Article

Immunological control of methicillin-resistant Staphylococcus aureus (MRSA) infection in an immunodeficient murine model of thermal injuries.

Department of Internal Medicine, The University of Texas Medical Branch, Galveston 77555-0435, USA.
Clinical & Experimental Immunology (impact factor: 3.36). 01/2006; 142(3):419-25. DOI:10.1111/j.1365-2249.2005.02944.x pp.419-25
Source: PubMed

ABSTRACT Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), is a major cause of sepsis in patients who are immunosuppressed by their burns. In this study, an immunological regulation of MRSA infection was attempted in a mouse model of thermal injury. SCIDbg mice were resistant to MRSA infection, while SCIDbgMN mice (SCIDbg mice depleted of neutrophils and macrophages (Mphi)) were susceptible to the same infection. Also, thermally injured SCIDbg mice were shown to be susceptible to MRSA infection. On the other hand, the resistance of SCIDbgMN mice to the infection was completely recovered after an inoculation with Mphi from normal mice. However, anti-MRSA resistance was not shown in SCIDbgMN mice inoculated with Mphi from thermally injured mice. Mphi from MRSA-infected thermally injured mice were identified as alternatively activated Mphi, and Mphi from MRSA-infected unburned mice were characterized as classically activated Mphi. Mphi from thermally injured SCIDbg mice previously treated with 2-carboxyethylgermanium sesquioxide (Ge-132) protected SCIDbgMN mice against MRSA infection. Ge-132 has been described as an inhibitor of alternatively activated Mphi generation. These results suggest that MRSA infection in thermally injured patients is controlled immunologically through the induction of anti-MRSA effector cells and elimination of burn-associated alternatively activated Mphi, which are cells that inhibit the generation of classically activated Mphi.

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Keywords

2-carboxyethylgermanium sesquioxide
 
activated Mphi
 
activated Mphi generation
 
anti-MRSA effector cells
 
anti-MRSA resistance
 
classically activated Mphi
 
immunological regulation
 
immunologically
 
major cause
 
methicillin-resistant S. aureus
 
mouse model
 
MRSA
 
MRSA infection
 
MRSA-infected thermally
 
MRSA-infected unburned mice
 
normal mice
 
SCIDbg mice
 
SCIDbgMN mice
 
SCIDbgMN mice inoculated
 
Staphylococcus aureus
 

T Katakura