Coagulase-negative Staphylococcal Bacteremia Research Articles

Continuous Versus Intermittent Vancomycin Infusions for Coagulase-negative Staphylococcus Bacteremia in Neonates: A Propensity-matched Cohort Study.

Coagulase-negative staphylococci (CONS) are a major cause of late-onset neonatal sepsis, particularly in preterm infants, with high morbidity and mortality. While vancomycin is the first-line treatment for these infections, the optimal administration in neonates remains uncertain. We aim to compare the outcomes of neonates with CONS bacteremia treated with adjusted continuous infusion (CIV) versus standard intermittent infusion (IIV) of vancomycin. This retrospective study included 110 neonates, with 29 in the CIV group and 47 in the IIV group after propensity score matching. The primary outcome was treatment failure defined by the persistence of a positive blood culture for the same organism after at least 48 hours of vancomycin treatment. After matching, the CIV group exhibited significantly lower treatment failure rates [5/29 (17%) vs. 26/47 (44%); P = 0.014] and a higher rate of achieving therapeutic vancomycin levels after 24 hours [20/29 (69%) vs. 26/47 (44%); P = 0.002] compared to the IIV group. No significant differences were observed in terms of acute kidney failure between the 2 groups. Adjusted continuous vancomycin infusion in neonates with CONS bacteremia is associated with a lower treatment failure rate without an increase in renal toxicity compared to standard intermittent infusion. However, due to the observational design, larger prospective studies are needed to validate these results.

Gut barrier dysfunction and the risk of ICU-acquired bacteremia- a case–control study

BackgroundImpaired intestinal barrier function can enable passage of enteric microorganisms into the bloodstream and lead to nosocomial bloodstream infections during critical illness. We aimed to determine the relative importance of gut translocation as a source for ICU-acquired enterococcal bacteremia of unknown origin.MethodsWe conducted a nested case–control study in two mixed medical-surgical tertiary ICUs in the Netherlands among patients enrolled between 2011 and 2018. We selected 72 cases with ICU-acquired bacteremia due to enterococci (which are known gastrointestinal tract commensals) and 137 matched controls with bacteremia due to coagulase-negative staphylococci (CoNS) (which are of non-intestinal origin). We measured intestinal fatty acid-binding protein, trefoil factor-3, and citrulline 48 h before bacteremia onset. A composite measure for Gut Barrier Injury (GBI) was calculated as the sum of standardized z-scores for each biomarker plus a clinical gastrointestinal failure score.ResultsNo single biomarker yielded statistically significant differences between cases and controls. Median composite GBI was higher in cases than in controls (0.58, IQR − 0.36–1.69 vs. 0.32, IQR − 0.53–1.57, p = 0.33) and higher composite measures of GBI correlated with higher disease severity and ICU mortality (p < 0.001). In multivariable analysis, higher composite GBI was not significantly associated with increased occurrence of enterococcal bacteremia relative to CoNS bacteremia (adjusted OR 1.12 95% CI 0.93–1.34, p = 0.22).ConclusionsWe could not demonstrate an association between biomarkers of gastrointestinal barrier dysfunction and an increased occurrence of bacteremia due to gut compared to skin flora during critical illness, suggesting against bacterial translocation as a major vector for acquisition of nosocomial bloodstream infections in the ICU.

Clinical Impact of Vancomycin MIC on Outcomes in Patients With Coagulase-negative Staphylococcal Bacteremia

