Gram-positive Bacteremia Research Articles

Pseudomonas monteilii bacteremia and sepsis following insertable cardiac monitor implantation: a case report

BackgroundInsertable cardiac monitor implantation is a simple and safe procedure commonly performed in patients with embolic stroke with undetermined source. Routine periprocedural antibiotic use is not recommended, because infection rate is very low, although some local infection or gram-positive bacteremia have been reported. We report a case of Pseudomonas monteilii sepsis immediately after insertable cardiac monitor implantation.Case presentationA 55-year-old Korean male with embolic stroke of undetermined source presented with gram-negative sepsis immediately after implantable cardiac monitor implantation as a first reported complication after the procedure. Pseudomonas monteilii was identified in the blood culture, and no other infection source was seen. He was treated with intravenous antibiotics without removing the device.ConclusionsPrompt diagnosis and adequate management is required in such a patient with sepsis post-insertable cardiac monitor implantation procedure. It can be managed with adequate antibiotic treatment without device removal if there is no sign of inflammation at the insertion site. Further reports or studies should be investigated to reinforce this finding.Learning objectivesThe infection rate after insertable cardiac monitor insertion is extremely low; however, sepsis may occur without pocket infections. Physicians should be aware of signs of systemic infection, particularly when the procedure is performed outside the catheterization room. Sepsis after insertable cardiac monitor implantation can be managed with adequate antibiotic treatment without device removal if there is no sign of inflammation at the insertion site.

Associations between maternal bacteremia during the peripartum period and early-onset neonatal sepsis: a retrospective cohort study

IntroductionEarly-onset neonatal sepsis (EONS) significantly impacts neonatal morbidity and mortality, with maternal bacteremia during the peripartum period being a potential risk factor. This study aims to explore the association between peripartum maternal bacteremia and EONS.MethodsA retrospective cohort study at the Women's Wellness and Research Center in Doha, Qatar (2015–2019) compared women with and without bacteremia, based on blood cultures taken from up to seven days before to 48 h after delivery, examining the association with EONS.ResultsAmong the 536 maternal blood cultures analyzed, 102 (19.0%) were positive. The most prevalent organisms were Group B streptococcus (GBS) (39.2%), followed by Escherichia coli (14.7%) and anaerobes (10.8%). Neonates from bacteremic mothers had lower birth weights (2913 ± 86 g vs. 3140 ± 745 g; MD 227.63 g; 95% CI 61.72 − 393.55; p = 0.007), required more resuscitation (27.5% vs. 13.2%; OR 2.48; 95% CI 1.48 − 4.17; p < 0.001), and received antibiotics for ≥ 7 days more frequently (41.2% vs. 16.6%; OR 3.51; 95% CI 2.20 − 5.62; p < 0.001) compared to those from non-bacteremic mothers. Maternal Gram-positive (GP) organisms were more commonly isolated in term gestation (67.9%) compared to Gram-negative (GN) (22.2%) and anaerobic bacteremias (9.9%). During intrapartum, GP bacteremia was predominant (67.1%) vs. GN (21.4%) and Anaerobes (11.4%), with GN bacteremia being more common in postpartum samples. Culture-proven EONS occurred in 0.75% of the cohort, affecting 3.9% of infants from bacteremic mothers vs. none in controls (OR 2.34; 95% CI 1.27 − 4.31; p < 0.001). Culture-negative EONS appeared in 14.7% of infants from bacteremic mothers vs. 7.8% in controls (OR 2.02; 95% CI, 1.05 − 3.88; p = 0.03). Among 40 cases of maternal GBS bacteremia, culture-proven GBS EONS occurred in 3 neonates (7.5%), all from mothers with negative GBS screening, compared to none in the control group. A strong association was found between EONS and maternal bacteremia due to any organism (aOR 2.34; 95% CI, 1.24 − 4.41; p = 0.009), GP bacteremia (aOR 3.66; 95% CI, 1.82 − 7.34; p < 0.001), or GBS (aOR 5.74; 95% CI, 2.57 − 12.81; p < 0.001). Bacteremia due to GN and Anaerobic organisms were not associated with EONS. Chorioamnionitis and antepartum fever were independent predictors for EONS associated with significant bacterial isolates.ConclusionThis study underscores the significant impact of maternal GP bacteremia, particularly from GBS, on EONS. The strong association highlights the need for vigilant monitoring and interventions in pregnancies complicated by bacteremia to reduce adverse neonatal outcomes.

