SEARCH · PubMed Health

Results for “Quorum sensing”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

27 records · Page 2Linked to original sources

PubMed2026

Perfluorooctane sulfonate drives the synergistic dissemination of antimicrobial resistance and pathogenicity during sludge anaerobic digestion.

Per- and polyfluoroalkyl substances, one of the most prevalent and persistent emerging contaminants in sludge, may drive the dissemination of antimicrobial resistance and pathogenicity during sludge treatment. However, the mechanisms underlying perfluorooctane sulfonate (PFOS)-mediated propagation of antibiotic resistance genes (ARGs) and virulence factors (VFs) remain poorly understood. This study investigated the effects of PFOS (1 and 10 μg/g-dw) on ARGs dynamics and virulence risks. Quantitative PCR and metagenomic analysis revealed that PFOS stress led to the widespread enrichment of ARGs, the total abundance of mobile genetic elements (MGEs) and VFs also increased by 33.22-37.62% and 6.71-8.41%, respectively. Metagenomic binning results demonstrated that most metagenome-assembled genomes carrying ARGs or VFs simultaneously harbored MGEs. Mechanistically, excessive reactive oxygen species production and enhanced substrate-level phosphorylation for ATP generation may contribute to the increased horizontal transfer potential of ARGs under PFOS stress, which further facilitated the convergence of antimicrobial resistance and virulence traits within pathogens. Furthermore, PFOS may have hindered the negative regulation of the RhlI/RhlR quorum sensing system on the Type III secretion system, stimulating the secretion of VFs. This study elucidates the mechanisms by which PFOS promotes the dissemination of ARGs and pathogenicity during anaerobic digestion, highlighting the potentially overlooked environmental health risks of PFOS during sludge disposal.

Alkanesulfonic Acids↗

PubMed2026

Systematic Genome Mining of Peptide Metallophore Pathways Uncovers Novel Dibenzo-α-Pyrone Siderophores in Streptomyces sp. HB-R818.

Metallophores are metal-chelating natural products that enable microorganisms to acquire essential metal ions and mediate processes such as iron uptake, quorum sensing, and interspecies competition. Metallophores also display potent antimicrobial and anticancer activities, highlighting their biomedical and biotechnological potential. Despite Streptomyces being prolific producers of bioactive metabolites, their metallophore pathways remain largely unexplored. Here, we systematically mined 519 reference Streptomyces genomes to elucidate the distribution, diversity, and structural features of metallophores and identified a new metallophore biosynthetic gene cluster (BGC) (ser) from sponge-derived Streptomyces sp. HB-R818. Using a metabologenomics-based strategy, five new siderophore analogs serobactins A-E (1-5) and known enterobactin (6) were isolated. These compounds show potential to inhibit tumor invasion and feature a unique dibenzo-α-pyrone scaffold in structure, formed through the cyclization of an extra 2,3-dihydroxybenzoic acid with 2,3-dihydroxybenzoyl serine. The BGC (ser) was validated by the nonribosomal peptide synthetase gene knockout; the biosynthesis of 1-6 was proposed.

Siderophores↗

PubMed2026

Whole-genome sequencing reveals hidden antimicrobial resistance genes in phenotypically susceptible probiotic candidate lactic acid bacteria.