Coagulase-negative staphylococci (CoNS) are Gram-positive organisms that are a known component of normal skin flora and the most common cause of nosocomial bacteremia. For CoNS species, the vancomycin MIC breakpoint for susceptibility set by the Clinical and Laboratory Standards Institute is ≤4 µg/mL. There has been published reports of vancomycin heteroresistance in CoNS with vancomycin MICs of 2 to 4 µg/mL. The aim of this retrospective cohort analysis was to assess the clinical impact of vancomycin MICs <2 µg/mL versus ≥2 µg/mL in adult patients with CoNS bloodstream infections. Adult patients admitted to University Medical Center New Orleans with a blood culture positive for CoNS were assessed. The primary outcome was difference in 30-day mortality. Secondary outcomes were in-hospital, all-cause mortality; duration of bacteremia; hospital length of stay; and percentage of oxacillin-resistant CoNS. There was no difference in mortality in the vancomycin MIC <2 µg/mL group versus the vancomycin MIC ≥2 µg/mL group at 30 days (15.4% vs 17.4%; P = 1). In-hospital, all-cause mortality was also not different between groups (11.5% vs 13%; P = 1). Hospital length of stay between groups was 28.2 days versus 21 days (P = 0.692). Median duration of bacteremia was 1 day in both groups (P = 0.975), and median scheduled duration of antibiotic therapy was 14.9 days and 19.5 days (P = 0.385). The source and mode of acquisition of CoNS were similar between groups. Of all CoNS isolates, 58.7% (44 of 75) were oxacillin resistant. Staphylococcus epidermidis was the most common CoNS species at 66.7% (50 of 75). Of all isolates, 30.7% (23 of 75) had a vancomycin MIC ≥2 µg/mL, and 87% (20 of 23) of these were S. epidermidis. There was a higher percentage of S. epidermidis in the vancomycin MIC ≥2 µg/mL group than in the MIC <2 µg/mL group (87% vs 57.7%; P = 0.012). CoNS with a vancomycin MIC ≥2 µg/mL were also more likely to be oxacillin resistant (78.3% vs 50%; P = 0.005). There was no difference in clinical outcomes in adult patients with a CoNS bloodstream infection with a vancomycin MIC <2 µg/mL versus ≥2 µg/mL. At present, vancomycin remains appropriate empiric therapy for CoNS bloodstream infection. Further research is needed to determine if there is a true clinical impact of a vancomycin MIC ≥2 µg/mL in CoNS infections.

Daptomycin Use for Persistent Coagulase-Negative Staphylococcal Bacteremia in a Neonatal Intensive Care Unit.

During the last two decades, the incidence of late-onset sepsis (LOS) has increased due to improved survival of premature neonates. Persistent bacteremia (PB) in LOS is defined as more than two positive blood cultures obtained on different calendar days during the same infectious episode. Although rare, PB should be treated aggressively to prevent adverse outcomes. Daptomycin, a lipopeptide antibiotic, has been used in neonates with persistent coagulase-negative staphylococci (CoNS) bacteremia with promising results, but studies reporting on the efficacy and safety of the agent are scarce. The purpose of this study was to evaluate the efficacy and safety of daptomycin use for persistent CoNS bacteremia in a neonatal cohort. This is a retrospective, observational, single-center study of neonates treated with daptomycin during 2011-2022 in the Tertiary Neonatal Intensive Care Unit (NICU) of the University General Hospital of Patras, Greece. For the years 2011-2022, there were 3.413 admissions to the NICU. During the last 3 years (2020-2022)-the active epidemiological surveillance period-123 infants (out of 851 admissions, 14.4%) developed CoNS bacteremia (LOS). During the study period, twelve infants with PB were treated with daptomycin. They had a median gestational age of 32 weeks (IQR 31-34) and mean (SD) birth weight of 1.840 (867) grams. CoNS bacteremia isolates were s. epidermidis (50%), s. haemolyticus (20%), s. hominis (20%) and s. warneri (10%). The decision to start daptomycin (6 mg/kg/dose twice daily) was taken on median day 10 (ΙQR 7-15) of infection. None of the infants had focal complications or meningitis. Daptomycin therapy caused no renal, hepatic, muscular or gastrointestinal adverse events. One neonate developed seizures, and one death occurred due to multiple complications of prematurity. Most infants (11/12) were successfully treated and eventually had negative blood culture. Daptomycin monotherapy showed an adequate cure rate in premature neonates with persistent CoNS bacteremia in a tertiary NICU. In our study, daptomycin was effective and well tolerated; the safety profile, however, needs to be confirmed in larger studies and randomized controlled trials.

Real-Life Vancomycin Therapeutic Drug Monitoring in Coagulase-Negative Staphylococcal Bacteremia in Neonatal and Pediatric Intensive Care Unit: Are We Underestimating Augmented Renal Clearance?

