Impact of Rapid Identification of Staphylococcus Species in Positive Blood Culture Using GeneXpert Methicillin-Resistant Staphylococcus aureus/ Staphylococcus aureus Blood Culture Assay Combined with Antibiotic Stewardship

2021 ◽  
Author(s):  
Hajar AlQahtani ◽  
Fulwah Yahya Alqahtani ◽  
Fadilah Sfouq Aleanizy ◽  
Saeed Baloch ◽  
Deanne Tabb
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Antibiotic Stewardship ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Rapid Identification ◽  
Methicillin Resistant

scholarly journals 1026. Is Empiric Coverage Necessary? Incidence of Pseudomonas aeruginosa and Methicillin-Resistant Staphylococcus aureus in Foot Infections

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S542-S542
Author(s):  
Scott G Bird ◽  
Nancy Crum-Cianflone ◽  
Samantha Bagsic
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Univariate Analysis ◽  
Methicillin Resistant ◽  
Empiric Antibiotics ◽  
Empiric Antibiotic ◽  
Antibiotic Coverage

Abstract Background Empiric antibiotics for foot infections often include coverage of Pseudomonas aeruginosa (PA) and Methicillin-resistant Staphylococcus aureus (MRSA) due to their presumed frequency and ability to cause severe infection. The purpose of this study was to: 1) determine the incidence of PA and MRSA in foot infections; 2) identify variables associated with the presence of PA or MRSA; and 3) examine empiric antibiotic trends for foot infections to determine if empiric coverage of PA and MRSA is warranted. Methods Retrospective study of foot infections at five large urban hospitals in San Diego during 2018. Data were collected from the medical records including demographics, host factors, laboratory data, pathology and imaging data, culture results, and empiric antibiotics. Patients with a foot infection treated as an inpatient in our healthcare system who had a culture collected were included. Results 310 patients with foot infections were included. Mean age was 61.6 years; 220 (71%) were male; 248 (80%) had diabetes; 40 (13%) had end-stage renal disease (ESRD), and 122 (39%) had peripheral arterial disease (PAD). PA was present in 28 (9%) cases. No patient had a positive blood culture for PA. MRSA was present in 55 (18%) cases. Only one patient had a positive blood culture for MRSA. On univariate analysis, wound location not in the forefoot (p=0.047) and presence of PAD (p=0.048) were associated with PA. These failed to remain significant in multivariate analysis (OR=0.42, p=0.074 and OR=2.54, p=0.0504, respectively). Factors associated with MRSA included shallower depth of wound (OR=0.36; p=0.043). 199/310 patients (64%) received empiric antibiotic coverage for PA while 262/310 patients (85%) received empiric MRSA coverage. Of those who received empiric anti-PA coverage, 174 were overtreated (87%). Of those who received empiric anti-MRSA coverage, 218 (83%) were overtreated. Conclusion The incidence of PA in foot infections was overall low, and none had positive blood cultures. MRSA was more often present, however, most patients did not have bacteremia or severe infections. In our study, the majority of empiric anti-PA, as well as anti-MRSA, antibiotic coverage for foot infections was unnecessary questioning the need for upfront, empiric coverage for these pathogens in foot infections. Disclosures All Authors: No reported disclosures

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 Reduced susceptibility to daptomycin in methicillin-resistant Staphylococcus aureus isolated from catheter-related bloodstream infections

2021 ◽  
Author(s):  
Sho Ohyatsu ◽  
Tomoyuki Nariyama ◽  
Kotaro Matsumoto ◽  
Yuki Moritoki ◽  
Kentaro Kikuchi
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Drug Treatment ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bloodstream Infections ◽  
High Dose ◽  
Methicillin Resistant ◽  
Treatment Methods ◽  
History Of ◽  
The Mean

Abstract Background The appearance of reduced susceptibility to daptomycin in methicillin-resistant Staphylococcus aureus (MRSA) has recently been reported. It is unclear how likely MRSA involved in catheter-related bloodstream infections (CRBSI) is to dampen susceptibility to daptomycin. We investigated the minimum inhibitory concentrations (MIC) of daptomycin in MRSA isolated from the blood of patients with CRBSI and examined how it was affected by previous anti-MRSA drug treatment. Methods A total of 115 patients whose blood culture samples were found to contain MRSA were enrolled in this study. The MIC of daptomycin and vancomycin and whether the subjects had a history of anti-MRSA drug treatment were investigated and compared between the CRBSI and non-CRBSI groups. Results The mean MIC of daptomycin was significantly higher for the 46 CRBSI-related MRSA isolates than for the 69 non-CRBSI-related MRSA isolates (0.78 vs. 0.33, respectively; p<0.0001). Among the CRBSI-related MRSA isolates, those collected from patients with a history of anti-MRSA drug treatment had significantly higher MIC (1.27 vs. 0.53, respectively; p <0.01). During treatment, MRSA was detected again in 10 CRBSI and 4 non-CRBSI patients, and all of the CRBSI-related MRSA isolates exhibited 1-2 log2 increases in their daptomycin MIC. Conclusions It is considered that when MRSA in catheter biofilms is exposed to anti-MRSA drugs, strains with reduced susceptibility to daptomycin are able to survive and disperse into the blood. Catheters should be removed if an MRSA-induced CRBSI is suspected. Further study of whether high-dose daptomycin treatment is effective when catheters cannot be immediately removed is needed.

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