209. What’s So Complicated About Complicated Staphylococcus aureus Bacteremia: Does Day 5 Matter?

Abstract Background Prolonged Staphylococcus aureus bacteremia (SAB) poses challenges in clinical practice, particularly when a source is not readily identified. While SAB greater than 3 days has been identified as a risk factor for complications, little is known about risk for specific complications with each successive day of bacteremia. We sought to determine the risk for specific complications with the duration of bacteremia. Methods We retrospectively reviewed all cases of SAB between 1 January 2017 and 31 December 2017 at a 500-bed academic hospital. Adult patients (≥18 years) with at least one blood culture positive for S. aureus were identified. Patients were excluded if withdrawal of care or death occurred within 48 hours of blood culture results or if the infection was associated with a ventricular assist device. Medical records were reviewed for the duration of bacteremia, complications, treatment decisions and clinical outcomes. This study was approved by the Institutional Review Board. Results One hundred forty-two discrete episodes of SAB were identified with a median age of 54 years (IQR 40–63). Most cases were community-acquired (83.8%) and 33.8% were MRSA. Active injection drug use was present in 22.5% (33.3% MRSA, 17% MSSA). The median duration of bacteremia was 2.6 days (IQR 1.8–4.6) and 3.9 days (IQR 2.2–7.5) for MSSA and MRSA, respectively. The median time to first source control procedure was twice as long with bacteremia over 5 days than with a shorter duration of bacteremia (2.6 vs. 1.3 days). Complication rates increased with bacteremia duration and bacteremia longer than 5 days was associated with significantly higher rates of endocarditis (46.2%, P < 0.001), epidural abscesses (35.9%, P = 0.001), intracranial infections (12.8%, P = 0.02), and presence of at least one endovascular nidus (76.9%, P < 0.001) compared with bacteremia less than 5 days (28.4%), but 30 day mortality rates were similar (7.7% and 9.8%, respectively). Conclusion Complication rates increase significantly with SAB greater than 5 days duration. Early source control and investigation to identify metastatic and especially endovascular foci of infection are paramount in patients with prolonged bacteremia even if complications are not discovered on initial evaluation. Disclosures All authors: No reported disclosures.

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292. Impact of the BACT/ALERT VIRTUO blood culture system in the management of Staphylococcus aureus bacteremia

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.335 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S145-S146

Author(s):

Miguel A Chavez ◽

Satish Munigala ◽

Carey-Ann Burnham ◽

David K Warren

Keyword(s):

Staphylococcus Aureus ◽

Blood Culture ◽

Median Time ◽

Culture System ◽

Source Control ◽

Similar Proportion ◽

Blood Culture System ◽

Staphylococcus Aureus Bacteremia ◽

Time To Positivity ◽

Implementation Period

Abstract Background Staphylococcus aureus bacteremia (SAB) is a major cause of mortality. Recovery of SA may be enhanced with new blood culture systems resulting in a longer observed duration of bacteremia. Methods We performed a 24-month retrospective study of adults hospitalized with SAB at a 1250-bed academic hospital. Between 1/2018-12/2018 the VersaTREK system was used and 1/2019-12/2019 the BACT/ALERT VIRTUO (VIRTUO) system was used. We excluded patients without an Infectious Diseases (ID) consult. We defined SAB duration as short (1–2 days), intermediate (3–6 days), or prolonged (>7 days). We compared SAB detection and management pre- and post-implementation of VIRTUO. Results 456 patients had SAB during study period; 420 (92%) had ID consultation: 178 (42%) pre- and 242 (58%) post-implementation. Similar proportion of methicillin-resistant SAB was seen (44.9% pre- vs. 36.8% post-implementation, p=0.09). Post-implementation, patients were more likely to have intermediate (22.4% pre- vs. 40.1% post-implementation; p< 0.001) and prolonged SAB duration (3.9% pre- vs. 13.6% post-implementation; p< 0.001). Median time to positivity for the index blood culture was shorter (19.9 pre- vs. 15.0 hours post-implementation, p< 0.001). Dual anti-staphylococcal therapy was used more frequently in the post-implementation period (6.2% pre- vs. 15.7% post-implementation, p=0.003). No difference was noted in frequency of diagnostic studies (transesophageal echocardiography, magnetic resonance imaging, and computed tomography). Source control was similar (46.1% pre- vs. 45.0% post-implementation; p=0.84) but the median time to source-control was shorter post-implementation (4 pre- vs. 2 days post-implementation; p=0.02). Median planned duration of intravenous antibiotics did not vary between pre- and post-implementation periods (6 vs. 6 weeks, p=0.31). There was no difference in 90-day readmissions (38.2% pre- vs. 34.3% post-implementation; p=0.41). Conclusion VIRTUO blood culture system decreased time to positivity and increased frequency of prolonged SAB compared to the VersaTREK system. This resulted in increased use of dual anti-staphylococcal therapy and shorter time to source-control, but no difference in interventions, planned duration of antibiotics, or readmissions. Disclosures All Authors: No reported disclosures

