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Microorganisms
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Staphylococcal Infections (Host and Pathogenic Factors) 2.0
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Staphylococcal Infections (Host and Pathogenic Factors) 2.0

A special issue of Microorganisms (ISSN 2076-2607). This special issue belongs to the section "Molecular Microbiology and Immunology".

Deadline for manuscript submissions: closed (28 February 2022) | Viewed by 17036

Special Issue Editor

Dr. Rajan P. Adhikari

E-Mail Website1 Website2
Guest Editor
Integrated Biotherapeutics, Inc., Rockville, MD, USA
Interests: bacterial toxins; host-pathogen interactions; bacterial pathogens; Staphylococcus aureus
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This Special Issue is the continuation of our previous special issue "Staphylococcal Infections (Host and Pathogenic Factors) 1.0".

Although 30% of the healthy human population is colonized with various Staphylococcus spp., some staphylococcal strains, referred to as opportunistic pathogens, can cause minor to life-threatening diseases. The pathogenicity of these bacteria depends on their virulence factors and the robustness of the regulatory networks expressing these virulence factors. Virulence factors of pathogenic Staphylococcus spp. consist of numerous toxins, enterotoxins (some of which act as superantigens), enzymes, and proteins (cytoplasmic, extracellular, and surface) that are regulated by two-component (TC) and quorum-sensing (QS) regulatory networks. For example, based on their homology with quorum-sensing molecules/components, one Staphylococcus aureus species can alter the toxin/surface protein production of another S. aureus species either synergistically or antagonistically. To invade this niche, some other Staphylococcus species, such as Staphylococcus simulans, produce a potent endopeptidase called lysostaphin, which can lyse and eradicate the pathogenic S. aureus. Some other Staphylococcus species produce autolysins and cationic peptides to win the intra- and inter-species competition. The outcome of this microbial invasion depends not only on pathogenic factors but also on the host’s internal and external defense mechanisms, including a healthy skin microbiome. A healthy skin microbiome population consisting of Staphylococcus epidermidis can prevent colonization by other major pathogens. As normal host microflora, these commensals establish a complex relationship with the host as well as the surrounding microbial communities. This Special Issue of Microorganisms is focused on studies and recent advancements in our understanding of staphylococcal virulence mechanisms that enable Staphylococcus spp. either to successfully establish themselves as a colonizer or to overcome the host’s defense system to cause infection.

Dr. Rajan P. Adhikari
Guest Editor

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 submissions that pass pre-check are 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. Microorganisms is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). 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

  • S. aureus
  • S. epidermidis
  • Staphylococcus spp.
  • pore-forming toxins (hemolysins and leukotoxins)
  • quorum sensing (QS) and two component (TC) systems
  • colonization
  • biofilm formation
  • surface proteins
  • enterotoxins (superantigens)

Published Papers (6 papers)

