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Microbiology Spectrum May 2024has been associated with progression of periodontitis, characterized by inflammation and destruction of periodontal tissues. Here, we report that matcha, a product of ,...
UNLABELLED
has been associated with progression of periodontitis, characterized by inflammation and destruction of periodontal tissues. Here, we report that matcha, a product of , hampers the adherence and survival of through multiple tactics. Matcha extract (ME) inhibited the growth not only of but also of s and , while it did not inhibit growth of nine species of oral streptococci and . ME-mediated growth inhibition was characterized by both morphological and physiological changes at the bacterial envelope, which were accompanied by nano-particle formation and decreased membrane fluidity/permeability without loss of membrane integrity. ME also triggered autoaggregation of in a major fimbriae (FimA)-dependent manner. In addition, adherence of was dramatically inhibited by ME, irrespective of fimbriae. Furthermore, a structure-activity relationship study tested a series of catechins isolated from ME and identified the pyrogallol-type B-ring of catechins as essential for growth inhibition. In a clinical study to assess the microbiological and therapeutic effects of matcha mouthwash in patients with periodontitis, the number in saliva was significantly reduced by matcha mouthwash compared to the pre-intervention level. A tendency toward improvement in probing pocket depth was observed in the matcha group, although the difference was not statistically significant. Taken together, we present a proof of concept, based on the multimodal inhibitory effect of matcha against , and that matcha may have clinical applicability for prevention and treatment of periodontitis.
IMPORTANCE
Periodontitis, a multifactorial inflammatory disease of the oral cavity, results in alveolar bone destruction, and is a major cause of tooth loss of humans. In addition, emerging evidence has demonstrated associations between periodontitis and a wide range of other chronic inflammation-driven disorders, including diabetes mellitus, preterm birth, cardiovascular disease, aspiration pneumonia, rheumatoid arthritis, cognitive disorder, and cancer. In the present study, we report that matcha, a product of , hampers , a major periodontal pathobiont, in not only a series of experiments but also a pilot intervention clinical trial of patients with periodontitis, in which matcha mouthwash statistically significantly reduced the number in saliva, as compared to the pre-intervention level. Taken together, we suggest that matcha may have clinical applicability for prevention and treatment of periodontitis.
PubMed: 38771061
DOI: 10.1128/spectrum.03426-23 -
MBio Jun 2024is one of the most common nosocomial pathogens worldwide, known for its virulence, drug resistance, and elaborate sensor-response network. The primary challenge...
UNLABELLED
is one of the most common nosocomial pathogens worldwide, known for its virulence, drug resistance, and elaborate sensor-response network. The primary challenge encountered by pathogens during the initial stages of infection is the immune clearance arising from the host. The resident macrophages of barrier organs serve as the frontline defense against these pathogens. Central to our understanding is the mechanism by which bacteria modify their behavior to circumvent macrophage-mediated clearance, ensuring their persistence and colonization. To successfully evade macrophage-mediated phagocytosis, bacteria must possess an adaptive response mechanism. Two-component systems provide bacteria the agility to navigate diverse environmental challenges, translating external stimuli into cellular adaptive responses. Here, we report that the well-documented histidine kinase, LadS, coupled to a cognate two-component response regulator, PA0034, governs the expression of a vital adhesin called chaperone-usher pathway pilus cupA. The LadS/PA0034 system is susceptible to interference from the reactive oxygen species likely to be produced by macrophages and further lead to a poor adhesive phenotype with scantily cupA pilus, impairing the phagocytosis efficiency of macrophages during acute infection. This dynamic underscores the intriguing interplay: as macrophages deploy reactive oxygen species to combat bacterial invasion, the bacteria recalibrate their exterior to elude these defenses.