Bloodstream infections (BSI) from coagulase-negative-staphylococci (CoNS) are among the most frequent healthcare-related infections. Their treatment involves the use of vancomycin, a molecule whose optimal pharmacokinetic/pharmacodynamic (PK/PD) target for efficacy and safety is an area-under-curve/minimum inhibitory concentration (AUC/MIC) ratio ≥ 400 with AUC < 600. BSIs from CoNS in pediatric and neonatal intensive care unit that occurred at the Gaslini Institute over five years were evaluated to investigate the efficacy of vancomycin therapy in terms of achieving the desired PK/PD target and determining whether any variables interfere with the achievement of this target. AUC/MIC ≥ 400 with AUC < 600 at 48 and 72 h after therapy initiation was achieved in only 21% of the neonatal population and 25% of the pediatric population. In the pediatric population, an inverse correlation emerged between estimated glomerular filtration rate (eGFR) and achieved AUC levels. Median eGFR at 72 h was significantly higher (expression of hyperfiltration) in events with AUC < 400, compared with those with AUC ≥ 400 (p < 0.001). A cut-off value of eGFR in the first 72 h has been identified (145 mL/min/1.73 m2), beyond which it is extremely unlikely to achieve an AUC ≥ 400, and therefore a higher dose or a different antibiotic should be chosen.

Risk of endocarditis among patients with coagulase-negative Staphylococcus bacteremia

Coagulase-negative staphylococci (CoNS) are currently considered typical microorganisms causing infective endocarditis (IE) in patients with prosthetic valves. The objective was to determine variables associated with IE in patients with CoNS bacteremia. We performed an analysis of the clinical characteristics of patients with CoNS bacteremia admitted to a university hospital in Madrid (Spain) from 2021 to December 2022 according to the occurrence of IE. This study is an evaluation of a bacteremia registry. During the study period, 106 patients with CoNS bacteremia were detected. In 85 patients an echocardiogram was performed during hospital admission to rule out IE. Among them, 12 episodes were detected that met IE criteria (14.2%). Of the 6 patients with heart valve prostheses, 5 patients (83.3%) had IE (p < 0.001). Patients with IE more frequently had positive blood cultures more than 12 h after the first draw (58.3% versus 13.4%; p < 0.001). There was a tendency to associate community-acquired bacteremia and to that all blood culture bottles obtained were positive with an increased risk of IE (p = 0.091 and p = 0,057, respectively). Attributable mortality to infection was higher in patients with IE relative to all other patients (16.7% vs. 0%; p = 0.033). The multivariable analysis included having valve prosthesis and persistent bacteremia for more than 12 h. Both were independently associated with IE: valve prosthesis OR 38.6 (95% CI 5.8–258; p < 0.001) and persistent bacteremia OR 2.6 (95% CI 1.1–6.8; p = 0.046). In conclusion, a high percentage of cases of CoNS bacteremia may be due to IE. Some of the variables related to a higher risk of IE, such as having a valvular prosthesis or presenting positive blood cultures for more than 12 h, should lead to rule out or confirm the presence of IE by performing echocardiography.

Bloodstream Infection Due to Coagulase-Negative Staphylococci: Impact of Species on Prevalence of Infective Endocarditis.

(1) Background: Coagulase-negative staphylococci (CoNS) are an important group of organisms that can cause bloodstream infection (BSI) and infective endocarditis (IE). The prevalence of IE in patients with BSI due to different CoNS species, however, has received limited attention; (2) Methods: A retrospective study of adults with monomicrobial CoNS BSI who had undergone echocardiography and a risk factor analysis was done to determine the most common CoNS species that cause definite IE; (3) Results: 247 patients with CoNS BSI were included in the investigation; 49 (19.8%) had definite IE, 124 (50.2%) possible IE, and 74 (30.0%) BSI only. The latter two entities were grouped in one category for further analysis. The most common species in CoNS BSI was Staphylococcus epidermidis (79.4%) and most patients (83.2%) had possible IE/BSI only. 59.1% of patients with BSI due to S. lugdunensis had definite IE. The majority of CoNS were healthcare-associated/nosocomial bacteremia. Multivariable analysis demonstrated that valve disease (p = 0.002) and a foreign cardiovascular material (p < 0.001) were risk factors associated with definite IE. Patients with S. lugdunensis BSI had an 8-fold higher risk of definite IE than did those with S. epidermidis BSI and nearly a 13-fold higher risk than did patients with BSI due to other species of CoNS (p = 0.002); (4) Conclusions: The prevalence of definite IE in patients with BSI due to different CoNS species was significant. CoNS bacteremia, particularly with S. lugdunensis, confers a significant risk of IE, particularly in patients with a valve disease or intravascular foreign body material and should not be immediately dismissed as a contaminant.

