Pervasive Sign Epistasis between Conjugative Plasmids and Drug-Resistance Chromosomal Mutations
2011

Sign Epistasis in Bacterial Resistance

Sample size: 50 publication 10 minutes Evidence: high

Author Information

Author(s): Silva Rui F., Mendonça Sílvia C. M., Carvalho Luís M., Reis Ana M., Gordo Isabel, Trindade Sandra, Dionisio Francisco

Primary Institution: Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa

Hypothesis

How do antibiotic-resistance mutations interact with conjugative plasmids in Escherichia coli?

Conclusion

The study found that the acquisition of additional resistance plasmids or mutations can increase the fitness of already resistant bacterial strains.

Supporting Evidence

  • 40% of combinations showed sign epistasis.
  • 52% of interactions exhibited positive epistasis.
  • The fitness cost of carrying both resistance determinants was lower than expected.

Takeaway

Sometimes, bacteria can become stronger when they get new resistance genes, making it harder to get rid of them.

Methodology

The study involved competition assays to measure fitness costs and epistatic interactions between plasmids and chromosomal mutations in E. coli.

Limitations

The study focused only on specific plasmids and mutations, which may not represent all possible interactions.

Statistical Information

P-Value

0.000968

Confidence Interval

[0.021; 0.065]

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pgen.1002181

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