scholarly journals Evaluation of the BD Max StaphSR Assay for Rapid Identification of Staphylococcus aureus and Methicillin-Resistant S. aureus in Positive Blood Culture Broths

2015 ◽  
Vol 53 (11) ◽  
pp. 3630-3632 ◽  
Author(s):  
Alexander H. Dalpke ◽  
Marjeta Hofko ◽  
Fiona Hamilton ◽  
Laura Mackenzie ◽  
Stefan Zimmermann ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Culture Medium ◽  
Direct Detection ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Alert System ◽  
Content Type ◽  
Bactec Fx

We evaluated the performance of the BD Max StaphSR assay for the direct detection ofStaphylococcus aureusfrom blood culture medium. In a two-center trial, 155 blood cultures from the BD Bactec FX system and 212 from the bioMérieux BacT/Alert system were tested; 170 bottles yieldedS. aureus, and all were identified correctly by the BD Max StaphSR assay. The assay required approximately 2.5 h, thus allowing rapid identification of blood cultures flagged positive.

scholarly journals Rapid molecular testing for Staphylococcus aureus bacteraemia improves clinical management

2020 ◽  
Vol 69 (4) ◽  
pp. 552-557
Author(s):  
Martin P. McHugh ◽  
Benjamin J. Parcell ◽  
Fiona M. MacKenzie ◽  
Kate E. Templeton ◽  
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Type Species ◽  
Patient Management ◽  
Blood Cultures ◽  
Diagnostic Methods ◽  
Content Type ◽  
Link Type ◽  
The Impact

Introduction. Staphylococcus aureus bacteraemia (SAB) causes significant morbidity and mortality. Standard diagnostic methods require 24–48 h to provide results, during which time management is guideline-based and may be suboptimal. Aim. Evaluate the impact of rapid molecular detection of S. aureus in positive blood culture bottle fluid on patient management. Methodology. Samples were tested prospectively at two clinical centres. Positive blood cultures with Gram-positive cocci in clusters on microscopy were tested with the Xpert MRSA/SA blood culture assay (Cepheid), as well as standard culture-based identification and antimicrobial sensitivity tests. Results were passed to clinical microbiologists in real time and used for patient management. Results. Of 264 blood cultures tested (184 and 80 from each centre), S. aureus was grown from 39 (14.8 %) with one identified as methicillin-resistant S. aureus ; all Xpert results agreed with culture results. Median turnaround time from culture flagging positive to result reporting for Xpert was 1.7 h, compared to 25.7 h for species identification by culture. Xpert results allowed early changes to management in 40 (16.8 %) patients, with Xpert positive patients starting specific therapy for SAB and Xpert negative patients stopping or avoiding empiric antimicrobials for SAB. Conclusion. Rapid and accurate detection of S. aureus with the Xpert MRSA/SA BC assay in positive blood culture bottles allowed earlier targeted patient management. Negative Xpert results are suggestive of coagulase negative staphylococci, allowing de-escalation of antimicrobial therapy if clinically appropriate.

scholarly journals 2559. Incidence and Clinical Impact of Discordant Genotypic and Phenotypic Categorization of Methicillin Susceptibility in Staphylococcus aureus Bacteremia

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S70-S70
Author(s):  
Jessica Gulliver ◽  
Brittney Jung-Hynes ◽  
Derrick Chen
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Clinical Laboratory ◽  
Laboratory Data ◽  
Rapid Identification ◽  
Clinical Impact ◽  
Staphylococcus Aureus Bacteremia ◽  
Oxacillin Resistance ◽  
Initial Hospitalization