IMPORTANCE
The notoriety of is underscored by its virulence, drug resistance, and elaborate sensor-response network. Yet, the mechanisms by which maneuvers to escape phagocytosis during acute infections remain elusive. This study pinpoints a two-component response regulator, PA0034, coupled with the histidine kinase LadS, and responds to macrophage-derived reactive oxygen species. The macrophage-derived reactive oxygen species can impair the LadS/PA0034 system, resulting in reduced expression of cupA pilus in the exterior of . Since the cupA pilus is an important adhesin of , its deficiency reduces bacterial adhesion and changes their behavior to adopt a planktonic lifestyle, subsequently inhibiting the phagocytosis of macrophages by interfering with bacterial adhesion. Briefly, reactive oxygen species may act as environmental cues for the LadS/PA0034 system. Upon recognition, may transition to a poorly adhesive state, efficiently avoiding engulfment by macrophages.
Topics: Pseudomonas aeruginosa; Phagocytosis; Macrophages; Mice; Animals; Bacterial Proteins; Pseudomonas Infections; Fimbriae Proteins; Gene Expression Regulation, Bacterial; Fimbriae, Bacterial; Histidine Kinase; Humans; RAW 264.7 Cells
PubMed: 38771052
DOI: 10.1128/mbio.00616-24 -
Current Biology : CB Jun 2024The bacterial type VI secretion system (T6SS) is a widespread, kin-discriminatory weapon capable of shaping microbial communities. Due to the system's dependency on...
The bacterial type VI secretion system (T6SS) is a widespread, kin-discriminatory weapon capable of shaping microbial communities. Due to the system's dependency on contact, cellular interactions can lead to either competition or kin protection. Cell-to-cell contact is often accomplished via surface-exposed type IV pili (T4Ps). In Vibrio cholerae, these T4Ps facilitate specific interactions when the bacteria colonize natural chitinous surfaces. However, it has remained unclear whether and, if so, how these interactions affect the bacterium's T6SS-mediated killing. In this study, we demonstrate that pilus-mediated interactions can be harnessed by T6SS-equipped V. cholerae to kill non-kin cells under liquid growth conditions. We also show that the naturally occurring diversity of pili determines the likelihood of cell-to-cell contact and, consequently, the extent of T6SS-mediated competition. To determine the factors that enable or hinder the T6SS's targeted reduction of competitors carrying pili, we developed a physics-grounded computational model for autoaggregation. Collectively, our research demonstrates that T4Ps involved in cell-to-cell contact can impose a selective burden when V. cholerae encounters non-kin cells that possess an active T6SS. Additionally, our study underscores the significance of T4P diversity in protecting closely related individuals from T6SS attacks through autoaggregation and spatial segregation.
Topics: Vibrio cholerae; Type VI Secretion Systems; Fimbriae, Bacterial; Microbial Interactions
PubMed: 38749426
DOI: 10.1016/j.cub.2024.04.041 -
Veterinary Microbiology Jul 2024Trueperella pyogenes is an opportunistic zoonotic bacterial pathogen, whose antimicrobial resistance, virulence, and genetic relatedness between strains from animals and...
Trueperella pyogenes is an opportunistic zoonotic bacterial pathogen, whose antimicrobial resistance, virulence, and genetic relatedness between strains from animals and humans are barely studied. These characteristics were therefore analyzed for clinical T. pyogenes strains from 31 animals of 11 different species and 8 humans determining their complete circular genome sequence and antimicrobial susceptibility. The MICs of 19 antimicrobials including 3 antiseptics correlated to the resistance genes identified in silico within the genomes revealing a predominance of resistance to streptomycin (aadA9), sulfamethoxazole (sul1), and tetracycline (tet(33), tet(W/N/W)) among strains from humans and cattle. Additional resistance genes (erm(X), erm(56), cmx, drfA1, aadA1, aph(3'')-Ib (strA), aph(6)-Id (strB), aac(3)-IVa, aph(4)-Ia) were found only sporadically. The resistance genes were localized on genetic elements integrated into the chromosome. A cgMLST-based phylogenetic analysis revealed two major clusters each containing genetically diverse strains. The human strains showed the closest relatedness to strains from cattle. Virulence genes coding for fimbriae (fimA, fimC), neuroamidase (nanP, nanH), pyolysin (plo), and collagen binding protein (cbpA) were identified in strains from different hosts, but no correlation was observed between virulence factors and strain origin. The existence of resistance genes typically found in Gram-negative bacteria within the Gram-positive T. pyogenes indicates a wider capacity to adapt to antimicrobial selective pressure. Moreover, the presence of similar antimicrobial resistance profiles found in cattle and human strains as well as their closest relatedness suggests common zoonotic features and cattle as the potential source for human infections.
