Susceptibility of colistin-resistant pathogens to predatory bacteria

Area of Science:

• Microbiology
• Bacteriology
• Antimicrobial Resistance

Background:

• The rise of multidrug-resistant Gram-negative bacteria necessitates alternative treatments.
• Colistin is a last-resort antibiotic, but the spread of the mcr-1 gene threatens its efficacy.
• Untreatable Gram-negative infections pose a significant global health threat.

Purpose of the Study:

• To investigate the potential of predatory bacteria as a therapeutic strategy against mcr-1-positive, colistin-resistant Gram-negative bacteria.
• To evaluate the efficacy of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus against these resistant strains.

Main Methods:

• Culturing and challenging clinically relevant mcr-1-positive Gram-negative bacteria with Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus.
• Assessing the predatory capabilities of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus on both free-swimming and biofilm forms of prey.
• Comparing predation rates on mcr-1-positive strains versus mcr-1-negative control strains.

Main Results:

• Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus demonstrated the ability to prey on mcr-1-positive, colistin-resistant Gram-negative bacteria.
• No significant difference was observed in the predatory efficiency of these bacteria against prey harboring the mcr-1 gene compared to those without it.
• Predation efficacy remained consistent on both planktonic and biofilm bacterial populations.

Conclusions:

• Predatory bacteria show promise as a viable therapeutic option to combat colistin-resistant Gram-negative infections.
• The presence of the mcr-1 gene does not impede the predatory activity of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus.
• Further research into predatory bacteria could lead to novel strategies against emerging antimicrobial resistance.