Early bacteremia following allogeneic hematopoietic stem cell transplantation without antibiotic prophylaxis: epidemiology and antimicrobial resistance

ObjectiveBacteremia is a serious complication in patients undergoing allogeneic hematopoietic stem cell transplantation. The aim of this study was to determine the frequency, epidemiological profile, and risk factors of bacteremia early after allogeneic hematopoietic stem cell transplantation. MethodsAn observational descriptive retrospective study was conducted in patients who received transplants between January 2016 and December 2021. Early bacteremia was defined as blood stream infection occurring between Day 0 and Day 100 after transplantation. ResultsForty episodes of early bacteremia occurred in 36/245 transplanted patients. Fifteen episodes (37.5%) were due to gram-positive bacteria and 25 (62.5%) to gram-negative bacteria. The most frequent species isolated were coagulase negative staphylococci (CoNS) in gram-positive bacteremia (n = 8/15), and Klebsiella species (8/25) and Pseudomonas species (8/25) in gram-negative bacteremia. Twenty-nine episodes of bacteremia (72.5%) occurred during the first 30 days after transplantation with a median time of nine days (range: 0-90 days). Coagulase negative staphylococci were methicillin-resistant in 75% of cases, the only Staphylococcus aureus isolated was methicillin-resistant. All gram-positive bacilli were penicillin-resistant. Gram-negative bacilli were multidrug resistant in 61.5% of cases. In multivariate analysis, bone marrow as source of graft (p-value = 0.02) and cytomegalovirus reactivation (p-value = 0.02) were significantly associated with an increased risk of bacteremia. Mortality attributable to bacteremia was 2.8%. The one-year overall survival was not significantly different between those with and without bacteremia. ConclusionsBacteremia was more frequent within the first 30 days after transplantation indicating the crucial role of neutropenia. An increase in multidrug resistant gram-negative bacteremia was noted.

Ciprofloxacin prophylaxis during haematopoietic cell transplantation: a role for use in patients with germ cell tumours?

Introduction. Fluoroquinolone prophylaxis during haematopoietic cell transplantation (HCT) can lead to antimicrobial resistance (AMR). Identifying the groups of patients that have the highest likelihood of benefiting from prophylactic antimicrobials is important for antimicrobial stewardship (AMS).Hypothesis. We aimed to identify groups of HCT recipients that have the highest likelihood of benefiting from prophylactic fluroquinolones.Methods. All admissions for HCT in a tertiary centre between January 2020 and December 2022 (N = 400) were retrospectively studied. Allogeneic HCT (allo-HCT) recipients had prophylaxis with ciprofloxacin during the chemotherapy-induced neutropenia, while autologous HCT (auto-HCT) recipients did not. Bacteraemias were recorded when non-contaminant bacterial pathogens were isolated in blood cultures.Results. Allo-HCT was performed for 43.3 % (173/400) of patients and auto-HCT was performed for 56.7 % (227/400). A bacteraemia was documented in 28.3 % (113/400) of cases. Allo-HCT recipients were more likely to have a Gram-positive bacteraemia (20.8%, 36/173, vs 10.1%, 23/227, P = 0.03), while a difference was not observed for Gram-negative bacteraemias (18.5%, 32/173 vs 18.1%, 41/227, P = 0.91). Among auto-HCT recipients not receiving ciprofloxacin prophylaxis, patients with germ cell tumours had the highest probability (P for trend 0.09) of recording any bacteraemia (43.5%, 10/23) followed by patients with lymphomas (32.5%, 13/40), other auto-HCT indications (22.2%, 2/9), multiple myeloma (22.1%, 29/131) and multiple sclerosis (12.5%, 3/24). The higher number of bacteraemias in patients with germ cell tumours was primarily driven by Gram-negative pathogens.Conclusions. Ciprofloxacin prophylaxis was associated with a reduced incidence of Gram-negative bacteraemias in allo-HCT recipients. Auto-HCT recipients due to germ cell tumours, not receiving ciprofloxacin prophylaxis, recorded the highest incidence of bacteraemias and represent a possible target group for this intervention.

Predictive value of thrombocytopenia for bloodstream infection in patients with sepsis and septic shock.