Abstract Background Methicillin-susceptible/methicillin-resistant Staphylococcus aureus (MSSA/MRSA) can be directly identified from positive blood culture bottles using molecular methods. This provides faster results than traditional phenotypic testing, but discrepancies between the two are occasionally found. We sought to determine the incidence and clinical impact of such discrepancies. Methods Positive blood culture bottles are routinely tested in the hospital clinical laboratory for mecA via Xpert MRSA/SA BC (PCR), and antimicrobial susceptibility testing (AST) via MicroScan PC33 is performed on recovered S. aureus isolates; discrepancies between PCR and AST are resolved by repeat and supplemental (Kirby-Bauer) testing. A retrospective review of medical and laboratory data from January 2015 to December 2017 was performed on all patients that had discordant PCR and AST results. Results Approximately 1,200 PCR assays were performed from January 2015 to December 2017, and there were 5 (0.4%) cases with discordant AST Results. Four cases were classified as MSSA by PCR but MRSA by AST, and 1 case was classified as MRSA by PCR but MSSA by AST. For the former group, antimicrobial therapy was changed in 2 patients to cover MRSA and 1 patient was readmitted, while the remaining 2 patients were already being treated for MRSA; for the latter case, this patient was treated for MRSA during the initial hospitalization, but was readmitted with disseminated MSSA and subsequently deceased. Based on genetic targets identified by PCR and cefoxitin and oxacillin AST, discrepancies were likely due to borderline oxacillin resistance (BORSA) (n = 1), presence of an SCCmec variant not detected by PCR (n = 1), or undetermined (n = 3). Conclusion Rapid identification of MRSA bacteremia via PCR provides actionable information to direct empiric treatment. While highly accurate, PCR results are infrequently not corroborated by AST. This rare possibility should be considered when modifying therapy based on initial PCR results, and there should be close communication between the clinical team and laboratory for these challenging cases. Disclosures All authors: No reported disclosures.

scholarly journals Resistance to Echinocandins inCandidaCan Be Detected by Performing the Etest Directly on Blood Culture Samples

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
María Ángeles Bordallo-Cardona ◽  
Laura Judith Marcos-Zambrano ◽  
Carlos Sánchez-Carrillo ◽  
Emilio Bouza ◽  
Patricia Muñoz ◽  
...  
Keyword(s):  
Blood Culture ◽  
Candida Parapsilosis ◽  
Blood Cultures ◽  
Rapid Testing ◽  
Wild Type ◽  
Becton Dickinson ◽  
Content Type ◽  
Sabouraud Agar ◽  
Reliable Procedure ◽  
Bactec Fx

ABSTRACTWe examined the rapid evaluation of susceptibility to echinocandins inCandidaspp. using the Etest performed directly on positive blood cultures and anidulafungin-containing agar plates. We prospectively collected 80 positive blood cultures (Bactec-FX system, Becton-Dickinson, Cockeysville, MD, USA) with echinocandin-susceptibleCandidaspp. (n= 60) and echinocandin-intermediateCandida parapsilosis(n= 20) from patients with candidemia. Additionally, blood culture bottles of nonfungemic/bacteremic patients were spiked with 35 echinocandin-resistantCandidaspecies isolates. A total of 2 to 4 drops of medium from each bottle were stroked directly onto both RPMI 1640 agar plates with micafungin and anidulafungin Etest strips (ETDIR) and Sabouraud agar plates containing 2 mg/liter of anidulafungin. The isolates were tested according to the EUCAST method and Etest standard (ETSD). Essential and categorical agreement between the methods was calculated. The essential agreement and categorical agreement between the EUCAST method and ETDIRand ETSDwere both >97.4%. The essential agreement between ETDIRand the EUCAST method for both echinocandins was >97%. The categorical agreement between theFKSsequence and ETDIRwas 97.4%. The ETDIRMICs of anidulafungin and micafungin (≥0.19 mg/liter and ≥0.064 mg/liter, respectively) effectively separated all susceptibleFKSwild-type isolates from the resistantFKSmutant isolates. The categorical agreement (62.6%) between the EUCAST method and growth on anidulafungin-containing plates was poor, with the best agreement observed forCandida glabrata(94.2%). When performed directly on positive blood cultures from patients with candidemia, the Etest with micafungin and anidulafungin is a reliable procedure for the rapid testing of susceptibility to echinocandins inCandidaspecies isolates.

scholarly journals Use of thermonuclease testing to identify Staphylococcus aureus by direct examination of blood cultures

2003 ◽  
Vol 9 (1-2) ◽  
pp. 185-190
Author(s):  
N. M. Kaplan
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Direct Detection ◽  
Blood Cultures ◽  
Military Hospital ◽  
Clinical Microbiology Laboratory ◽  
Microbiology Laboratory ◽  
Direct Examination ◽  
Gram Positive ◽  
Gram Positive Cocci

