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[Trimethoprim resistance plasmids: transferability and incompatibility groups (author's transl)]
Abstract:
Over a three year period, 119 strains of enterobacteria isolated from patients have been found resistant to trimethoprim (TMP) and sulfonamides (Su); 11 strains were resistant to TMP only. MIC of TMP were between 32 and 2048 microng/ml. Three groups of strains are described: (1) thymineless variants (2 strains); (2) TMP resistance non-transferable into Escherichia coli K12 (95 strains); (3) TMP resistance transferable into E. coli K12 (33 strains). TMP marker and Su marker have been transferred independantly from 13 strains; they were cotransferred from 20 strains. The incompatibility group of 31 plasmids has been determined: 10 belong to the fi+ type, group FII; 21 belong to the fi--type, group 6, group 7, group 10, group N and group I1. Epidemiological implications of such a wide range of incompatibility groups among a small number of plasmids specifying TMP resistance are discussed.
Insights
A three-year study found 119 enterobacteria strains resistant to trimethoprim and sulfonamides. Resistance mechanisms varied, with some trimethoprim resistance transferable via plasmids across multiple incompatibility groups.
Area of Science:
- Microbiology
- Molecular Biology
- Epidemiology
Context:
- Enterobacteria are common causes of infection.
- Antimicrobial resistance is a growing global health concern.
- Trimethoprim and sulfonamides are important antibiotics.
Purpose:
- To investigate trimethoprim and sulfonamide resistance in enterobacteria.
- To characterize the mechanisms of resistance, including plasmid-mediated transfer.
- To determine the diversity of plasmids conferring trimethoprim resistance.
Summary:
- Over three years, 119 enterobacteria strains showed resistance to trimethoprim (TMP) and sulfonamides (Su); 11 were TMP-resistant only.
- Minimum inhibitory concentrations (MICs) for TMP ranged from 32 to 2048 µg/ml.
- Strains were categorized into thymineless variants, non-transferable TMP resistance (95 strains), and transferable TMP resistance (33 strains).
- TMP and Su markers were transferred independently (13 strains) or cotransferred (20 strains).
- Plasmid incompatibility groups (31 analyzed) included fi+ (FII, 10 strains) and fi- (groups 6, 7, 10, N, I1, 21 strains).
Impact:
- Highlights the diverse plasmid landscape associated with TMP resistance in enterobacteria.
- Suggests potential for broad dissemination of antimicrobial resistance.
- Informs strategies for infection control and antibiotic stewardship.