Review of Potential Pseudomonas Weaponry, Relevant to the Pseudomonas–Aspergillus Interplay, for the Mycology Community

Pseudomonas aeruginosa is one of the most prominent opportunistic bacteria in airways of cystic fibrosis patients and in immunocompromised patients. These bacteria share the same polymicrobial niche with other microbes, such as the opportunistic fungus Aspergillus fumigatus. Their inter-kingdom interactions and diverse exchange of secreted metabolites are responsible for how they both fare in competition for ecological niches. The outcomes of their contests likely determine persistent damage and degeneration of lung function. With a myriad of virulence factors and metabolites of promising antifungal activity, P. aeruginosa products or their derivatives may prove useful in prophylaxis and therapy against A. fumigatus. Quorum sensing underlies the primary virulence strategy of P. aeruginosa, which serves as cell–cell communication and ultimately leads to the production of multiple virulence factors. Understanding the quorum-sensing-related pathogenic mechanisms of P. aeruginosa is a first step for understanding intermicrobial competition. In this review, we provide a basic overview of some of the central virulence factors of P. aeruginosa that are regulated by quorum-sensing response pathways and briefly discuss the hitherto known antifungal properties of these virulence factors. This review also addresses the role of the bacterial secretion machinery regarding virulence factor secretion and maintenance of cell–cell communication.

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Virulence factors regulation by the quorum-sensing and Rsm systems in the marine strain Pseudomonas aeruginosa ID4365, a natural mutant in lasR

FEMS Microbiology Letters ◽

10.1093/femsle/fnaa092 ◽

2020 ◽

Vol 367 (12) ◽

Cited By ~ 1

Author(s):

Miguel Cocotl-Yañez ◽

Martín Paolo Soto-Aceves ◽

Abigail González-Valdez ◽

Luis Servín-González ◽

Gloria Soberón-Chávez

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Virulence Factors ◽

Reference Strain ◽

Ecological Niches ◽

Human Pathogen ◽

Strain Pao1 ◽

Opportunistic Human Pathogen ◽

Marine Strain

ABSTRACT Pseudomonas aeruginosa is an opportunistic human pathogen that is able to produce several virulence factors such as pyocyanin, rhamnolipids and elastase. In the clinical reference strain PAO1, synthesis of these virulence factors is regulated transcriptionally by quorum sensing (QS) and post-transcriptionally by the Rsm system. Herein, we investigated the role of these systems in the control of the pyocyanin, rhamnolipids and elastase production in the marine strain ID4365. We found that this strain carries a nonsense mutation in lasR that makes it a natural mutant in the Las QS system. However, its QS response is still functional with the Rhl system activating virulence factors synthesis. We found that the Rsm system affects virulence factors production, since overexpression of RsmA reduces pyocyanin production whereas RsmY overexpression increases its synthesis. Unexpectedly, and in contrast to the type strain PAO1, inactivation of rsmA increases pyocyanin but reduces elastase and rhamnolipids production by a reduction of RhlR levels. Thus, QS and Rsm systems are involved in regulating virulence factors production, but this regulation is different to the PAO1 strain even though their genomes are highly conserved. It is likely that these differences are related to the different ecological niches in which these strains lived.

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Faculty Opinions recommendation of A cell-cell communication signal integrates quorum sensing and stress response.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717995806.793476388 ◽

2013 ◽

Author(s):

Fergal O'Gara

Keyword(s):

Stress Response ◽

Quorum Sensing ◽

Cell Communication ◽

Communication Signal ◽

A Cell ◽

Cell Cell

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Faculty Opinions recommendation of Non-autonomous role of Cdc42 in cell-cell communication during collective migration.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727259206.793528543 ◽

2017 ◽

Author(s):

Vivian Tang

Keyword(s):

Cell Communication ◽

Collective Migration ◽

Cell Cell

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Quorum Sensing – A Stratagem for Conquering Multi-Drug Resistant Pathogens

Current Pharmaceutical Design ◽

10.2174/1381612826666201210105638 ◽

2020 ◽

Vol 26 ◽

Author(s):

Madison Tonkin ◽

Shama Khan ◽

Mohmmad Younus Wani ◽

Aijaz Ahmad

Keyword(s):

Drug Resistance ◽

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation ◽

Cell Communication ◽

Natural Compounds ◽

Quorum Sensing Inhibitors ◽

Communication Technique ◽

Multicellular Organisms ◽

Chemical Strategies

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.

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Cross-kingdom inhibition of bacterial virulence and communication by probiotic yeast metabolites

Microbiome ◽

10.1186/s40168-021-01027-8 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Orit Malka ◽

Dorin Kalson ◽

Karin Yaniv ◽

Reut Shafir ◽

Manikandan Rajendran ◽

...

Keyword(s):

Quorum Sensing ◽

Gut Microbiome ◽

Bacterial Infections ◽

Pathogenic Bacteria ◽

Molecular Mechanisms ◽

Human Microbiome ◽

Cell Communication ◽

Probiotic Yeast ◽

Gut Pathogen ◽

Cell Cell

Abstract Background Probiotic milk-fermented microorganism mixtures (e.g., yogurt, kefir) are perceived as contributing to human health, and possibly capable of protecting against bacterial infections. Co-existence of probiotic microorganisms are likely maintained via complex biomolecular mechanisms, secreted metabolites mediating cell-cell communication, and other yet-unknown biochemical pathways. In particular, deciphering molecular mechanisms by which probiotic microorganisms inhibit proliferation of pathogenic bacteria would be highly important for understanding both the potential benefits of probiotic foods as well as maintenance of healthy gut microbiome. Results The microbiome of a unique milk-fermented microorganism mixture was determined, revealing a predominance of the fungus Kluyveromyces marxianus. We further identified a new fungus-secreted metabolite—tryptophol acetate—which inhibits bacterial communication and virulence. We discovered that tryptophol acetate blocks quorum sensing (QS) of several Gram-negative bacteria, particularly Vibrio cholerae, a prominent gut pathogen. Notably, this is the first report of tryptophol acetate production by a yeast and role of the molecule as a signaling agent. Furthermore, mechanisms underscoring the anti-QS and anti-virulence activities of tryptophol acetate were elucidated, specifically down- or upregulation of distinct genes associated with V. cholerae QS and virulence pathways. Conclusions This study illuminates a yet-unrecognized mechanism for cross-kingdom inhibition of pathogenic bacteria cell-cell communication in a probiotic microorganism mixture. A newly identified fungus-secreted molecule—tryptophol acetate—was shown to disrupt quorum sensing pathways of the human gut pathogen V. cholerae. Cross-kingdom interference in quorum sensing may play important roles in enabling microorganism co-existence in multi-population environments, such as probiotic foods and the gut microbiome. This discovery may account for anti-virulence properties of the human microbiome and could aid elucidating health benefits of probiotic products against bacterially associated diseases.

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