Staphylococcus aureus fibronectin-binding protein specifically binds IgE from patients with atopic dermatitis and requires antigen presentation for cellular immune responses

2011 ◽  
Vol 128 (1) ◽  
pp. 82-91.e8 ◽  
Author(s):  
Kavita Reginald ◽  
Kerstin Westritschnig ◽  
Birgit Linhart ◽  
Margarete Focke-Tejkl ◽  
Beatrice Jahn-Schmid ◽  
...  
2010 ◽  
Vol 10 (1) ◽  
pp. 160 ◽  
Author(s):  
Fiona M Burke ◽  
Niamh McCormack ◽  
Simonetta Rindi ◽  
Pietro Speziale ◽  
Timothy J Foster

2021 ◽  
Author(s):  
Hossein Jafari Soghondicolaei ◽  
Mohammad Ahanjan ◽  
Mehrdad Gholami ◽  
Bahman Mirzaei ◽  
Hamid Reza Goli

Abstract Biofilm production increases Staphylococcus aureus resistance to antibiotics and also host defense mechanisms. The current study aims to evaluate the biofilm formation by S. aureus and to determine the prevalence of fibronectin-binding protein genes, also its correlation with drug resistance. In this study, 100 clinical isolates of S. aureus were collected. The antibiotic susceptibility pattern of the isolates was evaluated by the disk agar diffusion method. The ability of biofilm formation in the studied isolates was also determined by microplate colorimetric assay. Then, all isolates were screened by polymerase chain reaction for the fnbA and fnbB genes. Out of 100 clinical isolates of S. aureus, the highest and lowest antibiotic resistance rates were against penicillin (94%) and vancomycin (6%). Thirty-two cases were found to be multi-drug resistant (MDR) among the all strains. The ability of biofilm production was observed in 89% of the isolates. The PCR results showed that the prevalence of fnbA and fnbB genes were 91% and 17%, respectively. Moreover, 100% and 21.8% of the MDR strains harbored the fnbA and fnbB genes respectively. The ability to form biofilm in MDR isolates of S. aureus is more than non-MDR isolates, especially fnbA positive ones. As the bacteria in the biofilm are difficult to kill by antibiotics, attention to the removal or control of the biofilm production seems to be necessary.


2002 ◽  
Vol 70 (7) ◽  
pp. 3865-3873 ◽  
Author(s):  
Mary C. McElroy ◽  
David J. Cain ◽  
Christine Tyrrell ◽  
Timothy J. Foster ◽  
Christopher Haslett

ABSTRACT Fibronectin-binding proteins mediate Staphylococcus aureus internalization into nonphagocytic cells in vitro. We have investigated whether fibronectin-binding proteins are virulence factors in the pathogenesis of pneumonia by using S. aureus strain 8325-4 and isogenic mutants in which fibronectin-binding proteins were either deleted (DU5883) or overexpressed [DU5883(pFnBPA4)]. We first demonstrated that fibronectin-binding proteins mediate S. aureus internalization into alveolar epithelial cells in vitro and that S. aureus internalization into alveolar epithelial cells requires actin rearrangement and protein kinase activity. Second, we established a rat model of S. aureus-induced pneumonia and measured lung injury and bacterial survival at 24 and 96 h postinoculation. S. aureus growth and the extent of lung injury were both increased in rats inoculated with the deletion mutant (DU5883) in comparison with rats inoculated with the wild-type (8325-4) and the fibronectin-binding protein-overexpressing strain DU5883(pFnBPA4) at 24 h postinfection. Morphological evaluation of infected lungs at the light and electron microscopic levels demonstrated that S. aureus was present within neutrophils from both 8325-4- and DU5883-inoculated lungs. Our data suggest that fibronectin-binding protein-mediated internalization into alveolar epithelial cells is not a virulence mechanism in a rat model of pneumonia. Instead, our data suggest that fibronectin-binding proteins decrease the virulence of S. aureus in pneumonia.


Blood ◽  
2010 ◽  
Vol 116 (11) ◽  
pp. 1876-1884 ◽  
Author(s):  
Markus Moll ◽  
Sofia K. Andersson ◽  
Anna Smed-Sörensen ◽  
Johan K. Sandberg

AbstractDendritic cells (DCs) play an important role in viral infections both as initiators of immunity and as viral targets. Interaction between DCs and the innate-like CD1d-restricted natural killer T (NKT) cells results in the mutual activation of both cells and the subsequent initiation of cellular immune responses. Here, we show that HIV-1 inhibits the surface expression of CD1d in productively infected DCs and identify this as a novel activity of the HIV-1 vpu gene product. Interestingly, the viral protein U (Vpu) does not enhance constitutive CD1d endocytosis or induce rapid CD1d degradation. Instead, the Vpu protein interacts with CD1d and suppresses its recycling from endosomal compartments to the cell surface by retaining CD1d in early endosomes. This interference with the CD1d antigen presentation pathway strongly inhibits the ability of infected DCs to activate CD1d-restricted NKT cells. Given that the interaction with CD1d-expressing DCs is central to the ability of NKT cells to regulate immunity, these data suggest that interference with the CD1d antigen presentation pathway represents an HIV-1 strategy to evade innate cellular immune responses and imply a role for the innate-like CD1d-restricted NKT cells in the host defense against HIV-1.


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