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Research

18 pages, 2098 KiB  
Article
Effects of Growth Stage on the Characterization of Enterotoxin A-Producing Staphylococcus aureus-Derived Membrane Vesicles
by Yuka Yamanashi, Yuko Shimamura, Haruka Sasahara, Misaki Komuro, Kuniaki Sasaki, Yasujiro Morimitsu and Shuichi Masuda
Microorganisms 2022, 10(3), 574; https://doi.org/10.3390/microorganisms10030574 - 06 Mar 2022
Cited by 4 | Viewed by 2224
Abstract
Virulence factors, such as staphylococcal enterotoxin A (SEA), are contained within membrane vesicles (MVs) in the cell membrane of Staphylococcus aureus. In this study, the effects of the growth stage on quantitative and qualitative changes in the components contained in the MVs [...] Read more.
Virulence factors, such as staphylococcal enterotoxin A (SEA), are contained within membrane vesicles (MVs) in the cell membrane of Staphylococcus aureus. In this study, the effects of the growth stage on quantitative and qualitative changes in the components contained in the MVs of S. aureus SEA-producing strains were examined. Changes in the expression levels of S. aureus genes were examined at each growth stage; phenol-soluble modulin (PSM) gene reached a maximum after 8 h, and the expression of cell membrane-related genes was decreased after 6 h. Based on these gene expression patterns, MVs were prepared at 6, 17, and 24 h. The particle size of MVs did not change depending on the growth stage. MVs prepared after culture for 17 h maintained their particle size when stored at 23 °C. The amount of SEA in the culture supernatant and MVs were not correlated. Bifunctional autolysin, a protein involved in cell wall biosynthesis/degradation, was increased in MVs at 17 h. The expression pattern of inflammation-related genes in human adult low calcium high temperature (HaCaT) cells induced by MVs was different for each growth stage. The inclusion components of S. aureus-derived MVs are selective, depend on the stage of growth, and may play an important role in toxicity. Full article
(This article belongs to the Special Issue Staphylococcal Infections (Host and Pathogenic Factors) 2.0)
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15 pages, 6556 KiB  
Article
Three Lipid Emulsions Reduce Staphylococcus aureus-Stimulated Phagocytosis in Mouse RAW264.7 Cells
by Ming-Shan Chen, Yi-Wei Tung, Chia-Lin Hu, Hui-Ju Chang, Wen-Chun Lin and Shew-Meei Sheu
Microorganisms 2021, 9(12), 2479; https://doi.org/10.3390/microorganisms9122479 - 30 Nov 2021
Cited by 2 | Viewed by 2018
Abstract
Soybean oil (SO)-, SO medium-chain triglyceride (MCT)-, olive oil (OO)-, and fish oil (FO)-based lipid emulsions are generally applied in clinical practice via intravenous injection for patients with nutritional requirements. The function of lipid emulsions on immune modulation remains inconsistent, and their effects [...] Read more.
Soybean oil (SO)-, SO medium-chain triglyceride (MCT)-, olive oil (OO)-, and fish oil (FO)-based lipid emulsions are generally applied in clinical practice via intravenous injection for patients with nutritional requirements. The function of lipid emulsions on immune modulation remains inconsistent, and their effects on macrophages are limited. In the present study, we used a model of S. aureus-infected mouse RAW264.7 macrophages to determine the influence of three different compositions of lipid emulsions (Lipofundin, ClinOleic, and Omegaven) on reactive oxygen species (ROS) production, phagocytosis, and bacterial survival. The three individual lipid emulsions similarly enhanced bacterial survival but reduced S. aureus-stimulated ROS, phagocytosis of S. aureus bioparticles conjugate, polymerization of F-actin, and phosphorylation of AKT, JNK, and ERK. Compared with the JNK and ERK inhibitors, the PI3K inhibitor markedly suppressed the phagocytosis of S. aureus bioparticles conjugate and the polymerization of F-actin, whereas it significantly increased the bacterial survival. These results suggest that the three lipid emulsions diminished ROS production and phagocytosis, resulting in increased bacterial survival. PI3K predominantly mediated the inhibitory effects of the lipid emulsions on the phagocytosis of mouse RAW264.7 macrophages. Full article
(This article belongs to the Special Issue Staphylococcal Infections (Host and Pathogenic Factors) 2.0)
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11 pages, 1123 KiB  
Communication
Genetic Diversity of Staphylococcus aureus Strains from a Tertiary Care Hospital in Rawalpindi, Pakistan