Phenotypic assays commonly used to evaluate probiotic safety may fail to detect clinically relevant antimicrobial resistance (AMR), potentially allowing genetically concerning strains to appear acceptable based on MIC testing alone. To explore this issue, we applied whole-genome sequencing (WGS) to three lactic acid bacteria (LAB) isolates previously identified as probiotic candidates based on acid and bile tolerance, antagonism against enteric pathogens, and biofilm formation in vitro: Lactiplantibacillus plantarum L25F and L22F (from pigs) and Ligilactobacillus salivarius AF2319 (from a chicken). Genome annotation identified extensive repertoires of probiotic-associated genes (46-47 per strain) linked to stress tolerance, adhesion, immunomodulation, and quorum sensing, supporting functional potential. The two L. plantarum strains exhibited broader predicted metabolic capacities than L. salivarius AF2319. However, genomic analysis revealed acquired AMR genes with complex genotype-phenotype relationships not fully apparent from phenotypic testing. The L. plantarum strains harbored lnu(A) (99.79% identity) on extrachromosomal DNA, conferring the L-phenotype (lincomycin resistance, clindamycin susceptibility); clindamycin MICs (1 mg/L) were concordant with this genotype, though lincomycin MICs were not determined. L. salivarius AF2319 carried tet(M), tet(L), and erm(C) (99.48%, 99.49%, and 99.45% identity by ResFinder, respectively) on extrachromosomal DNA; notably, the erythromycin MIC (1 mg/L) was precisely at the EFSA breakpoint (≤ 1 mg/L), representing borderline genotype-phenotype discordance potentially due to silent gene expression. Under current EFSA QPS criteria, these acquired ARGs would preclude all three strains from approval as probiotic feed additives despite favorable functional profiles, underscoring the indispensable role of WGS-based AMR gene detection in modern probiotic safety evaluation.

Probiotics↗

PubMed2026

Revealing Functional Traits of Insect Pest Suppressive Rhizobacterial Strains Through Comparative Genomics.

Root inoculation with rhizobacteria is an emerging strategy to enhance plant resistance to aphid herbivory, yet the microbial functional traits underpinning these responses remain poorly characterised. Here, we present a comparative genomic analysis of five rhizobacteria (Acidovorax radicis N35, Bacillus subtilis B171, Bacillus velezensis FZB42, Rhizobium radiobacter F4 and Pseudomonas simiae WCS417r) that suppress aphids when inoculated onto barley. As expected, functional variation largely reflected phylogenetic relatedness; however, candidate traits implicated in modulation of plant immune defences were conserved across all strains, including biosynthesis of 2,3-butanediol, riboflavin and salicylic acid. Additional shared functions, linked to plant defence signalling, included phytoene and squalene biosynthesis (absent in P. simiae) and N-acyl homoserine lactone quorum sensing (absent in Bacillus spp.). Strain-specific traits were also identified, including surfactin production in Bacillus spp. and hydrogen cyanide biosynthesis in A. radicis and P. simiae. Comparison with a broader collection of rhizobacteria revealed that many putative plant-beneficial functions identified were widely conserved, including among closely related phytopathogens. This extensive functional overlap suggests aphid suppression cannot be explained solely by presence or absence of broad functional traits, but rather by specific trait combinations, regulatory differences, or context-dependent expression. This highlights the need for genome-informed approaches for bioinoculant discovery.

Animals↗

PubMed2025

Genomic and stress resistance characterization of Lactiplantibacillus plantarum GX17, a potential probiotic for animal feed applications.

UNLABELLED: Lactobacilli, recognized as beneficial bacteria within the human body, are celebrated for their multifaceted probiotic functions, including the regulation of intestinal flora, enhancement of body immunity, and promotion of nutrient absorption. This study comprehensively analyzed the genotypic and phenotypic characteristics of Lactiplantibacillus plantarum (L. plantarum) strains isolated from the intestines of healthy chicks and assessed their potential as probiotics. The assembled genome consists of 29,521,986 bp, and a total of 1,771 coding sequences (CDSs) were predicted. Based on the entire genome sequence analysis, 50 stress resistance genes and seven virulence factors were identified. The results of the phenotypic experiments showed that the strain had good resistance to high temperature, low temperature, acid, alkali, salt, artificial gastrointestinal fluid, and strong antioxidant capacity. Additionally, transcriptomic analysis confirmed that under stress conditions, the expression levels of key genes were significantly upregulated. Therefore, the phenotypic characteristics of L. plantarum GX17 align well with its genotypic features, demonstrating promising probiotic properties. This strain holds great potential as a probiotic candidate, and further investigation into its beneficial effects on human health is warranted. IMPORTANCE: In humans, Lactiplantibacillus plantarum may synergize with host microbiota to ameliorate dysbiosis-related pathologies, enhance immunomodulation, and facilitate micronutrient bioavailability. For livestock, its application could improve feed conversion ratios, suppress enteric pathogens through competitive exclusion, and mitigate antibiotic overuse, "a critical strategy in One Health frameworks." Further investigations into strain-specific mechanisms (e.g., postbiotic metabolites, quorum sensing regulation) are warranted to translate these genomic-phenotypic advantages into sustainable health solutions across species.

