Detection of clumping factor-positive Staphylococcus lugdunensis by Staphaurex Plus®

Abstract

Staphaurex Plus® (Murex Diagnostics), a rapid agglutination test for detecting Staphylococcus aureus, was combined with the free coagulase test to search for the coagulase-negative species Staphylococcus lugdunensis and for S. aureus. Staphaurex Plus® detected 29 S. lugdunensis and 1602 S. aureus in our routine laboratory over 6 months. Furthermore, 10 out of 902 coagulase-negative staphylococci other than S. lugdunensis reacted with Staphaurex Plus®. The sensitivity and specificity for detecting S. aureus were 99.7% and 95.7%, respectively. Clumping factor-positive S. lugdunensis can bind fibrinogen coated on the latex particles of Staphaurex Plus®. If this agglutination was considered true positive, the specificity for S. aureus was 98.9%. We conclude that Staphaurex Plus® is a highly sensitive and specific agglutination test for S. aureus and simultaneously detects clumping factor-positive S. lugdunensis.