Topics: Animals; Humans; Phylogeny; Cattle; Anti-Bacterial Agents; Virulence; Genome, Bacterial; Microbial Sensitivity Tests; Drug Resistance, Bacterial; Actinomycetaceae; Whole Genome Sequencing; Virulence Factors; Actinomycetales Infections; Drug Resistance, Multiple, Bacterial
PubMed: 38749210
DOI: 10.1016/j.vetmic.2024.110102 -
BioRxiv : the Preprint Server For... Apr 2024Although horizontal gene transfer is pervasive in the intestinal microbiota, we understand only superficially the roles of most exchanged genes and how the mobile...
Although horizontal gene transfer is pervasive in the intestinal microbiota, we understand only superficially the roles of most exchanged genes and how the mobile repertoire affects community dynamics. Similarly, little is known about the mechanisms underlying the ability of a community to recover after a perturbation. Here, we identified and functionally characterized a large conjugative plasmid that is one of the most frequently transferred elements among Bacteroidales species and is ubiquitous in diverse human populations. This plasmid encodes both an extracellular polysaccharide and fimbriae, which promote the formation of multispecies biofilms in the mammalian gut. We use a hybridization-based approach to visualize biofilms in clarified whole colon tissue with unprecedented 3D spatial resolution. These biofilms increase bacterial survival to common stressors encountered in the gut, increasing strain resiliency, and providing a rationale for the plasmid's recent spread and high worldwide prevalence.
PubMed: 38746121
DOI: 10.1101/2024.04.29.590671 -
PLoS Computational Biology May 2024In this work, we quantitatively compare computer simulations and existing cell tracking data of P. aeruginosa surface motility in order to analyse the underlying...
In this work, we quantitatively compare computer simulations and existing cell tracking data of P. aeruginosa surface motility in order to analyse the underlying motility mechanism. We present a three dimensional twitching motility model, that simulates the extension, retraction and surface association of individual Type IV Pili (TFP), and is informed by recent experimental observations of TFP. Sensitivity analysis is implemented to minimise the number of model parameters, and quantitative estimates for the remaining parameters are inferred from tracking data by approximate Bayesian computation. We argue that the motility mechanism is highly sensitive to experimental conditions. We predict a TFP retraction speed for the tracking data we study that is in a good agreement with experimental results obtained under very similar conditions. Furthermore, we examine whether estimates for biologically important parameters, whose direct experimental determination is challenging, can be inferred directly from tracking data. One example is the width of the distribution of TFP on the bacteria body. We predict that the TFP are broadly distributed over the bacteria pole in both walking and crawling motility types. Moreover, we identified specific configurations of TFP that lead to transitions between walking and crawling states.
Topics: Pseudomonas aeruginosa; Models, Biological; Computer Simulation; Fimbriae, Bacterial; Computational Biology; Bayes Theorem; Movement
PubMed: 38743804
DOI: 10.1371/journal.pcbi.1012063 -
BMC Genomics May 2024Pseudomonas syringae pv. actinidiae (Psa) is an important bacterial plant pathogen that causes severe damage to the kiwifruit industry worldwide. Three Psa strains were... (Comparative Study)
Comparative Study
BACKGROUND
Pseudomonas syringae pv. actinidiae (Psa) is an important bacterial plant pathogen that causes severe damage to the kiwifruit industry worldwide. Three Psa strains were recently obtained from different kiwifruit orchards in Anhui Province, China. The present study mainly focused on the variations in virulence and genome characteristics of these strains based on the pathogenicity assays and comparative genomic analyses.