Probiotics↗

PubMed2026

Whole-genome profiling of antimicrobial resistance and virulence determinants in extensively-drug resistant Pseudomonas aeruginosa isolates causing ventilator associated pneumonia in Egypt.

Among critically ill ICU patients under prolonged mechanical ventilation, Pseudomonas aeruginosa is one of the most common cause of ventilator-associated pneumonia (VAP), with antimicrobial pressure leading to emergence of multidrug, extensively drug and pandrug-resistant (PDR) strains. In Egypt, very little genomic data exist on P. aeruginosa associated with VAP. This study aimed at characterizing the antimicrobial resistance (AMR) determinants, virulence repertoire, MGEs, and sequence types of two highly drug-resistant Pseudomonas aeruginosa isolates, including one pandrug-resistant colistin-resistant isolate and one extensively drug-resistant colistin-susceptible isolate from respiratory tract of Egyptian ICU patients suffering from VAP. The two isolates were identified conventionally and confirmed to the species level using MALDI-TOF MS. Antibiotic susceptibility was assessed using the VITEK-2 Compact system and the broth microdilution method. Genome analysis was performed using PATRIC, ResFinder, CARD, and Mobile Element Finder. For both isolates, resistance was found to all antibiotics routinely tested, however, one isolate had high-level colistin resistance (MIC > 64 µg/mL), while the other isolate was still colistin susceptible. Whole-genome sequencing identified two rare sequence types, ST2023 and ST2685, both 6.5-7.6 Mb in size with a 66% GC content. The presence of 21 MGEs in the SRR36105565 genome shows that it has high genomic flexibility, including a broader resistome than other strains, such as blaVIM-2 and OXA variants, aminoglycoside-modifying enzymes, crpP, and disinfectant-resistance markers. Both isolates retained large virulence determinants including Type III and Type VI secretion systems, alginate regulation genes, quorum-sensing networks, and siderophore biosynthesis clusters. It also represents one of the first genomic studies of VAP associated PDR P. aeruginosa from Egypt. The combination of widespread AMR with intact virulence supports the potential value of future genomic surveillance efforts and improved antimicrobial stewardship in local ICUs.

Pneumonia, Ventilator-Associated↗

PubMed2026

Convergent evolution of immune evasion in ESKAPE pathogens: A cross-pathogen architecture of conserved host-defense checkpoints.

Antimicrobial resistance in ESKAPE pathogens is primarily attributed to resistance genes, yet persistent infections despite appropriate therapy implicate immune evasion as an independent driver of treatment failure. Although immune-evasion mechanisms have been extensively characterized in individual pathogens, their shared architecture across the ESKAPE group remains insufficiently integrated. This review synthesizes current evidence to show that phylogenetically diverse ESKAPE pathogens have convergently evolved conserved strategies to evade host immunity under comparable selective pressures. A cross-pathogen immune-evasion framework emerges, encompassing impaired pathogen recognition, complement inhibition, phagocyte dysfunction, immunometabolic reprogramming, biofilm-mediated protection, and persistence-promoting inflammation, together with pathogen-specific virulence mechanisms. These processes intersect with adaptive immune dysfunction and emerging concepts, including quorum-sensing-mediated immunomodulation, trained immunity, and the itaconate-succinate immunometabolic axis, forming an interconnected persistence network rather than isolated virulence traits. This systems-level perspective identifies conserved host-directed therapeutic targets that may complement conventional antimicrobial therapy across species. However, host-directed therapies, immunotherapeutics, and vaccines remain largely preclinical or have shown inconsistent clinical efficacy. Mechanistic evidence is strongest for Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, whereas substantial knowledge gaps persist for Enterococcus faecium, Acinetobacter baumannii, and Enterobacter spp. Overcoming persistent ESKAPE infections will require targeting conserved host-pathogen interactions alongside pathogen-specific antimicrobial resistance mechanisms.

