Bacteriocin Production, Acid–Bile Tolerance and Antagonistic Activity of Locally Isolated Lactobacillus Species against Multidrug-Resistant Uropathogens and Enteropathogens

Lamyaasabeeh Abdullah

doi:10.70604/jmtbas.v3i2.223

Authors

Lamyaasabeeh Abdullah Ministry of Education General Directorate of Al-Qadisiyah Education, Diwaniyah, Iraq

Abstract

Multidrug-resistant (MDR) bacteria are now responsible for a considerable proportion of urinary and gastrointestinal infections and this has directed research toward antimicrobials from biological origin as alternatives to conventional antibiotics. A total of 45 Lactobacillus strains isolated from locally available fermented milk products and vaginal swab samples were used. Phenotypic tests and 16S rRNA gene sequencing placed them in five species: Lactobacillus plantarum, L. rhamnosus, L. acidophilus, L. fermentum, and L. casei. Every isolate was tested for survival at pH 2.0 and 3.0, for tolerance of 0.3% and 0.5% oxgall, and for bacteriocin production. Cell-free supernatant (CFS) from twelve selected isolates inhibited MDR strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhimurium, and Shigella flexneri in the agar well diffusion assay. One strain was conspicuous. The greatest results in the overall collection were found for L. plantarum LP-7, which maintained 87.2% of its viable count at pH 2.0 after 3 h and 82.5% in 0.3% oxgall. The LP-7 bacteriocin was partially purified by ammonium sulphate precipitation at 70% saturation and showed minimum inhibitory concentration (MIC) values ranging from 25 to 200 μg/mL. Its molecular weight was estimated to be about 6.5 kDa by SDS-PAGE. Thus, local Lactobacillus isolates, most all LP-7, seem to be feasible candidates for antimicrobial drugs against MDR uropathogens and enteropathogens.

Keywords:

Lactobacillus, Bacteriocin, Acid–bile tolerance, Multidrug resistance, Uropathogens, Enteropathogens, Probiotic, Cell-free supernatant

DOI

https://doi.org/10.70604/jmtbas.v3i2.223

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