ijms-logo

Journal Browser

Journal Browser

Special Issue "Biofilms and Bacterial Virulence"

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Molecular Microbiology".

Deadline for manuscript submissions: 31 January 2020.

Special Issue Editors

Dr. Shiro Jimi
E-Mail
Guest Editor
Central Lab for Pathology and Morphology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
Tel. +81-92-801-1011
Interests: biofilm infection; biofilm virulence; biofilm prevention; risks of biofilm formation; eradication methods of biofilm; assay system using different substrates; inter-bacterial biofilm regulation system; MRSA
Dr. Atsushi Togawa
E-Mail
Guest Editor
1. Division of Infectious Diseases, Fukuoka University Hospital, Fukuoka, Japan;
2. Division of Medical Oncology, Hematology, and Infectious Diseases, Department of Medicine, Fukuoka University, Fukuoka, Japan
Tel. +81-92-801-1011
Interests: clinical infectious diseases; biofilm infection; Klebsiella pneumoniae infection; travel medicine
Dr. Motoyasu Miyazaki
E-Mail
Guest Editor
Department of Pharmacy, Fukuoka University Chikushi Hospital, Fukuoka, Japan
Tel. +81-92-921-1011
Interests: antimicrobial resistance; risks of biofilm formation; epidemiology of MRSA; infection control

Special Issue Information

Dear Colleagues,

Biofilm infections are serious problems in clinical settings. Some bacteria, including Staphylococcus and Pseudomonas aeruginosa, have the ability to form biofilms during their life cycle. Biofilms contribute to bacterial survival and virulence. Most biofilm investigators believe that bacterial properties change when they settle on a surface and form biofilms, which includes the acquisition of nonspecific resistance to anti-bacterial compounds. Biofilms enhance drug resistance more than one hundred times compared to bacteria in the planktonic state, as a consequence of the biofilm’s structural rigidity and/or phenotypic alterations by environmental selection, or gene reconstitution within the confines of the biofilms. The precise nature of these changes is still being unraveled. Even if these changes are understood, eradication of biofilms with drugs is not feasible because the high concentrations required may adversely affect us. For such a disparate situation, the only recourse is to go back to the basics. We may have overlooked something important, such as the exact biofilm risk and bacterial virulence, particularly in the body. This can verify the previous approaches of biofilm investigations.

In this Special Issue, we take a fresh look at this subject with the aim of challenging previous methods and concepts of biofilms. We welcome your articles in this exciting biomedical field.

Dr. Shiro Jimi
Dr. Atsushi Togawa
Dr. Motoyasu Miyazaki
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. International Journal of Molecular Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. There is an Article Processing Charge (APC) for publication in this open access journal. For details about the APC please see here. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Biofilm-forming bacteria
  • Virulence
  • Biofilm eradication
  • Substrates
  • Anti-biofilm compounds
  • Biofilm assay system

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle
Detection and Quantification of eDNA-Associated Bacterial Membrane Vesicles by Flow Cytometry
Int. J. Mol. Sci. 2019, 20(21), 5307; https://doi.org/10.3390/ijms20215307 - 25 Oct 2019
Abstract
Bacteria generate membrane vesicles, which are structures known as extracellular vesicles (EVs), reported to be involved in different pathogenic mechanisms, as it has been demonstrated that EVs participate in biofilm formation, cell-to-cell communication, bacteria–host interactions, and nutrients supply. EVs deliver nucleic acids, proteins, [...] Read more.
Bacteria generate membrane vesicles, which are structures known as extracellular vesicles (EVs), reported to be involved in different pathogenic mechanisms, as it has been demonstrated that EVs participate in biofilm formation, cell-to-cell communication, bacteria–host interactions, and nutrients supply. EVs deliver nucleic acids, proteins, and polysaccharides. It has been reported that Helicobacter pylori (H. pylori) and Lactobacillus reuteri (L. reuteri), of both planktonic and biofilm phenotypes, produce EVs carrying extracellular DNA (eDNA). Here, we used polychromatic flow cytometry (PFC) to identify, enumerate, and characterize EVs as well as the eDNA-delivering EV compartment in the biofilm and planktonic phenotypes of H.pylori ATCC 43629 and L. reuteri DSM 17938. Biofilm formation was demonstrated and analyzed by fluorescence microscopy, using a classical live/dead staining protocol. The enumeration of EVs and the detection of eDNA-associated EVs were performed by PFC, analyzing both whole samples (cells plus vesicles) and EVs isolated by ultracentrifugation confirm EVs isolated by ultracentrifugation. PFC analysis was performed relying on a known-size beaded system and a mix of three different fluorescent tracers. In detail, the whole EV compartment was stained by a lipophilic cationic dye (LCD), which was combined to PKH26 and PicoGreen that selectively stain lipids and DNA, respectively. Fluorescence microscopy results displayed that both H. pylori and L. reuteri produced well-structured biofilms. PFC data highlighted that, in both detected bacterial species, biofilms produced higher EVs counts when paralleled to the related planktonic phenotypes. Furthermore, the staining with PicoGreen showed that most of the generated vesicles were associated with eDNA. These data suggest that the use of PFC, set according to the parameters here described, allows for the study of the production of eDNA-associated EVs in different microbial species in the same or several phases of growth, thus opening new perspectives in the study of microbial derived EVs in clinical samples. Full article
(This article belongs to the Special Issue Biofilms and Bacterial Virulence)
Show Figures

