Antibacterial activity of two newly isolated strains on serovars of food safety concern.

UNLABELLED

are obligate predators and have been described as living antibiotics since their predatory lifestyle enables them to kill pathogenic bacteria, making a promising biological control agent. strains were isolated from sampling sites in an urban watershed and tested for their killing activity on strains associated with human infections. An enrichment technique was used to isolate from surface water samples from local tributaries to the Oconee River, employing Infantis as the prey bait. The isolated strains were sequenced; their prey range activity was tested against a panel of clinically significant serovars, while predation efficiency was tested on . Infantis. The result demonstrated the ability of two newly isolated periplasmic strains, YOA24 and YOA38, to kill 11 antibiotic-resistant serovars and effectively reduce . Infantis populations. The strains were identified as periplasmic and members of based on phenotypic, microscopic, and genotypic characterization. YOA 24 and YOA38 demonstrated the ability to reduce . Infantis by 2 logs in 24 h. The killing activity of YOA24 and YOA38 indicates their potential to manage outbreaks. Therefore, strains YOA24 and YOA38 can be considered for development as therapeutic agents or probiotics against .

IMPORTANCE

is the most studied obligate predatory bacteria. It has potential for use as biological control of gram-negative bacteria in health, agriculture, and the food industry. Most basic research and applications use the type strain HD100 or a closely related strain 109J. Screening for other strains and their killing activity should be explored, knowing that prey range and efficiency could differ among strains. This study presents two newly isolated strains, YOA24 and YOA38, with lytic activity on serovars. YOA24 and YOA38 represent a biological control agent for foodborne serovars due to their killing activity on the important strains tested.