Antimicrobial Sensitivity Assay for Bdellovibrio bacteriovorus.

Area of Science:

• Microbiology
• Bacteriology
• Antimicrobial Resistance

Background:

• Bdellovibrio bacteriovorus is an obligate predatory bacterium with probiotic potential for disinfection and treating bacterial infections.
• Combining B. bacteriovorus with antimicrobials could enhance treatment efficacy, but its own antibiotic resistance is largely unknown.
• Standard antimicrobial sensitivity assays are unsuitable for B. bacteriovorus due to its small size and reliance on larger prey bacteria for growth.

Purpose of the Study:

• To establish a reliable method for determining the antimicrobial sensitivity of B. bacteriovorus.
• To enable direct comparison of B. bacteriovorus antimicrobial resistance levels with other bacterial species.
• To facilitate the development of B. bacteriovorus as a probiotic in combination antimicrobial therapies.

Main Methods:

• A novel antimicrobial sensitivity assay was developed based on the reduction of optical density at 600 nm (OD600).
• The assay measures prey lysis caused by B. bacteriovorus in the presence and absence of varying antimicrobial concentrations.
• Minimal inhibitory concentration (MIC) values are determined by monitoring absorbance changes in mixed predator/prey cultures.

Main Results:

• The described method allows for the determination of B. bacteriovorus antimicrobial MIC values.
• This assay provides a basis for comparing antimicrobial resistance between B. bacteriovorus and reference organisms under similar experimental conditions.
• The procedure can be adapted for other predatory bacteria, prey species, and antimicrobials.

Conclusions:

• A viable method for assessing B. bacteriovorus antimicrobial sensitivity has been established.
• This assay is essential for evaluating the potential of B. bacteriovorus in combination antimicrobial therapies.
• The developed procedure offers a standardized approach for studying antimicrobial resistance in predatory bacteria.