Staphylococcus Aureus Bacteremia Research Articles

Predictors of infectious foci on FDG PET/CT in Staphylococcus aureus bacteremia

We looked for predicting factors for the detection of infectious foci on 18F-fluorodeoxyglucose-positron emission tomography in combination with computed tomography (FDG PET/CT) among patients with Staphylococcus aureus bacteremia (SAB) who participated in an interventional study that was conducted at Rambam Health Care Campus, between July 1, 2015 and February 1, 2019. The primary outcome was an infectious focus detected by FDG PET/CT. Independent predictors for detection of focal infection were identified using univariate followed by a logistic regression multivariate analysis. We included 149 patients with 151 separate episodes of SAB who underwent FDG-PET/CT. Focal infections were detected in 107 patients (70.8%). Independent predictors for focal infection detection were community acquisition of bacteremia with odds ratio (OR) 3.03 [95% confidence interval (CI) 1.04–8.77], p-0.042 and C reactive protein (CRP) with OR 1.09 [95% CI 1.04–1.14], p < 0.001. Primary bacteremia was inversely associated with focal infection detection with OR 0.27 [0.10–0.69], p = 0.007, as were the pre-scan blood glucose levels OR 0.9 [0.98–0.99], p-0.004. The latter stayed significant in the subgroup of patients with diabetes mellitus. To conclude, patients with community-acquired bacteremia or high CRP levels should be carefully investigated for focal infection. Patients who present with primary bacteremia seem to be at low risk for focal infection.

Effectiveness of adjunctive rifampicin for treatment of Staphylococcus aureus bacteraemia: a systematic review and meta-analysis of randomized controlled trials.

To assess whether the addition of rifampicin to conventional treatment of Staphylococcus aureus bacteraemia (SAB) reduces bacteriological or clinical failure or death. PubMed, Embase and Cochrane CENTRAL databases were searched from inception to 31 December 2022. Reference lists and PubMed citations of eligible studies were checked. Two study authors independently identified randomized controlled trials (RCTs) involving adult participants with SAB, in which an intervention group received adjunctive rifampicin and the control group received usual care with or without a placebo. Dichotomous data (bacteriological and clinical failure and deaths) were analysed and pooled across studies using risk ratio (RR) with 95% confidence intervals (CI) using a Mantel-Haenszel random-effect model. The key variable of interest being whether rifampicin was used. Six RCTs including 894 participants-of which 758 (85%) were from one trial-met the inclusion criteria. The addition of rifampicin to conventional treatment of SAB significantly reduced bacteriological failure by 59% (RR 0.41, 95% CI 0.21-0.81, I2 = 0%, number need to treat 27). However, it did not reduce clinical failure (RR 0.70, 95% CI 0.47-1.03, I2 = 0%) or deaths (RR 0.96, 95% CI 0.70-1.32, I2 = 0%). Further, it did not reduce the duration of bacteraemia, or the length of hospital stay. Adjunctive rifampicin reduced SAB recurrences (1% versus 4%, P = 0.01). Emergence of rifampicin resistance during treatment was uncommon (<1%). Although adjunctive rifampicin reduced the risk of bacteriological failure and recurrences, we found no mortality benefit to support its use in SAB.