Thrombocytopenia is common in patients with sepsis and septic shock. To analyse the decrease in the number of platelets for predicting bloodstream infection in patients with sepsis and septic shock in the intensive care unit. A retrospective analysis of patients admitted with sepsis and septic shock in Xingtai People Hospital was revisited. Patient population characteristics and laboratory data were collected for analysis. The study group consisted of 85 (39%) inpatients with bloodstream infection, and the control group consisted of 133 (61%) with negative results or contamination. The percentage decline in platelet counts (PPCs) in patients positive for pathogens [57.1 (41.3-74.6)] was distinctly higher than that in the control group [18.2 (5.1-43.1)] (P < 0.001), whereas the PPCs were not significantly different among those with gram-positive bacteraemia, gram-negative bacteraemia, and fungal infection. Using receiver operating characteristic curves, the area under the curve of the platelet drop rate was 0.839 (95%CI: 0.783-0.895). The percentage decline in platelet counts is sensitive in predicting bloodstream infection in patients with sepsis and septic shock. However, it cannot identify gram-positive bacteraemia, gram-negative bacteraemia, and fungal infection.

Association between blood culture turnaround time and clinical prognosis in emergency department patients with community acquired bloodstream infection: A retrospective study based on electronic medical records

ImportancePrevious investigations have found that time to positive blood culture (TTP) is a prognostic factor for clinical outcomes. In fact, what the emergency physician sees from the medical information system is TAT (turnaround time) defined as time required to post a bacterial culture report. We propose a definition of blood culture TAT that more closely aligns with clinical considerations by measuring the time from starting specimen culture to the release of an official blood culture report.We were curious to know whether the duration of TAT is as intricately linked to the prognosis of bacteremia as TTP. ObjectivesTo examine the association between TAT and outcomes of adult patients who present to the ED with community acquired bacteremia. DesignSetting, and Participants: This retrospective study utilized electronic medical records from Kaohsiung Veterans General Hospital (KVGH), a 1000-bed tertiary medical center in Taiwan. Patients were adults aged 18 years and older who presented to ED (Emergency department) for initial diagnosis of community acquired bacteremia from January 1, 2016 to March 31, 2021. Data analysis was performed from December 2022 to January 2023.Main outcomes and measures.The primary outcomes included mortality in the ED, all-cause in-hospital mortality, length of hospital stay, and all-cause 30-day mortality in relation to the individual first report of positive blood culture TAT. ResultsA total of 4011 eligible patients with bacteremia were evaluated, of which 207 patients had a blood culture TAT of ≤48 h. The overall 30-day all-cause mortality rate was 13%. Contrary to expectation, no statistically significant differences were observed in clinical prognosis between the TAT groups (≤48 versus >48 h). Subgroup analyses indicated that the length of TAT did not have a significant effect on clinical prognosis in patients who underwent lactate level assessment. Furthermore, no difference in clinical outcome was noted between TAT groups (≤48 versus >48 h) in terms of Gram-negative bacilli or Gram-positive cocci bacteremia. However, in patients with delayed antibiotic treatment (>3 h), a shorter TAT was significantly associated with a fatal outcome. ConclusionIn adults with community-acquired bacteremia, this study did not observe a significant association between blood culture TAT and clinical prognosis, except in cases of delayed antibiotic treatment.

Risk factors for resistant gram-positive bacteremia in febrile neutropenic patients with cancer

BackgroundGram-positive bacteria are frequently resistant to empirical beta‐lactams in febrile neutropenic patients with cancer. As microbiology and antibiotic susceptibility changes, we reevaluated the risk factors for resistant Gram-positive bacteremia in febrile neutropenic patients with cancer. MethodsEpisodes of bacteremic febrile neutropenia in Seoul National University Hospital from July 2019 to June 2022 were reviewed. Resistant Gram-positive bacteria were defined as a pathogen susceptible only to glycopeptide or linezolid in vitro (e.g., methicillin-resistant staphylococci, penicillin-resistant viridans streptococci, and ampicillin-resistant enterococci). Episodes were compared to identify independent risk factors for resistant Gram-positive bacteremia. ResultsOf 225 episodes, 78 (34.7%) involved resistant Gram-positive bacteremia. Multivariate analysis revealed that breakthrough bacteremia while being administered antibiotics (adjusted odds ratio [aOR], 6.794; 95% confidence interval [95% CI], 3.130–14.749; P < 0.001) and catheter-related infection (aOR 4.039, 95% CI 1.366–11.946; P = 0.012) were associated with resistant Gram-positive bacteremia. Chronic liver disease (aOR 0.231, 95% CI 0.059–0.905; P = 0.035) and hypotension at bacteremia (aOR 0.454, 95% CI 0.218–0.945; P = 0.035) were inversely associated with resistant Gram-positive bacteremia. ConclusionsResistant Gram-positive bacteria should be considered in breakthrough bacteremia and catheter-related infection in febrile neutropenic patients with cancer.

Inflammatory biomarkers and physiomarkers of late-onset sepsis and necrotizing enterocolitis in premature infants.

