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Nucleic Acids Research Jan 2024Pseudomonas aeruginosa harbors sophisticated transcription factor (TF) networks to coordinately regulate cellular metabolic states for rapidly adapting to changing...
Pseudomonas aeruginosa harbors sophisticated transcription factor (TF) networks to coordinately regulate cellular metabolic states for rapidly adapting to changing environments. The extraordinary capacity in fine-tuning the metabolic states enables its success in tolerance to antibiotics and evading host immune defenses. However, the linkage among transcriptional regulation, metabolic states and antibiotic tolerance in P. aeruginosa remains largely unclear. By screening the P. aeruginosa TF mutant library constructed by CRISPR/Cas12k-guided transposase, we identify that rccR (PA5438) is a major genetic determinant in aminoglycoside antibiotic tolerance, the deletion of which substantially enhances bacterial tolerance. We further reveal the inhibitory roles of RccR in pyruvate metabolism (aceE/F) and glyoxylate shunt pathway (aceA and glcB), and overexpression of aceA or glcB enhances bacterial tolerance. Moreover, we identify that 2-keto-3-deoxy-6-phosphogluconate (KDPG) is a signal molecule that directly binds to RccR. Structural analysis of the RccR/KDPG complex reveals the detailed interactions. Substitution of the key residue R152, K270 or R277 with alanine abolishes KDPG sensing by RccR and impairs bacterial growth with glycerol or glucose as the sole carbon source. Collectively, our study unveils the connection between aminoglycoside antibiotic tolerance and RccR-mediated central carbon metabolism regulation in P. aeruginosa, and elucidates the KDPG-sensing mechanism by RccR.
Topics: Aminoglycosides; Anti-Bacterial Agents; Carbon; Pseudomonas aeruginosa; Bacterial Proteins; Gene Regulatory Networks
PubMed: 38096062
DOI: 10.1093/nar/gkad1201 -
Future Microbiology Jan 2024requires a significant breach in the host defense to cause an infection. While its virulence factors are well studied, its tropism cannot be explained only by studying... (Review)
Review
requires a significant breach in the host defense to cause an infection. While its virulence factors are well studied, its tropism cannot be explained only by studying its interaction with the host. Why are infections so rare in the intestine compared with the lung and skin? There is not enough evidence to claim specificity in virulence factors deployed by in each anatomical site, and host physiology differences between the lung and the intestine cannot easily explain the observed differences in virulence. This perspective highlights a relatively overlooked parameter in virulence, namely, potential synergies with bacteria found in the human skin and lung, as well as antagonisms with bacteria of the human intestine.
Topics: Humans; Virulence; Pseudomonas aeruginosa; Bacteria; Virulence Factors; Pseudomonas Infections; Lung; Intestines
PubMed: 37843410
DOI: 10.2217/fmb-2022-0155 -
Microbiology (Reading, England) Jun 2024Long-term administration of certain macrolides is efficacious in patients with persistent pulmonary infection, despite how limited the clinically achievable...
Long-term administration of certain macrolides is efficacious in patients with persistent pulmonary infection, despite how limited the clinically achievable concentrations are, being far below their MICs. An increase in the sub-MIC of macrolide exposure-dependent sensitivity to nitrosative stress is a typical characteristic of . However, a few clinical isolates do not respond to sub-MIC of macrolide treatment. Therefore, we examined the effects of sub-MIC of erythromycin (EM) on the sensitivity to nitrosative stress together with an efflux pump inhibitor (EPI) phenylalanine arginyl β-naphthylamide (PAβN). The sensitivity to nitrosative stress increased, suggesting that the efflux pump was involved in inhibiting the sub-MIC of macrolide effect. Analysis using efflux pump-mutant revealed that MexAB-OprM, MexXY-OprM, and MexCD-OprJ are factors in reducing the sub-MIC of macrolide effect. Since macrolides interfere with quorum sensing (QS), we demonstrated that the QS-interfering agent furanone C-30 (C-30) producing greater sensitivity to nitric oxide (NO) stress than EM. The effect of C-30 was decreased by overproduction of MexAB-OprM. To investigate whether the increase in the QS-interfering agent exposure-dependent sensitivity to nitrosative stress is characteristic of clinical isolates, we examined the viability of treated with NO. Although treatment with EM could reduce cell viability, a high variability in EM effects was observed. Conversely, C-30 was highly effective at reducing cell viability. Treatment with both C-30 and PAβN was sufficiently effective against the remaining isolates. Therefore, the combination of a QS-interfering agent and an EPI could be effective in treating infections.
