Bromophenazine derivatives with potent inhibition, dispersion and eradication activities against Staphylococcus aureus biofilms

RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1120-1124 ◽  
Author(s):  
Aaron T. Garrison ◽  
Fang Bai ◽  
Yasmeen Abouelhassan ◽  
Nicholas G. Paciaroni ◽  
Shouguang Jin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Responses ◽  
Bacterial Biofilms ◽  
Host Immune Responses ◽  
Potent Inhibition ◽  
Human Infections

Bacterial biofilms are surface-attached communities of bacteria that are: (1) highly prevalent in human infections, and (2) resistant to conventional antibiotic treatments and host immune responses.

scholarly journals Staphylococcus aureus synthesizes adenosine to escape host immune responses

2009 ◽  
Vol 206 (11) ◽  
pp. 2417-2427 ◽  
Author(s):  
Vilasack Thammavongsa ◽  
Justin W. Kern ◽  
Dominique M. Missiakas ◽  
Olaf Schneewind
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Immune Responses ◽  
Virulence Factor ◽  
Adenosine Monophosphate ◽  
Healthy Individuals ◽  
Subsequent Formation ◽  
Host Immune Responses ◽  
A Cell ◽  
Exogenous Supply

Staphylococcus aureus infects hospitalized or healthy individuals and represents the most frequent cause of bacteremia, treatment of which is complicated by the emergence of methicillin-resistant S. aureus. We examined the ability of S. aureus to escape phagocytic clearance in blood and identified adenosine synthase A (AdsA), a cell wall–anchored enzyme that converts adenosine monophosphate to adenosine, as a critical virulence factor. Staphylococcal synthesis of adenosine in blood, escape from phagocytic clearance, and subsequent formation of organ abscesses were all dependent on adsA and could be rescued by an exogenous supply of adenosine. An AdsA homologue was identified in the anthrax pathogen, and adenosine synthesis also enabled escape of Bacillus anthracis from phagocytic clearance. Collectively, these results suggest that staphylococci and other bacterial pathogens exploit the immunomodulatory attributes of adenosine to escape host immune responses.

scholarly journals Staphylococcus aureus internalisation enhances bacterial survival through modulation of host immune responses and mast cell activation

Allergy ◽  
2020 ◽  
Author(s):  
Timothy C. Biggs ◽  
Rana S. Abadalkareem ◽  
Stephen M. Hayes ◽  
Rebecca E. Holding ◽  
Laurie C. Lau ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mast Cell ◽  
Immune Responses ◽  
Cell Activation ◽  
Mast Cell Activation ◽  
Bacterial Survival ◽  
Host Immune Responses

scholarly journals Staphylococcus aureus and Host Immunity in Recurrent Furunculosis

Dermatology ◽  
2019 ◽  
Vol 235 (4) ◽  
pp. 295-305 ◽  
Author(s):  
Danuta Nowicka ◽  
Ewelina Grywalska
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Responses ◽  
Bacterial Colonization ◽  
Clinical Findings ◽  
Host Immunity ◽  
Acquired Immunity ◽  
Host Immune Responses ◽  
Infection Susceptibility ◽  
Inflammatory Processes ◽  
Recurrent Furunculosis

Staphylococcus aureus is one of the severest and most persistent bacterial pathogens. The most frequent S. aureus infections include impetigo, folliculitis, furuncles, furunculosis, abscesses, hidradenitis suppurativa, and mastitis. S. aureus produces a great variety of cellular and extracellular factors responsible for its invasiveness and ability to cause pathological lesions. Their expression depends on the growth phase, environmental factors, and location of the infection. Susceptibility to staphylococcal infections is rooted in multiple mechanisms of host immune responses and reactions to bacterial colonization. Immunological and inflammatory processes of chronic furunculosis are based on the pathogenicity of S. aureus as well as innate and acquired immunity. In-depth knowledge about them may help to discover the whole pathomechanism of the disease and to develop effective therapeutic options. In this review, we focus on the S. aureus-host immune interactions in the pathogenesis of recurrent furunculosis according to the most recent experimental and clinical findings.

