scholarly journals Xylitol Inhibits Growth and Blocks Virulence in Serratia marcescens

2021 ◽  
Vol 9 (5) ◽  
pp. 1083
Author(s):  
Ahdab N. Khayyat ◽  
Wael A. H. Hegazy ◽  
Moataz A. Shaldam ◽  
Rasha Mosbah ◽  
Ahmad J. Almalki ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Therapeutic Option ◽  
Nosocomial Pathogen ◽  
Swarming Motility ◽  
Natural Ligand ◽  
In Silico Study ◽  
Virulence Factor Production

Serratia marcescens is an opportunistic nosocomial pathogen and causes wound and burn infections. It shows high resistance to antibiotics and its pathogenicity is mediated by an arsenal of virulence factors. Another therapeutic option to such infections is targeting quorum sensing (QS), which controls the expression of different S. marcescens virulence factors. Prevention of QS can deprive S. marcescens from its bacterial virulence without applying stress on the bacterial growth and facilitates the eradication of the bacteria by immunity. The objective of the current study is to explore the antimicrobial and antivirulence activities of xylitol against S. marcescens. Xylitol could inhibit the growth of S. marcescens. Sub-inhibitory concentrations of xylitol could inhibit biofilm formation, reduce prodigiosin production, and completely block protease activity. Moreover, xylitol decreased swimming motility, swarming motility and increased the sensitivity to hydrogen peroxide. The expression of rsmA, pigP, flhC, flhD fimA, fimC, shlA bsmB, and rssB genes that regulate virulence factor production was significantly downregulated by xylitol. In silico study showed that xylitol could bind with the SmaR receptor by hydrophobic interaction and hydrogen bonding, and interfere with the binding of the natural ligand with SmaR receptor. An in vivo mice survival test confirmed the ability of xylitol to protect mice against the virulence of S. marcescens. In conclusion, xylitol is a growth and virulence inhibitor in S. marcescens and can be employed for the treatment of S. marcescens wound and burn infections.

scholarly journals Trigonella foenum-graceum(Seed) Extract Interferes with Quorum Sensing Regulated Traits and Biofilm Formation in the Strains ofPseudomonas aeruginosaandAeromonas hydrophila

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Fohad Mabood Husain ◽  
Iqbal Ahmad ◽  
Mohd Shahnawaz Khan ◽  
Nasser Abdulatif Al-Shabib
Keyword(s):  
Virulence Factors ◽  
Biofilm Formation ◽  
Significant Inhibition ◽  
Seed Extract ◽  
Methanol Fraction ◽  
Swarming Motility ◽  
C Elegans ◽  
Medicinal Properties ◽  
Aquatic Pathogen

Trigonella foenum-graecumL. (Fenugreek) is an important plant of the Leguminosae family known to have medicinal properties. However, fraction based antiquorum sensing and antibiofilm activities have not been reported from this plant. In the present studyT. foenum-graecumseed extract was sequentially fractionated and sub-MICs were tested for above activities. The methanol fraction of the extract demonstrated significant inhibition of AHL regulated virulence factors: protease, LasB elastase, pyocyanin production, chitinase, EPS, and swarming motility inPseudomonas aeruginosaPAO1 and PAF79. Further, QS dependent virulence factor in the aquatic pathogenAeromonas hydrophilaWAF38 was also reduced. Application ofT. foenum-graecumseed extract to PAO1, PAF79, and WAF38 decreased the biofilm forming abilities of the pathogens by significant levels. The extract also exhibited reduced AHL levels and subsequent downregulation oflasBgene.In vivostudy showed an enhanced survival of PAO1-preinfectedC. elegansafter treatment with extract at 1 mg/mL. Further, the major compound detected by GC-MS, caffeine, reduced the production of QS regulated virulence factors and biofilm at 200 µg/mL concentration indicating its role in the activity of the methanol extract. The results of the present study reveal the potential anti-QS and antibiofilm property ofT. foenum-graceumextract and caffeine.

scholarly journals Attenuation of Aeromonas hydrophila Infection in Carassius auratus by YtnP, a N-acyl Homoserine Lactonase from Bacillus licheniformis T-1

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 631
Author(s):  
Mengfan Peng ◽  
Wentao Tong ◽  
Zhen Zhao ◽  
Ling Xiao ◽  
Zhaoyue Wang ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Bacillus Licheniformis ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Carassius Auratus ◽  
Quorum Quenching ◽  
Inhibition Rate ◽  
Sequence Identity

