Vascular graft infection by Staphylococcus aureus: efficacy of linezolid, teicoplanin and vancomycin systemic prophylaxis protocols in a rat model

OBJECTIVE We investigated experimentally the in vivo prophylactic efficacies of linezolid, teicoplanin and vancomycin in subcutaneously implanted dacron graft infection caused by methicillin-resistant Staphylococcus aureus (MRSA). MATERIALS AND METHODS Dacron grafts (1 cm(2)) were aseptically implanted into subcutaneous pockets that were surgically prepared in the backs of 50 rats. Ten of these rats were used as the control group (group I). Grafts in the remaining 40 rats were infected by inoculation of MRSA at the concentration of 2 x 10(7) colony-forming units (CFU)/ml. Ten of these rats constituted the contaminated, untreated group II. The other three study groups comprising 10 rats each were contaminated and then treated with linezolid (group III), teicoplanin (group IV) and vancomycin (group V), respectively. All rats were sacrificed and the grafts were removed after seven days and evaluated. RESULTS The bacterial count decreased in the rats from the groups treated with linezolid, teicoplanin and vancomycin. The linezolid and teicoplanin groups, however, showed a significantly lower bacterial number than the vancomycin group (p = 0.009 and p = 0.01). The intensity of inflammation was highest in the contaminated, untreated group, as expected. CONCLUSIONS Single-dose linezolid, teicoplanin and vancomycin for peri-operative prophylaxis may prevent bacterial growth in vascular graft infections. The effect of linezolid and teicoplanin seemed similar and their effect was greater than that of vancomycin.