scholarly journals Novel insights from molecular docking of SdiA from Salmonella Enteritidis and Escherichia coli with quorum sensing and quorum quenching molecules

2016 ◽  
Vol 99 ◽  
pp. 178-190 ◽  
Author(s):  
Felipe Alves de Almeida ◽  
Uelinton Manoel Pinto ◽  
Maria Cristina Dantas Vanetti
Keyword(s):  
Escherichia Coli ◽  
Molecular Docking ◽  
Quorum Sensing ◽  
Salmonella Enteritidis ◽  
Quorum Quenching

scholarly journals A Novel Quorum-Quenching N-Acylhomoserine Lactone Acylase from Acidovorax sp. Strain MR-S7 Mediates Antibiotic Resistance

2017 ◽  
Vol 83 (13) ◽  
Author(s):  
Hiroyuki Kusada ◽  
Hideyuki Tamaki ◽  
Yoichi Kamagata ◽  
Satoshi Hanada ◽  
Nobutada Kimura
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Cell Communication ◽  
Quorum Quenching ◽  
Multidrug Resistant ◽  
Bifunctional Enzyme ◽  
Content Type ◽  
Acylhomoserine Lactone ◽  
Multidrug Resistant Bacterium

ABSTRACT N-Acylhomoserine lactone acylase (AHL acylase) is a well-known enzyme responsible for disrupting cell-cell communication (quorum sensing) in bacteria. Here, we isolated and characterized a novel and unique AHL acylase (designated MacQ) from a multidrug-resistant bacterium, Acidovorax sp. strain MR-S7. The purified MacQ protein heterologously expressed in Escherichia coli degraded a wide variety of AHLs, ranging from C6 to C14 side chains with or without 3-oxo substitutions. We also observed that AHL-mediated virulence factor production in a plant pathogen, Pectobacterium carotovorum, was dramatically attenuated by coculture with MacQ-overexpressing Escherichia coli, whereas E. coli with an empty vector was unable to quench the pathogenicity, which strongly indicates that MacQ can act in vivo as a quorum-quenching enzyme and interfere with the quorum-sensing system in the pathogen. In addition, this enzyme was found to be capable of degrading a wide spectrum of β-lactams (penicillin G, ampicillin, amoxicillin, carbenicillin, cephalexin, and cefadroxil) by deacylation, clearly indicating that MacQ is a bifunctional enzyme that confers both quorum quenching and antibiotic resistance on strain MR-S7. MacQ has relatively low amino acid sequence identity to any of the known acylases (<39%) and has among the broadest substrate range. Our findings provide the possibility that AHL acylase genes can be an alternative source of antibiotic resistance genes posing a threat to human health if they migrate and transfer to pathogenic bacteria. IMPORTANCE N-Acylhomoserine lactones (AHLs) are well-known signal molecules for bacterial cell-cell communication (quorum sensing), and AHL acylase, which is able to degrade AHLs, has been recognized as a major target for quorum-sensing interference (quorum quenching) in pathogens. In this work, we succeeded in isolating a novel AHL acylase (MacQ) from a multidrug-resistant bacterium and demonstrated that the MacQ enzyme could confer multidrug resistance as well as quorum quenching on the host organism. Indeed, the purified MacQ protein was found to be bifunctional and capable of degrading not only various AHL derivatives but also multiple β-lactam antibiotics by deacylation activities. Although quorum quenching and antibiotic resistance have been recognized to be distinct biological functions, our findings clearly link the two functions by discovering the novel bifunctional enzyme and further providing the possibility that a hitherto-overlooked antibiotic resistance mechanism mediated by the quorum-quenching enzyme may exist in natural environments and perhaps in clinical settings.

Molecular docking, quorum quenching effect, antibiofilm activity and safety profile of silver-complexed sulfonamide on Pseudomonas aeruginosa

Biofouling ◽  
2021 ◽  
pp. 1-17
Author(s):  
Fallon dos Santos Siqueira ◽  
Camilla Filippi dos Santos Alves ◽  
Alencar Kolinski Machado ◽  
Josiéli Demétrio Siqueira ◽  
Thiago dos Santos ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Molecular Docking ◽  
Safety Profile ◽  
Quorum Quenching ◽  
Antibiofilm Activity ◽  
Quenching Effect

scholarly journals In silico molecular docking and in vitro antimicrobial efficacy of phytochemicals against multi-drug-resistant enteroaggregative Escherichia coli and non-typhoidal Salmonella spp.

Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Padikkamannil Abishad ◽  
Pollumahanti Niveditha ◽  
Varsha Unni ◽  
Jess Vergis ◽  
Nitin Vasantrao Kurkure ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Docking ◽  
In Silico ◽  
Docking Studies ◽  
Antimicrobial Efficacy ◽  
Drug Resistant ◽  
Protein Motifs ◽  
Phytochemical Compounds ◽  
In Silico Molecular Docking

Abstract Background In the wake of emergence of antimicrobial resistance, bioactive phytochemical compounds are proving to be important therapeutic agents. The present study envisaged in silico molecular docking as well as in vitro antimicrobial efficacy screening of identified phytochemical ligands to the dispersin (aap) and outer membrane osmoporin (OmpC) domains of enteroaggregative Escherichia coli (EAEC) and non-typhoidal Salmonella spp. (NTS), respectively. Materials and methods The evaluation of drug-likeness, molecular properties, and bioactivity of the identified phytocompounds (thymol, carvacrol, and cinnamaldehyde) was carried out using Swiss ADME, while Protox-II and StopTox servers were used to identify its toxicity. The in silico molecular docking of the phytochemical ligands with the protein motifs of dispersin (PDB ID: 2jvu) and outer membrane osmoporin (PDB ID: 3uu2) were carried out using AutoDock v.4.20. Further, the antimicrobial efficacy of these compounds against multi-drug resistant EAEC and NTS strains was determined by estimating the minimum inhibitory concentrations and minimum bactericidal concentrations. Subsequently, these phytochemicals were subjected to their safety (sheep and human erythrocytic haemolysis) as well as stability (cationic salts, and pH) assays. Results All the three identified phytochemicals ligands were found to be zero violators of Lipinski’s rule of five and exhibited drug-likeness. The compounds tested were categorized as toxicity class-4 by Protox-II and were found to be non- cardiotoxic by StopTox. The docking studies employing 3D model of dispersin and ompC motifs with the identified phytochemical ligands exhibited good binding affinity. The identified phytochemical compounds were observed to be comparatively stable at different conditions (cationic salts, and pH); however, a concentration-dependent increase in the haemolytic assay was observed against sheep as well as human erythrocytes. Conclusions In silico molecular docking studies provided useful insights to understand the interaction of phytochemical ligands with protein motifs of pathogen and should be used routinely before the wet screening of any phytochemicals for their antibacterial, stability, and safety aspects.

Screening of Commercial and Pecan Shell–Extracted Liquid Smoke Agents as Natural Antimicrobials against Foodborne Pathogens

2012 ◽  
Vol 75 (6) ◽  
pp. 1148-1152 ◽  
Author(s):  
ELLEN J. VAN LOO ◽  
D. BABU ◽  
PHILIP G. CRANDALL ◽  
STEVEN C. RICKE
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Antioxidant Properties ◽  
Inhibitory Effects ◽  
Natural Antimicrobials ◽  
E Coli ◽  
Liquid Smoke ◽  
Water Based ◽  
Smoke Sample

Liquid smoke extracts have traditionally been used as flavoring agents, are known to possess antioxidant properties, and serve as natural alternatives to conventional antimicrobials. The antimicrobial efficacies of commercial liquid smoke samples may vary depending on their source and composition and the methods used to extract and concentrate the smoke. We investigated the MICs of eight commercial liquid smoke samples against Salmonella Enteritidis, Staphylococcus aureus, and Escherichia coli. The commercial liquid smoke samples purchased were supplied by the manufacturer as water-based or concentrated extracts of smoke from different wood sources. The MICs of the commercial smokes to inhibit the growth of foodborne pathogens ranged from 0.5 to 6.0% for E. coli, 0.5 to 8.0% for Salmonella, and 0.38 to 6% for S. aureus. The MIC for each liquid smoke sample was similar in its effect on both E. coli and Salmonella. Solvent-extracted antimicrobials prepared using pecan shells displayed significant differences between their inhibitory concentrations depending on the type of solvent used for extraction. The results indicated that the liquid smoke samples tested in this study could serve as effective natural antimicrobials and that their inhibitory effects depended more on the solvents used for extraction than the wood source.

