Pathogen killing pathogen: antimicrobial substance from Acinetobacter active against foodborne pathogens

Area of Science:

• Microbiology
• Food Science
• Antimicrobial Research

Background:

• Antimicrobial substances (AMS) from bacteria can control pathogenic and spoilage microbes in food.
• This study investigated AMS production in Acinetobacter baumannii/calcoaceticus (ABC) complex isolates from infant milk formula (IMF) and associated utensils.

Purpose of the Study:

• To screen Acinetobacter isolates for antimicrobial substance (AMS) production.
• To evaluate the spectrum of activity and potential applications of AMS produced by Acinetobacter.

Main Methods:

• Agar-spot assays were used to determine AMS production and spectrum of activity.
• Growth conditions were optimized for enhanced AMS production.

Main Results:

• Three of 16 (17.6%) Acinetobacter isolates produced AMS against Salmonella Typhi.
• Isolate JE6 inhibited multiple Gram-negative and Gram-positive bacteria, including multidrug-resistant (MDR) strains of ABC complex and Shigella dysenteriae.
• The AMS produced by JE6 was stable against proteolytic enzymes, and the producer strain was immune to its own substance.

Conclusions:

• Acinetobacter isolates can produce AMS with significant potential for controlling foodborne pathogens.
• The AMS from isolate JE6 demonstrates broad-spectrum activity against MDR strains relevant to food safety, a novel finding.