Clinical significance of follow-up blood culture in patients with a single Staphylococcus aureus-positive blood culture

2019 ◽  
Vol 52 (3) ◽  
pp. 207-212
Author(s):  
Taeeun Kim ◽  
Seung Cheol Lee ◽  
Min Jae Kim ◽  
Jiwon Jung ◽  
Heungsup Sung ◽  
...  
Author(s):  
John Raymond Go ◽  
Douglas Challener ◽  
Cristina Corsini Campioli ◽  
M Rizwan Sohail ◽  
Raj Palraj ◽  
...  

Abstract Clinical significance of a single positive blood culture bottle (SPBCB) with Staphylococcus aureus is unclear. We aimed to assess the significance of a SPBCB by looking at the associated outcomes. We performed a retrospective, multicenter study of patients with a SPBCB with S. aureus using data collected from both electronic health records and the clinical microbiology laboratory. Overall, 534 patients with S. aureus bacteremia were identified and 118 (22.1%) had a SPBCB. Among cases with a SPBCB, 106 (89.8%) were classified as clinically significant while 12 (10.2%) were considered contaminated or of unclear significance. A majority (92.4%) of patients received antibiotic therapy but patients with clinically significant bacteremia were treated with longer courses (25.9 vs 5.7 days, P<0.001). Significant differences in both frequency of echocardiography (65.1% vs 84.6%, P<0.001), and infective endocarditis diagnosis (3.8% vs 14.2%, P=0.002) were seen in those with a single positive blood culture bottle compared to those with multiple positive bottles. A longer hospital length of stay, and higher 90-day, 6-month, and 1-year mortality rates were seen in patients with multiple positive blood culture bottles. A SPBCB with S. aureus was common among our patients. While this syndrome has a more favorable prognosis as compared to those with multiple positive blood cultures, clinicians should remain concerned as it portends a risk of infective endocarditis and mortality.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S5-S6
Author(s):  
John Raymond U Go ◽  
Douglas Challener ◽  
Cristina G Corsini Campioli ◽  
Muhammad R Sohail ◽  
Raj Palraj ◽  
...  

Abstract Background Staphylococcus aureus bacteremia (SAB) is common and is characterized by high rates of morbidity and mortality. The clinical importance of a single positive blood culture bottle (SPBCB), however, is poorly defined despite it being a frequent laboratory finding. We therefore examined patients with SPBCB to determine its clinical significance and to understand the rationale of current practice. Methods We performed a retrospective, multicenter study of patients with a SPBCB for S. aureus in initial cultures from January 2019 to December 2019 using data collected from both electronic health records and the clinical microbiology laboratory. Results Overall, 534 patients with SAB were identified, and 118 (22.1%) had a SPBCB. Among SPBCB cases, 106 (89.3%) were classified as clinically significant while 12 were considered contaminated or of unclear clinical significance. Baseline characteristics were similar between the groups (Table 1). A majority (92.4%) received antibiotic therapy, but patients with clinically significant bacteremia were treated with a longer antibiotic course (25.9 vs 5.7 days, p< 0.001). Outcomes between those with SPBCB (contaminant vs clinically significant) were similar (Table 2). Of note, while there was no difference in use of echocardiography based on PREDICT criteria between the clinically significant SPBCB vs. the multiple positive blood culture bottles (MPBC) cohorts (Table 3), significant differences were seen in both frequency of echocardiography (65.1% vs. 84.6%, P< 0.001) and IE diagnosis (3.8% vs. 14.2%, P=0.002) for patients in the SPBCB vs. MPBC groups, respectively. In addition, those with MPBC had higher 90-day, 6-month and 1-year mortality rates. Conclusion SPBCB was documented in almost one-quarter of SAB cases and should trigger a thorough investigation as its associated mortality was high and complications, including IE, occurred. Although some SPBCB cases may represent contamination, antibiotic treatment of SPBCB was commonplace. Patients with clinically significant SPBCB were less likely to undergo echocardiography and had a reduced prevalence of an IE diagnosis as compared to those with MPBC. Patients with SPBCB may have a more favorable long-term prognosis as compared to that in patients with MPBC. Disclosures Muhammad R. Sohail, MD, Medtronic (Consultant)Philips (Consultant) Larry M. Baddour, MD, Boston Scientific (Individual(s) Involved: Self): Consultant; Botanix Pharmaceuticals (Individual(s) Involved: Self): Consultant; Roivant Sciences (Individual(s) Involved: Self): Consultant


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S149-S149
Author(s):  
Mohammed Aldhaeefi ◽  
Jeffrey Pearson ◽  
Sanjat Kanjilal ◽  
Brandon Dionne