Figure 1

Open AccessArticle
Role of CpxR in Biofilm Development: Expression of Key Fimbrial, O-Antigen and Virulence Operons of Salmonella Enteritidis
Int. J. Mol. Sci. 2019, 20(20), 5146; https://doi.org/10.3390/ijms20205146 - 17 Oct 2019
Abstract
Salmonella Enteritidis is a non-typhoidal serovar of great public health significance worldwide. The RpoE sigma factor and CpxRA two-component system are the major regulators of the extracytoplasmic stress response. In this study, we found that the CpxR has highly significant, but opposite effects [...] Read more.
Salmonella Enteritidis is a non-typhoidal serovar of great public health significance worldwide. The RpoE sigma factor and CpxRA two-component system are the major regulators of the extracytoplasmic stress response. In this study, we found that the CpxR has highly significant, but opposite effects on the auto-aggregation and swarming motility of S. Enteritidis. Auto-aggregation was negatively affected in the ∆cpxR mutant, whereas the same mutant significantly out-performed its wild-type counterpart with respect to swarming motility, indicating that the CpxR plays a role in biofilm-associated phenotypes. Indeed, biofilm-related assays showed that the CpxR is of critical importance in biofilm development under both static (microtiter plate) and dynamic (flow cell) media flow conditions. In contrast, the RpoE sigma factor showed no significant role in biofilm development under dynamic conditions. Transcriptomic analysis revealed that the cpxR mutation negatively affected the constitutive expression of the operons critical for biosynthesis of O-antigen and adherence, but positively affected the expression of virulence genes critical for Salmonella-mediated endocytosis. Conversely, CpxR induced the expression of curli csgAB and fimbrial stdAC operons only during biofilm development and flagellar motAB and fliL operons exclusively during the planktonic phase, indicating a responsive biofilm-associated loop of the CpxR regulator. Full article
(This article belongs to the Special Issue Biofilms and Bacterial Virulence)
Show Figures

Figure 1

Review

Jump to: Research

Open AccessReview
Plant-Derived Inhibitors of AHL-Mediated Quorum Sensing in Bacteria: Modes of Action
Int. J. Mol. Sci. 2019, 20(22), 5588; https://doi.org/10.3390/ijms20225588 - 08 Nov 2019
Abstract
Numerous gram-negative phytopathogenic and zoopathogenic bacteria utilise acylated homoserine lactone (AHL) in communication systems, referred to as quorum sensing (QS), for induction of virulence factors and biofilm development. This phenomenon positions AHL-mediated QS as an attractive target for anti-infective therapy. This review focused [...] Read more.
Numerous gram-negative phytopathogenic and zoopathogenic bacteria utilise acylated homoserine lactone (AHL) in communication systems, referred to as quorum sensing (QS), for induction of virulence factors and biofilm development. This phenomenon positions AHL-mediated QS as an attractive target for anti-infective therapy. This review focused on the most significant groups of plant-derived QS inhibitors and well-studied individual compounds for which in silico, in vitro and in vivo studies provide substantial knowledge about their modes of anti-QS activity. The current data about sulfur-containing compounds, monoterpenes and monoterpenoids, phenylpropanoids, benzoic acid derivatives, diarylheptanoids, coumarins, flavonoids and tannins were summarized; their plant sources, anti-QS effects and bioactivity mechanisms have also been summarized and discussed. Three variants of plant-derived molecules anti-QS strategies are proposed: (i) specific, via binding with LuxI-type AHL synthases and/or LuxR-type AHL receptor proteins, which have been shown for terpenes (carvacrol and l-carvone), phenylpropanoids (cinnamaldehyde and eugenol), flavonoid quercetin and ellagitannins; (ii) non-specific, by affecting the QS-related intracellular regulatory pathways by lowering regulatory small RNA expression (sulphur-containing compounds ajoene and iberin) or c-di-GMP metabolism reduction (coumarin); and (iii) indirect, via alteration of metabolic pathways involved in QS-dependent processes (vanillic acid and curcumin). Full article
(This article belongs to the Special Issue Biofilms and Bacterial Virulence)
Show Figures

Graphical abstract

Back to TopTop