RESULTS
Three strains were identified as biovar 3 (Psa3), along with strain QSY6 showing higher virulence than JZY2 and YXH1 in pathogenicity assays. The whole genome assembly revealed that each of the three strains had a circular chromosome and a complete plasmid. The chromosome sizes ranged from 6.5 to 6.6 Mb with a GC content of approximately 58.39 to 58.46%, and a predicted number of protein-coding sequences ranging from 5,884 to 6,019. The three strains clustered tightly with 8 Psa3 reference strains in terms of average nucleotide identity (ANI), whole-genome-based phylogenetic analysis, and pangenome analysis, while they were evolutionarily distinct from other biovars (Psa1 and Psa5). Variations were observed in the repertoire of effectors of the type III secretion system among all 15 strains. Moreover, synteny analysis of the three sequenced strains revealed eight genomic regions containing 308 genes exclusively present in the highly virulent strain QSY6. Further investigation of these genes showed that 16 virulence-related genes highlight several key factors, such as effector delivery systems (type III secretion systems) and adherence (type IV pilus), which might be crucial for the virulence of QSY6.
CONCLUSION
Three Psa strains were identified and showed variant virulence in kiwifruit plant. Complete genome sequences and comparative genomic analyses further provided a theoretical basis for the potential pathogenic factors responsible for kiwifruit bacterial canker.
Topics: Pseudomonas syringae; Phylogeny; Genome, Bacterial; China; Actinidia; Virulence; Plant Diseases; Genomics
PubMed: 38734623
DOI: 10.1186/s12864-024-10384-1 -
MBio May 2024Extracellular cytochrome filaments are proposed to serve as conduits for long-range extracellular electron transfer. The primary functional physiological evidence has...
UNLABELLED
Extracellular cytochrome filaments are proposed to serve as conduits for long-range extracellular electron transfer. The primary functional physiological evidence has been the reported inhibition of Fe(III) oxide reduction when the gene for the filament-forming cytochrome OmcS is deleted. Here we report that the OmcS-deficient strain from that original report reduces Fe(III) oxide as well as the wild-type, as does a triple mutant in which the genes for the other known filament-forming cytochromes were also deleted. The triple cytochrome mutant displayed filaments with the same 3 nm diameter morphology and conductance as those produced by heterologously expressing the PilA pilin gene. Fe(III) oxide reduction was inhibited when the pilin gene in cytochrome-deficient mutants was modified to yield poorly conductive 3 nm diameter filaments. The results are consistent with the concept that 3 nm diameter electrically conductive pili (e-pili) are required for long-range extracellular electron transfer. In contrast, rigorous physiological functional evidence is lacking for cytochrome filaments serving as conduits for long-range electron transport.
IMPORTANCE
Unraveling microbial extracellular electron transfer mechanisms has profound implications for environmental processes and advancing biological applications. This study on challenges prevailing beliefs on cytochrome filaments as crucial components thought to facilitate long-range electron transport. The discovery of an OmcS-deficient strain's unexpected effectiveness in Fe(III) oxide reduction prompted a reevaluation of the key conduits for extracellular electron transfer. By exploring the impact of genetic modifications on ' performance, this research sheds light on the importance of 3-nm diameter electrically conductive pili in Fe(III) oxide reduction. Reassessing these mechanisms is essential for uncovering the true drivers of extracellular electron transfer in microbial systems, offering insights that could revolutionize applications across diverse fields.
Topics: Electron Transport; Geobacter; Cytochromes; Oxidation-Reduction; Ferric Compounds; Fimbriae, Bacterial; Fimbriae Proteins
PubMed: 38717196
DOI: 10.1128/mbio.00690-24 -
Frontiers in Cellular and Infection... 2024Detailed assessment of the population structure of group B (GBS) among adults is still lacking in Saudi Arabia. Here we characterized a representative collection of...
INTRODUCTION
Detailed assessment of the population structure of group B (GBS) among adults is still lacking in Saudi Arabia. Here we characterized a representative collection of isolates from colonized and infected adults.
METHODS
GBS isolates (n=89) were sequenced by Illumina and screened for virulence and antimicrobial resistance determinants. Genetic diversity was assessed by single nucleotide polymorphisms and core-genome MLST analyses.