Bacteremia due to non–Staphylococcus aureus gram-positive cocci and risk of cardiovascular implantable electronic device infection

Cardiovascular implantable electronic device (CIED) infection carries significant morbidity and mortality with bacteremia being a possible marker of device infection. A clinical profile of non-Staphylococcus aureus gram-positive cocci (non-SA GPC) bacteremia in patients with CIED has been limited. To examine characteristics of patients with CIED who developed non-SA GPC bacteremia and risk of CIED infection. We reviewed all patients with CIED who developed non-SA GPC bacteremia at the Mayo Clinic between 2012 and 2019. The 2019 European Heart Rhythm Association Consensus Document was used to define CIED infection. A total of 160 patients with CIED developed non-SA GPC bacteremia. CIED infection was present in 90 (56.3%) patients, in whom 60 (37.5%) were classified as definite and 30 (18.8%) as possible. This included 41 (45.6%) cases of coagulase-negative Staphylococcus (CoNS), 30 (33.3%) cases of Enterococcus, 13 (14.4%) cases of viridans group streptococci (VGS), and 6 (6.7%) cases of other organisms. The adjusted odds of CIED infection in cases due to CoNS, Enterococcus, and VGS bacteremia were 19-, 14-, and 15-fold higher, respectively, as compared with other non-SA GPC. In patients with CIED infection, the reduction in risk of 1-year mortality associated with device removal was not statistically significant (hazard ratio 0.59; 95% confidence interval 0.26-1.33; P = .198). The prevalence of CIED infection in non-SA GPC bacteremia was higher than previously reported, particularly in cases due to CoNS, Enterococcus species, and VGS. However, a larger cohort is needed to demonstrate the benefit of CIED extraction in patients with infected CIED due to non-SA GPC.

Usefulness of leadless pacemaker implantation to continue chemotherapy for Burkitt's lymphoma without device infection despite repeated systemic infections.

Usefulness of leadless pacemaker implantation to continue chemotherapy for Burkitt's lymphoma without device infection despite repeated systemic infections.

Clinical Characteristics and Outcomes of Persistent Staphylococcal Bacteremia in a Tertiary Care Hospital

Clinical outcomes of persistent staphylococcal bacteremia vary depending on the causative organism. This secondary data analysis study compared the clinical characteristics of persistent Staphylococcus aureus (S. aureus)- and coagulase-negative staphylococci (CoNS)-caused bacteremia, focusing on the methicillin-resistant status. This study used data collected from patients who underwent blood cultures between January 2012 and December 2021 at Tohoku University Hospital, Japan. Patients with persistent staphylococcal bacteremia were divided into groups based on the pathogen and methicillin-resistant status, and their characteristics were analyzed. The primary outcomes were early (30-day), late (30-90 days), and 90-day mortality rates. The early, late, and 90-day mortality rates were similar between the persistent CoNS and S. aureus bacteremia groups. Patients with persistent methicillin-resistant S. aureus (MRSA) bacteremia tended to have higher early, late, and 90-day mortality rates than those with persistent methicillin-susceptible S. aureus bacteremia (not statistically significant). No differences were observed between the methicillin-resistant and-susceptible CoNS groups. In patients with persistent CoNS bacteremia, mortality tended to increase, especially in debilitated or immunocompromised patients with distant metastases, underscoring the importance of infection source control. Mortality tended to be high in patients with persistent MRSA bacteremia, especially when persistent bacteremia clearance was not confirmed, illustrating the need for careful therapeutic management.

