vary widely and depend on complex interactions between the mutation, genetic background, and environment. We test the ability of the Rough Mount Fuji fitness landscape model to reproduce the empirical data in simulation. We identify model parameters that reasonably capture the variation in fitness effects due to genetic variation. However, the model fails to accommodate the observed variation when considering multiple growth environments. Overall, this study reveals a wealth of variation in the fitness effects of resistance mutations owing to genetic background and environmental conditions, that will ultimately impact their persistence in natural populations.

show abstract

Section: Methodsmentioning

confidence: 99%

Unpredictability of the Fitness Effects of Antimicrobial Resistance Mutations Across Environments in Escherichia coli

Hinz,

Amado,

Kassen

et al. 2024

Molecular Biology and Evolution

View full text Add to dashboard Cite

show abstract

“…LB and M9-Glucose were prepared as described [70]. Synthetic urine media is a defined media containing 416 mM urea and 10 mM creatinine and was modified from published recipes [49,80] by the addition of Casamino acids to augment bacterial growth. Synthetic colon media is a tryptone-based medium supplemented with 0.4% Bile Salts and was prepared as described [50].…”

Section: Methodsmentioning

confidence: 99%

Unpredictability of the fitness effects of antimicrobial resistance mutations across environments inEscherichia coli

Hinz,

Amado,

Kassen

et al. 2023

Preprint

View full text Add to dashboard Cite

The evolution of antimicrobial resistance (AMR) in bacteria is a major public health concern. When resistant bacteria are highly prevalent in microbial populations, antibiotic restriction protocols are often implemented to reduce their spread. These measures rely on the existence of deleterious fitness effects (i.e., costs) imposed by AMR mutations during growth in the absence of antibiotics. According to this assumption, resistant strains will be outcompeted by susceptible strains that do not pay the cost during the period of restriction. Hence, the success of a given intervention depends on the magnitude and direction of fitness effects of mutations, which can vary depending on the genetic and environmental context. However, the fitness effects of AMR mutations are generally studied in laboratory reference strains and estimated in a limited number of environments, usually a standard laboratory growth medium. In this study, we systematically measure how three sources of variation impact the fitness effects of AMR mutations: the type of resistance mutation, the genetic background of the host, and the growth environment. We demonstrate that while AMR mutations are generally costly in antibiotic-free environments, their fitness effects vary widely and depend on complex interactions between the AMR mutation, genetic background, and environment. We test the ability of the Rough Mount Fuji genotype-fitness model to reproduce the empirical data in simulation. We identify model parameters that reasonably capture the variation in fitness effects due to genetic variation. However, the model fails to accommodate variation when considering multiple growth environments. Overall, this study reveals a wealth of variation in the fitness effects of resistance mutations owing to genetic background and environmental conditions, that will ultimately impact their persistence in natural populations.

show abstract

The Effect of Environmental Heterogeniety on the Fitness of Antibiotic Resistant Escherichia Coli

Cited by 2 publications

References 88 publications

Unpredictability of the Fitness Effects of Antimicrobial Resistance Mutations Across Environments in Escherichia coli

Unpredictability of the Fitness Effects of Antimicrobial Resistance Mutations Across Environments in Escherichia coli

Unpredictability of the fitness effects of antimicrobial resistance mutations across environments inEscherichia coli

Contact Info

Product

Resources

About