Early diagnosis of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in very low birth weight (VLBW, <1,500 g) infants is challenging due to non-specific clinical signs. Inflammatory biomarkers increase in response to infection, but non-infectious conditions also cause inflammation. Cardiorespiratory data contain physiological biomarkers, or physiomarkers, of sepsis that may be useful in combination with inflammatory hematologic biomarkers for sepsis diagnosis. To determine whether inflammatory biomarkers measured at the time of LOS or NEC diagnosis differ from times without infection and whether biomarkers correlate with cardiorespiratory sepsis physiomarkers in VLBW infants. Remnant plasma sample collection from VLBW infants occurred with blood draws for routine laboratory testing and suspected sepsis. We analyzed 11 inflammatory biomarkers and a pulse oximetry sepsis warning score (POWS). We compared biomarker levels obtained at the time of gram-negative (GN) bacteremia or NEC, gram-positive (GP) bacteremia, negative blood cultures, and no suspected infection. We analyzed 188 samples in 54 VLBW infants. Several biomarkers were increased at the time of GN LOS or NEC diagnosis compared with all other samples. POWS was higher in patients with LOS and correlated with five biomarkers. IL-6 had 78% specificity at 100% sensitivity to detect GN LOS or NEC and added information to POWS. Inflammatory plasma biomarkers discriminate sepsis due to GN bacteremia or NEC and correlate with cardiorespiratory physiomarkers.

Community-acquired Bacteremia: when should endocarditis be suspected?

This article examines the risk of infective endocarditis (IE) linked to various bacterial species causing bacteremia. While the European Society of Cardiology (ESC) and the American Heart Association (AHA) guidelines do not specify the diagnostic workup to perform based on bacterial species, certain bacteria are acknowledged to pose a higher IE risk. Community-acquired bacteremia has a higher IE risk than nosocomial bacteremia. Implantable electronic cardiovascular devices (IECD) and a history of IE or valve surgery also increase this risk. Several risk stratification systems (RSS) have been developed to guide clinicians on the necessity of echocardiography in patients with Gram-positive bacteremia, particularly S. aureus, streptococci, and enterococci. An evaluation algorithm based on these RSS is proposed to assist clinical investigations.

Clinical usefulness of procalcitonin/albumin and blood urea nitrogen/albumin ratios for the early detection of bacteremia

Background: Early prediction of bacteremia is important because sepsis may develop if bacteremia is not treated in time. We aimed to determine whether blood tests are clinically useful in predicting gram-negative versus gram-positive bacteremia. Methods: We retrospectively analyzed the medical records of 16,569 patients who underwent blood culture testing among those who visited St. Mary’s Hospital of Uijeongbu, Catholic University from January 1, 2018 to December 31, 2018. After excluding 15,580 patients with insufficient data for analysis, the total study population was 989. Results: In the multivariable logistic regression analysis for gram-negative bacteremia, after adjusting for major variables, procalcitonin (odds ratio [OR] 1.02, P &lt; 0.001), high-sensitivity C-reactive protein (OR 1.03, P = 0.010), and albumin (OR 0.55, P = 0.010) were significant. In the same model, lactic acid (OR 1.08, P = 0.010), blood urea nitrogen (BUN) (OR 1.02, P = 0.010), and albumin (OR 0.50, P = 0.005) were significant for gram-positive bacteremia. We constructed blood indicators by combining blood tests that were significant in multivariable logistic regression analysis. Comparing the area under the curve (AUC) of the receiver operating characteristic curve, the AUC of the procalcitonin/albumin ratio in gramnegative bacteremia was significantly higher than that of procalcitonin (0.846 vs. 0.837, P = 0.005), and the AUC of the BUN/albumin ratio in gram-positive bacteremia was significantly higher than that of BUN (0.709 vs. 0.679, P = 0.007). Conclusion: The procalcitonin/albumin ratio is expected to be helpful in the early prediction of gram-negative bacteremia, whereas the BUN/albumin ratio in the early prediction of gram-positive bacteremia.

