scholarly journals A Model of an Integrated Immune System Pathway in Homo sapiens and Its Interaction with Superantigen Producing Expression Regulatory Pathway in Staphylococcus aureus: Comparing Behavior of Pathogen Perturbed and Unperturbed Pathway

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e80918 ◽  
Author(s):  
Namrata Tomar ◽  
Rajat K. De
Author(s):  
Jing Qiao ◽  
Shuolin Cui ◽  
May Xiong

Bacteria can evade the immune system once they are engulfed by phagocytic host cells. This protects them against the bactericidal action of antibiotics and allows the infection to remain latent...


2020 ◽  
Author(s):  
ahmed Al Ghaithi ◽  
Sultan Al Mastari ◽  
John Husband ◽  
Mohammed al kindi ◽  
Atika Al Bimani

AbstractPurposeOsteomyelitis is an infectious bone process leading to bone necrosis and destruction. Published reports on pathogen biofilm thus far have focused on indirect bone resorption mediated by host cells and factors secondary to immune system activation. However, direct bone resorption due to biofilm pathogen has not been adequately studied yet. This study aims to investigate the effect of biofilm pathogen in ex-vivo human bones in the absence of the host immune response using Raman spectroscopy and Scanning electron microscopy.MethodsBone samples collected from patients who underwent knee replacement surgeries were inoculated with Staphylococcus aureus bacteria. Bacterial direct effects on the bone quality were then examined, at various time intervals, using Raman spectroscopy and scanning electron microscopy.ResultsRaman spectroscopy and scanning electron demonstrated the destruction of bone structure and drop in bone quality.ConclusionThis experiment shows the direct effect of bacteria on bone during osteomyelitis in addition to the recognised destruction caused by the host immune system.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1740
Author(s):  
Elena Trizna ◽  
Diana Baidamshina ◽  
Anna Gorshkova ◽  
Valentin Drucker ◽  
Mikhail Bogachev ◽  
...  

While in a biofilm, bacteria are extremely resistant to both antimicrobials and the immune system, leading to the development of chronic infection. Here, we show that bovine hyaluronidase fused with a copolymer of 1,4-ethylenepiperazine N-oxide and (N-carboxymethyl) -1,4-ethylenepiperazinium bromide (Longidaza®) destroys both mono- and dual-species biofilms formed by various bacteria. After 4 h of treatment with 750 units of the enzyme, the residual biofilms of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae preserved about 50–70% of their initial mass. Biomasses of dual-species biofilms formed by S. aureus and the four latter species were reduced 1.5-fold after 24 h treatment, while the significant destruction of S. aureus–P. aeruginosa and S. aureus–K. pneumoniae was also observed after 4 h of treatment with Longidaza®. Furthermore, when applied in combination, Longidaza® increased the efficacy of various antimicrobials against biofilm-embedded bacteria, although with various increase-factor values depending on both the bacterial species and antimicrobials chosen. Taken together, our data indicate that Longidaza® destroys the biofilm structure, facilitating the penetration of antimicrobials through the biofilm, and in this way improving their efficacy, lowering the required dose and thus also potentially reducing the associated side effects.


2021 ◽  
Vol 7 (4) ◽  
pp. 513-527
Author(s):  
Alexis M. Hobbs ◽  
◽  
Kennedy E. Kluthe ◽  
Kimberly A. Carlson ◽  
Austin S. Nuxoll

<abstract> <p><italic>Staphylococcus aureus</italic> is widely known for its resistance and virulence causing public health concerns. However, antibiotic tolerance is also a contributor to chronic and relapsing infections. Previously, it has been demonstrated that persister formation is dependent on reduced tricarboxylic acid (TCA) cycle activity. Persisters have been extensively examined in terms of antibiotic tolerance but tolerance to antimicrobial peptides (AMPs) remains largely unexplored. AMPs are a key component of both the human and <italic>Drosophila</italic> innate immune response. TCA cycle mutants were tested to determine both antibiotic and AMP tolerance. Challenging with multiple classes of antibiotics led to increased persister formation (100- to 1,000-fold). Similarly, TCA mutants exhibited AMP tolerance with a 100- to 1,000-fold increase in persister formation when challenged with LL-37 or human β-defensin 3 (hβD3). The ability of TCA cycle mutants to tolerate the innate immune system was further examined with a <italic>D. melanogaster</italic> model. Both males and females infected with TCA cycle mutants exhibited increased mortality and had higher bacterial burdens (1.5 log) during the course of the infection. These results suggest increasing the percentage of persister cells leads to increased tolerance to components of the innate immune system.</p> </abstract>


2020 ◽  
Vol 14 (4) ◽  
pp. 2219-2234
Author(s):  
Hesham A. Malak ◽  
Hussein H. Abulreesh ◽  
Sameer R. Organji ◽  
Khaled Elbanna ◽  
Mohammed R. Shaaban ◽  
...  

Staphylococcus aureus is a major human pathogen that may cause a wide range of infections and is a frequent cause of soft tissue and bloodstream infections. It is a successful pathogen due to its collective virulence factors and its ability to evade the host immune systems. The review aims to highlight how S. aureus destroys and damage the host cells and explains how immune cells can respond to this pathogen. This review may also provide new insights that may be useful for developing new strategy for combating MRSA and its emerging clones such as community-associated methicillin-resistant S. aureus (CA-MRSA).


2020 ◽  
Vol 42 (5) ◽  
pp. 589-605 ◽  
Author(s):  
Aurelia Santoro ◽  
Jiangchao Zhao ◽  
Lu Wu ◽  
Ciriaco Carru ◽  
Elena Biagi ◽  
...  

AbstractDuring the course of evolution, bacteria have developed an intimate relationship with humans colonizing specific body sites at the interface with the body exterior and invaginations such as nose, mouth, lung, gut, vagina, genito-urinary tract, and skin and thus constituting an integrated meta-organism. The final result has been a mutual adaptation and functional integration which confers significant advantages to humans and bacteria. The immune system of the host co-evolved with the microbiota to develop complex mechanisms to recognize and destroy invading microbes, while preserving its own bacteria. Composition and diversity of the microbiota change according to development and aging and contribute to humans’ health and fitness by modulating the immune system response and inflammaging and vice versa. In the last decades, we experienced an explosion of studies on the role of gut microbiota in aging, age-related diseases, and longevity; however, less reports are present on the role of the microbiota at different body sites. In this review, we describe the key steps of the co-evolution between Homo sapiens and microbiome and how this adaptation can impact on immunosenescence and inflammaging. We briefly summarized the role of gut microbiota in aging and longevity while bringing out the involvement of the other microbiota.


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