Abstract:
:The emerging prevalence of multidrug-resistance in Gram-negative pathogens, due to conventional antimicrobial therapeutics, has led the researchers to emphasize on development of alternative novel strategies to suppress the bacterial virulence and pathogenicity through inhibition of quorum sensing (QS) and biofilms. QS is a bacterial communication system to produce density-dependent response via chemical signalling that controls pathogenesis and biofilms formation. Leaves of green tea are used worldwide as beverage which is also known for its broad-spectrum therapeutic efficacy. In this work, we have identified and characterized the most bioactive faction of green tea extract and evaluated the anti-QS and antibiofilm activity of green tea ethyl acetate fraction (GTEF) i.e. most active fraction, on three different Gram-negative bacterial pathogens. GTEF inhibited the violacein production by >75% in C. violaceum 12472. Many virulence factors of P. aeruginosa PAO1 viz. pyocyanin, pyoverdin, exoprotease, elastase, rhamnolipid production, and swimming motility were remarkably reduced in presence of sub-MICs of GTEF. Moreover, prodigiosin, protease activity, cell surface hydrophobicity, and swimming of S. marcescens MTCC 97 were also decreased significantly by the supplementation of GTEF in culture media. GTEF exhibited broad-spectrum antibiofilm action with >80% reduction in biofilm formation of test pathogens. In silico studies gave a mechanistic insight of action of GTEF. Molecular modelling revealed that phytoconstituents detected by GC/MS exhibited affinity (in order of 104 M-1) towards AHL synthases (LasI and EsaI). The molecular binding between phytocompounds and receptor proteins (LasR, RhlR, and PqsR) of QS circuit was also energetically favourable (ΔG°≥ 5.0 kcal mol-1) and supported by hydrogen bonds and hydrophobic interactions. These compounds were found to be docked in ligand binding domain of CviR and occupied same cavity as that of its antagonist. Squalene and thunbergol interacted with LasA at tartaric acid binding pocket and the complex was strengthened with binding energy -5.9 kcal mol-1. Moreover, interaction of thunbergol with biofilm-associated proteins viz. PilT and PilY1, might be disabling the pilus assembly and consequently inhibiting biofilm formation. In vivo validation of results suggested the protective role GTEF against QS-mediated pathogenicity and it might become a novel non-antibiotic QS inhibitor to control bacterial infection.
journal_name
Microb Pathogjournal_title
Microbial pathogenesisauthors
Qais FA,Khan MS,Ahmad Idoi
10.1016/j.micpath.2018.11.030subject
Has Abstractpub_date
2019-01-01 00:00:00pages
379-392eissn
0882-4010issn
1096-1208pii
S0882-4010(18)31643-7journal_volume
126pub_type
杂志文章abstract::The oral cavity is regarded as a relevant site for Staphylococcus aureus colonization. However, characterization of virulence mechanisms of oral S. aureus remains to be uncovered. In this study, twenty one S. aureus strains isolated from the oral cavity of Tunisian patients were screened for adherence, invasion and cy...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2015.05.010
更新日期:2015-09-01 00:00:00
abstract::In this paper, we have reported the synthesis, characterization, and evaluation of antimicrobial and antioxidant potential of monodispersed Zinc Oxide (ZnO) nanoparticles synthesized by the room temperature precipitation (aqueous phase) and polyol method (organic phase). ZnO nanoparticle synthesized by both the method...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2018.03.048
更新日期:2018-06-01 00:00:00
abstract::Siderophores are low molecular weight molecules that allow bacteria to acquire iron from host cell proteins. 2,3-dihydroxybenzoic acid (DHBA) is the only known siderophore produced by the intracellular pathogen Brucella abortus. Here its role in virulence was assessed by evaluating the ability of a mutant with a disru...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1006/mpat.2002.0500
更新日期:2002-05-01 00:00:00
abstract::The focus of this study was the phenotypic characterization of Salmonella typhimurium mutants lacking the function of the response regulator mviA. The inactivation of mviA+ (mviA::kan) is shown to induce a significant change in the growth of most virulent strains, as reflected in the size of the colonies formed on aga...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1006/mpat.1996.0117
更新日期:1997-06-01 00:00:00
abstract::Clinical isolates of Pseudomonas aeruginosa are either invasive or cytotoxic towards mammalian epithelial cells, endothelial cells, and macrophages. Invasion requires host cell actin cytoskeleton function, and ExsA-regulated proteins of P. aeruginosa that inhibit invasion (ExoS and ExoT) can disrupt the cytoskeleton. ...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1006/mpat.2002.0521
更新日期:2002-09-01 00:00:00
abstract::Porphyromonas gingivalis is capable of in vitro growth when iron sources are either complexed to hemin or host iron transport proteins, or exist in an inorganic form. This study examined the effect of these iron sources on outer membrane protein (OMP) expression in P. gingivalis W50. Hemin (iron) starved P. gingivalis...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/0882-4010(92)90032-j
更新日期:1992-07-01 00:00:00
abstract::It has been shown that N-linked high mannose type oligosaccharides competitively inhibits attachment to and infectivity of chlamydiae in HeLa cells. To further study whether mannose moieties are involved in the infectivity of chlamydiae, the susceptibility of mannose-receptor negative J774A and positive J774E mouse ma...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1006/mpat.2001.0479
