Enterocin Cross-Resistance Mediated by ABC Transport Systems

Area of Science:

• Microbiology
• Bacterial genetics
• Molecular biology

Background:

• Bacteria produce bacteriocins (antimicrobial peptides) for inter-bacterial competition.
• Bacteriocin producers possess immunity genes to prevent self-inhibition.
• Cross-resistance mechanisms between different bacteriocin types are not well-understood.

Purpose of the Study:

• To investigate the role of the ABC transporter in enterocin AS-48 in cross-resistance.
• To determine if Transporter-2 is involved in cross-resistance between AS-48 and MR10A/B enterocin producers.
• To identify the MR10A/B immunity gene system.

Main Methods:

• Construction of mutant strains (Tn5 derivative and deletion mutants) of the enterocin AS-48 gene cluster in *Enterococcus faecalis*.
• Cloning of mutant gene clusters into the pAM401 shuttle vector.
• Antimicrobial activity assays to assess cross-resistance.

Main Results:

• Enterocin AS-48 Transporter-2 was identified as the key mediator of cross-resistance.
• This transporter confers resistance against both AS-48 and MR10A/B enterocin producers.
• The study successfully identified the MR10A/B immunity gene system.

Conclusions:

• The ABC transporter Transporter-2 in enterocin AS-48 plays a crucial role in mediating cross-resistance.
• These findings elucidate a mechanism for resistance beyond homologous bacteriocins.
• This research opens new avenues for studying inter-bacterial resistance mechanisms.