1518. Bacteremia due to Non-Staphylococcus aureus Gram-positive Cocci and Risk of Cardiovascular Implantable Devices Infection

Abstract Background Cardiovascular implantable electronic devices (CIED) infection carries significant morbidity, mortality, and financial burden. Bacteremia in patients with CIED increases risk of CIED infection. While several investigations have examined Staphylococcus aureus bacteremia and risk of CIED infection, data regarding non-S. aureus gram-positive coccal (non-SA GPC) bacteremia in patients with CIED has been both limited and dated. The current study examined the clinical characteristics of patients with CIED who developed non-SA GPC bacteremia and their proclivity of CIED infection. Methods We reviewed all patients with CIED who developed non-SA GPC bacteremia at Mayo Clinic between 2012–2019. Cases with a left ventricular assist device, non-hospitalization, and contaminated blood culture were excluded. The 2019 European Heart Rhythm Association International Consensus Document was used to define CIED infection. Results A total of 160 patients with CIED developed non-SA GPC bacteremia during the period. Ninety (56.2%) patients had CIED infection, with 60 (37.5%) classified as definite and 30 (18.8%) possible. This included 41/64 (64.1%) patients with coagulase-negative Staphylococcus (CoNS), 30/41 (73.2%) patients with Enterococcus, 13/19 (68.4%) patients with viridans group streptococci (VGS), and 6/36 (16.6%) patients with other non-SA GPC. The odds of CIED infection (with 95% CI) for CoNS, Enterococcus, and VGS bacteremia were 8.9 (3.2–24.6), 13.6 (4.5–41.6), and 10.8 (2.9–40.0) -fold higher, respectively, as compared to other non-SA GPC. Among those with infected CIED, 51 (56.7%) patients underwent complete device extraction after a median of 6 (IQR 3.5–10) days. In an unadjusted analysis of patients with CIED infection, the reduction in one-year mortality following device removal was not statistically significant (HR 0.59, 95% CI 0.26–1.33, p=0.198). Conclusion The overall prevalence of CIED infection following non-SA GPC bacteremia was higher than previously reported, particularly that due to CoNS, Enterococcus, and VGS. Further study with a larger cohort is needed to demonstrate the survival benefit from CIED extraction in patients with infected CIED due to non-SA GPC. Disclosures Larry M. Baddour, M.D., Boston Scientific: Advisor/Consultant|Botanix Pharmaceuticals: Advisor/Consultant|Roivant Sciences: Advisor/Consultant|UpToDate, Inc.: Royalty payments - authorship duties Rizwan Sohail, M.D., Aziyo Biologics: Advisor/Consultant|Boston Scientific: Advisor/Consultant|Medtronic: Advisor/Consultant|Philips: Advisor/Consultant|Philips: Honoraria Malini Madhavan, M.B.B.S., Biosense Webster: Advisor/Consultant|Biotronik Inc: Advisor/Consultant|Boston Scientific: Grant/Research Support|Convatec: Advisor/Consultant.

Efficacy of Teicoplanin Lock Therapy in the Treatment of Port-related Coagulase-negative Staphylococci Bacteremia in Pediatric Oncology Patients.

The number of studies evaluating teicoplanin lock therapy in coagulase-negative staphylococcus-associated catheter infection in pediatric malignancies is limited. The aim of this study was to evaluate the efficacy of teicoplanin lock therapy in pediatric cancer cases. Twenty-two patients with coagulase-negative staphylococcus-associated totally implantable venous access device infection, who had undergone teicoplanin closure treatment, were included in the study. Demographic data, number of lock treatment days, and treatment success data were obtained from the medical files of the patients. Fourteen of the patients (63.6%) had acute lymphocytic leukemia, 3 (13.6%) had acute myelocytic leukemia, and 5 (22.7%) had solid cancer. The median neutrophil count was 240×10 3 /μL (interquartile range: 0 to 1195×10 3 /μL). Between patients with and without catheter removal, no statistically significant difference was found in terms of baseline C-reactive protein, absolute neutrophil count, and the day of starting systemic teicoplanin treatment ( P >0.05). The overall port survival rate of teicoplanin lock therapy was 72.7%. Within an average of 4 days, negative cultures of 16 (72.7%) patients whose catheters had not been removed were obtained. In conclusion, we suggest that teicoplanin lock therapy is an effective and safe treatment for catheter-related infections, caused by methicillin-resistant coagulase-negative staphylococcus.

