Acyl homoserine lactone-based quorum sensing stimulates biofilm formation by Salmonella Enteritidis in anaerobic conditions

A functional luxIR-type Quorum Sensing (QS) system is present in Acidithiobacillus ferrooxidans. However, cell-cell communication among various acidophilic chemolithoautotrophs growing on pyrite has not been studied in detail. These aspects are the scope of this study with emphasis on the effects exerted by the N-acyl-homoserine lactone (AHL) type signaling molecules which are produced by Acidithiobacillus ferrooxidans. Their effects on attachment and leaching efficiency by other leaching bacteria, such as Acidithiobacillus ferrivorans, Acidiferrobacter spp. SPIII/3 and Leptospirillum ferrooxidans in pure and mixed cultures growing on pyrite is shown.

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Influence of Glucose Concentrations on Biofilm Formation, Motility, Exoprotease Production, and Quorum Sensing in Aeromonas hydrophila

Journal of Food Protection ◽

10.4315/0362-028x.jfp-12-321 ◽

2013 ◽

Vol 76 (2) ◽

pp. 239-247 ◽

Cited By ~ 51

Author(s):

IQBAL KABIR JAHID ◽

NA-YOUNG LEE ◽

ANNA KIM ◽

SANG-DO HA

Keyword(s):

Quorum Sensing ◽

Aeromonas Hydrophila ◽

Biofilm Formation ◽

Opportunistic Pathogen ◽

Homoserine Lactone ◽

Protease Production ◽

Acyl Homoserine Lactone ◽

Human Pathogen ◽

Initial Biofilm ◽

Motility Inhibition

Aeromonas hydrophila recently has received increased attention because it is opportunistic and a primary human pathogen. A. hydrophila biofilm formation and its control are a major concern for food safety because biofilms are related to virulence. Therefore, we investigated biofilm formation, motility inhibition, quorum sensing, and exoprotease production of this opportunistic pathogen in response to various glucose concentrations from 0.05 to 2.5% (wt/vol). More than 0.05% glucose significantly impaired (P < 0.05) quorum sensing, biofilm formation, protease production, and swarming and swimming motility, whereas bacteria treated with 0.05% glucose had activity similar to that of the control (0% glucose). A stage shift biofilm assay revealed that the addition of glucose (2.5%) inhibited initial biofilm formation but not later stages. However, addition of quorum sensing molecules N-3-butanoyl-DL-homoserine lactone and N-3-hexanoyl homoserine lactone partially restored protease production, indicating that quorum sensing is controlled by glucose concentrations. Thus, glucose present in food or added as a preservative could regulate acyl-homoserine lactone quorum sensing molecules, which mediate biofilm formation and virulence in A. hydrophila.

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Role of N-acyl-homoserine lactone (AHL) based quorum sensing on biofilm formation on packing media in wastewater treatment process

RSC Advances ◽

10.1039/c5ra23466b ◽

2016 ◽

Vol 6 (14) ◽

pp. 11128-11139 ◽

Cited By ~ 32

Author(s):

Huizhi Hu ◽

Junguo He ◽

Jian Liu ◽

Huarong Yu ◽

Jian Tang ◽

...

Keyword(s):

Wastewater Treatment ◽

Quorum Sensing ◽

Biofilm Formation ◽

Treatment Process ◽

Single Species ◽

Homoserine Lactone ◽

Acyl Homoserine Lactone ◽

Wastewater Treatment Process

Quorum sensing (QS) signaling has been extensively studied in granules and single species populations.

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Mechanistic analysis of a synthetic inhibitor of the Pseudomonas aeruginosa LasI quorum-sensing signal synthase

Scientific Reports ◽

10.1038/srep16569 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 29

Author(s):

O. Lidor ◽

A. Al-Quntar ◽

E. C. Pesci ◽

D. Steinberg

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

In Silico ◽

Biofilm Formation ◽

Homoserine Lactone ◽

Site Directed Mutagenesis ◽

Great Promise ◽

Acyl Homoserine Lactone ◽

Virulence Determinants

Abstract Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen responsible for many human infections. LasI is an acyl-homoserine lactone synthase that produces a quorum-sensing (QS) signal that positively regulates numerous P. aeruginosa virulence determinants. The inhibition of the LasI protein is therefore an attractive drug target. In this study, a novel in silico to in vitro complementation was applied to screen thiazolidinedione-type compounds for their ability to inhibit biofilm formation at concentrations not affecting bacterial growth. The compound (z)-5-octylidenethiazolidine-2, 4-dione (TZD-C8) was a strong inhibitor of biofilm formation and chosen for further study. Structural exploration of in silico docking predicted that the compound had high affinity for the LasI activity pocket. The TZD-C8 compound was also predicted to create hydrogen bonds with residues Arg30 and Ile107. Site-directed mutagenesis (SDM) of these two sites demonstrated that TZD-C8 inhibition was abolished in the lasI double mutant PAO-R30D, I107S. In addition, in vitro swarming motility and quorum sensing signal production were affected by TZD-C 8, confirming this compound alters the cell to cell signalling circuitry. Overall, this novel inhibitor of P. aeruginosa quorum sensing shows great promise and validates our mechanistic approach to discovering inhibitors of LuxI-type acyl-homoserine lactone synthases.

