The indiscriminate and excessive use of antibiotics has ultimately led to the emergence of bacterial resistant mutants or superbugs. These superbugs are difficult to control with conventional antibiotics. Disabling quorum sensing (QS), a population-density-dependent cell-to-cell communication process used by bacteria to coordinate the expression of virulence genes and biofilm formation, with dietary phytochemicals is emerging as a non-antibiotic strategy to inhibit bacterial pathogenicity. Although curcumin is an anti-QS agent and its delivery to cells has been a challenge due to poor bioavailability, ZnO/curcumin nanocomposites (ZnC-NCs) were fabricated with enhanced delivery of curcumin inside the bacterial superbug PAO1 for effective inhibition of its QS and biofilm formation. Sustained release of curcumin from ZnC-NCs was observed where 51% curcumin at pH 7.2 and 83% curcumin at pH 5.5 were released within 48 h. ZnC-NCs also decreased the production of virulence factors and biofilm formation without affecting planktonic cell growth. Both LasR and RhlR QS systems were inhibited by ZnC-NCs. ZnC-NCs were also capable of protecting both mice as well as lung epithelial cells from killing by PAO1. The superoxide anions (O) were also found as key players in suppressing PAO1 QS systems by ZnC-NCs. Overall, ZnC-NCs enhanced curcumin bioavailability for effective inhibition of QS signaling in via LasR-RhlR suppression and O generation.
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http://dx.doi.org/10.1021/acs.molpharmaceut.9b00179 | DOI Listing |
Mol Biotechnol
December 2024
Department of Biochemistry, Central University of Punjab, Ghudda, Bathinda, Punjab, 151401, India.
Staphylococcus warneri is a gram-positive mesophilic bacterium, resilient to extreme environmental conditions. To unravel its Osmotic Tolerance Response (OTR), we conducted proteomic and metabolomic analyses under drought (PEG) and salt (NaCl) stresses. Our findings revealed 1340 differentially expressed proteins (DEPs) across all treatments.
View Article and Find Full Text PDFJ Mol Histol
December 2024
Department of Clinical Laboratory, The Second Hospital of Shandong University, 247 Beiyuan Street, Jinan City, 250000, Shandong Province, China.
The purpose of this study was to explore the inhibitory effect of andrographolide on the expression of key regulatory genes involved in the biofilm formation of Staphylococcus epidermidis (SE). Taking the film-producing strain Staphylococcus epidermidis SE1457 as the research object, the effect of andrographolide on the formation of Staphylococcus epidermidis biofilms was analyzed via crystal violet staining, and biofilm models of SE adhesion, aggregation and maturity were established in vitro. RT‒PCR was used to detect the effects of the expression of icaA-, atlE-, aap- and luxS-related genes of andrographolide on biofilm formation in SE.
View Article and Find Full Text PDFMicrobiol Mol Biol Rev
December 2024
Department of Microbiology & Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA.
SUMMARY is a significant resident of the gastrointestinal tract of most animals, including humans. Although generally non-pathogenic in healthy hosts, this microbe is adept at the exploitation of compromises in host immune functions, resulting in life-threatening opportunistic infections whose treatments are complicated by a high degree of intrinsic and acquired resistance to antimicrobial chemotherapy. Historically, progress in enterococcal research was limited by a lack of experimental models that replicate natural infection pathways and the relevance of studies to the natural biology of the organism.
View Article and Find Full Text PDFNanoscale
December 2024
School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia.
Innovations in nanostructured surfaces have found a practical place in the medical area with use in implant materials for post-operative infection prevention. These textured surfaces should be dual purpose: (1) bactericidal on contact and (2) resistant to biofilm formation over prolonged periods. Here, hydrothermally etched titanium surfaces were tested against two highly antimicrobial resistant microbial species, methicillin-resistant and .
View Article and Find Full Text PDFUnlabelled: Two-component systems (TCS) enable bacteria to sense and respond to environmental signals, facilitating rapid adaptation. , a key oral pathobiont, employs the CarSR TCS to modulate coaggregation with various Gram-positive partners by regulating the expression of , encoding a surface adhesion protein, as revealed by RNA-Seq analysis. However, the direct regulation of the -containing operon ( ) by the response regulator CarR, the broader CarR regulon, and the signals sensed by this system remain unclear.
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