Persistent Coagulase-Negative Staphylococcal Bacteremia in Neonates: Clinical, Microbiological Characteristics and Changes within a Decade.

Atypical outbreaks of persistent coagulase-negative staphylococci (CoNS) bacteremias, defined as three or more consecutive positive blood cultures with the same CoNS species, at least 48 h apart, have been reported in neonatal intensive-care units (NICUs). Our aim was to describe the profile of these cases in our NICU over a two-year period with the objective of assessing possible changes within a decade. Demographics, clinical and microbiological data were recorded for all CoNS bacteremias in our tertiary NICU during 2016–2017 and compared with the results of the same study in 2006–2007. Fifty-six cases of CoNS sepsis were recorded. Fourteen (25%) of them were persistent. There were no significant differences in demographic and clinical characteristics between cases with persistent vs. non-persistent bacteremia. Staphylococcus epidermidis was the most common species. In logistic regression analysis, biofilm production (β = 2.464, p = 0.04) was the most significant determinant for the development of persistent CoNS bacteremia. Our isolates were less likely to produce biofilm and carry ica operon as compared to those of 2006–2007. The cases of persistent CoNS sepsis have decreased within a decade, which could be attributed to the implementation of intensive infection control practices. Biofilm production remains the most important risk factor.

The Validity of Positive Coagulase-Negative Staphylococcus Cultures for the Diagnosis of Sepsis in the Neonatal Unit.

Coagulase-negative Staphylococcus (CoNS) is the most frequent pathogen causing late-onset sepsis (LOS) in neonatal intensive care units (NICUs). Technical difficulties hinder blood culture (BC) collection and obtaining only one culture before initiating antibiotic therapy is a common practice. We sought to assess specific clinical information and CoNS cultures for the diagnosis of true bacteremia in the NICU. This historical cohort study was conducted in NICUs at the Hadassah-Hebrew University Medical Center of Jerusalem in Israel. Clinical and laboratory data in every CoNS bacteremia were collected and compared between bacteremia groups as follows: true positive, two positive BCs; contaminant, one positive BC out of two; undefined, one BC obtained and found positive. For 3.5 years, CoNS was isolated in 139 episodes. True positive was identified in 44 of 139 (31.7%), contaminant in 42 of 139 (30.2%), and the event was undefined in 53 of 139 (38.1%). Vancomycin treatment was more frequent in the true positive and undefined groups than the contaminant group (100, 90.6, and 73.8% respectively, p = 0.001); treatment was also prolonged in these two groups (p < 0.001). No clinical variables were associated with true bacteremia on multivariable analysis. Diagnosis should definitely be based on at least two positive BCs, despite objective difficulties in obtaining BCs in neonates. · CoNS is a frequent pathogen causing LOS in neonates.. · Due to technical difficulties, often only one culture is collected prior to antibiotic therapy.. · No clinical/laboratory variables were associated with the diagnosis of true CoNS bacteremia..

180. Duration of Therapy and Clinical Outcomes in Adult Oncology Patients with Uncomplicated Coagulase Negative Staphylococcal Bacteremia