Abstract Background Staphylococcus aureus bacteremia is a significant cause of mortality. Penicillin (PCN) may have a role in the treatment of penicillin-susceptible Staphylococcus aureus (PSSA) bacteremia as it has a narrower spectrum of activity than cefazolin and is better tolerated than antistaphylococcal penicillins (ASPs). The aim of this study is to evaluate the safety and effectiveness of PCN versus cefazolin or ASPs in the treatment of PSSA bacteremia. Methods This is a single-center, retrospective study at a tertiary academic medical center. All patients with a PSSA blood culture from January 1, 2012 to September 1, 2019 were screened. Patients were excluded if they were treated with a definitive antibiotic (defined as antimicrobial therapy received 72 hours after positive blood culture) other than the study comparators, or if they received combination antibiotic therapy >72 hours from the initial positive blood culture result. The primary outcome was 60-day clinical failure, which was a composite endpoint of change in antibiotic after 72 hours of definitive therapy, recurrence of PSSA bacteremia, infection-related readmission, or all-cause mortality. Results Of 277 patients with PSSA bacteremia, 101 patients were included in the study; 62 (61%) were male and 11 (11%) had a β-lactam allergy. At baseline, 40 patients (40%) had hardware, 25 (25%) had an intravenous line, 6 (6%) were on dialysis, and 4 (4%) had active IV drug use, with similar distribution across antibiotic groups. Penicillin was the most common antibiotic used (Table 1). There was a significant difference among groups with respect to the 60-day clinical failure (log-rank p=0.019). In terms of unadjusted 60-day clinical failure, penicillin had similar outcomes to cefazolin (95% CI -0.29 to 0.104, p=0.376), however, it had statistically significant better outcomes in comparison to the ASPs, nafcillin or oxacillin (95% CI 0.023 to 0.482, p=0.031) (Table 1). Table 1. 60-day outcomes of PSSA bacteremia Conclusion Penicillin is effective and safe in the treatment of PSSA bacteremia and may be preferable to antistaphylococcal penicillins Disclosures All Authors: No reported disclosures


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S70-S70
Author(s):  
Jessica Gulliver ◽  
Brittney Jung-Hynes ◽  
Derrick Chen

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.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S147-S148
Author(s):  
Naomi Hauser ◽  
Justin Kim ◽  
Paul Luethy ◽  
Sarah Schmalzle ◽  
Jacqueline Bork

Abstract Background Staphylococcus lugdunensis is a coagulase negative Staphylococcus (CoNS) species with the potential to cause aggressive infection. Guidance surrounding S. lugdunensis bacteremia (SLB) is lacking, especially in the case of a single positive set of blood cultures. Methods We performed a multicenter, retrospective observational cohort review of adult patients with SLB from at least one blood culture set within the University of Maryland Medical System from November 2015-November 2019. Objectives were to (1) describe baseline characteristics, (2) compare available criteria for evaluating clinical significance, and (3) evaluate the clinical outcomes among patients with SLB in 1 vs ≥2 positive blood culture sets. Descriptive statistics with Chi-squared and Mann-Whitney U tests were carried out. Results There were 5,548 CoNS-positive blood culture sets, 49 (0.88%) with S. lugdunensis comprising 36 adult patients (24 with 1 positive set and 12 with ≥2 positive sets). Patients with ≥2 positive sets were more likely to be on hemodialysis (HD) (p=0.029) and to have an HD catheter present (p=0.10) (Table 1). Thirty-five of the 36 patients fulfilled at least one of the following: systemic inflammatory response syndrome (SIRS), Souvenir criteria, or clinical criteria (infectious focus on imaging and/or second positive culture site) (Table 2). Twenty-eight (78%) patients were treated with antimicrobial therapy and/or central line removal. SIRS criteria were met more often among patients with 1 positive set (p=0.05). Patients with ≥2 positive sets were more often treated with antibiotics for longer than 2 weeks (p=0.02). The mean time of positive cultures to discharge was 11 days and was longer for patients with only one set of positive blood cultures (13 vs. 6 days), although this difference was not statistically significant (p=0.29) (Table 3). Conclusion SLB was rare and occurred more frequently as a single set of positive blood cultures. Though limited by sample size, this study found similar patient characteristics, clinical significance and outcomes between patients with one set and those with ≥2 sets of blood cultures positive for S. lugdunensis. Given the potential severity of SLB, it seems prudent to treat S. lugdunensis in a single blood culture, but larger studies are needed. Disclosures All Authors: No reported disclosures


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