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New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers

Staphylococcus aureus strains isolated from diabetic foot ulcers (DFUs) have less virulence, but still cause severe infections. Furthermore, hypovirulent S. aureus strains appear to be localized in the deep tissues of diabetic foot osteomyelitis, indicating that the unique environment within DFUs af...

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Autores principales: Wu, Yuan, Chen, Ti, Wang, Yanle, Huang, Mao, Wang, Yurong, Luo, Zhen
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10416727/
https://www.ncbi.nlm.nih.gov/pubmed/37577369
http://dx.doi.org/10.3389/fcimb.2023.1234994
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author Wu, Yuan
Chen, Ti
Wang, Yanle
Huang, Mao
Wang, Yurong
Luo, Zhen
author_facet Wu, Yuan
Chen, Ti
Wang, Yanle
Huang, Mao
Wang, Yurong
Luo, Zhen
author_sort Wu, Yuan
collection PubMed
description Staphylococcus aureus strains isolated from diabetic foot ulcers (DFUs) have less virulence, but still cause severe infections. Furthermore, hypovirulent S. aureus strains appear to be localized in the deep tissues of diabetic foot osteomyelitis, indicating that the unique environment within DFUs affects the pathogenicity of S. aureus. In this study, the cell-free culture medium (CFCM) of S. aureus strains isolated from DFUs exhibited higher cytotoxicity to human erythrocytes than those isolated from non-diabetic patients with sepsis or wounds. Among these S. aureus strains isolated from DFUs, β-toxin negative strains have less virulence than β-toxin positive strains, but induced a higher expression of inflammatory cytokines. Our study and previous studies have shown that the synergistic effect of phenol-soluble modulin α and β-toxin contributes to the higher hemolytic activity of β-toxin positive strains. However, lysis of human erythrocytes by the CFCM of β-toxin negative strains was greatly inhibited by an autolysin inhibitor, sodium polyanethole sulfonate (SPS). A high level of glucose greatly reduced the hemolytic activity of S. aureus, but promoted the expression of interleukin-6 (IL-6) in human neutrophils. However, 5 mM glucose or glucose-6-phosphate (G6P) increased the hemolytic activity of SA118 (a β-toxin negative strain) isolated from DFUs. Additionally, patients with DFUs with growth of S. aureus had lower level of serum IL-6 than those with other bacteria, and the CFCM of S. aureus strains significantly reduced lipopolysaccharide-induced IL-6 expression in human neutrophils. Therefore, the virulence and inflammatory response of S. aureus strains isolated from DFUs are determined by the levels of glucose and its metabolites, which may explain why it is the predominant bacteria isolated from DFUs.
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spelling pubmed-104167272023-08-12 New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers Wu, Yuan Chen, Ti Wang, Yanle Huang, Mao Wang, Yurong Luo, Zhen Front Cell Infect Microbiol Cellular and Infection Microbiology Staphylococcus aureus strains isolated from diabetic foot ulcers (DFUs) have less virulence, but still cause severe infections. Furthermore, hypovirulent S. aureus strains appear to be localized in the deep tissues of diabetic foot osteomyelitis, indicating that the unique environment within DFUs affects the pathogenicity of S. aureus. In this study, the cell-free culture medium (CFCM) of S. aureus strains isolated from DFUs exhibited higher cytotoxicity to human erythrocytes than those isolated from non-diabetic patients with sepsis or wounds. Among these S. aureus strains isolated from DFUs, β-toxin negative strains have less virulence than β-toxin positive strains, but induced a higher expression of inflammatory cytokines. Our study and previous studies have shown that the synergistic effect of phenol-soluble modulin α and β-toxin contributes to the higher hemolytic activity of β-toxin positive strains. However, lysis of human erythrocytes by the CFCM of β-toxin negative strains was greatly inhibited by an autolysin inhibitor, sodium polyanethole sulfonate (SPS). A high level of glucose greatly reduced the hemolytic activity of S. aureus, but promoted the expression of interleukin-6 (IL-6) in human neutrophils. However, 5 mM glucose or glucose-6-phosphate (G6P) increased the hemolytic activity of SA118 (a β-toxin negative strain) isolated from DFUs. Additionally, patients with DFUs with growth of S. aureus had lower level of serum IL-6 than those with other bacteria, and the CFCM of S. aureus strains significantly reduced lipopolysaccharide-induced IL-6 expression in human neutrophils. Therefore, the virulence and inflammatory response of S. aureus strains isolated from DFUs are determined by the levels of glucose and its metabolites, which may explain why it is the predominant bacteria isolated from DFUs. Frontiers Media S.A. 2023-07-28 /pmc/articles/PMC10416727/ /pubmed/37577369 http://dx.doi.org/10.3389/fcimb.2023.1234994 Text en Copyright © 2023 Wu, Chen, Wang, Huang, Wang and Luo https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Cellular and Infection Microbiology
Wu, Yuan
Chen, Ti
Wang, Yanle
Huang, Mao
Wang, Yurong
Luo, Zhen
New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers
title New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers
title_full New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers
title_fullStr New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers
title_full_unstemmed New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers
title_short New insight into the virulence and inflammatory response of Staphylococcus aureus strains isolated from diabetic foot ulcers
title_sort new insight into the virulence and inflammatory response of staphylococcus aureus strains isolated from diabetic foot ulcers
topic Cellular and Infection Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10416727/
https://www.ncbi.nlm.nih.gov/pubmed/37577369
http://dx.doi.org/10.3389/fcimb.2023.1234994
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