A 78-year-old Man Presented with Knee Pain and Recurrent Fever

&lt;p&gt;發燒為常見臨床症狀，本案例是一位78歲末期腎臟疾病接受長期血液透析治療男性，近一個月曾發生永久性透析導管感染合併金黃色葡萄球菌菌血症，此次因左膝關節疼痛就醫，理學檢查發現關節發熱腫脹，診斷感染性關節炎入院治療， 關節液及血液培養顯示金黃色葡萄球菌，在抗生素治療及行左膝切除關節成形術後仍反覆發燒， 經由專科護理師完整病史收集、全身理學檢查、實驗室檢驗結果，排除導管感染及心內膜炎等相關鑑別診斷，電腦斷層血管攝影顯示囊狀主動脈合併周圍積液確診為感染性動脈瘤。因年紀大合併多種慢性共病（塵肺症、慢性阻塞性肺病及末期腎臟疾病等），在家屬考量動脈瘤切除、結紮及血管重建手術利弊後決定採保守治療（6週Piperacillin-Tazobactam和Vancomycin抗生素靜脈注射療程），發燒及低血壓狀況改善，且血液培養亦未發現新的感染。臨床上，當病人主訴反覆發燒合併金黃色葡萄球菌菌血症時，根據我們的案例及文獻回顧，應強調以焦點式理學檢查積極探查可能的轉移性感染（包括：導管感染、軟組織感染、感染性關節炎、心內膜炎及感染性動脈瘤等），輔以影像學檢查。以此案例提升專科護理師於類似複雜案例時的照顧能力，利於醫療團隊即早確定診斷及介入治療，以降低延遲治療對於脆弱老年病人帶來負面影響。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Fever is a common symptom in clinical practice. A 78-year-old male with end-stage kidney disease (ESKD) who underwent hemodialysis was admitted due to left knee pain. Upon physical examination, there were signs of joint heat, swelling, and tenderness in addition to febrile state, suggesting a diag&amp;shy;nosis of septic arthritis. Staphylococcus aureus (SA) was later identified in both the synovial fluid and blood culture. However, the patient experienced recurrent fever despite receiving appropriate antimi&amp;shy;crobial treatment and undergoing left knee resectional arthroplasty. To rule out other potential diagno&amp;shy;ses related to SA bacteremia, a thorough evaluation involving medical history, physical examination, and laboratory tests was conducted. The computed tomography angiography revealed the presence of a saccular aortic aneurysm with perianeurysmal fluid collection, confirming a diagnosis of mycotic an&amp;shy;eurysm. The patient and his family carefully considered the advantages and disadvantages of surgical options, such as aneurysm excision, ligation, or vessel reconstruction. Under the considerations of the age and underlying comorbidities such as pneumoconiosis, chronic obstructive pulmonary disease, and ESKD, conservative treatment was performed (a 6-week course of intravenous piperacillin-tazobactam and vancomycin). The fever and hypotension gradually subsided, and there was no evidence of blood&amp;shy;stream infection. Based on our case and extensive literature reviews, it is crucial to actively evaluate metastatic complications, including infective endocarditis, catheter infection, septic arthritis, and my&amp;shy;cotic aneurysm, among patients who present with persistent fever and concurrent SA bacteremia. This case aims to enhance the abilities of nurse practitioners in conducting comprehensive assessments, providing vital information to the medical team, facilitating accurate diagnoses, timely interventions, and ultimately reducing the adverse impact of delayed treatment in vulnerable older adults.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Global Differences in the Management of Staphylococcus aureus Bacteremia: No International Standard of Care.

Despite being the leading cause of mortality from bloodstream infections worldwide, little is known about regional variation in treatment practices for Staphylococcus aureus bacteremia (SAB). The aim of this study was to identify global variation in management, diagnostics, and definitions of SAB. During a 20-day period in 2022, physicians throughout the world were surveyed on SAB treatment practices. The survey was distributed through listservs, e-mails, and social media. In total, 2031 physicians from 71 different countries on 6 continents (North America [701, 35%], Europe [573, 28%], Asia [409, 20%], Oceania [182, 9%], South America [124, 6%], and Africa [42, 2%]) completed the survey. Management-based responses differed significantly by continent for preferred treatment of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) bacteremia, use of adjunctive rifampin for prosthetic material infection, and use of oral antibiotics (P < .01 for all comparisons). The 18F-FDG PET/CT scans were most commonly used in Europe (94%) and least frequently used in Africa (13%) and North America (51%; P < .01). Although most respondents defined persistent SAB as 3-4 days of positive blood cultures, responses ranged from 2 days in 31% of European respondents to 7 days in 38% of Asian respondents (P < .01). Large practice variations for SAB exist throughout the world, reflecting the paucity of high-quality data and the absence of an international standard of care for the management of SAB.

A Retrospective Study of Staphylococcus aureus Bacteremia in a Tertiary Hospital and Factors Associated with Mortality.