scholarly journals Structure–functionality relationship and pharmacological profiles of Pseudomonas aeruginosa alkylquinolone quorum sensing modulators

2017 ◽  
Vol 15 (21) ◽  
pp. 4620-4630 ◽  
Author(s):  
Ahmed A. M. Kamal ◽  
Lucia Petrera ◽  
Jens Eberhard ◽  
Rolf W. Hartmann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Molecular Docking ◽  
Quorum Sensing ◽  
Structural Requirements ◽  
Inverse Agonists ◽  
Pharmacological Profiles

Alkylquinolone derived compounds revealed four pharmacological profiles for PqsR modulation. Molecular docking illuminated the structural requirements. Only inverse agonists were effective pathoblockers inhibiting pyocyanin.

scholarly journals Quorum Sensing Is a Global Regulatory Mechanism in Enterohemorrhagic Escherichia coli O157:H7

2001 ◽  
Vol 183 (17) ◽  
pp. 5187-5197 ◽  
Author(s):  
Vanessa Sperandio ◽  
Alfredo G. Torres ◽  
Jorge A. Girón ◽  
James B. Kaper
Keyword(s):  
Escherichia Coli ◽  
Quorum Sensing ◽  
Type Strain ◽  
Wild Type Strain ◽  
Regulatory Mechanism ◽  
Sos Response ◽  
Enterohemorrhagic Escherichia Coli ◽  
Trna Genes ◽  
Wild Type ◽  
E Coli

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is responsible for outbreaks of bloody diarrhea and hemolytic-uremic syndrome in many countries. EHEC virulence mechanisms include the production of Shiga toxins (Stx) and formation of attaching and effacing (AE) lesions on intestinal epithelial cells. We recently reported that genes involved in the formation of the AE lesion were regulated by quorum sensing through autoinducer-2, which is synthesized by the product of the luxS gene. In this study we hybridized an E. coli gene array with cDNA synthesized from RNA that was extracted from EHEC strain 86-24 and its isogenicluxS mutant. We observed that 404 genes were regulated by luxS at least fivefold, which comprises approximately 10% of the array genes; 235 of these genes were up-regulated and 169 were down-regulated in the wild-type strain compared to in theluxS mutant. Down-regulated genes included several involved in cell division, as well as ribosomal and tRNA genes. Consistent with this pattern of gene expression, theluxS mutant grows faster than the wild-type strain (generation times of 37.5 and 60 min, respectively, in Dulbecco modified Eagle medium). Up-regulated genes included several involved in the expression and assembly of flagella, motility, and chemotaxis. Using operon::lacZ fusions to class I, II, and III flagellar genes, we were able to confirm this transcriptional regulation. We also observed fewer flagella by Western blotting and electron microscopy and decreased motility halos in semisolid agar in the luxS mutant. The average swimming speeds for the wild-type strain and the luxS mutant are 12.5 and 6.6 μm/s, respectively. We also observed an increase in the production of Stx due to quorum sensing. Genes encoding Stx, which are transcribed along with λ-like phage genes, are induced by an SOS response, and genes involved in the SOS response were also regulated by quorum sensing. These results indicate that quorum sensing is a global regulatory mechanism for basic physiological functions of E. coli as well as for virulence factors.

Antibiofilm, Anti-Quorum Sensing Activities, and Molecular Docking Studies of Seriphidium quettense Essential Oil

2021 ◽  
Author(s):  
Rubina Naz Qaisrani ◽  
Shah Iram Niaz ◽  
Muhammad Akram ◽  
Abdul Rafey ◽  
Amanullah ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Quorum Sensing ◽  
Essential Oil ◽  
Docking Studies ◽  
Molecular Docking Studies
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