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Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
09:00

Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance

Published on: May 2, 2018

Plasmid-mediated sulfonamide resistance in Neisseria meningitidis

B Facinelli1, P E Varaldo

  • 1Institute of Microbiology, University of Ancona Medical School, Italy.

Antimicrobial Agents and Chemotherapy
|October 1, 1987
PubMed

Insights

A plasmid conferring sulfonamide resistance was identified in Neisseria meningitidis. This resistance is likely due to a plasmid-encoded dihydropteroate synthetase, a key enzyme in folate synthesis.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Sulfonamide antibiotics are crucial for treating bacterial infections.
  • Antibiotic resistance poses a significant public health threat.
  • Understanding resistance mechanisms is vital for developing effective treatments.

Purpose of the Study:

  • To investigate the genetic basis of sulfonamide resistance in a clinical isolate of Neisseria meningitidis.
  • To identify the specific genetic element responsible for conferring resistance.

Main Methods:

  • Plasmid isolation and characterization.
  • Plasmid elimination experiments to assess its role in resistance.
  • Transformation experiments in Escherichia coli to confirm gene function.
  • Enzyme complementation assays to elucidate the resistance mechanism.

Main Results:

  • An 8.5-megadalton plasmid carrying sulfonamide resistance genes was identified.
  • The plasmid was successfully transferred to a recipient strain, conferring resistance.
  • The plasmid complemented a mutation affecting dihydropteroate synthetase in E. coli.

Conclusions:

  • The identified plasmid is responsible for sulfonamide resistance in this Neisseria meningitidis isolate.
  • The resistance mechanism involves a plasmid-encoded dihydropteroate synthetase.
  • This finding highlights the potential for plasmid-mediated resistance to sulfonamides in Neisseria species.

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