Staphylococcus aureus bacteremia (SAB) is a severe infection frequently associated with significant morbidity and mortality. Recent studies have shown that SAB mortality has decreased during the last decades. However, about 25% of patients suffering from the disease will ultimately die. Hence, there is an urgent need for more timely and efficient treatment of patients with SAB. The aim of the present study was to retrospectively evaluate a cohort of SAB patients hospitalized in a tertiary hospital and to identify factors independently associated with mortality. All 256 SAB patients hospitalized from January 2005 to December 2021 in the University Hospital of Heraklion, Greece, were evaluated. Their median age was 72 years, while 101 (39.5%) were female. Most SAB patients were cared for in medical wards (80.5%). The infection was community-acquired in 49.5%. Among all strains 37.9% were methicillin-resistant S. aureus (MRSA), however, definite treatment with an antistaphylococcal penicillin was given only in 22% of patients. Only 14.4% of patients had a repeat blood culture after the initiation of antimicrobial treatment. Infective endocarditis was present in 8%. In-hospital mortality has reached 15.9%. Female gender, older age, higher McCabe score, previous antimicrobial use, presence of a central venous catheter, neutropenia, severe sepsis, septic shock, and MRSA SAB were positively associated with in-hospital mortality, while monomicrobial bacteremia was negatively associated. The multivariate logistic regression model identified only severe sepsis (p = 0.05, odds ratio = 12.294) and septic shock (p = 0.007, odds ratio 57.18) to be independently positively associated with in-hospital mortality. The evaluation revealed high rates of inappropriate empirical antimicrobial treatment and non-adherence to guidelines, as shown, by the lack of repeat blood cultures. These data underline the urgent need for interventions with antimicrobial stewardship, increased involvement of infectious diseases physicians, educational sessions, and creation and implementation of local guidelines for improvement of the necessary steps for timely and efficient SAB treatment. Optimization of diagnostic techniques is needed to overcome challenges such as heteroresistance that may affect treatment. Clinicians should be aware of the factors associated with mortality in patients with SAB to identify those who are at a higher risk and optimize medical management.

Dalbavancin vs standard of care for Staphylococcus aureus bacteraemia in patients unable to receive outpatient parenteral antimicrobial therapy

This study compared dalbavancin with standard of care (SOC) for patients with Staphylococcus aureus bacteraemia (SAB) who were unable to receive outpatient parenteral antimicrobial therapy (OPAT). This retrospective cohort compared re-admission rates related to the index infection between patients treated with dalbavancin or SOC for SAB. Patients aged ≥18 years seen by the infectious diseases consult service who had received at least one dose of dalbavancin or at least 1 week of SOC parenteral antibacterials as directed therapy for SAB at the time of discharge were included. The SOC group consisted of patients transferred from the main hospital to one of the post-acute care facilities to complete parenteral antibacterials. The primary outcome was re-admission rate within 30 days of completion of therapy. Secondary outcomes included re-admission rate within 90 days of completion of therapy and adherence to the antibacterial regimen. Twenty-seven patients received dalbavancin and 27 patients received SOC. Baseline demographics were comparable between groups, although more patients in the SOC group had indwelling prostheses or hardware (4% vs 22%). The majority of SAB was caused by methicillin-susceptible S. aureus (56% vs 59%). Re-admission rates for the dalbavancin group were similar to those for the SOC group within 30 days (15% vs 22%; P=0.484) and 90 days (19% vs 22%; P=0.735) of completion of therapy. Adherence to the antibacterial regimen was significantly higher among patients treated with dalbavancin compared with SOC (85% vs 44%; P<0.001). Dalbavancin offers similar clinical outcomes to SOC for patients with SAB who are unable to receive OPAT.

Impact of the COVID-19 Pandemic on the Management of Staphylococcus aureus Bloodstream Infections in a Tertiary Care Hospital.

Staphylococcus aureus bacteremia (SAB) is associated with a high mortality rate. The clinical outcome of SAB patients highly depends on early diagnosis, adequate antibiotic therapy and source control. In the context of the COVID-19 pandemic, the health care system faced additional organizational challenges and the question arose whether structured screening and triaging for COVID-19 and shifting resources influence the management of SAB. Patients (n = 115) with SAB were enrolled in a retrospective comparative study with historical controls (March 2019-February 2021). The quality of SAB therapy was assessed with a point score, which included correct choice of antibiotic, adequate dosage of antibiotic, sufficient duration of therapy, early start of therapy after receipt of findings, focus search and taking control blood cultures 3-4 days after starting adequate antibiotic therapy. The quality of treatment before and after the onset of the COVID-19 pandemic were compared. No significant differences in the total score points were found between the pre-COVID-19 and COVID-19 cohort. All quality indicators, except the correct duration of antibiotic therapy, showed no significant differences in both cohorts. Furthermore, there were no significant differences in the outcome between both cohorts. The treatment quality of SAB therapy was comparable before and during the COVID-19 pandemic.