BackgroundAlthough they are often considered contaminants, coagulase negative staphylococci (CoNS) can be pathogens especially in immunocompromised patients. National and local guidelines recommend treatment durations of 7 to 14 days, depending on specific clinical scenarios. The objective was to characterize the duration of treatment for CoNS bacteremia and clinical outcomes at our cancer center. MethodsWe conducted a retrospective chart review of adult patients ≥18 years old with ≥1 blood culture with growth of CoNS between 1/1/17 and 12/31/19 at our cancer center. Patients with complicated CoNS bacteremia and polymicrobial infections were excluded.ResultsAmong 128 patients identified during the study period, 98 met inclusion criteria (Figure 1). Most patients (N= 92; 94%) had a hematologic malignancy as the underlying oncologic diagnosis, and 68 (69%) were hematopoietic stem cell transplant recipients. The median total antibiotic duration was 13 days, and median duration from the date of 1st negative blood culture was 12 days; 29 (30%) patients were treated for a total duration of >14 days (Figure 2). The catheter was retained in 67 (68%) and exchanged in 4 (4%) of the cases. Three (3%) patients had recurrence of bacteremia within 30 days of treatment completion, and 8 (8%) patients were transferred to the ICU within 7 days of the index blood culture. The 30-day crude mortality rate was 10%. The most commonly used antibiotic for treatment was vancomycin (N= 95; 97%), and 32 (34%) patients on vancomycin had an increase in serum creatinine of ≥ 50% from baseline. Five (5%) patients discontinued vancomycin due to nephrotoxicity, and 4 (4%) patients required hemodialysis.Figure 1. Results Overview Among 128 patients identified during the study period, 98 met inclusion criteria. Of those included, 36 had one set of blood cultures that were positive for CoNS and 62 patients had at least two sets of blood cultures that were positive for CoNS.Figure 2. Duration of Antibiotic Treatment We evaluated duration of treatment based on total antibiotic duration and duration from date of 1st negative blood culture. The number of patients is noted above each bar.ConclusionAlthough the majority of patients were treated for ≤14 days for uncomplicated CoNS bacteremia, nearly 1/3 of patients were treated for > 14 days. Recurrent bacteremia was uncommon despite catheter retention in most patients. Relatively high rates of vancomycin associated nephrotoxicity highlight opportunities for antimicrobial stewardship to limit duration of vancomycin therapy among cancer patients with uncomplicated CoNS bacteremia. Disclosures All Authors: No reported disclosures

1110. In Vivo Pharmacodynamics of Vancomycin Against Staphylococci in Young Infants

BackgroundCoagulase-negative staphylococci are the predominant pathogen causing late onset sepsis in young infants, however, the pharmacodynamic target for vancomycin therapy is unknown. This study aimed to determine the pharmacodynamic target of vancomycin in young infants with staphylococcal infections.MethodsRetrospective data were collected for infants aged 0-90 days with methicillin-resistant Staphylococcus aureus (MRSA or coagulase-negative staphylococci (CoNS) bacteraemia over a 4-year period at the Royal Children’s Hospital Melbourne, Australia. Vancomycin broth microdilution minimum inhibitory concentrations (MIC) were determined. A published pharmacokinetic model was externally validated using the study dataset and a time-to-event pharmacodynamic model developed using non-linear mixed effects modelling, with the event being the first negative blood culture. Simulations were performed to determine the 24-hour trough vancomycin concentration correlating with a 90% probability target attainment (PTA) of the area under the curve in the first 24-hours (AUC0-24) exceeding the identified target.ResultsThirty infants, 28 with CoNS and two with MRSA bacteraemia, who had 165 vancomycin concentrations determined were included. The vancomycin broth microdilution MIC was determined for 24 CoNS and one MRSA isolate, both with a median MIC of 1 mg/L (CoNS range 0.5 to 4). An AUC0-24 ≥3 00 mg/L·h was associated with a 7.8-fold increase in the chance of bacteriological cure for all staphylococci at any time point compared to an AUC0-24 < 300 mg/L·h (hazard ratio 95% CI: 3.21-18.8). The 24-hour trough concentrations associated with a 90% PTA of achieving this target were > 13-16 mg/L and > 8-12 mg/L for 6 and 12-hourly dosing, respectively. ConclusionOur study found that an AUC0-24 ≥ 300 mg/L·h was associated with a 7.8-fold increase in bacteriological cure in young infants with staphylococcal bloodstream infections. Disclosures All Authors: No reported disclosures

Coagulase negative Staphylococcus bacteremia in hematopoietic stem cell transplant recipients: Clinical features and molecular characterization.

