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Predominance of dfrG as determinant of trimethoprim resistance in imported Staphylococcus aureus

D Nurjadi1, J Schäfer2, B Friedrich-Jänicke3

  • 1Department of Infectious Diseases, Medical Microbiology and Hygiene, Heidelberg University Hospital, Heidelberg, Germany.

Clinical Microbiology and Infection : the Official Publication of the European Society of Clinical Microbiology and Infectious Diseases
|September 8, 2015
PubMed

Insights

Trimethoprim resistance in Staphylococcus aureus is often caused by the dfrG gene. Travel to South Asia increases the risk of acquiring trimethoprim-sulfamethoxazole-resistant S. aureus infections globally.

Area of Science:

  • Microbiology
  • Genetics
  • Epidemiology

Background:

  • Antimicrobial resistance is a growing global health concern.
  • Trimethoprim-sulfamethoxazole is a commonly prescribed antibiotic combination.
  • Understanding resistance mechanisms and prevalence is crucial for effective treatment.

Purpose of the Study:

  • To determine the global prevalence of trimethoprim-sulfamethoxazole resistance in Staphylococcus aureus.
  • To identify the genetic mechanisms responsible for trimethoprim resistance.
  • To assess the impact of travel on the acquisition of resistant strains.

Main Methods:

  • Analysis of Staphylococcus aureus isolates from travel-associated skin and soft-tissue infections across 13 European travel clinics.
  • Phenotypic antimicrobial susceptibility testing.
  • Genetic analysis to identify resistance determinants, focusing on dfr genes.

Main Results:

  • 38% of S. aureus isolates were resistant to trimethoprim, and 21% were resistant to trimethoprim-sulfamethoxazole.
  • The dfrG gene was identified as the primary cause of trimethoprim resistance, explaining 92% of cases.
  • Travel to South Asia was significantly associated with an increased risk of carrying trimethoprim-sulfamethoxazole-resistant S. aureus.

Conclusions:

  • The dfrG gene is the predominant genetic determinant of trimethoprim resistance in human S. aureus infections worldwide.
  • Travel plays a significant role in the global dissemination of antibiotic-resistant S. aureus.
  • Public health strategies should consider travel history in managing S. aureus infections.
Keywords:
Communicable diseasesPanton–Valentine leukocidinemerging drug resistancemethicillin-resistant Staphylococcus aureusmolecular epidemiologysentinel surveillancestaphylococcal skin infectionstraveltrimethoprim–sulfamethoxazole combination

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