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Inhibitive Effect of Eugenol and Its Nanoemulsion on Quorum Sensing–Mediated Virulence Factors and Biofilm Formation by Pseudomonas aeruginosa

Journal of Food Protection ◽

10.4315/0362-028x.jfp-18-196 ◽

2019 ◽

Vol 82 (3) ◽

pp. 379-389 ◽

Cited By ~ 8

Author(s):

ZAIXIANG LOU ◽

KEKGABILE S. LETSIDIDI ◽

FUHAO YU ◽

ZEJUN PEI ◽

HONGXIN WANG ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Biofilm Formation ◽

Homoserine Lactone ◽

Expression Level ◽

Signal Molecules ◽

Acyl Homoserine Lactone ◽

Swarming Motility ◽

Violacein Production ◽

Virulence Factor Production

ABSTRACT The aim of the present study was to evaluate the quorum sensing (QS) inhibition potential of eugenol and eugenol nanoemulsion against QS-dependent virulence factor production and gene expression, as well as biofilm formation in Pseudomonas aeruginosa. In the current study, eugenol nanoemulsion at a sub-MIC of 0.2 mg/mL specifically inhibited about 50% of the QS-mediated violacein production in Chromobacterium violaceum, as well as the production of N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL) and C4-HSL N-acyl homoserine lactone signal molecules, pyocyanin, and swarming motility in P. aeruginosa. The inhibitive effect of eugenol and its nanoemulsion on the expression of the QS synthase genes was concentration dependent, displaying 65 and 52% expression level for lasI, respectively, and 61 and 45% expression level for rhlI, respectively, at a concentration of 0.2 mg/mL. In addition, the inhibitive effect of eugenol and its nanoemulsion on the expression of the rhlA gene responsible for the production of rhamnolipid was also concentration dependent, displaying 65 and 51% expression level for the rhlA gene, respectively, at a concentration of 0.2 mg/mL. Eugenol and its nanoemulsion also displayed 36 and 63% respective inhibition of biofilm formation by P. aeruginosa at the 0.2 mg/mL concentration. Therefore, the nanoemulsion could be used as a novel QS-based antibacterial and antibiofilm agent for the control of harmful bacteria.

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BIOFILM FORMATION AND QUORUM SENSING ANALYSIS OF UROPATHOGENIC MULTIDRUG RESISTANCE ESCHERICHIA COLI

International Journal of Current Pharmaceutical Research ◽

10.22159/ijcpr.2021v13i2.41549 ◽

2021 ◽

pp. 61-63

Author(s):

MOHANA PRIYA M. ◽

G. BHUVANESHWARI

Keyword(s):

Escherichia Coli ◽

Multidrug Resistance ◽

Quorum Sensing ◽

Biofilm Formation ◽

Homoserine Lactone ◽

Retardation Factor ◽

Clinical Microbiology Laboratory ◽

Acyl Homoserine Lactone ◽

Chromatography Method ◽

E Coli

Objective: Escherichia coli (E. coli) are gram-negative facultative anaerobes which are commonly found in the lower intestine. Biofilm production in E. coli promotes colonization and leads to an increase rate of infections, and such infections may be difficult to treat as they exhibit multidrug resistance (MDR). Methods: 50 strains of uropathogenic E. coli were collected from Clinical Microbiology laboratory at Saveetha medical college and hospital for a time period of 3 mo. Strains were identified by conventional biochemical methods. Biofilm formation and quorum sensing analysis were performed by the Microtitre plate method and Thin Layer Chromatography method (TLC), respectively. Results: In this study, 46 (92%) of E. coli strains were strong, 3(6%) were intermediate and 1(2%) were weak biofilm producers. From TLC analysis, 34 (68%) of the strains produced Acyl Homoserine Lactone molecules. Out of which, 16 isolates were shown unknown analytes of Retardation factor (Rf) value greater than 1. The Rf values identified were 3 unsubstituted C4 (5), 3 unsubstituted C6 (3), 3 oxo C8 (3), 3 oxo C4 (4), 3 oxo C6 (2), 3 oxo C1 (1). Conclusion: In this study, 100% of isolates were biofilm producers. Of which 18 strains produced known Acyl Homoserine Lactone molecules and 16 isolates produced unknown analytes. Thus, quorum sensing molecules plays a major role in biofilm formation.