Topics: Pseudomonas aeruginosa; Quorum Sensing; Microbial Sensitivity Tests; Anti-Bacterial Agents; Nitrosative Stress; Erythromycin; Membrane Transport Proteins; Furans; Dipeptides; Macrolides; Pseudomonas Infections; Humans; Bacterial Outer Membrane Proteins; Bacterial Proteins
PubMed: 38900549
DOI: 10.1099/mic.0.001464 -
Applied Microbiology and Biotechnology Dec 2024With the inappropriate use of antibiotics, antibiotic resistance has emerged as a major dilemma for patients infected with Pseudomonas aeruginosa. Elastase B (LasB), a...
With the inappropriate use of antibiotics, antibiotic resistance has emerged as a major dilemma for patients infected with Pseudomonas aeruginosa. Elastase B (LasB), a crucial extracellular virulence factor secreted by P. aeruginosa, has been identified as a key target for antivirulence therapy. Quercetin, a natural flavonoid, exhibits promising potential as an antivirulence agent. We aim to evaluate the impact of quercetin on P. aeruginosa LasB and elucidate the underlying mechanism. Molecular docking and molecular dynamics simulation revealed a rather favorable intermolecular interaction between quercetin and LasB. At the sub-MICs of ≤256 μg/ml, quercetin was found to effectively inhibit the production and activity of LasB elastase, as well as downregulate the transcription level of the lasB gene in both PAO1 and clinical strains of P. aeruginosa. Through correlation analysis, significant positive correlations were shown between the virulence gene lasB and the QS system regulatory genes lasI, lasR, rhlI, and rhlR in clinical strains of P. aeruginosa. Then, we found the lasB gene expression and LasB activity were significantly deficient in PAO1 ΔlasI and ΔlasIΔrhlI mutants. In addition, quercetin significantly downregulated the expression levels of regulated genes lasI, lasR, rhlI, rhlR, pqsA, and pqsR as well as effectively attenuated the synthesis of signaling molecules 3-oxo-C12-HSL and C4-HSL in the QS system of PAO1. Quercetin was also able to compete with the natural ligands OdDHL, BHL, and PQS for binding to the receptor proteins LasR, RhlR, and PqsR, respectively, resulting in the formation of more stabilized complexes. Taken together, quercetin exhibits enormous potential in combating LasB production and activity by disrupting the QS system of P. aeruginosa in vitro, thereby offering an alternative approach for the antivirulence therapy of P. aeruginosa infections. KEY POINTS: • Quercetin diminished the content and activity of LasB elastase of P. aeruginosa. • Quercetin inhibited the QS system activity of P. aeruginosa. • Quercetin acted on LasB based on the QS system.
Topics: Humans; Quercetin; Virulence; Pseudomonas aeruginosa; Molecular Docking Simulation; Pancreatic Elastase
PubMed: 38180553
DOI: 10.1007/s00253-023-12890-w -
Microbial Pathogenesis Dec 2023Pseudomonas aeruginosa is a Gram-negative bacteria and it has been demonstrated that immunization with the outer membrane proteins of the microbe produces most of the... (Review)
Review
Pseudomonas aeruginosa is a Gram-negative bacteria and it has been demonstrated that immunization with the outer membrane proteins of the microbe produces most of the relevant human antibodies. The peritrichous P. aeruginosa strain with MSHA fimbriae (PA-MSHA strain) has been found to be effective in the inhibition of growth and proliferation of different types of cancer cells. Furthermore, it has been revealed that PA-MSHA exhibits cytotoxicity because of the presence of MSHA and therefore it possesses anti-carcinogenic ability against different types of human cancer cell lines including, gastric, breast, hepatocarcinoma and nasopharyngeal cells. Studies have revealed that PA-MSHA exhibits therapeutic potential against cancer growth by induction of apoptosis, arrest of cell cycle, activating NF-κB/TLR5 pathway, etc. In China, PA-MSHA injections have been approved for the treatment of malignant tumor patients from very long back. The present review article demonstrates the therapeutic potential of PA-MSHA against various types of human cancers and explains the underlying mechanism.