更新日期:2002-01-01 00:00:00
abstract::Thanks to the progress and decreasing costs in genome sequencing technologies, more than 250,000 bacterial genomes are currently available in public databases, covering most, if not all, of the major human-associated phylogenetic groups of these microorganisms, pathogenic or not. In addition, for many of them, sequenc...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2020.104275
更新日期:2020-12-01 00:00:00
abstract::Peste des petits ruminants (PPR), an economically important viral transboundary disease of small ruminants is not only prevalent in Pakistan but also in other countries where people rely on agriculture and animal products. The present study was aimed at describing the pathology and antigen localization in natural PPR ...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2018.02.009
更新日期:2018-04-01 00:00:00
abstract::Staphylococcus aureus (S. aureus) is a major cause of pneumonia that often affects young and immunocompetent patients. Inflammation plays an important role in the development of S. aureus-induced pneumonia. Geniposide, a major iridoid glucoside component of gardenia fruit, has been reported to have anti-inflammatory a...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2017.09.050
更新日期:2017-11-01 00:00:00
abstract::The closely related Shiga toxins, Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2), can bind to Gb3 receptors. However, Stx2-producing enterohemorrhagic Escherichia coli (EHEC) strains are more commonly associated with serious human disease (viz., hemolytic-uremic syndrome) than Stx1-producing strains. To clarify the rel...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2007.04.003
更新日期:2007-08-01 00:00:00
abstract::Streptococcus pneumoniae attach to human pharyngeal epithelial cells through the specific interaction of bacterial surface adhesins with glycoconjugate receptors. The present study defines the adhesin as a molecule bridging between an anchoring site in the bacterial cell wall and the epithelial cell receptor. The natu...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/0882-4010(88)90087-3
更新日期:1988-04-01 00:00:00
abstract:BACKGROUND:Obesity is associated with alteration of the gut microbiota. In order to clarify the effect of Lactobacillus-containing probiotics (LCP) on weight we performed a meta-analysis of clinical studies and experimental models. We intended to assess effects by Lactobacillus species. METHODS:A broad search with no ...
journal_title:Microbial pathogenesis
pub_type: 杂志文章,meta分析
doi:10.1016/j.micpath.2012.05.007
更新日期:2012-08-01 00:00:00
abstract::Thymol and carvacrol from the class of monoterpene phenols are one of the most potent plant essential oil components possessing antimicrobial effects. Known for their wide bioactive spectrum, these positional isomers of isopropyl cresol deplete ergosterol content, compromise membrane permeability, block efflux pumps a...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2015.02.004
更新日期:2015-03-01 00:00:00
abstract::The extracellular hemolysin (AHH1) gene of Aeromonas hydrophila ATCC7966 was cloned into Charomid9-28 in Escherichia coli DH1, and its complete nucleotide sequence determined. Escherichia coli carrying this gene expressed an extracellular heat-labile hemolysin for rabbit red blood cells. The minimum size of the coding...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/0882-4010(91)90049-g
更新日期:1991-09-01 00:00:00
abstract::The first occurrences and dissemination of resistant microorganisms led to the inefficacy of many antibiotics, available in the market nowadays, therefore, the search for new substances with antimicrobial activity from natural sources has gained a great importance. The purpose of this work is to evaluate the antibacte...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2017.01.028
更新日期:2017-03-01 00:00:00
abstract::This work illustrates a new role for the membranotropic peptide gH625 and its derivative gH625-GCGKKK in impairing formation of polymicrobial biofilms. Mixed biofilms composed of Candida and bacterial species cause frequently infections and failure of medical silicone devices and also show a major drug resistance than...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2018.09.027
更新日期:2018-12-01 00:00:00
abstract::During the course of infection, Yersinia enterocolitica invades tissues where macrophages and polymorphonuclear leucocytes (PMNs) constitute the first line of defence. As expression of virulence in Y. enterocolitica is governed in part by a c. 70 kilobase virulence plasmid (pYV), we investigated the influence of this ...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/0882-4010(92)90018-j
更新日期:1992-09-01 00:00:00
abstract::A collection of Haemophilus ducreyi isolates were screened for the ability to bind to fibrinogen, fibronectin, collagen, gelatin and laminin by a particle agglutination test using latex beads coated with the individual proteins. Thirteen of 21 isolates reacted with all five extracellular matrix proteins. Binding of or...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/0882-4010(92)90034-l
更新日期:1992-07-01 00:00:00
abstract::As an adaptation to the iron-restricted environment of the host, some bacterial pathogens possess iron acquisition pathways mediated by surface receptors that specifically bind transferrin from the host. The receptor is composed of two receptor proteins, TbpA and TbpB, which are both capable of binding to transferrin....