Which trial do we need? Next-generation sequencing to individualize therapy in Staphylococcus aureus bacteraemia

We propose a two-stage clinical trial in patients with Staphylococcus aureus bacteremia (SAB). In Stage 1 we will evaluate metagenomic next generation sequencing from blood as a quantitative biological surrogate for clinical endpoint in patients with SAB, similar to quantitative HIV viral load in HIV-infected patients. In Stage 2, we will conduct a randomized controlled trial to individualize duration of antibiotic therapy for based upon the presence of S. aureus genetic material in patients' blood. The proposed study addresses two critical aspects of treatment of patients with SAB: the identification of a surrogate biological endpoint for future clinical trials, and a new approach by which to individualize patient management.

Impact of antimicrobial stewardship with the Xpert MRSA/SA BC assay at a tertiary hospital in Japan

IntroductionGenetic testing is gaining increasing importance as a part of antimicrobial stewardship (AS). Rapid identification and determination of methicillin susceptibility using the Xpert MRSA/SA BC assay can improve the management of Staphylococcus aureus bacteremia (SAB) and reduce inappropriate antibiotic use. However, few reports have described the effectiveness of this approach. MethodsThe present study aimed to assess the influence of AS using the Xpert MRSA/SA BC assay. Cases were classified into the pre-intervention group (n = 98 patients), in which SAB was identified by traditional culture (November 2017 to November 2019), and the post-intervention group (n = 97 patients), in which the Xpert MRSA/SA BC assay was performed when necessary (December 2019 to December 2021). ResultsPatient characteristics, prognosis, duration of antimicrobial use, and length of hospital stay were compared between the groups. The Xpert assay was performed in 66 patients in the post-intervention group (68.0%). The two groups showed no significant differences in severity and mortality. The rate of cases treated with anti-MRSA agents reduced following the intervention (65.3% vs. 40.4%, p = 0.008). The number of cases involving definitive therapy within 24 h was higher in the post-intervention group (9.2% vs. 24.7%, p = 0.007). The hospitalization rate at >60 days was lower in Xpert implementation cases among MRSA bacteremia cases (28.6% vs. 0%, p = 0.01). ConclusionsThus, the Xpert MRSA/SA BC assay has potential as an AS tool, especially for early definitive treatment to SAB and reduction of long-term hospitalization in MRSA bacteremia cases.

Staphylococcus aureus bacteraemia treatment outcomes in patients receiving ticagrelor vs a propensity-matched cohort receiving clopidogrel.

Ticagrelor may improve the outcomes in Staphylococcus aureus bacteraemia (SAB). However, treatment outcome data for these patients remain limited. The primary objective of this study was to characterize the outcomes of patients with SAB who received ticagrelor compared with a cohort who received clopidogrel. This was a retrospective, nationwide propensity-matched analysis of patients with SAB who were prescribed ticagrelor or clopidogrel concomitantly with antistaphylococcal therapy. The primary outcome was the comparative all-cause 30-day mortality rate between propensity-matched groups. In total, 1509 patients were prescribed concomitantly with ticagrelor or clopidogrel during treatment of S. aureus bacteraemia; of these, 194 patients were excluded from this study due to an inadequate number of antiplatelet doses within the first week of therapy (n=171) or non-admission to hospital (n=23). Of the remaining 1315 patients, 74 patients received ticagrelor and 1241 patients received clopidogrel. There was no significant difference in all-cause 30-day mortality between the groups [6/74 (8.1%) in the ticagrelor group vs 10/74 (13.5%) in the clopidogrel group; P=0.29]. Multi-variate logistic regression demonstrated that elevated aspartate aminotransferase, systolic blood pressure <90 mmHg, elevated serum creatinine and neurological comorbidity were independently associated with all-cause 30-day mortality. This study found no difference in all-cause 30-day mortality between the two groups, although overall mortality appeared to be lower compared with other reports. Randomized controlled trials of P2Y12 inhibitors as adjunctive agents to antibiotic therapy for the treatment of serious S. aureus infections are warranted.

Propensity-matched analysis of the protective effect of ticagrelor versus clopidogrel on the risk of developing Staphylococcus aureus bacteremia.

