title: Use of thermonuclease testing to identify Staphylococcus aureus by direct examination of blood cultures.
abstract: Blood cultures submitted to the Clinical Microbiology Laboratory, Queen Alia Military Hospital, Amman during 1999-2001 were examined to evaluate thermonuclease testing for identifying Staphylococcus aureus in blood culture broths growing gram-positive cocci. Of 170 cultures studied, 129 yielded gram-positive staphylococci and 41 yielded other gram-positive cocci. Toluidine blue-deoxynucleic acid agar plates were used to test for thermonuclease activity. Standard tube coagulase tests were performed on the isolates. Direct detection of thermonuclease activity in 76 blood culture broths containing gram-positive staphylococci showed 100% correlation with subsequent tube coagulase tests. The thermonuclease test provides a fast, specific and reliable confirmation of S. aureus bacteraemia by direct examination of blood culture broths that contain gram-positive cocci. This allows for timely, optimal antibiotic therapy.
authors.affiliation: Department of Pathology, Queen Alia Military Hospital, Amman, Jordan.
authors.forename: N M
authors.initials: NM
authors.lastname: Kaplan
mesh_terms: D016470:Bacteremia / Q000097:blood / Q000175:diagnosis / Q000382:microbiology*; D015373:Bacterial Typing Techniques / Q000379:methods* / Q000592:standards; D003030:Coagulase; D004396:Coloring Agents; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods; D004269:DNA, Bacterial / Q000187:drug effects; D006772:Hospitals, Military; D006801:Humans; D007597:Jordan; D008826:Microbial Sensitivity Tests; D008836:Micrococcal Nuclease; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000097:blood / Q000175:diagnosis / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D013997:Time Factors; D014048:Tolonium Chloride
chemical_list: D003030:Coagulase; D004396:Coloring Agents; D003470:Culture Media; D004269:DNA, Bacterial; D014048:Tolonium Chloride; D008836:Micrococcal Nuclease