The purpose of our study was to investigate the epidemiology of coagulase negative staphylococci (CoNS) responsible for bacteremia in hematopoietic stem cell transplant (HSCT) recipients and to determine the prevalence and the genetic background of methicillin resistance. The prevalence of CoNS bacteremia was 7.4% (54/728), higher in allograft (10.7%) than in autograft (4.7%) recipients. A sepsis or a septic shock were observed in 9% of cases. No deaths were attributable to CoNS bacteremia. The methicillin resistance rate was 81%. All MR-CoNS, harbored mecA gene and 90% were typeable with SCCmec typing using PCR amplification. The SCCmec type IV was the most frequent (44%). Clonal dissemination of MR- Staphylococcus epidermidis strains was limited. Our study showed a low prevalence and favorable outcome of CoNS bacteremia in HSCT recipients with limited clonal diffusion. However, they were associated with a significant rate of severe infections and a high rate of methicillin resistance, mediated by SCCmec IV element in most cases.

The Use of Daptomycin in the Treatment of Persistent Coagulase-Negative Staphylococcal Sepsis in Premature Infants: A Case Series.

Daptomycin is a lipopeptide antibiotic with rapid bactericidal activity against Gram-positive bacteria. Reports regarding the use of daptomycin in infants are still limited. Thus, the objective of this report is to describe the safety and efficacy of daptomycin in premature infants with persistent coagulase-negative staphylococci (CoNS) infection. This was a retrospective chart review of 10 premature infants with persistent CoNS infection who received daptomycin therapy between January 2018 and September 2019. Four patients had endocarditis and 1 had bacterial meningitis and infectious endocarditis. The other 5 patients had persistent CoNS bacteraemia only. Daptomycin treatment was successful for 5 patients. The others died owing to multiple factors such as prematurity, sepsis, and chronic lung disease. Adverse drug reactions, including elevation of creatine phosphokinase and/or hepatotoxicity, were noted in 4 patients. Large and randomized studies are necessary to ensure daptomycin's safety and efficacy for the treatment of infants with persistent sepsis caused by Gram-positive bacteria.

Hospital-wide ELectronic medical record evaluated computerised decision support system to improve outcomes of Patients with staphylococcal bloodstream infection (HELP): study protocol for a multicentre stepped-wedge cluster randomised trial

IntroductionStaphylococci are the most commonly identified pathogens in bloodstream infections. Identification of Staphylococcus aureus in blood culture (SAB) requires a prompt and adequate clinical management. The detection of coagulase-negative staphylococci...

Incidence of coagulase-negative staphylococcal bacteremia among ICU patients: decontamination studies as a natural experiment.

The epidemiology of coagulase-negative staphylococcal (CNS) bacteremia among adult ICU patients remains unclear. Decontamination studies among ICU patients provide a unique opportunity to study the impacts of different diagnostic criteria, exposure to various decontamination interventions, and various other factors, on its incidence over three decades. Decontamination studies among ICU patients reporting CNS bacteremia incidence data were obtained mostly from recent systematic reviews. The CNS bacteremia incidence within component (control and intervention) groups of decontamination studies was benchmarked versus studies without intervention (observational groups). The impacts of antibiotic versus chlorhexidine decontamination interventions, control group concurrency, publication year, and diagnostic criteria were examined in meta-regression models. Among non-intervention (observational) studies which did versus did not specify stringent (≥ 2 positive blood cultures) diagnostic criteria, the mean CNS bacteremia incidence per 100 patients (and 95% CI; n) is 1.3 (0.9–2.0; n = 23) versus 3.6 (1.8–6.9; n = 8), respectively, giving an overall benchmark of 1.8 (1.2–2.4; n = 31). Versus the benchmark incidence, the mean incidence is high among concurrent control (5.7; 3.6–9.1%) and intervention (5.2; 3.6–6.9%), but not non-concurrent control (1.0; 0.4–3.9%) groups of 21 antibiotic studies, nor among eleven component groups of chlorhexidine studies. This high incidence remained apparent (p < 0.01) in meta-regression models adjusting for group wide factors such as diagnostic criteria and publication year. The incidence of CNS bacteremia within both intervention and concurrent (but not non-concurrent) control groups of antibiotic-based decontamination studies are unusually high even accounting for variable diagnostic criteria and other factors.Electronic supplementary materialThe online version of this article (10.1007/s10096-019-03763-0) contains supplementary material, which is available to authorized users.