Recent data indicate that ticagrelor, used in acute coronary syndromes (ACS), has antibacterial effects against Staphylococcus sp. and other effects that may help management of infection. The primary objective of this study was to evaluate the protective effect of ticagrelor in patients who have had an ACS event and the risk of developing Staphylococcus aureus bacteremia (SAB) compared to a propensity-matched cohort receiving clopidogrel. This study was a retrospective, nationwide analysis of all patients presenting to any percutaneous coronary intervention-performing Veterans Affairs Medical Center with an ACS episode and resultant prescription for clopidogrel or ticagrelor. The primary outcome was the comparative rate of SAB in patients receiving ticagrelor vs. clopidogrel. Analysis involved 24 456 patients on ticagrelor and 277 277 patients on clopidogrel. There was a statistically significant difference in the number of patients developing SAB between the propensity-matched groups (32 [0.13%] of 24 456 for ticagrelor vs. 71 [0.29%] of 24 456 for clopidogrel; odds ratio (OR), 0.43; 95% confidence interval (CI), 0.28-0.65; P<0.0001). Multivariate logistic regression showed that receipt of clopidogrel, comorbid dermatologic condition, comorbid hematologic condition, and baseline anemia were independently associated with the development of SAB. The study findings align with recent reports that ticagrelor may have a beneficial role in the prevention of SAB.

Safe shortening of antibiotic treatment duration for complicated Staphylococcus aureus bacteraemia (SAFE trial): protocol for a randomised, controlled, open-label, non-inferiority trial comparing 4 and 6 weeks of antibiotic treatment

IntroductionA major knowledge gap in the treatment of complicated Staphylococcus aureus bacteraemia (SAB) is the optimal duration of antibiotic therapy. Safe shortening of antibiotic therapy has the potential to reduce...

Staphylococcus aureus bacteraemia, cardiac implantable electronic device, and the risk of endocarditis: a retrospective population–based cohort study

Patients with cardiac implantable electronic device (CIED) and Staphylococcus aureus bacteraemia (SAB) are at risk of having infective endocarditis (IE). The objectives were to describe a Swedish population-based cohort of patients with CIED and SAB, to identify risk factors, and to construct a predictive score for IE. Patients over 18 years old in the Stockholm Region identified to have SAB in the Karolinska Laboratory database from January 2015 through December 2019 were matched to the Swedish Pacemaker and Implantable Cardioverter-Defibrillator ICD Registry to identify the study cohort. Data were collected from study of medical records. A cohort of 274 patients with CIED and SAB was identified and in 38 episodes (14%) IE were diagnosed, 19 with changes on the CIED, and 35 with changes on the left side of the heart. The risk factors predisposition for IE, community acquisition, embolization, time to positivity of blood cultures, and growth in blood culture after start of therapy in blood cultures were independently associated to IE. A score to identify patients with IE was constructed, the CTEPP score, and the chosen cut-off generated a sensitivity of 97%, specificity of 25%, and a negative predictive value of 98%. The score was externally validated in a population-based cohort of patients with CIED and SAB from another Swedish region. We found that 14% of patients with CIED and SAB had definite IE diagnosed. The CTEPP-score can be used to predict the risk of IE and, when negative, the risk is negligible.

Evaluation of Clinical Approach and Outcomes Staphylococcus aureus Bacteremia.

Despite appropriate treatment and early diagnosis methods, Staphylococcus aureus bacteremia (SAB) is still associated with a high mortality rate. This study aims to evaluate the clinical features and approaches to SAB and to analyze the parameters that may affect 7-day and 30-day mortality. Adult patients with SAB data between 2011 and 2018 were evaluated retrospectively. Clinical data, patient demographics, and 7-day and 30-day mortality rates were obtained from their medical records. In total, 144 patients were included in the study; 57.6% (83/144) of patients were men, and the mean age was 65.2±16.5 years. The most common source of infection was the central-line catheter (38.9%), followed by intra-abdominal (21%), respiratory (16.7), infective endocarditis (5.6%), and osteoarticular foci (2.1%). Fifteen percent (15%) of the strains were methicillin resistant. Transthoracic echocardiography (TTE) was performed for 80.6% (116/144) patients. Infectious diseases specialist consultation within 96 hours from blood culture signal was requested in 79.9%. Overall, 7-day mortality was 11.8%, and 30-day mortality was 21.5%. Staying in intensive care units (ICU) increased the risk of 30-day mortality by 1.1 times, and respiratory-focused SAB increased the risk by 4.3 times. SAB is still a big threat. Staphylococcal pneumonia remains a severe infection. Several prognostic factors influence mortality. Identifying the source, ensuring source control, and appropriate initial therapy as soon as possible are critical for reducing mortality and morbidity in SAB.