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N-acyl homoserine lactone molecules assisted quorum sensing: effects consequences and monitoring of bacteria talking in real life

Archives of Microbiology ◽

10.1007/s00203-021-02381-9 ◽

2021 ◽

Author(s):

Ömür Acet ◽

Demet Erdönmez ◽

Burcu Önal Acet ◽

Mehmet Odabaşı

Keyword(s):

Quorum Sensing ◽

Real Life ◽

Homoserine Lactone ◽

Acyl Homoserine Lactone

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Signal Integration in Quorum Sensing Enables Cross-Species Induction of Virulence in Pectobacterium wasabiae

mBio ◽

10.1128/mbio.00398-17 ◽

2017 ◽

Vol 8 (3) ◽

Cited By ~ 13

Author(s):

Rita S. Valente ◽

Pol Nadal-Jimenez ◽

André F. P. Carvalho ◽

Filipe J. D. Vieira ◽

Karina B. Xavier

Keyword(s):

Signal Transduction ◽

Quorum Sensing ◽

Plant Pathogen ◽

Bacterial Species ◽

Homoserine Lactone ◽

Signal Molecules ◽

Acyl Homoserine Lactone ◽

Interspecies Interactions ◽

Major Factors

ABSTRACT Bacterial communities can sense their neighbors, regulating group behaviors in response to cell density and environmental changes. The diversity of signaling networks in a single species has been postulated to allow custom responses to different stimuli; however, little is known about how multiple signals are integrated and the implications of this integration in different ecological contexts. In the plant pathogen Pectobacterium wasabiae (formerly Erwinia carotovora), two signaling networks—the N-acyl homoserine lactone (AHL) quorum-sensing system and the Gac/Rsm signal transduction pathway—control the expression of secreted plant cell wall-degrading enzymes, its major virulence determinants. We show that the AHL system controls the Gac/Rsm system by affecting the expression of the regulatory RNA RsmB. This regulation is mediated by ExpR2, the quorum-sensing receptor that responds to the P. wasabiae cognate AHL but also to AHLs produced by other bacterial species. As a consequence, this level of regulation allows P. wasabiae to bypass the Gac-dependent regulation of RsmB in the presence of exogenous AHLs or AHL-producing bacteria. We provide in vivo evidence that this pivotal role of RsmB in signal transduction is important for the ability of P. wasabiae to induce virulence in response to other AHL-producing bacteria in multispecies plant lesions. Our results suggest that the signaling architecture in P. wasabiae was coopted to prime the bacteria to eavesdrop on other bacteria and quickly join the efforts of other species, which are already exploiting host resources. IMPORTANCE Quorum-sensing mechanisms enable bacteria to communicate through small signal molecules and coordinate group behaviors. Often, bacteria have various quorum-sensing receptors and integrate information with other signal transduction pathways, presumably allowing them to respond to different ecological contexts. The plant pathogen Pectobacterium wasabiae has two N-acyl homoserine lactone receptors with apparently the same regulatory functions. Our work revealed that the receptor with the broadest signal specificity is also responsible for establishing the link between the main signaling pathways regulating virulence in P. wasabiae. This link is essential to provide P. wasabiae with the ability to induce virulence earlier in response to higher densities of other bacterial species. We further present in vivo evidence that this novel regulatory link enables P. wasabiae to join related bacteria in the effort to degrade host tissue in multispecies plant lesions. Our work provides support for the hypothesis that interspecies interactions are among the major factors influencing the network architectures observed in bacterial quorum-sensing pathways. IMPORTANCE Quorum-sensing mechanisms enable bacteria to communicate through small signal molecules and coordinate group behaviors. Often, bacteria have various quorum-sensing receptors and integrate information with other signal transduction pathways, presumably allowing them to respond to different ecological contexts. The plant pathogen Pectobacterium wasabiae has two N-acyl homoserine lactone receptors with apparently the same regulatory functions. Our work revealed that the receptor with the broadest signal specificity is also responsible for establishing the link between the main signaling pathways regulating virulence in P. wasabiae. This link is essential to provide P. wasabiae with the ability to induce virulence earlier in response to higher densities of other bacterial species. We further present in vivo evidence that this novel regulatory link enables P. wasabiae to join related bacteria in the effort to degrade host tissue in multispecies plant lesions. Our work provides support for the hypothesis that interspecies interactions are among the major factors influencing the network architectures observed in bacterial quorum-sensing pathways.

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