Clinical risk factors and prediction model for infective endocarditis in patients with gram-positive bacteremia

Abstract Introduction Gram-positive bacteremia (GPB) is a common condition in clinical practice that potentially leads to infective endocarditis (IE), a high morbidity and mortality disease. Clinicians still encounter challenges in determining the likelihood of developing IE in GPB patients. Comprehensive and invasive cardiac investigations in every patient with GPB for IE could be unnecessary and potentially harmful while missing proper investigations might result in the delay or misdiagnosis of this fatal condition. Objective We aimed to determine the significant clinical risk factors and develop the prediction model for IE in patients with GPB. Methods Data were obtained from medical records of hospitalized adult patients with GPB in our hospital from January 2016 to December 2020. IE was defined by the ‘definite’ group according to modified Duke criteria. The cohort was divided into training (80%) and test (20%) sets. We identified the association between clinical risk factors and the development of IE by logistic regression analyses. Significantly associated clinical risk factors in multivariate analysis were used in the prediction model. The area under the receiver operating characteristic curve (AUROC) was utilized to evaluate model performances. Results A total of 794 patients with GPB were included in the study. IE was diagnosed in 89 patients (11.2%). Among 21 selected clinical risk factors from univariate analysis, 10 variables, including the unknown origin of bacteremia, mechanical and bioprosthetic heart valve, duration of symptoms more than 7 days, presence of Roth spot, neurological symptoms, murmur, heart failure, number of positive hemoculture more than 2 specimens, and Staphylococcus aureus septicemia, were significantly associated with IE in multivariate analysis (Figure 1) and were utilized in the prediction model. The AUROC of prediction models were 0.943 and 0.865 in training and test sets, respectively. Conclusions Our prediction model based on clinical risk factors can precisely predict IE in patients with GPB. Using this model allows clinicians to address patients at risk and guide decision-making in which cases need an urgent and comprehensive workup for IE or a wait-and-see strategy.Figure 1

Clinical Characteristics and Risk Factors for Bloodstream Infections in Children with Cancer: A Report from a Pediatric Hematology Oncology Unit.

Infections are a major cause of morbidity and mortality in children with haematologic malignancies and solid tumors as well as those undergoing hematopoietic stem cell transplantation (HSCT). The purpose of our study was to record the epidemiological characteristics and outcomes of bacteremias, focusing on pathogens, as well as risk factors and mortality rates in patients of a pediatric hematology-oncology unit from Northern Greece. A retrospective analysis was conducted, which included all positive blood cultures from pediatric hematology oncology patients aged from 1 to 16 years old admitted to the Pediatric and Adolescent Hematology Oncology Unit of AHEPA University Hospital of Thessaloniki between January 2014 and December 2018. Data were collected from patients' printed and electronic medical records. 73 episodes of bacteremias were identified (41% male and 32% female with a ratio of 1.28:1; median age 6.5 years; 13.7% solid tumor, 72.6% acute lymphoblastic leukemia, 13.7% acute myeloid leukemia, and 95.8% with an indwelling permanent catheter). 49.3% of the isolates were Gram-positive bacteria and 50.7% Gram-negative, and the ratio of Gram-negative to Grampositive was 1.02. Coagulase-negative staphylococci were most frequent (39.7%), followed by E. coli (17.8%) and Klebsiella pneumoniae (17.8%). Out of all Gram-negatives, 13.5% carbapenemase producers and 8.1% ESBL-producers were found. In relation to Gram-positive, 79.3% were identified as methicillin-resistant CoNS. During the study period, 10.9% of indwelling catheters were removed, and 2.73% of episodes resulted in ICU transfer. The 3-month mortality rate was 8.2%. This study demonstrated an almost equal distribution of Gram-positive and Gramnegative bacteremias in total in this population but with an increase in the isolation of Grampositive bacteria over the last years, which is consistent with other similar studies in this patient group. Knowledge of the local epidemiology and bacterial antimicrobial resistance is important to prevent and timely treat these life-threatening infections in immunocompromised pediatric oncology patients.

Machine learning model for the prediction of gram-positive and gram-negative bacterial bloodstream infection based on routine laboratory parameters

