Matrine reverses the resistance of Haemophilus parasuis to cefaclor by inhibiting the mutations in penicillin-binding protein genes (ftsI and mrcA)

Deciphering antibiotic resistance, quorum sensing, and biofilm forming genes of Micrococcus luteus from hemodialysis tunneled cuffed catheter tips of renal failure patients

Catheter-related bloodstream infections create a significant challenge in healthcare system, often complicated by antibiotic resistance and biofilm formation of multi-drug resistance and virulent bacterial pathogens. This study focused on biofilm-forming efficiency, and underlying genetic mechanisms in Micrococcus luteus HL_Chru_C3, isolated from a hemodialysis catheter tip. The isolate exhibited resistance to multiple antibiotic classes, including beta-lactams and glycopeptides. Biofilm assays revealed that M. luteus HL_Chru_C3 formed optimum biofilms at high concentration of carbohydrates (500 mM), and pH 5 but there was no significant role of mineral salts. Whole-genome sequencing and bioinformatic analysis using CARD, KAAS, and KEGG databases identified genes associated with antibiotic resistance (ftsI, pbp1a/2, vanY, alr, ddl, murF, mraY, and murG), quorum sensing (genes from the opp family, sec, cylA, ccfA, phnA, phnB, phzC, rpfB, clp, and toxE), and biofilm formation (phnA, phnB, cyaB, vfr, vps, glgC, wecB, wecC, and cysE). The predicted mechanisms of action for these genes, based on homology to other organisms, suggest complex interactions contributing to the observed phenotypes. This study provides an insight into the genetic basis of antibiotic resistance and biofilm formation in M. luteus HL_Chru_C3 isolated from a hemodialysis catheter, highlighting the need for effective infection control strategies to combat CRBSIs.

Bitter Perception and Effects of Foods Rich in Bitter Compounds on Human Health: A Comprehensive Review

Bitter food, because of its unique taste, is not popular with the public, and is even considered to be difficult to swallow. By binding to specific sites of bitter receptors (26 hTAS2Rs), bitter compounds activate the downstream signaling pathways mediated by G protein, which convert chemical signals into electrical signals that are ultimately transmitted to the brain to produce the bitter perception. The intensity of bitterness is mainly determined by the hydrophobic recognition region of bitter receptors. The bitter compounds in foods mainly include alkaloids, polyphenols, terpenoids, amino acids, etc. Foods rich in bitter taste are mostly natural such as beans, nuts, and coffee, etc. Studies have proven that bitter foods have biological activities such as preventing hyperlipidemia, hypertension, hyperglycemia, anti-inflammatory, antitumor, antibacterial, antioxidant, and exhibit neuroprotective effects and other biological activities. The purpose of this review is to explore the bitter perception and the biological activity of bitter compounds, clarify the mechanism of their action on human health, and provide theoretical guidance for the development and application of functional foods.