Dairy origin lactobacilli: functional analyses and antagonistic potential against multidrug-resistant foodborne pathogens


Citation

Saqalein M., . and Kabir S., . and Khurshid M., . and Nisar M. A., . and Hayat S., . and Muzammil S., . and Taj Z., . and Shahid M., . and Waseem M., . and Shahzad A., . and Rasool M. H., . and Rizvi N. B., . and Waheed S., . and Nawaz Z., . Dairy origin lactobacilli: functional analyses and antagonistic potential against multidrug-resistant foodborne pathogens. pp. 131-140. ISSN 2231-7546

Abstract

The present work was designed to characterise novel indigenous strains of lactobacilli and to identify and evaluate their antagonistic activity against enteric pathogens. A total of four lactobacilli strains were isolated from Dahi samples (continental yogurt) and characterised using phenotypic and biochemical tests and by 16S rDNA sequencing. The isolates were identified as Lactobacillus paracasei SABA3 L. paracasei SABA4 L. fermentum SABA5 and L. casei SABA6. The probiotic potential of these strains was assessed under the gastrointestinal simulating environment. The antagonistic activity of lactic acid bacilli (LAB) strains against multidrug-resistant (MDR) test pathogens was determined by in vitro assays. Moreover the bactericidal activity of cell-free culture supernatant (CFCS) was determined by agar well diffusion and growth inhibition assays. All the LAB strains were tolerant to 0.3 bile salts extreme acidic conditions (stomach environment) as well as pH 6.5 (small intestine); and can efficiently grow at 37C. Moreover the isolates were found as non-haemolytic which confirms their safety and use as potential probiotics. The genetic screening has shown the presence of qnrS tetK tetW vanR vanX and qnrA antibiotic-resistant determinants. The L. fermentum SABA5 exhibited the strongest bactericidal activity against the pathogenic bacterial species among all of these potential probiotic strains. The CFCS inhibited the proliferation of pathogenic bacterial species in a concentration-dependent manner. The chromatographic profiling of all isolates depicted lactic acid as a major fermentation product.


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Abstract

The present work was designed to characterise novel indigenous strains of lactobacilli and to identify and evaluate their antagonistic activity against enteric pathogens. A total of four lactobacilli strains were isolated from Dahi samples (continental yogurt) and characterised using phenotypic and biochemical tests and by 16S rDNA sequencing. The isolates were identified as Lactobacillus paracasei SABA3 L. paracasei SABA4 L. fermentum SABA5 and L. casei SABA6. The probiotic potential of these strains was assessed under the gastrointestinal simulating environment. The antagonistic activity of lactic acid bacilli (LAB) strains against multidrug-resistant (MDR) test pathogens was determined by in vitro assays. Moreover the bactericidal activity of cell-free culture supernatant (CFCS) was determined by agar well diffusion and growth inhibition assays. All the LAB strains were tolerant to 0.3 bile salts extreme acidic conditions (stomach environment) as well as pH 6.5 (small intestine); and can efficiently grow at 37C. Moreover the isolates were found as non-haemolytic which confirms their safety and use as potential probiotics. The genetic screening has shown the presence of qnrS tetK tetW vanR vanX and qnrA antibiotic-resistant determinants. The L. fermentum SABA5 exhibited the strongest bactericidal activity against the pathogenic bacterial species among all of these potential probiotic strains. The CFCS inhibited the proliferation of pathogenic bacterial species in a concentration-dependent manner. The chromatographic profiling of all isolates depicted lactic acid as a major fermentation product.

Additional Metadata

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Item Type: Article
AGROVOC Term: Dairy products
AGROVOC Term: Lactobacillus
AGROVOC Term: Antagonistic microorganisms
AGROVOC Term: Foodborne diseases
AGROVOC Term: Pathogens
AGROVOC Term: Probiotics
AGROVOC Term: analysis
AGROVOC Term: Sampling
AGROVOC Term: Biochemical reactions
AGROVOC Term: Gastrointestinal agents
Depositing User: Mr. AFANDI ABDUL MALEK
Last Modified: 24 Apr 2025 00:54
URI: http://webagris.upm.edu.my/id/eprint/8980

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