BackgroundBacterial bloodstream infection is responsible for the majority of cases of sepsis and septic shock. Early recognition of the causative pathogen is pivotal for administration of adequate empiric antibiotic therapy and for the survival of the patients. In this study, we developed a feasible machine learning (ML) model to predict gram-positive and gram-negative bacteremia based on routine laboratory parameters.MethodsData for 2118 patients with bacteremia were obtained from the Medical Information Mart for Intensive Care dataset. Patients were randomly split into the training set and test set by stratified sampling, and 374 routine laboratory blood test variables were retrieved. Variables with missing values in more than 40% of the patients were excluded. Pearson correlation test was employed to eliminate redundant features. Five ML algorithms were used to build the model based on the selected features. Additionally, 132 patients with bacteremia who were treated at Qilu Hospital of Shandong University were included in an independent test cohort to evaluate the model.ResultsAfter feature selection, 32 variables remained. All the five ML algorithms performed well in terms of discriminating between gram-positive and gram-negative bacteremia, but the performance of convolutional neural network (CNN) and random forest (RF) were better than other three algorithms. Consider of the interpretability of models, RF was chosen for further test (ROC-AUC = 0.768; 95%CI = 0.715–0.798, with a sensitivity of 75.20% and a specificity of 63.79%). To expand the application of the model, a decision tree (DT) was built utilizing the major variables, and it achieved an AUC of 0.679 (95%CI = 0.632–0.723), a sensitivity of 66%, and a specificity of 67.82% in the test cohort. When tested in the Qilu Hospital cohort, the ROC-AUC of the RF and DT models were 0.666 (95%CI = 0.579–0.746) and 0.615 (95%CI = 0.526–0.698), respectively. Finally, a software was developed to make the RF- and DT-based prediction models easily accessible.ConclusionThe present ML-based models could effectively discriminate between gram-positive and gram-negative bacteremia based on routine laboratory blood test results. This simple model would be beneficial in terms of guiding timely antibiotic selection and administration in critically ill patients with bacteremia before their pathogen test results are available.

Evaluation of glycopeptide prescription in high-risk febrile neutropenia: A monocentric study of North Africa.

High-risk febrile neutropenia (FN) is one of the main causes of morbidity and mortality in onco-hematology. The initiation of empirical antibiotic therapy is an emergency that can change the prognosis of some patients. Given the emergence of increasingly resistant Gram-positive bacteremia, glycopeptides, as an empirical treatment, have an important place in the management of high-risk FN. The aim of this study is to evaluate the appropriateness of glycopeptide prescription in high-risk FN patients. This study was conducted in the Hematology Department of Fattouma Bourguiba University Hospital of Monastir, Tunisia. Patients with high-risk FN were enrolled during the period between January 1 and December 31, 2020. Of the 29 patients included in this study, 88 FN episodes were noted of which 39 episodes treated with glycopeptides were evaluated. Twenty-four febrile episodes were empirically treated with glycopeptides (27.3%) of which 17 prescriptions (70.8%) were appropriate according to the European Conference on Infection in Leukemia and the Infectious Diseases Society of America recommendations. A therapeutic escalation using glycopeptides was noted in 17% of cases and appropriately opted in 6 FN episodes (40%). Prescriptions of glycopeptides were appropriate according to the international recommendations in 71% of the empirical prescriptions and in 40% of the therapeutic escalation using glycopeptides. In high-risk FN episodes, glycopeptides prescriptions should be rationalized and limited to the indications detailed in the international guidelines to control the emergence of multidrug-resistant bacteria.

Predictors of Positive Repeat Blood Cultures in Patients With Gram-Negative Bacilli Bacteremia

Introduction Bloodstream infections occur commonly in the United States and are associated with significant morbidity and mortality. Bacteremia caused by gram-positive organisms has established guidelines for the use of follow-up blood cultures (FUBCs), whereas the use of FUBCs in bacteremia due to gram-negative bacilli (GNBs) does not. One study showed that positive FUBCs were more common in gram-positive coccus bacteremia (21%) than in GNB bacteremia (6%), calling into question the overall clinical utility of using FUBCs in GNB bacteremia. We investigated the factors associated with positive FUBCs in patients with GNB bacteremia in our institution to better guide clinical practice. Methods We used a case-control design for this study. We included patients 18 years or older admitted to our hospitals between January 1, 2014, and December 31, 2018, for a duration of ≥24 hours and who had a positive blood culture (BC) for GNB. Cases were defined as any patient with a positive FUBC drawn ≥24 hours after the initial positive BC. Control subjects were defined as patients with a negative FUBC after an initial positive BC. Characteristics of cases and control subjects were compared using descriptive statistics. A multivariable regression model using stepwise variable selection was used to identify factors significantly associated with having a positive FUBC. Results We identified 70 cases meeting the inclusion criteria. We compared these 70 cases with 528 control subjects. The cases and control subjects did not differ significantly in age, sex, race, or other predefined comorbid conditions. Significant predictors for having a positive FUBC included (1) organism resistance to initial antibiotic therapy (odds ratio [OR], 3.26; P = 0.035), (2) glomerular filtration rate less than 30 mL/min (OR, 2.35; P = 0.010), (3) initial admission to critical care unit (OR, 1.72; P = 0.049), (4) central line–associated infection (OR, 3.99; P = 0.004), (5) Klebsiella group infection (OR, 2.18; P = 0.015), and (6) Serratia marcescens infection (OR, 3.53; P = 0.037). Initial discordant BC was a negative predictive factor (OR, 0.44; P = 0.018). Follow-up blood culture drawn more than 48 hours after the initial positive BC had a lower likelihood of being positive than those drawn 24 to 48 hours after the initial BC (OR, 0.59; P = 0.037). Discussion We identified 6 independent risk factors for positive FUBCs as delineated previously. These factors provide guidance for further research and for future guideline development. The timing of the FUBCs had a significant impact on positivity. Follow-up blood cultures in GNB bacteremia should be obtained more than 48 hours after the initial positive BC.