RESULTS
Genome sequences revealed 28 sequence types (STs) and nine distinct serotypes, including uncommon serotypes VII and VIII. Majority of these STs (n=76) belonged to the human-associated clonal complexes (CCs) CC1 (33.71%), CC19 (25.84%), CC17 (11.24%), CC10/CC12 (7.87%), and CC452 (6.74%). Major CCs exhibited intra-lineage serotype diversity, except for the hypervirulent CC17, which exclusively expressed serotype III. Virulence profiling revealed that nearly all isolates (94.38%) carried at least one of the four alpha family protein genes (i.e., , , , and ), and 92.13% expressed one of the two serine-rich repeat surface proteins Srr1 or Srr2. In addition, most isolates harbored the pilus island (PI)-2a alone (15.73%) or in combination with PI-1 (62.92%), and those carrying PI-2b alone (10.11%) belonged to CC17. Phylogenetic analysis grouped the sequenced isolates according to CCs and further subdivided them along with their serotypes. Overall, isolates across all CC1 phylogenetic clusters expressed Srr1 and carried the PI-1 and PI-2a loci, but differed in genes encoding the alpha-like proteins. CC19 clusters were dominated by the III///PI-1+PI-2a (43.48%, 10/23) and V///PI-1+PI-2a (34.78%, 8/23) lineages, whereas most CC17 isolates (90%, 9/10) had the same III///P1-2b genetic background. Interestingly, genes encoding the CC17-specific adhesins HvgA and Srr2 were detected in phylogenetically distant isolates belonging to ST1212, suggesting that other highly virulent strains might be circulating within the species. Resistance to macrolides and/or lincosamides across all major CCs (n=48) was associated with the acquisition of (62.5%, 30/48), (27.1%, 13/48), (8.3%, 4/48), and (2.1%, 1/48) genes, whereas resistance to tetracycline was mainly mediated by presence of (64.18%, 43/67) and (20.9%, 14/67) alone or in combination (13.43%, 9/67).
DISCUSSION
These findings underscore the necessity for more rigorous characterization of GBS isolates causing infections.
Topics: Humans; Saudi Arabia; Streptococcus agalactiae; Streptococcal Infections; Virulence; Multilocus Sequence Typing; Drug Resistance, Bacterial; Genome, Bacterial; Genetic Variation; Serogroup; Virulence Factors; Polymorphism, Single Nucleotide; Anti-Bacterial Agents; Adult; Phylogeny; Whole Genome Sequencing; Genomics; Genotype; Microbial Sensitivity Tests; Female
PubMed: 38711928
DOI: 10.3389/fcimb.2024.1377993 -
Science Advances May 2024Tad (tight adherence) pili, part of the type IV pili family, are crucial for mechanosensing, surface adherence, bacteriophage (phage) adsorption, and cell-cycle...
Tad (tight adherence) pili, part of the type IV pili family, are crucial for mechanosensing, surface adherence, bacteriophage (phage) adsorption, and cell-cycle regulation. Unlike other type IV pilins, Tad pilins lack the typical globular β sheet domain responsible for pilus assembly and phage binding. The mechanisms of Tad pilus assembly and its interaction with phage ΦCb5 have been elusive. Using cryo-electron microscopy, we unveiled the Tad pilus assembly mechanism, featuring a unique network of hydrogen bonds at its core. We then identified the Tad pilus binding to the ΦCb5 maturation protein (Mat) through its β region. Notably, the amino terminus of ΦCb5 Mat is exposed outside the capsid and phage/pilus interface, enabling the attachment of fluorescent and affinity tags. These engineered ΦCb5 virions can be efficiently assembled and purified in , maintaining infectivity against , which presents promising applications, including RNA delivery and phage display.
Topics: Caulobacter crescentus; Fimbriae, Bacterial; Cryoelectron Microscopy; Bacteriophages; Fimbriae Proteins; Escherichia coli; Viral Proteins
PubMed: 38701202
DOI: 10.1126/sciadv.adl4450