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Defining the Breakpoint Duration of Staphylococcus aureus Bacteremia Predictive of Poor Outcomes

Clinical Infectious Diseases ◽

10.1093/cid/ciz257 ◽

2019 ◽

Vol 70 (4) ◽

pp. 566-573 ◽

Cited By ~ 2

Author(s):

Emi Minejima ◽

Nikki Mai ◽

Nancy Bui ◽

Melissa Mert ◽

Wendy J Mack ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Primary Objective ◽

Source Control ◽

Control Procedure ◽

Characteristic Analysis ◽

Risk Of Death ◽

Staphylococcus Aureus Bacteremia ◽

Pertinent Data ◽

Multicenter Prospective Observational Study ◽

Poor Outcomes

Abstract Background Persistent Staphylococcus aureus bacteremia (SAB) is defined based on varying duration in literature. The primary objective was to determine the risk of poor outcomes in relation to bacteremia duration. Methods Multicenter, prospective, observational study of adult hospitalized patients with SAB. Medical records were reviewed for pertinent data. Patients were grouped by bacteremia duration: short (1–2 days), intermediate (3–6 days), and prolonged (≥7 days) and compared for risk factors and outcomes. Results Of 884 patients, 63% had short, 28% intermediate, and 9% prolonged bacteremia. Overall mean age was 57 years, and 70% were male. The prolonged group had the highest proportion of methicillin-resistant SAB (P < .0001). Choice of antibiotic therapy did not significantly affect bacteremia duration; however, time to source-control procedure was delayed in the prolonged and intermediate groups compared with the short group (3.5 vs 3 vs 1 day, P < .0001). Metastatic complications, length of stay, and 30-day mortality were progressively worse as bacteremia duration increased (P < .0001). Every continued day of bacteremia was associated with a relative risk of death of 1.16 (95% confidence interval, 1.10–1.22; P < .0001), with a significant increase in risk starting at 3 days as determined by receiver operating characteristic analysis. Conclusions Optimal management of SAB should target bacterial clearance as soon as possible to minimize incremental risk of mortality with each day of positive blood culture. Delay in source control but not type of antistaphylococcal therapy was significantly associated with prolonged bacteremia and worse outcomes.

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196. Impact of BioFire FilmArray® Blood Culture Identification on the Management of Staphylococcus aureus Bacteremia

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.271 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S117-S117

Author(s):

Kiet Nguyen ◽

Lacie McKamey ◽

Sarah Green

Keyword(s):

