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Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus MRSA
Published on: February 9, 2011
Bactericidal fully human single-chain fragment variable antibodies protect mice against methicillin-resistant
Behnoush Soltanmohammadi1,2, Somayeh Piri-Gavgani1,2, Eilnaz Basardeh1,2
1Department of Mycobacteriology and Pulmonary Research Pasteur Institute of Iran Tehran Iran.
Objectives:
The increasing prevalence of antibiotic-resistant Staphylococcus aureus, besides the inadequate numbers of effective antibiotics, emphasises the need to find new therapeutic agents against this lethal pathogen.
Methods:
In this study, to obtain antibody fragments against S. aureus, a human single-chain fragment variable (scFv) library was enriched against living methicillin-resistant S. aureus (MRSA) cells, grown in three different conditions, that is human peripheral blood mononuclear cells with plasma, whole blood and biofilm. The antibacterial activity of scFvs was evaluated by the growth inhibition assay in vitro. Furthermore, the therapeutic efficacy of anti-S. aureus scFvs was appraised in a mouse model of bacteraemia.
Results:
Three scFv antibodies, that is MEH63, MEH158 and MEH183, with unique sequences, were found, which exhibited significant binding to S. aureus and reduced the viability of S. aureus in in vitro inhibition assays. Based on the results, MEH63, MEH158 and MEH183, in addition to their combination, could prolong the survival rate, reduce the bacterial burden in the blood and prevent inflammation and tissue destruction in the kidneys and spleen of mice with MRSA bacteraemia compared with the vehicle group (treated with normal saline).
Conclusion:
The combination therapy with anti-S. aureus scFvs and conventional antibiotics might shed light on the treatment of patients with S. aureus infections.
Insights
New antibody fragments targeting antibiotic-resistant Staphylococcus aureus show promise. These single-chain variable fragments (scFvs) effectively reduced bacterial viability and improved survival in a mouse model of MRSA infection.
Area of Science:
- Immunology
- Microbiology
- Pharmacology
Background:
- Antibiotic resistance in Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), poses a significant global health threat.
- Limited development of new effective antibiotics necessitates novel therapeutic strategies against S. aureus infections.
Purpose of the Study:
- To develop and evaluate novel antibody fragments (scFvs) targeting S. aureus.
- To assess the in vitro antibacterial activity and in vivo therapeutic efficacy of these scFvs against MRSA.
Main Methods:
- A human single-chain variable fragment (scFv) library was enriched against live MRSA cells under various conditions.
- Antibacterial activity was determined using in vitro growth inhibition assays.
- Therapeutic efficacy was evaluated in a mouse model of MRSA bacteraemia.
Main Results:
- Three unique scFv antibodies (MEH63, MEH158, MEH183) demonstrated significant binding to S. aureus and reduced bacterial viability in vitro.
- These scFvs, individually and in combination, prolonged survival, reduced bacterial load, and mitigated inflammation and tissue damage in mice with MRSA bacteraemia.
Conclusions:
- The developed anti-S. aureus scFvs show potential as therapeutic agents against S. aureus infections.
- Combination therapy involving these scFvs and conventional antibiotics may offer a new treatment avenue for S. aureus infections.