Predictors of early port infection in adult patients with acute myeloid leukemia.

7041 Background: The most concerning complications following port placement are infection and thrombosis. Early infections in patients with hematological malignancies are reported at 2-5% post-placement. However, data specific to patients with Acute Myeloid Leukemia (AML) is sparse. Here, we report infection rates within 30 days of placement and factors associated with increased risk of infection in patients with AML. Methods: We retrospectively reviewed charts of patients ≥ 18 years with AML who had ports placed between January 2019 to September 2022 at our institution. Baseline and peri-placement characteristics were collected. Port infection was defined as at least one of the following: 1) site infection, 2) gram-positive bacteremia, or 3) bacteremia that was documented by Infectious Disease consultants as a port source. Infections were classified as very early ( &lt; 7 days) and early (7-30 days). Variables were compared in each group by using Pearson’s chi-square test. Results: A total of 101 ports were placed in 98 patients with AML. The median age at placement was 64 years and 58% of patients were female. A total of 14 (13.9%) port infections were identified; 5 (35.7%) were very early and 9 (64.2%) were early infections. The median time to infection was 15 days (range 1-25 days). 5 (35.7%) patients had site-only infections, 6 (42.8%) had isolated bacteremia, and 3 (21.4%) had both. 13 (93%) patients were hospitalized, and 1 patient died from infectious complications. 8 (57%) of infected ports were removed. 57 patients were on regimen-specific prophylactic antibiotics at the time of placement, of whom 12 developed an infection (21%). The infection rate was 10% vs 23% (p = 0.1) in patients with ANC ≥ 500 /µL and ANC &lt; 500/µL respectively at 1 week after port placement, with no difference based on ANC at the time of placement. The infection rate was 21.9% vs. 6.5% in patients with platelets &lt; 100 x103/µL and ≥ 100 x103/µL (p = 0.01) at the time of placement; 28% vs. 8.6% in patients with albumin &lt; 3.5 g/L and ≥ 3.5 g/L (p = 0.02). The infection rate was numerically higher in Venetoclax-based regimens (19%) compared with cytarabine-based regimens (8%) (p = 0.06). Rates of infection were similar among inpatient and outpatient placements (14%). 5/53 patients (9.4%) were in complete remission (CR), 3/29 (10.3%) of newly diagnosed, and 6/19 (31.5%) relapsed/refractory (R/R) AML patients developed an infection (p = 0.02). Conclusions: In our single-institution study, a higher-than-expected port infection rate of 14% was seen in patients with AML. Platelets ≤100 x103/µL and albumin &lt; 3.5 g/L at the time of placement, Venetoclax-based regimens, and R/R state were associated with significantly higher rates of infection. Interestingly ANC at the time of placement was not associated with an increased infection rate. Strategies to prevent early infections in these high-risk patients are much needed.

Bacterial ecology of sepsis in febrile neutropenics on hematology-oncology services