Staphylococcus Aureus ◽

Blood Culture ◽

Composite Endpoint ◽

Source Control ◽

Rapid Diagnostics ◽

Staphylococcus Aureus Bacteremia ◽

Definitive Therapy ◽

Appropriate Therapy ◽

Culture Identification ◽

The Impact

Abstract Background Staphylococcus aureus bacteremia (SAB) is associated with 30-day mortality rates that are as high as 20 to 40%. In order to reduce mortality and treatment failures, SAB management should include prompt infectious diseases (ID) consult, repeat blood cultures, source control, intravenous antibiotics for the entirety of treatment, and optimal treatment duration. The objective of this study was to determine the impact of BioFire FilmArray® Blood Culture Identification (BCID) on the implementation of these standard of care measures in the management of SAB across a large health system. Methods This study was an IRB approved, retrospective chart review evaluating the impact of rapid diagnostics on the management of SAB before and after implementation of BCID. The composite endpoint consisted of mortality at 30 days, persistent SAB (≥7 days), and recurrence of S. aureus infection within 30 days. Patients were included if they were ≥18 years old and at least one blood culture was positive with S. aureus. The pre-BCID period was between September 1, 2016 and March 31, 2017. The post-BCID period was between April 1, 2017 and July 31, 2018. Fisher’s exact test, student’s t-test, and descriptive statistics were used in the analysis. Results A total of 200 patients met eligibility (pre-BCID, n = 102; post-BCID, n = 98). The composite endpoint was met in 34% of patients in the pre-BCID group and 29% in the post-BCID group (P = 0.45). Mortality at 30 days (17% vs. 17%, P = 1.00), persistent SAB (16% vs. 13%, P = 0.69), and rates of recurrence within 30 days (4% vs. 1%, P = 0.37) were similar between groups. ID consult increased after BCID implementation (83% vs. 92%, P = 0.001). More patients in the post-BCID received appropriate durations of antibiotics (75% vs. 86%, P = 0.04) and had decreased time, in hours, to definitive therapy (7 ± 17 vs. 1 ± 5, P ≤ 0.05). Conclusion The management of SAB after implementation of BCID did not show a decrease in the primary outcome but did show an improved time to appropriate therapy. A larger study is needed to determine whether improved time to appropriate therapy translates to an improvement in patient outcomes. Disclosures All authors: No reported disclosures.

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Susceptibility Pattern of Pathogens Causing Blood Stream Infections in a Tertiary Care Hospital: A Two-year Retrospective Study from Southern Nigeria

Microbiology Research Journal International ◽

10.9734/mrji/2021/v31i330306 ◽

2021 ◽

pp. 53-60

Author(s):

Bassey Ewa Ekeng ◽

Ubleni Ettah Emanghe ◽

Bernard Ekpan Monjol ◽

Anthony Achizie Iwuafor ◽

Ernest Afu Ochang ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Blood Culture ◽

Blood Stream ◽

Multidrug Resistant ◽

Diffusion Method ◽

Disc Diffusion ◽

Blood Stream Infections ◽

Gram Negative ◽

Antimicrobial Sensitivity ◽

Culture Positive

Aim: Bloodstream infections are a major cause of morbidity and mortality worldwide. The prevalence of causative microorganisms varies from one geographical region to another. This study was aimed at determining the etiological agents prevalent in our environment and their susceptibility profile. Study design: This is a retrospective study carried out at the University of Calabar Teaching Hospital, Calabar, Nigeria. Methodology: Blood culture results of patients documented over a two-year period were retrieved and analyzed. Blood culture positive isolates were detected using conventional method and Oxoid signal blood culture systems. Antimicrobial sensitivity tests were carried out by Kirby-Bauer disc diffusion method. Methicillin resistance in Staphylococcus aureus and coagulase negative Staphylococcus species (CoNS) was detected by disk diffusion method using 30 µg cefoxitin disk. ESBL production was detected by phenotypic confirmatory disc diffusion test (PCDDT) and the double disc synergy test (DDST). Results: A total of 413 blood culture antimicrobial susceptibility test results were analyzed, of which 116 (28.09%) were identified as culture positive. Sixty-nine (59%) of the positive isolates were from female patients. Out of 116 positive cultures, 58.62% (68/116) were Gram positive organisms, 40.52% (47/116) were Gram negative organisms, non albicans Candida accounted for 0.86% (1/116). Staphylococcus aureus (n=41, 35.3%) was the predominant isolate and showed high sensitivity to levofloxacin (100%), Linezolid (100%) and Amikacin (100%). Twelve isolates of S. aureus were methicillin resistant, while 1 isolate was inducible clindamycin resistant. Of the 116 isolates identified in this study, forty-three (43) were multidrug resistant with highest number of multidrug resistant isolates from Staphylococcus aureus (n=20). 21.28% (n=10) of the Gram-negative isolates were positive for extended spectrum beta lactamases. Conclusion: A high rate of antimicrobial resistance is observed among microorganisms causing blood stream infections. This emphasizes the need for antimicrobial sensitivity testing in the management of blood stream infections.