Topics: Humans; Signal Transduction; Pseudomonas aeruginosa; Hemagglutinins; Mannose; Cell Proliferation; Liver Neoplasms
PubMed: 37871855
DOI: 10.1016/j.micpath.2023.106422 -
Methods in Molecular Biology (Clifton,... 2024Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system has been developed as a robust genome engineering tool in a variety of organisms...
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system has been developed as a robust genome engineering tool in a variety of organisms attributed to its high efficiency and versatility. In this chapter, we described the detailed procedures of CRISPR-Cas9-based genetic manipulation in Pseudomonas aeruginosa, including precise gene deletion and insertion via Cas9-mediated DNA double-strand break and homologous recombination repair. In addition, we provided a detailed protocol for cytidine base editor, a highly efficient gene inactivation and point mutation tool in Pseudomonas aeruginosa.
Topics: Gene Editing; CRISPR-Cas Systems; Pseudomonas aeruginosa; Point Mutation; Recombinational DNA Repair
PubMed: 37819511
DOI: 10.1007/978-1-0716-3473-8_1 -
Journal of Infection in Developing... Jul 2023Pseudomonas aeruginosa (PA) has emerged as a significant cause of Gram-negative infections, particularly in patients with impaired host defenses. It is one of the six... (Review)
Review
Pseudomonas aeruginosa (PA) has emerged as a significant cause of Gram-negative infections, particularly in patients with impaired host defenses. It is one of the six ESKAPE pathogens that majorly cause severe nosocomial infections. In addition to biofilm formation, PA possesses various virulence factors. It can be life-threatening due to his remarkable capacity to resist antibiotics, either intrinsically, developing adaptative resistance, or following the acquisition of resistance genes. The situation worsens when these mechanisms co-exist, conferring worrying multi-resistant phenotypes. Therapeutic options are becoming limited, which has led to the development of new antibiotics and novel alternative therapeutic strategies that require the exploration of other therapeutic avenues. Although mostly at the preclinical stages, many recent studies have reported several innovative therapeutic technologies that have demonstrated pronounced effectiveness in fighting against drug-resistant Pa strains. This literature review aims to discuss the mechanism of pyocyanic bacillus resistance to antibiotics, highlight the current state of some novel antibiotics and combination therapies, and the new alternative therapeutic approaches for treating PA infections.
Topics: Humans; Virulence Factors; Pseudomonas aeruginosa; Anti-Bacterial Agents; Phenotype; Pseudomonas Infections
PubMed: 37515798
DOI: 10.3855/jidc.17739 -
International Journal of Molecular... Aug 2023is an opportunistic Gram-negative bacterium responsible for severe nosocomial infections and is considered a critical pulmonary pathogen for both immunocompromised and...
is an opportunistic Gram-negative bacterium responsible for severe nosocomial infections and is considered a critical pulmonary pathogen for both immunocompromised and cystic fibrosis patients. Planktonic cells of possess intrinsic and acquired resistances, inactivating several classes of conventional antibiotics. Additionally, this bacterium can grow, forming biofilms, and complex structures, further hampering the action of multiple antibiotics. Here, we report the biological properties of D-Q53 CecB, an all-D enantiomer of the silkworm natural peptide Q53 CecB. Compared to the L-variant, D-Q53 CecB was resistant to in vitro degradation by humans and elastases and showed an enhanced bactericidal activity against planktonic bacteria. D-Q53 CecB was thermostable and maintained its antimicrobial activity at high salt concentrations and in the presence of divalent cations or fetal-bovine serum, although at reduced levels. Against different types of human cells, D-Q53 CecB showed cytotoxic phenomena at concentrations several folds higher compared to those active against When L- and D-Q53 CecB were compared for their antibiofilm properties, both peptides were active in inhibiting biofilm formation. However, the D-enantiomer was extremely effective in inducing biofilm degradation, suggesting this peptide as a favorable candidate in an anti- therapy.
