Transferable resistance to trimethoprim in enteric pathogens isolated in Kuwait

Area of Science:

• Microbiology
• Antimicrobial Resistance
• Molecular Biology

Background:

• Trimethoprim is a crucial antibiotic for treating bacterial infections.
• Rising antimicrobial resistance poses a significant global health threat.
• Understanding resistance mechanisms is vital for effective treatment strategies.

Purpose of the Study:

• To investigate the prevalence of trimethoprim resistance in Salmonella, Shigella, and Escherichia coli.
• To determine the role of plasmids in mediating trimethoprim resistance in these bacteria.
• To identify potential non-transferable resistance mechanisms in Salmonella.

Main Methods:

• Phenotypic detection of trimethoprim resistance in bacterial isolates from diarrheal patients.
• Determination of Minimum Inhibitory Concentrations (MICs) for high-level resistance.
• Conjugal transfer experiments to assess plasmid-mediated resistance.
• Mobilization assays using known transfer factors.

Main Results:

• Trimethoprim resistance was observed in 14.8% of Salmonella, 43.1% of Shigella, and 59% of E. coli strains.
• Plasmid-mediated trimethoprim resistance was confirmed in all tested Shigella and E. coli strains.
• Two out of 47 Salmonella strains showed non-transferable trimethoprim resistance.

Conclusions:

• Plasmid-mediated trimethoprim resistance is a significant factor in Shigella and E. coli infections.
• The presence of non-transferable trimethoprim resistance in some Salmonella strains warrants further investigation into alternative resistance mechanisms.
• These findings highlight the complex nature of antimicrobial resistance in common enteric pathogens.