Comparative effectiveness of β-lactams for empirical treatment of methicillin-susceptible Staphylococcus aureus bacteraemia: a prospective cohort study.

Standard once-daily dosing of ceftriaxone may not lead to adequate antibiotic exposure in all cases of Staphylococcus aureus bacteraemia (SAB). Therefore, we compared clinical effectiveness of empirical antibiotic treatment with flucloxacillin, cefuroxime and ceftriaxone in adult patients with MSSA bacteraemia. We analysed data from the Improved Diagnostic Strategies in Staphylococcus aureus bacteraemia (IDISA) study, a multicentre prospective cohort study of adult patients with MSSA bacteraemia. Duration of bacteraemia and 30 day SAB-related mortality were compared between the three groups using multivariable mixed-effects Cox regression analyses. In total, 268 patients with MSSA bacteraemia were included in the analyses. Median duration of empirical antibiotic therapy was 3 (IQR 2-3) days in the total study population. Median duration of bacteraemia was 1.0 (IQR 1.0-3.0) day in the flucloxacillin, cefuroxime and ceftriaxone groups. In multivariable analyses, neither ceftriaxone nor cefuroxime was associated with increased duration of bacteraemia compared with flucloxacillin (HR 1.08, 95% CI 0.73-1.60 and HR 1.22, 95% CI 0.88-1.71). In multivariable analysis, neither cefuroxime nor ceftriaxone was associated with higher 30 day SAB-related mortality compared with flucloxacillin [subdistribution HR (sHR) 1.37, 95% CI 0.42-4.52 and sHR 1.93, 95% CI 0.67-5.60]. In this study, we could not demonstrate a difference in duration of bacteraemia and 30 day SAB-related mortality between patients with SAB empirically treated with flucloxacillin, cefuroxime or ceftriaxone. Since sample size was limited, it is possible the study was underpowered to find a clinically relevant effect.

Treatment and outcome of gram-positive bacteremia in patients receiving extracorporeal membrane oxygenation

BackgroundWhile guidance exists for management of blood stream infections with various invasive devices, there are currently limited data to guide antibiotic selection and duration for bacteremia in patients receiving extracorporeal membrane oxygenation (ECMO). ObjectiveTo evaluate the treatment and outcomes of thirty-six patients with Staphylococcus aureus and Enterococcus bacteremia on ECMO support. MethodsBlood culture data was retrospectively analyzed from patients with Staphylococcus aureus bacteremia (SAB) or Enterococcus bacteremia who underwent ECMO support between March 2012 and September 2021 at Brooke Army Medical Center. ResultsOf the 282 patients who received ECMO during this study period, there 25 (9%) patients developed Enterococcus bacteremia and 16 (6%) developed SAB. SAB occurred earlier in ECMO as compared to Enterococcus (median day 2 IQR (1–5) vs. 22 (12–51), p = 0.01). The most common duration of antibiotics was 28 days after clearance for SAB and 14 days after clearance for Enterococcus. 2 (5%) patients underwent cannula exchange with primary bacteremia, and 7 (17%) underwent circuit exchange. 1/3 (33%) patients with SAB and 3/10 (30%) patients with Enterococcus bacteremia who remained cannulated after completion of antibiotics had a second episode of SAB or Enterococcus bacteremia. ConclusionThis single center case series is the first to describe the specific treatment and outcomes of patients receiving ECMO complicated by SAB and Enterococcus bacteremia. For patients who remain on ECMO after completion of antibiotics, there is a risk of a second episode of Enterococcus bacteremia or SAB.