Topics: Animals; Humans; Anti-Bacterial Agents; Biofilms; Bombyx; Cecropins; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections
PubMed: 37569868
DOI: 10.3390/ijms241512496 -
Letters in Applied Microbiology Sep 2023Pseudomonas aeruginosa is a Gram-negative bacillus associated with waterborne diseases. The objective of this study was to determine whether particular P. aeruginosa...
Pseudomonas aeruginosa is a Gram-negative bacillus associated with waterborne diseases. The objective of this study was to determine whether particular P. aeruginosa sequence types (STs) were associated with drinking water contamination in Brazil. This was achieved by searching the Pseudomonas PubMLST database, which contains the records for 8358 strains collected between 1938 and 2023. The majority (97.2%) had the complete 7-loci multilocus sequence typing profile and were assigned to 3486 STs. After eBURST (an algorithm used to infer patterns of evolutionary descent among clusters), 1219 groups with single-locus variant and 575 groups with double-locus variant were formed. Brazil was the South American country with the most isolates (n = 219, 58.24%), and the Simpson's index was 0.9392. Of the 219 Brazilian isolates, eight were isolated in water and identified as STs 252, 1417, 1605, 2502, 2620, 3078, and 3312. ST252, 1417, and 3078 have already been isolated from clinical cases worldwide. Furthermore, ST1605 and 2620, after the eBURST, they were grouped in the same clonal complex as STs involved in human infections. In conclusion, P. aeruginosa STs involved in human infections were found in bottled drinking water commercialized in Brazil, revealing that these types of drinking waters can be a vehicle of contamination.
Topics: Humans; Multilocus Sequence Typing; Drinking Water; Pseudomonas aeruginosa; Brazil; Genotype; Pseudomonas Infections
PubMed: 37738442
DOI: 10.1093/lambio/ovad109 -
PLoS Pathogens Jan 2024Pseudomonas aeruginosa is a highly pathogenic bacterium known for its ability to sense and coordinate the production of virulence factors in response to host immune...
Pseudomonas aeruginosa is a highly pathogenic bacterium known for its ability to sense and coordinate the production of virulence factors in response to host immune responses. However, the regulatory mechanisms underlying this process have remained largely elusive. In this study, we investigate the two-component system CprRS in P. aeruginosa and unveil the crucial role of the sensor protein CprS in sensing the human host defense peptide LL-37, thereby modulating bacterial virulence. We demonstrate that CprS acts as a phosphatase in the presence of LL-37, leading to the phosphorylation and activation of the response regulator CprR. The results prove that CprR directly recognizes a specific sequence within the promoter region of the HigBA toxin-antitoxin system, resulting in enhanced expression of the toxin HigB. Importantly, LL-37-induced HigB expression promotes the production of type III secretion system effectors, leading to reduced expression of proinflammatory cytokines and increased cytotoxicity towards macrophages. Moreover, mutations in cprS or cprR significantly impair bacterial survival in both macrophage and insect infection models. This study uncovers the regulatory mechanism of the CprRS system, enabling P. aeruginosa to detect and respond to human innate immune responses while maintaining a balanced virulence gene expression profile. Additionally, this study provides new evidence and insights into the complex regulatory system of T3SS in P. aeruginosa within the host environment, contributing to a better understanding of host-microbe communication and the development of novel strategies to combat bacterial infections.
Topics: Humans; Pseudomonas aeruginosa; Pseudomonas Infections; Virulence Factors; Virulence; Type III Secretion Systems; Bacterial Proteins; Gene Expression Regulation, Bacterial
PubMed: 38198506
DOI: 10.1371/journal.ppat.1011946