Transfer of gentamicin resistance between coagulase-negative and coagulase-positive staphylococci on skin

Area of Science:

• Microbiology
• Epidemiology
• Antimicrobial Resistance

Background:

• Staphylococcus aureus is a common cause of hospital-acquired infections.
• Gentamicin is an antibiotic used to treat Staphylococcus infections.
• The emergence of antibiotic-resistant bacteria poses a significant public health threat.

Purpose of the Study:

• To investigate the transfer of gentamicin resistance between Staphylococcus species on skin.
• To compare the frequency of resistance transfer on skin versus in broth.
• To explore the role of skin transfer in the spread of gentamicin resistance.

Main Methods:

• Co-culturing of gentamicin-resistant Staphylococcus hominis with gentamicin-susceptible Staphylococcus aureus strains on human and murine skin models.
• Incubation in the absence of selective antibiotic pressure.
• Quantification of resistant Staphylococcus aureus transconjugants via selective plating.
• Comparison of transfer frequencies with in vitro broth cultures.

Main Results:

• Gentamicin resistance transfer occurred between S. hominis and S. aureus on both human and murine skin.
• Transfer frequency was significantly higher on skin surfaces compared to standard broth cultures.
• Successful transfer was observed without the presence of a selective agent (gentamicin).

Conclusions:

• Skin surfaces facilitate efficient horizontal gene transfer of antibiotic resistance.
• The skin environment may be a critical factor in the rapid dissemination of gentamicin resistance among staphylococci.
• These findings highlight the importance of infection control measures to prevent the spread of antibiotic resistance in healthcare settings.