Sequential oral antibiotic in uncomplicated Staphylococcus aureus bacteraemia: a propensity-matched cohort analysis

ObjectivesWe aimed to analyse the efficacy and safety of oral sequential therapy (OST) in uncomplicated Staphylococcus aureus bacteraemia (SAB). MethodsSingle-centre observational cohort at a tertiary hospital in Spain, including all patients with the first SAB episode from January 2015 to December 2020. We excluded patients with complicated SAB and those who died during the first week. Patients were classified into the OST group (patients who received oral therapy after initial intravenous antibiotic therapy [IVT]), and IVT group (patients who received exclusively IVT). We performed a propensity-score matching to balance baseline differences. The primary composite endpoint was 90-day mortality or microbiological failure. Secondary endpoints included 90-day SAB relapse. ResultsOut of 407 SAB first episodes, 230 (56.5%) were included. Of these, 112 (n = 48.7%) received OST and 118 (51.3%) IVT exclusively. Transition to oral therapy was performed after 7 days (interquartile range, 4–11).The primary endpoint occurred in 10.7% (11/112) in OST vs. 30.5% (36/118) in IVT (p < 0.001). SAB relapses occurred in 3.6% (4/112) vs. 1.7% (2/118) (p 0.436). None of the deaths in OST were related to SAB or its complications.After propensity-score matching, the primary endpoint was not more frequent in the OST group (relative risk, 0.42; 95% CI, 0.22–0.79). Ninety-day relapses occurred similarly in both groups (relative risk, 1.35; 95% CI, 0.75–2.39). DiscussionAfter an initial intravenous antibiotic, patients with uncomplicated SAB can safely be switched to oral antibiotics without apparent adverse outcomes. This strategy could save costs and complications of prolonged hospital stays. Prospective randomized studies are needed.

Prognostic significance of early platelet dynamics in Staphylococcus aureus bacteremia

BackgroundPlatelets are recognized as key immune effectors, but they are targets of bacterial virulence factors. In the present study, we aimed to examine the relationship between early platelet dynamics and the outcome of Staphylococcus aureus bacteremia (SAB).MethodElectronic medical records of adult patients hospitalized for SAB between July 2012 and November 2020 were retrospectively reviewed for relevant demographic, laboratory, and clinical data. The outcome endpoints were mortality and microbial persistence.ResultsAmong the 811 patients evaluated, 29% experienced thrombocytopenia on Day 1. Platelet count nadir occurred on Days 2–3 following SAB onset, and Day 4 was a determining point of platelet count trajectory and mortality. Mortality risk was 6% or less for those with normal platelet count by Day 4 regardless of whether they experienced thrombocytopenia on Day 1, but the risk increased to 16–21% for those who experienced thrombocytopenia on Day 4 regardless of whether they had normal platelet count on Day 1 or sustained thrombocytopenia. The duration of bacteremia was prolonged by one day (median 3 d vs. 2 d) for those with sustained thrombocytopenia compared to those without.ConclusionEarly platelet dynamics during SAB have prognostic significance and represent an early window for potential platelet-directed therapeutic interventions to improve outcome.

All Staphylococcus aureus bacteraemia-inducing strains can cause infective endocarditis: Results of GWAS and experimental animal studies

We aimed at determining whether specific S. aureus strains cause infective endocarditis (IE) in the course of Staphylococcus aureus bacteraemia (SAB). A genome-wide association study (GWAS) including 924 S. aureus genomes from IE (274) and non-IE (650) SAB patients from international cohorts was conducted, and a subset of strains was tested with two experimental animal models of IE, one investigating the early step of bacterial adhesion to inflamed mice valves, the second evaluating the local and systemic developmental process of IE on mechanically-damaged rabbit valves. The genetic profile of S. aureus IE and non-IE SAB strains did not differ when considering single nucleotide polymorphisms, coding sequences, and k-mers analysed in GWAS. In the murine inflammation-induced IE model, no difference was observed between IE and non-IE SAB strains both in terms of adhesion to the cardiac valves and in the propensity to cause IE; in the mechanical IE-induced rabbit model, there was no difference between IE and non-IE SAB strains regarding the vegetation size and CFU. All strains of S. aureus isolated from SAB patients must be considered as capable of causing this common and lethal infection once they have accessed the bloodstream.

Clinical reasoning for performance of transesophageal echocardiography in veterans with Staphylococcus aureus bacteremia.

This study examined physicians' reasoning about obtaining transesophageal echocardiography (TEE) in cases of Staphylococcus aureus bacteremia (SAB). In 221 cases of SAB over 5 years, the most common reasons for not performing TEE were clinical response to antibiotics, negative TTE results, and the expectation that TEE would not change management.