by Muhammad Ali Syed, Bushra Jamil, Hazem Ramadan, Maria Rukan, Shahzad Ali, Shahid Ahmad Abbasi, Tiffanie A. Woodley and Charlene R. Jackson
Microorganisms 2021, 9(11), 2301; https://doi.org/10.3390/microorganisms9112301 - 05 Nov 2021
Cited by 3 | Viewed by 2862
Abstract
Staphylococcus aureus is an important healthcare-associated bacterium that causes a multitude of infections in humans such as superficial skin and soft tissue infections, necrotizing pneumonia, foodborne illnesses and postsurgical infections. Treatment of S. aureus infections has become more complicated due to the emergence [...] Read more.
Staphylococcus aureus is an important healthcare-associated bacterium that causes a multitude of infections in humans such as superficial skin and soft tissue infections, necrotizing pneumonia, foodborne illnesses and postsurgical infections. Treatment of S. aureus infections has become more complicated due to the emergence of Methicillin-Resistant Staphylococcus aureus (MRSA), some of which are multidrug resistant. The present study aimed to characterize S. aureus isolates from a tertiary care hospital in the Rawalpindi district of Pakistan. Staphylococci were isolated from 300 clinical samples collected from January 2018 to January 2019 and S. aureus isolates were tested for antimicrobial susceptibility and analyzed using Pulsed-Field Gel Electrophoresis (PFGE), Multi-Locus Sequence Typing (MLST), staphylococcal cassette chromosome mec (SCCmec) and spa typing. Approximately 25.3% (76/300) of the clinical samples were positive for S. aureus; of those, 88.2% (67/76) were mecA+ (MRSA). In addition to the β-lactam antibiotics, high levels of resistance were also found to the fluoroquinolones (ciprofloxacin, gatifloxacin and levofloxacin (73.7% each)). Of the 23 different spa types identified, the majority of isolates belonged to spa type t632 and t657 (9/66; 13.6% each spa type). ST772-t657 (Bengal Bay clone) was the most commonly identified clone in this study although other clones circulating around different regions of the world were also found indicating the diversity in MRSA isolates from this area of Pakistan. This study emphasizes the need to monitor MRSA in the clinical setting for improved infection control and treatment options. Full article
(This article belongs to the Special Issue Staphylococcal Infections (Host and Pathogenic Factors) 2.0)
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30 pages, 6147 KiB  
Article
Staphylococcus aureus Transcriptome Data and Metabolic Modelling Investigate the Interplay of Ser/Thr Kinase PknB, Its Phosphatase Stp, the glmR/yvcK Regulon and the cdaA Operon for Metabolic Adaptation
by Chunguang Liang, Ana B. Rios-Miguel, Marcel Jarick, Priya Neurgaonkar, Myriam Girard, Patrice François, Jacques Schrenzel, Eslam S. Ibrahim, Knut Ohlsen and Thomas Dandekar
Microorganisms 2021, 9(10), 2148; https://doi.org/10.3390/microorganisms9102148 - 14 Oct 2021
Cited by 4 | Viewed by 3115
Abstract
Serine/threonine kinase PknB and its corresponding phosphatase Stp are important regulators of many cell functions in the pathogen S. aureus. Genome-scale gene expression data of S. aureus strain NewHG (sigB+) elucidated their effect on physiological functions. Moreover, metabolic modelling from these [...] Read more.
Serine/threonine kinase PknB and its corresponding phosphatase Stp are important regulators of many cell functions in the pathogen S. aureus. Genome-scale gene expression data of S. aureus strain NewHG (sigB+) elucidated their effect on physiological functions. Moreover, metabolic modelling from these data inferred metabolic adaptations. We compared wild-type to deletion strains lacking pknB, stp or both. Ser/Thr phosphorylation of target proteins by PknB switched amino acid catabolism off and gluconeogenesis on to provide the cell with sufficient components. We revealed a significant impact of PknB and Stp on peptidoglycan, nucleotide and aromatic amino acid synthesis, as well as catabolism involving aspartate transaminase. Moreover, pyrimidine synthesis was dramatically impaired by stp deletion but only slightly by functional loss of PknB. In double knockouts, higher activity concerned genes involved in peptidoglycan, purine and aromatic amino acid synthesis from glucose but lower activity of pyrimidine synthesis from glucose compared to the wild type. A second transcriptome dataset from S. aureus NCTC 8325 (sigB−) validated the predictions. For this metabolic adaptation, PknB was found to interact with CdaA and the yvcK/glmR regulon. The involved GlmR structure and the GlmS riboswitch were modelled. Furthermore, PknB phosphorylation lowered the expression of many virulence factors, and the study shed light on S. aureus infection processes. Full article