In this experiment, the quorum quenching gene ytnP of Bacillus licheniformis T-1 was cloned and expressed, and the effect against infection of Aeromonas hydrophila ATCC 7966 was evaluated in vitro and vivo. The BLAST results revealed a 99% sequence identity between the ytnP gene of T-1 and its homolog in B.subtilis sub sp. BSP1, and the dendroGram showed that the similarity in the YtnP protein in T-1 was 100% in comparison with B.subtilis 3610, which was categorized as the Aidc cluster of the MBL family. The AHL lactonase activity of the purified YtnP was detected as 1.097 ± 0.7 U/mL with C6-HSL as the substrate. Otherwise, purified YtnP protein could significantly inhibit the biofilm formation of A.hydrophila ATCC 7966 with an inhibition rate of 68%. The MIC of thiamphenicol and doxycycline hydrochloride against A. hydrophila reduced from 4 μg/mL and 0.5 μg/mL to 1 μg/mL and 0.125 μg/mL, respectively, in the presence of YtnP. In addition, YtnP significantly inhibited the expression of five virulence factors hem, ahyB, ast, ep, aerA of A. hydrophila ATCC 7966 as well (p < 0.05). The results of inhibition on virulence showed a time-dependence tendency, while the strongest anti-virulence effects were within 4–24 h. In vivo, when the YtnP protein was co-injected intraperitoneally with A. hydrophila ATCC 7966, it attenuated the pathogenicity of A. hydrophila and the accumulated mortality was 27 ± 4.14% at 96 h, which was significantly lower than the average mortality of 78 ± 2.57% of the Carassius auratus injected with 108 CFU/mL of A. hydrophila ATCC 7966 only (p < 0.001). In conclusion, the AHL lactonase in B. licheniformis T-1 was proven to be YtnP protein and could be developed into an agent against infection of A. hydrophila in aquaculture.

scholarly journals Inhibition of Quorum Sensing in Serratia marcescens AS-1 by Synthetic Analogs of N-Acylhomoserine Lactone

2007 ◽  
Vol 73 (20) ◽  
pp. 6339-6344 ◽  
Author(s):  
Tomohiro Morohoshi ◽  
Toshitaka Shiono ◽  
Kiyomi Takidouchi ◽  
Masashi Kato ◽  
Norihiro Kato ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Serratia Marcescens ◽  
Biofilm Formation ◽  
Acyl Chain ◽  
Regulatory System ◽  
Homoserine Lactone ◽  
Signal Molecule ◽  
Swarming Motility ◽  
Gram Negative ◽  
Acylhomoserine Lactone

ABSTRACT Quorum sensing is a regulatory system for controlling gene expression in response to increasing cell density. N-Acylhomoserine lactone (AHL) is produced by gram-negative bacteria, which use it as a quorum-sensing signal molecule. Serratia marcescens is a gram-negative opportunistic pathogen which is responsible for an increasing number of serious nosocomial infections. S. marcescens AS-1 produces N-hexanoyl homoserine lactone (C6-HSL) and N-(3-oxohexanoyl) homoserine lactone and regulates prodigiosin production, swarming motility, and biofilm formation by AHL-mediated quorum sensing. We synthesized a series of N-acyl cyclopentylamides with acyl chain lengths ranging from 4 to 12 and estimated their inhibitory effects on prodigiosin production in AS-1. One of these molecules, N-nonanoyl-cyclopentylamide (C9-CPA), had a strong inhibitory effect on prodigiosin production. C9-CPA also inhibited the swarming motility and biofilm formation of AS-1. A competition assay revealed that C9-CPA was able to inhibit quorum sensing at four times the concentration of exogenous C6-HSL and was more effective than the previously reported halogenated furanone. Our results demonstrated that C9-CPA was an effective quorum-sensing inhibitor for S. marcescens AS-1.

In vitro and in vivo efficacy of rosmarinic acid on quorum sensing mediated biofilm formation and virulence factor production in Aeromonas hydrophila

Biofouling ◽  
2016 ◽  
Vol 32 (10) ◽  
pp. 1171-1183 ◽  
Author(s):  
Kannan Rama Devi ◽  
Ramanathan Srinivasan ◽  
Arunachalam Kannappan ◽  
Sivasubramanian Santhakumari ◽  
Murugan Bhuvaneswari ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Virulence Factor ◽  
Aeromonas Hydrophila ◽  
Rosmarinic Acid ◽  
Biofilm Formation ◽  
In Vivo Efficacy ◽  
Factor Production ◽  
Virulence Factor Production

Piper betle and its bioactive metabolite phytol mitigates quorum sensing mediated virulence factors and biofilm of nosocomial pathogen Serratia marcescens in vitro