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. St and ard 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

scholarly journals Evaluation of Four Methods for Rapid Identification of Staphylococcus aureus from Blood Cultures

1998 ◽  
Vol 36 (4) ◽  
pp. 1032-1034 ◽  
Author(s):  
David J. Speers ◽  
Thomas R. Olma ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Culture System ◽  
Rapid Identification ◽  
Culture Broth ◽  
Blood Cultures ◽  
Blood Culture System ◽  
Variable Sensitivity ◽  
Rapid Tests ◽  
Gram Positive Cocci

The identification of Staphylococcus aureus directly from blood cultures is clinically relevant, but it requires a test that is both rapid and reliable. Previously, biochemical, immunological, tube coagulase, and thermostable-endonuclease methods have shown variable sensitivity and specificity. Testing directly from blood culture broth has not been described for the latex kit Staphaurex Plus (Murex Diagnostics Ltd.), and the modified conventional tests have not been used with the newer, continuously monitored blood culture systems. In addition, the commercial RAPIDEC staph kit (bioMerieux Vitek, Inc.) has been used to detect S. aureus directly from the Vital blood culture system (bioMerieux, Marcy l’Etoile, France), but its performance has not been evaluated with other continuously monitored systems. A total of 201 clinical blood cultures (BACTEC 9240 culture system; Johnston Laboratories, Inc.) in which a Gram stain showed gram-positive cocci resembling staphylococci were evaluated prospectively. The Staphaurex Plus kit, the tube coagulase test, the thermostable-endonuclease test, and the RAPIDEC staph kit were compared. The sensitivities were 23, 92, 85, and 98% and the specificities were 99, 100, 93, and 100%, respectively. The RAPIDEC staph kit was the most reliable test, with a diagnostic accuracy comparable to that of the best published results for any of the rapid tests. However, it was the most expensive of the tests and relatively labor-intensive. The tube coagulase test was also sensitive, the simplest to perform, and inexpensive.

scholarly journals An Evaluation Of Direct Identification Of Pathogens From Blood Cultures By Maldi-Tof Mass Spectrometry

2016 ◽  
Vol 26 (5) ◽  
pp. 69-73
Author(s):  
Lina Savickaitė ◽  
Jelena Kopeykinienė
Keyword(s):  
Mass Spectrometry ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Antimicrobial Therapy ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Direct Identification ◽  
Maldi Tof Mass Spectrometry ◽  
Maldi Tof ◽  
Mass Spectrometry Identification

Rapid identification of the infecting organism may aid in choosing appropriate antimicrobial therapy. We used MALDI-TOF mass spectrometry to identify bacteria directly from the positive blood culture samples (n=21). 85,71 percent of these results was identified using of MALDI-TOF mass spectrometry. Identification time of bacteria directly from the blood culture takes more than 1 hour for 27,8 percent results.

scholarly journals Rapid Detection of Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible S. aureus Directly from Positive Blood Cultures by Use of the BD Max StaphSR Assay

2015 ◽  
Vol 53 (12) ◽  
pp. 3900-3904 ◽  
Author(s):  
Justin A. Ellem ◽  
Tom Olma ◽  
Matthew V. N. O'Sullivan
Keyword(s):  
Staphylococcus Aureus ◽  
Predictive Value ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Direct Detection ◽  
Blood Cultures ◽  
Coagulase Negative Staphylococcus ◽  
Methicillin Resistant ◽  
Content Type ◽  
Standard Culture

The BD Max StaphSR assay is an automated qualitativein vitrodiagnostic test for the direct detection and differentiation of methicillin-susceptibleStaphylococcus aureus(MSSA) and methicillin-resistantS. aureus(MRSA). A total of 460 specimens were tested, and the results were compared with standard culture-based identification. MRSA was detected in 48 samples (sensitivity of 100%; positive predictive value [PPV] of 100%). MSSA was detected in 112 samples (sensitivity of 99.1%; PPV of 100%), and 299 samples containing coagulase-negative staphylococcus and nonstaphylococcal species were negative by the BD Max StaphSR assay (specificity of 100%; negative predictive value [NPV] of 99.7 to 100%).

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