scholarly journals Identifying protective antigens of Staphylococcus aureus , a pathogen that suppresses host immune responses

2011 ◽  
Vol 25 (10) ◽  
pp. 3605-3612 ◽  
Author(s):  
Hwan Keun Kim ◽  
Hye‐Young Kim ◽  
Olaf Schneewind ◽  
Dominique Missiakas
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Responses ◽  
Host Immune Responses ◽  
Protective Antigens

scholarly journals Prosthesis infections after orthopedic joint replacement: the possible role of bacterial biofilms

2013 ◽  
Vol 5 (2) ◽  
pp. 14 ◽  
Author(s):  
Zhijun Song ◽  
Lotte Borgwardt ◽  
Niels Høiby ◽  
Hong Wu ◽  
Torben Sandberg Sørensen ◽  
...  
Keyword(s):  
Immune Responses ◽  
Joint Replacement ◽  
Recent Progress ◽  
Treatment Options ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Host Immune Responses ◽  
Surgical Measures ◽  
Treatment Of Infection

Prosthesis-related infection is a serious complication for patients after orthopedic joint replacement, which is currently difficult to treat with antibiotic therapy. Consequently, in most cases, removal of the infected prosthesis is the only solution to cure the infection. It is, therefore, important to understand the comprehensive interaction between the microbiological situation and the host immune responses that lead to prosthesis infections. Evidence indicates that prosthesis infections are actually biofilm-correlated infections that are highly resistant to antibiotic treatment and the host immune responses. The authors reviewed the related literature in the context of their clinical experience, and discussed the possible etiology and mechanism leading to the infections, especially problems related to bacterial biofilm, and prophylaxis and treatment of infection, including both microbiological and surgical measures. Recent progress in research into bacterial biofilm and possible future treatment options of prosthesis-related infections are discussed.

scholarly journals During the Early Stages of Staphylococcus aureus Biofilm Formation, Induced Neutrophil Extracellular Traps Are Degraded by Autologous Thermonuclease

2019 ◽  
Vol 87 (12) ◽  
Author(s):  
Andi R. Sultan ◽  
Tamara Hoppenbrouwers ◽  
Nicole A. Lemmens-den Toom ◽  
Susan V. Snijders ◽  
Johan W. van Neck ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Responses ◽  
Structural Stability ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Extracellular Dna ◽  
Content Type ◽  
Host Immune Responses ◽  
Early Stages ◽  
Biofilm Development

ABSTRACT Staphylococcus aureus extracellular DNA (eDNA) plays a crucial role in the structural stability of biofilms during bacterial colonization; on the contrary, host immune responses can be induced by bacterial eDNA. Previously, we observed production of S. aureus thermonuclease during the early stages of biofilm formation in a mammalian cell culture medium. Using a fluorescence resonance energy transfer (FRET)-based assay, we detected thermonuclease activity of S. aureus biofilms grown in Iscove’s modified Dulbecco’s medium (IMDM) earlier than that of widely studied biofilms grown in tryptic soy broth (TSB). The thermonuclease found was Nuc1, confirmed by mass spectrometry and competitive Luminex assay. These results indicate that biofilm development in IMDM may not rely on eDNA for structural stability. A bacterial viability assay in combination with wheat germ agglutinin (WGA) staining confirmed the accumulation of dead cells and eDNA in biofilms grown in TSB. However, in biofilms grown in IMDM, minimal amounts of eDNA were found; instead, polysaccharide intercellular adhesin (PIA) was detected. To investigate if this early production of thermonuclease plays a role in immune modulation by biofilm, we studied the effect of thermonuclease on human neutrophil extracellular trap (NET) formation using a nuc knockout and complemented strain. We confirmed that thermonuclease produced by early-stage biofilms grown in IMDM degraded biofilm-induced NETs. Additionally, neither the presence of biofilms nor thermonuclease stimulated an increase in reactive oxygen species (ROS) production by neutrophils. Our findings indicated that S. aureus, during the early stages of biofilm formation, actively evades the host immune responses by producing thermonuclease.

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