The Influence of Lactobacillus spp. Secondary Metabolites Isolated from Immature Egyptian Honey on Human Pathogens, Transcription of Virulence Genes and Lung Cancer

• Published in: Indian journal of microbiology 2024-06, Vol.64 (2), p.671-682
• Main Authors: Elsayed, Tarek R., Nour, Eman, Hamed, Ahmed A., Hassan, Ashwak Abdel-Moneim, Elenany, Yasser Essam
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Antiinfectives and antibacterials; Bacteria; Beehives; Biological control; Biomedical and Life Sciences; Cell viability; Cytotoxicity; E coli; Gene expression; Gene sequencing; Genes; High performance liquid chromatography; Honey; Lactic acid; Lactic acid bacteria; Lactobacillus acidophilus; Levilactobacillus brevis; Life Sciences; Liquid chromatography; Lung cancer; Mass spectrometry; Mass spectroscopy; Medical Microbiology; Metabolites; Microbiology; Original; Original Research Article; Pathogens; Quadrupoles; rRNA 16S; Secondary metabolites; Virulence
• ISSN: 0046-8991; 0973-7715
• DOI: 10.1007/s12088-024-01224-7

This work aimed to isolate, and identify Lactic Acid Bacteria LAB from Egyptian immature citrus honey, and characterize their secondary metabolites, as well as determine the antibacterial activities and transcription of virulence genes (stx1, stx2, and eae) influenced by these bacterial secondary metabolites. From twenty hives, twenty immature citrus bee honey samples were taken. Traditional cultural and biochemical testing were used, followed by molecular confirmation. Further, LAB isolates' antibacterial and cytotoxic properties were investigated. 16S rRNA gene sequencing were assessed and, two lactic acid bacterial isolates were identified as Lactobacillus acidophilus Ch 2 and Levilactobacillus brevis Ch 1 . Both isolates have good antagonistic action against clinical pathogens, with Levilactobacillus brevis Ch 1 exhibiting the best antibacterial activity against all indicator pathogens examined. When compared to untreated cancer cells, the isolates demonstrated significant cytotoxic activity. Ch 1 and Ch 2 cell viability percentages were 39.5% and 18.76%, respectively. Furthermore, when exposed to Levilactobacillus brevis Ch 1 metabolites, Shiga-producing Escherichia coli (STEC) virulence gene expression was suppressed. To identify bacterial secondary metabolites, a high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF) approach was developed. Twenty-seven metabolites from diverse chemical classes were discovered in the crude extracts with antibacterial and anticancer characteristics. This is the first thorough investigation on the metabolic profile of LAB isolated from immature Egyptian honey and the findings suggested that isolates or their secondary metabolites could be used in the food sector as medicinal alternatives or as a biocontrol agent.