(This article belongs to the Special Issue Staphylococcal Infections (Host and Pathogenic Factors) 2.0)
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10 pages, 2600 KiB  
Communication
IL-17C and IL-17RE Promote Wound Closure in a Staphylococcus aureus-Based Murine Wound Infection Model
by Linda Pätzold, Alexandra Stark, Felix Ritzmann, Carola Meier, Thomas Tschernig, Jörg Reichrath, Robert Bals, Markus Bischoff and Christoph Beisswenger
Microorganisms 2021, 9(9), 1821; https://doi.org/10.3390/microorganisms9091821 - 27 Aug 2021
Cited by 4 | Viewed by 2602
Abstract
The epithelial cytokine interleukin-17C (IL-17C) mediates inflammation through the interleukin 17 receptor E (IL-17RE). Prior studies showed a detrimental role of IL-17C in the pathogenesis of immune-mediated skin diseases (e.g., psoriasis). Here, we examined the role of IL-17C/IL-17RE in wound closure in a [...] Read more.
The epithelial cytokine interleukin-17C (IL-17C) mediates inflammation through the interleukin 17 receptor E (IL-17RE). Prior studies showed a detrimental role of IL-17C in the pathogenesis of immune-mediated skin diseases (e.g., psoriasis). Here, we examined the role of IL-17C/IL-17RE in wound closure in a Staphylococcus aureus wound infection model. We demonstrate that wound closure is significantly delayed in IL-17RE (Il-17re−/−)- and 17C (Il-17c−/−)-deficient mice. There was no significant difference between WT, Il-17re−/−, and Il-17c−/− mice in the absence of infection. Deficiency for IL-17RE and IL-17C did not significantly affect the elimination of bacteria. IL-17C expression was increased in the epidermis of human S. aureus-infected skin. Our results indicate that the IL-17C/IL-17RE axis contributes to the closure of infected wounds but does not contribute to the elimination of S. aureus. Full article
(This article belongs to the Special Issue Staphylococcal Infections (Host and Pathogenic Factors) 2.0)
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10 pages, 415 KiB  
Communication
Nasal Methicillin-Resistant Staphylococcus aureus Colonization in Patients with Type 1 Diabetes in Taiwan
by Chun-Ya Kang, Eugene Yu-Chuan Kang, Chi-Chun Lai, Wei-Che Lo, Kun-Jen Chen, Wei-Chi Wu, Laura Liu, Yih-Shiou Hwang, Fu-Sung Lo and Yhu-Chering Huang
Microorganisms 2021, 9(6), 1296; https://doi.org/10.3390/microorganisms9061296 - 15 Jun 2021
Viewed by 2588
Abstract
Nasal methicillin-resistant Staphylococcus aureus (MRSA) colonies are an essential reservoir of infection, especially for patients with diabetes. However, data on MRSA colonization in patients with type 1 diabetes are limited. We investigated the epidemiology of MRSA colonization in patients with type 1 diabetes. [...] Read more.
Nasal methicillin-resistant Staphylococcus aureus (MRSA) colonies are an essential reservoir of infection, especially for patients with diabetes. However, data on MRSA colonization in patients with type 1 diabetes are limited. We investigated the epidemiology of MRSA colonization in patients with type 1 diabetes. This prospective cross-sectional study was conducted in a medical center (Chang Gung Memorial Hospital) in Taiwan from 1 July to 31 December 2020. Nasal sampling and MRSA detection were performed. The molecular characteristics of MRSA isolates were tested, and factors associated with MRSA colonization were analyzed. We included 245 patients with type 1 diabetes; nasal MRSA colonization was identified in 13 (5.3%) patients. All isolates belonged to community-associated MRSA genetic strains; the most frequent strain was clonal complex 45 (53.8%), followed by ST59 (30.8%) (a local community strain). MRSA colonization was positively associated with age ≤ 10 years, body mass index < 18 kg/m2, and diabetes duration < 10 years; moreover, it was negatively associated with serum low-density lipoprotein cholesterol ≥ 100 mg/dL. No independent factor was reported. The nasal MRSA colonization rate in type 1 diabetes is approximately 5% in Taiwan. Most of these colonizing strains are community strains, namely clonal complex 45 and ST59. Full article
(This article belongs to the Special Issue Staphylococcal Infections (Host and Pathogenic Factors) 2.0)
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