Natural microbial communities supporting the transfer of the IncP-1β plasmid pB10 exhibit a higher initial content of...

Area of Science:

• Environmental microbiology
• Molecular biology
• Public health

Background:

• Antibiotic resistance gene transfer via plasmids is a significant public health issue.
• Identifying environments permissive to plasmid dissemination remains challenging.
• Previous work established a quantitative PCR (qPCR) method to track plasmid pB10 in natural microbial communities.

Purpose of the Study:

• To investigate factors influencing the transfer of the IncP-1β plasmid pB10 in diverse environmental matrices.
• To correlate microbial community structure and plasmid abundance with matrix permissiveness for plasmid transfer.

Main Methods:

• Conjugative plasmid transfer experiments using the IncP-1β plasmid pB10.
• Utilized 13 different environmental matrices in microcosm studies.
• Employed quantitative PCR (qPCR) to estimate plasmid abundance and monitor transfer.
• Analyzed microbial community structure using TTGE (Temperature Gradient Gel Electrophoresis).

Main Results:

• Plasmid pB10 transfer was rare and highly dependent on the environmental matrix.
• TTGE analysis was insufficient to identify common features in permissive microbial communities.
• Higher IncP-1 plasmid abundance correlated with increased permissiveness for pB10 transfer.
• The abundance of IncP-1 plasmids appears to be a key factor in determining matrix permissiveness.

Conclusions:

• The permissiveness of an environmental matrix for IncP-1 plasmid transfer is strongly influenced by the existing IncP-1 plasmid content.
• High relative abundance of IncP-1 plasmids may override superinfection immunity, promoting plasmid transfer.
• This finding offers a predictive indicator for environments prone to plasmid dissemination and antibiotic resistance spread.