Convergent immune evasion↗

PubMed2025

Characterization of gut microbiota signatures in Indian preterm infants with necrotizing enterocolitis: a shotgun metagenomic approach.

INTRODUCTION: Necrotizing enterocolitis (NEC) is an inflammatory bowel disease that primarily affects preterm infants. Predisposing risk factors for NEC include prematurity, formula feeding, anemia, and sepsis. To date, no studies have investigated the gut microbiota of preterm infants with NEC in India. METHOD: In the current study, shotgun metagenomic sequencing was performed on fecal samples from premature infants with NEC and healthy preterm infants (n = 24). Sequencing was conducted using the NovaSeq X Plus platform, generating 2 × 150 bp paired-end reads. The infants were matched based on gestational age and postnatal age. RESULT: The median time to NEC diagnosis was 9 days (range: 1-30 days). Taxonomic analysis revealed a high prevalence of Enterobacteriaceae at the family level, with the genera Klebsiella and Escherichia particularly prominent in neonates with NEC. No statistically significant differences in alpha or beta diversity were observed between stool samples from infants with and without NEC. Linear regression analysis demonstrated that Enterobacteriaceae were significantly more abundant in stool samples from infants with NEC than without NEC (q < 0.05). Differential abundance analysis using Linear Discriminant Analysis Effect Size (LEfSe) identified Klebsiella pneumoniae and Escherichia coli as enriched in the gut microbiota of preterm infants with NEC. Functional analysis revealed an increase in genes associated with lipopolysaccharide (LPS) O-antigen, the type IV secretion system (T4SS), the L-rhamnose pathway, quorum sensing, and iron transporters, including ABC transporters, in stool samples from infants with NEC. CONCLUSION: The high prevalence of Enterobacteriaceae and enrichment of LPS O-antigen and T4SS genes may be associated with NEC in Indian preterm infants.

Humans↗

PubMed2026

Boosting domestic wastewater treatment with quorum signal-augmented heterotrophic nitrification-aerobic denitrification bacterial-algal aerobic granular sludge.

The aerobic bacterial-algal granular sludge (ABGS) enhanced with heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria, as a novel symbiotic technology, exhibits fluctuating treatment efficiency and unstable performance primarily due to the unstable symbiotic relationship. This study proposes an innovative approach to strengthening the bacteria-algae symbiosis by introducing exogenous signaling molecules. Concurrently, high-throughput, correlation analysis of environmental factors and metagenomic sequencing techniques are employed to elucidate the enhancement mechanisms of the signaling molecules. The results demonstrate that signaling molecule enhancement boosted total nitrogen (TN) removal efficiency by 24.51 % in the bacteria-algae symbiotic system (X1). Scanning electron microscopy (SEM) characterization revealed that the addition of signaling molecules resulted in more compact aerobic granular sludge (AGS) and markedly improved stability. High-throughput sequencing showed signaling molecules enriched denitrifying bacteria (Hydrogenophaga, Pseudoxanthomonas, Thauera, Zoogloea) and organic-degrading Desulfomicrobium, optimizing microbial diversity and enhancing nitrogen/organic removal. Correlation analysis of environmental factors indicate that the addition of C8-HSL facilitates the enrichment and functional activation of specific genera. Metagenomic analysis revealed that signaling molecules enhanced the system's denitrification performance by modulating gene expression and associated metabolic pathways. Quantitative polymerase chain reaction (qPCR) analysis further confirmed that the signaling molecules upregulated the expression of the napA, nirK, and nirS genes. An increased abundance of the napA gene facilitated aerobic denitrification (NO₃⁻-N→NO₂⁻-N), while upregulated abundance of the nirK and nirS genes accelerated nitrite reduction (NO₂⁻-N→N₂). This study aims to provide theoretical and practical foundations for implementing advanced bacteria-algae symbiotic technologies.

Denitrification↗