Staphylococcus aureus biofilms promote horizontal transfer of antibiotic resistance

Area of Science:

• Microbiology
• Bacterial genetics
• Antibiotic resistance

Background:

• Staphylococcus aureus can develop antibiotic resistance through mutations during biofilm growth.
• Horizontal gene transfer is a key mechanism for spreading antibiotic resistance determinants.

Purpose of the Study:

• To investigate the impact of biofilm growth on the horizontal transfer of plasmid-borne antibiotic resistance in Staphylococcus aureus.
• To determine if standard laboratory conjugation induction methods are affected by biofilm presence.

Main Methods:

• Culturing Staphylococcus aureus in both planktonic and biofilm states.
• Quantifying the frequency of plasmid-borne antibiotic resistance gene transfer via conjugation and mobilization.
• Comparing conjugation efficiency under standard laboratory induction conditions with and without biofilms.

Main Results:

• Biofilm growth significantly increases the rate of horizontal transfer of plasmid-borne antibiotic resistance determinants.
• Standard laboratory practices for inducing conjugation in staphylococci are most efficient when bacteria are grown as a biofilm.
• Biofilm formation enhances both conjugation and mobilization of resistance plasmids.

Conclusions:

• Biofilm development in Staphylococcus aureus is a critical factor that not only promotes resistance emergence via mutation but also accelerates the spread of existing resistance through horizontal gene transfer.
• The findings highlight the importance of considering biofilm dynamics in understanding and combating antibiotic resistance.
• Optimized laboratory protocols for studying bacterial conjugation can leverage biofilm formation for increased efficiency.