| Summary: | Lactic acid bacteria (LAB) from fermented foods are proven to be able to hinder the growth and activities of some foodborne pathogens. Antagonistic effects and sensitivity to antibiotics are important factors that need to be considered during the screening of potential probiotic strains. This study aims to evaluate the in vitro antagonistic activities with hemolytic activity and antibiotic susceptibility of LAB isolated from Malaysian fermented food, Pekasam Senek. Twenty LAB isolates were assessed for their antagonistic activities against Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, and Shigella sonnei via the spot overlay method. LAB isolates with positive results in antagonistic proceeded with subsequent assay, hemolytic assay, and antibiotic susceptibility test. Bacterial cultures were streaked on a fresh blood agar plate to examine the signs of β-hemolysis, α-hemolysis, and γ-hemolysis. The antibiotic susceptibility patterns of the strains to six types of antibiotics were assessed through the disc diffusion method. Antagonistic evaluation tests showed that all LAB isolates were able to inhibit the growth of pathogenic bacteria with the highest inhibition zone (31 mm) produced by PS26 against E. coli. Twelve (12) isolates showed negative hemolytic activity which indicates that they are safe and screened out for their antibiotic susceptibility testing. Furthermore, all twelve isolates were susceptible to ampicillin, bacitracin, chloramphenicol, and erythromycin while resistant to streptomycin. This study indicates that LAB isolated from Pekasam Senek had significant antagonism ability against the tested pathogens with negative hemolysis. Meanwhile, the resistance patterns of the isolates varied depending on the different types of antibiotics. © 2023 Malaysian Society for Biochemistry and Molecular Biology. All rights reserved.
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