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1006/mpat.1997.0174
更新日期:1998-02-01 00:00:00
abstract::Neisseria meningitidis is normally a human nasopharyngeal commensal but is also capable of causing life-threatening sepsis and meningitis. N. meningitidis secretes several virulence-associated proteins including Neisserial autotransporter lipoprotein (NalP), an immunogenic, type Va autotransporter harboring an S8-fami...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2018.08.001
更新日期:2018-11-01 00:00:00
abstract::Pneumococcal surface protein A (PspA) is a widely studied pneumococcal protein, exposed at the surface of all strains. It is an important virulence factor, preventing complement deposition as well as inhibiting the lytic effects of lactoferrin over pneumococci. Several studies have investigated the use of PspA as a ca...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2017.06.004
更新日期:2017-08-01 00:00:00
abstract::Human leishmaniasis is a spectral disease that includes asymptomatic self-resolving infection, localized skin lesions, and progressive visceral leishmaniasis. With some overlap, visceral and cutaneous leishmaniasis are usually caused by different species of Leishmania. This review focuses on host responses to infectio...
journal_title:Microbial pathogenesis
pub_type: 杂志文章,评审
doi:10.1016/j.micpath.2004.11.002
更新日期:2005-04-01 00:00:00
abstract::Three coagulase-negative Staphylococcus species (CNS) (Staphylococcus epidermidis, Staphylococcus xylosus and Staphylococcus hyicus), from the milk of cows with mastitis, were used to evaluate adherence to and internalization by bovine mammary epithelial cells, and to investigate involvement of host cell signal transd...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1006/mpat.2001.0465
更新日期:2001-11-01 00:00:00
abstract:BACKGROUND AND OBJECTIVES:Bacterial vaginosis (BV) is the most common vaginal infection in women of reproductive age. It shifts the paradigms of the vagina from healthy, beneficial microbiota to facultative and strict anaerobes. BV remains one of the most arduous and controversial challenges in modern-day clinical micr...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2020.104588
更新日期:2020-12-01 00:00:00
abstract::Heterosporosis is an increasingly important microsporidian disease distributed worldwide, impacting wild and farmed-raised fish in both fresh and marine water environments. Twenty three out of 130 (17.69%) of the lizardfish Saurida lessepsianus were found to be naturally infected with microsporidian parasites. The rat...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2019.02.025
更新日期:2019-05-01 00:00:00
abstract::Monocyte chemoattractant protein-1 (MCP-1), a chemoattractant for monocytes, is presumed to play a pivotal role in the recruitment and accumulation of monocytes in various diseases including pulmonary infections. We examined here whether or not Pseudomonas nitrite reductase (PNR), a recently identified IL-8 inducer in...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1006/mpat.1999.0320
更新日期:2000-01-01 00:00:00
abstract:BACKGROUND:Rickettsia prowazekii is the etiological agent of epidemic typhus and is an obligate intracellular bacterium that grows as a parasite freely within the cytoplasm of a eukaryotic host cell. Previous studies have shown that rOmpA and rOmpB which belong to the family of rickettsial cell surface antigens are inv...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2011.01.009
更新日期:2011-05-01 00:00:00
abstract::CpG DNA is a potent activator of the innate immune system. Here the protective effects of CpG DNA are assessed against the facultative intracellular pathogen Francisella tularensis. Dosing of mice with CpG DNA provided protection against disease caused by F. tularensis subsp. holarctica live vaccine strain (LVS) but d...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2013.04.013
更新日期:2013-10-01 00:00:00
abstract::The oligopeptide permease (Opp) cassette, an oligopeptide transport system belongs to the superfamily of ATP-binding cassette (ABC) transporter, is widely distributed in bacteria, including Streptococcus suis (S. suis). It is encoded by the opp operon containing oppA, oppB, oppC, oppD, and oppF. In addition to the upt...
journal_title:Microbial pathogenesis
pub_type: 杂志文章
doi:10.1016/j.micpath.2018.03.061
更新日期:2018-05-01 00:00:00