Test performance for detection of pathogens in ulcer secretions by SPR using in vitro antibodies, compared with conventional culture techniques, showed results for S. aureus with 87.5 % sensitivity, 100 % specificity, positive predictive value (PPV) 100 % and negative predictive value (NPV) 94 % and for E. fecalis with 100 % sensitivity, 91.3 % specificity, PPV 33.3 % and NPV 100 % (Tables 2 and 3).Table 3Test performance of binding to the produced antibodies immobilized in SPR system in comparison to conventional ulcer secretion culturesSPR/cultureFalse positive (SPR)True positive (culture)False negative (SPR)True negative (culture)Total Staphylococcus aureus 0711624 Enterococcus fecalis 2102124Sensitivity for Staphylococcus aureus was 87.5 %, specificity 100 %, PPV 100 % and NPV 94 %. Sensitivity for Enterococcus fecalis was 100 %, specificity 91.3 %, PPV 33.3 % and NPV 100 %