2016 ◽  
Vol 193 ◽  
pp. 592-603 ◽  
Author(s):  
Ramanathan Srinivasan ◽  
Kannan Rama Devi ◽  
Arunachalam Kannappan ◽  
Shunmugiah Karutha Pandian ◽  
Arumugam Veera Ravi
Keyword(s):  
Quorum Sensing ◽  
Serratia Marcescens ◽  
Virulence Factors ◽  
Piper Betle ◽  
Nosocomial Pathogen ◽  
Bioactive Metabolite

scholarly journals Cephalosporins target quorum sensing and suppress virulence of Pseudomonas aeruginosa in Caenorhabditis elegans infection model

2020 ◽  
Author(s):  
Lokender Kumar ◽  
Nathanael Brenner ◽  
John Brice ◽  
Judith Klein-Seetharaman ◽  
Susanta K. Sarkar
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Caenorhabditis Elegans ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Host Cells ◽  
Infection Model ◽  
Host Immune System ◽  
Bacterial Cells

ABSTRACTPseudomonas aeruginosa utilizes a chemical social networking system referred to as quorum sensing (QS) to strategically co-ordinate the expression of virulence factors and biofilm formation. Virulence attributes damage the host cells, impair the host immune system, and protect bacterial cells from antibiotic attack. Thus, anti-QS agents may act as novel anti-infective therapeutics to treat P. aeruginosa infections. The present study was performed to evaluate the anti-QS, anti-biofilm, and anti-virulence activity of β-lactam antibiotics (carbapenems and cephalosporins) against P. aeruginosa. The anti-QS activity was quantified using Chromobacterium violaceum CV026 as a QS reporter strain. Our results showed that cephalosporins including cefepime (CP), ceftazidime (CF), and ceftriaxone (CT) exhibited potent anti-QS and anti-virulence activities against P. aeruginosa PAO1. These antibiotics significantly impaired motility phenotypes, decreased pyocyanin production, and reduced the biofilm formation by P. aeruginosa PAO1. In the present study, we studied isogenic QS mutants of PAO1: ΔLasR, ΔRhlR, ΔPqsA, and ΔPqsR and found that the levels of virulence factors of antibiotic-treated PAO1 were comparable to QS mutant strains. Molecular docking predicted high binding affinities of cephalosporins for the ligand-binding pocket of QS receptors (CviR, LasR, and PqsR). In addition, our results showed that the anti-microbial activity of aminoglycosides increased in the presence of sub-inhibitory concentrations (sub-MICs) of CP against P. aeruginosa PAO1. Further, utilizing Caenorhabditis elegans as an animal model for the in vivo anti-virulence effects of antibiotics, cephalosporins showed a significant increase in C. elegans survival by suppressing virulence factor production in P. aeruginosa. Thus, our results indicate that cephalosporins might provide a viable anti-virulence therapy in the treatment of infections caused by multi-drug resistant P. aeruginosa.

Virulence Factors in Candida species

2020 ◽  
Vol 21 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Monika Staniszewska
Keyword(s):  
Virulence Factors ◽  
Biofilm Formation ◽  
Hydrolytic Enzymes ◽  
Signal Transduction Pathway ◽  
In Vivo Studies ◽  
Ergosterol Biosynthesis ◽  
High Morbidity ◽  
Type Locus

: Fungal diseases are severe and have very high morbidity as well as up to 60% mortality for patients diagnosed with invasive fungal infection. In this review, in vitro and in vivo studies provided us with the insight into the role of Candida virulence factors that mediate their success as pathogens, such as: membrane and cell wall (CW) barriers, dimorphism, biofilm formation, signal transduction pathway, proteins related to stress tolerance, hydrolytic enzymes (e.g. proteases, lipases, haemolysins), and toxin production. The review characterized the virulence of clinically important C. albicans, C. parapsilosis, C. tropicalis, C. glabrata and C. krusei. Due to the white-opaque transition in the mating-type locus MTL-homozygous cells, C. albicans demonstrates an advantage over other less related species of Candida as a human commensal and pathogen. It was reviewed that Candida ergosterol biosynthesis genes play a role in cellular stress and are essential for Candida pathogenesis both in invasive and superficial infections. Hydrolases associated with CW are involved in the host-pathogen interactions. Adhesins are crucial in colonization and biofilm formation, an important virulence factor for candidiasis. Calcineurin is involved in membrane and CW stress as well as virulence. The hyphae-specific toxin, named candidalysin, invades mucosal cells facilitating fungal invasion into deeper tissues. Expression of this protein promotes resistance to neutrophil killing in candidiasis. The virulence factors provide immunostimulatory factors, activating dendric cells and promoting T cell infiltration and activation. Targeting virulence factors, can reduce the risk of resistance development in Candida infections.

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