Description:
<jats:title>ABSTRACT</jats:title><jats:p>Rapid diagnosis is essential for the management of<jats:named-content content-type="genus-species">Staphylococcus aureus</jats:named-content>infections. A host recognition protein from<jats:named-content content-type="genus-species">S. aureus</jats:named-content>bacteriophage phiSLT was recombinantly produced and used to coat streptavidin latex beads to develop a latex agglutination test (LAT). The diagnostic accuracy of this bacteriophage-based test was compared with that of a conventional LAT, Pastorex Staph-Plus, by investigating a clinical collection of 86<jats:named-content content-type="genus-species">S. aureus</jats:named-content>isolates and 128 coagulase-negative staphylococci (CoNS) from deep tissue infections. All of the clinical<jats:named-content content-type="genus-species">S. aureus</jats:named-content>isolates were correctly identified by the bacteriophage-based test. While most of the CoNS were correctly identified as non-<jats:named-content content-type="genus-species">S. aureus</jats:named-content>isolates, 7.9% of the CoNS caused agglutination. Thus, the sensitivity of the bacteriophage-based LAT for identification of<jats:named-content content-type="genus-species">S. aureus</jats:named-content>among clinical isolates was 100%, its specificity was 92.1%, its positive predictive value (PPV) was 89.6%, and its negative predictive value (NPV) was 100%. The sensitivity, specificity, PPV, and NPV of the Pastorex LAT for the identification of<jats:named-content content-type="genus-species">S. aureus</jats:named-content>were 100%, 99.2%, 98.9%, and 100%, respectively. Among the additionally tested 35<jats:named-content content-type="genus-species">S. aureus</jats:named-content>and 91 non-<jats:named-content content-type="genus-species">S. aureus</jats:named-content>staphylococcal reference and type strains, 1 isolate was false negative by each system; 13 and 8 isolates were false positive by the bacteriophage-based and Pastorex LATs, respectively. The ability of the phiSLT protein to detect<jats:named-content content-type="genus-species">S. aureus</jats:named-content>was dependent on the presence of wall teichoic acid (WTA) and corresponded to the production of ribitol phosphate WTA, which is found in most<jats:named-content content-type="genus-species">S. aureus</jats:named-content>clones but only a small minority of CoNS. Bacteriophage-based LAT identification is a promising strategy for rapid pathogen identification. Finding more specific bacteriophage proteins would increase the specificity of this novel diagnostic approach.</jats:p>