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301. Penicillin Versus Cefazolin or Anti-staphylococcal Penicillins for Penicillin-Susceptible Staphylococcus aureus Bacteremia

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.344 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S149-S149

Author(s):

Mohammed Aldhaeefi ◽

Jeffrey Pearson ◽

Sanjat Kanjilal ◽

Brandon Dionne

Keyword(s):

Staphylococcus Aureus ◽

Blood Culture ◽

Positive Blood Culture ◽

Medical Center ◽

Academic Medical Center ◽

Similar Distribution ◽

Clinical Failure ◽

Staphylococcus Aureus Bacteremia ◽

Definitive Therapy ◽

Significant Difference

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

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Adjunctive ceftaroline in combination with daptomycin or vancomycin for complicated methicillin-resistant Staphylococcus aureus bacteremia after monotherapy failure

Therapeutic Advances in Infectious Disease ◽

10.1177/2049936119886504 ◽

2019 ◽

Vol 6 ◽

pp. 204993611988650 ◽

Cited By ~ 1

Author(s):

Joseph Patrik Hornak ◽

Seher Anjum ◽

David Reynoso

Keyword(s):

Staphylococcus Aureus ◽

Combination Therapy ◽

Methicillin Resistant Staphylococcus Aureus ◽

Treatment Options ◽

Source Control ◽

Optimal Timing ◽

Methicillin Resistant ◽

Staphylococcus Aureus Bacteremia ◽

Persistent Bacteremia

Background: Methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B) may fail to improve with standard monotherapy, particularly in patients with multifocal infection, incomplete source control, or persistent bacteremia. Synergy observed in vitro between ceftaroline (CPT) and daptomycin (DAP) or vancomycin (VAN) may translate into clinical benefit. Here, we describe our experience with DAP/CPT and VAN/CPT for complicated MRSA-B after monotherapy failure. Methods: Single-center, retrospective review of consecutive patients treated with DAP/CPT or VAN/CPT for MRSA-B after monotherapy failure from 1 January 2016 to 30 November 2018. Results: We identified 11 instances of combination therapy in 10 patients (DAP/CPT = 6, VAN/CPT = 5) with 1 patient receiving VAN/CPT followed by DAP/CPT. Rates of multifocal infection, incomplete source control, persistent bacteremia, and infective endocarditis were high (100%, 80%, 60%, and 60%, respectively). Combination therapy was initiated most commonly for persistent bacteremia (60%). When patients were persistently bacteremic, median preceding duration was 13 days and median time to clearance was 3 days. Total microbiologic cure rate was 100%. There were zero instances of bacteremia relapse at 30 days (30D) or 60 days (60D). All-cause 30D and 60D mortality rates were 11.1% and 33.3%, respectively. Conclusions: Combination therapy demonstrated success in diverse cases of refractory MRSA-B, including instances of persistent bacteremia paired with incomplete source control. Optimal timing and therapeutic cadence for combination therapy remain unclear. Our findings suggest that DAP/CPT and VAN/CPT can be considered for complicated MRSA bacteremia when other treatment options fail or are unavailable. We propose persistent bacteremia with incomplete source control to be a clinical niche particularly worthy of further investigation.

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

Open Forum Infectious Diseases ◽

10.1093/ofid/ofy209.167 ◽

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.

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