Introduction: Febrile neutropenia is a hematologic emergency that develops following treatment of hematologic malignancies. It exposes patients to the risk of sepsis, which is a major cause of morbidity and mortality. Currently, coagulase-negative staphylococci are the most common bloodborne isolates while enterobacteria are isolated less frequently. The objective of our study is to determine the epidemiological, bacteriological and antibiotic susceptibility profile of strains isolated from blood cultures collected from febrile neutropenic patients at Hassan II University Hospital, Fez. Materials and methods: This is a prospective study, over a period of 4 years (January 2019 - December 2022) including 83 patients with bacteremia hospitalized in the department of hemato-oncology. Identification and detection of antibiotic resistance was performed according to conventional bacteriology methods and CA-SFM/EUCAST recommendations. Results: Among 524 blood cultures received, we diagnosed 83 cases of bacteremia. The average age of the patients was 55 years. The average age of the patients was 55 years. The predominance of women was noted, with a sex ratio of 0.88. The majority of the episodes, 94.87%, occurred in patients followed for a neoplastic pathology. Hematological malignancies were the most responsible with a rate of 61.54% against 33.33% of solid tumors. Gram-positive bacteria represent 56.6%, and 43.4% of Gram-negative bacteria. The proportions of the different bacterial classes (BGN / CG+) have remained stable over the last 4 years, Staphylococcus epidermidis was the most frequent isolated Gram-positive bacteria 24.1℅(n=29) then Staphylococcus aureus 24.6% (n=18), followed by Gram-negative bacteria of enterobacteria type especially Escherichia coli which was the most frequently isolated pathogen (16.86%), followed by Klebsiella pneumoniae (10.84℅) and non-fermenting Gram-negative bacteria such as Pseudomonas aeruginosa (8.4) and Acinetobacter baumanii (6℅). Bacteria of clinical interest have shown increasingly worrisome levels of beta-lactam resistance, with extended-spectrum beta-lactamase (ESBL)-producing strains of Klebsiella pneumoniae accounting for 4, 8% with only one case of carbapenemase, meticillin-resistant Staphylococcus aureus was 3.61% while no imipenem-resistant Pseudomonas aeruginosa or vancomycin-resistant enterococci were found. While Acinetobacter baumanii isolates (n=5) showed increased resistance to the majority of antibiotics tested, especially to imipenem which was 100%. Discussion and conclusion: Gram-positive bacteremia of the genus coagulase-negative staphylococcus is the most common type of infection in febrile neutropenias showing an increasingly resistant profile to first-line antibiotics. However, Gram-negative infections have shown decreased susceptibility compared to previous years. A regular study of the bacterial ecology of blood culture isolates and a determination of antibiotic susceptibility are necessary to optimize the probabilistic antibiotic therapy of bacteremia.

Risk Factors and Outcome Analysis of Gram-Positive Bacteremia in Critically Ill Patients.

Introduction Bloodstream infection (BSI) is a common problem for patients in the intensive care unit (ICU). Nearly 60% of primary bloodstream infections are caused by Gram-positive cocci. Gram-positive bacteria gain access to the bloodstream through invasive procedures and various patient care equipment like catheters, intravenous lines, and mechanical ventilators.S. aureus is considered to be the major cause of septicemia. Knowledge of healthcare-associated infections and the antimicrobial susceptibility patterns of the isolates are crucial in guiding empirical treatment. Methods This prospective observational study was conducted in Medical ICU, Dayanand Medical College & Hospital, Ludhiana over a period of one year (December 2015 to November 2016). Patients whose blood cultures tested positive for Gram-positive bacteria were included in the study. This study was carried out to assess the implications and risk factors for nosocomial BSI and several factors, including the age of the patient, the severity of illness, the presence of catheters, and the microorganisms causing the BSI to independently predict mortality. Chief complaints and risk factors were evaluated. APACHE-II scores were calculated for all patients and outcomes were analyzed. Results In our study, the mean age of patients was 50.93±14.09 years. Central line insertion was found as the most common risk factor (58.7%). A statistically significant correlation was obtained between APACHE-II scores and the presence of risk factors i.e. central line insertion (p-value=0.010) and diabetes mellitus (p-value=0.003). The most common Gram-positive pathogen isolated by blood culture was methicillin-sensitive S. aureus (44.2%). For management, the majority of the patients were prescribed teicoplanin (58.7%). The 28-dayoverall mortality rate in our study was 52.9%. Conclusion We conclude that independent risk factors like diabetes mellitus, central line insertion, and acute pancreatitis in adult patients with Gram-positive bacteremia were associated with higher mortality. We have also concluded that the administration of early appropriate antibiotics improves patient outcomes.

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.

No Significant Differences in Presepsin Levels According to the Causative Microorganism of Bloodstream Infection.

CD14 recognizes lipopolysaccharide (LPS), and presepsin is a fragment of soluble CD14. Still, it remains uncertain whether Gram-negative bacteria induce higher presepsin levels than other microorganisms. To address this question, this study aimed to analyze presepsin levels based on microorganisms isolated in blood cultures. This study was a single-center study comprising suspected sepsis patients enrolled from July 2020 to September 2020. A total of 95 patients with a single isolate confirmed in blood culture were analyzed to evaluate if there are any differences in presepsin levels according to microbial isolates. Plasma presepsin level was measured using PATHFAST assay kit and analyzer (LSI Medience Corporation, Tokyo, Japan). There were 26 Gram-positive bacteremia, 65 Gram-negative bacteremia, and 3 fungemia patients with median presepsin levels of 869, 1,439, and 11,951 pg/mL, respectively. Besides, one case of algaemia demonstrated a presepsin level of 1,231 pg/mL. Our results showed no statistically significant difference in presepsin levels among patients with Gram-positive bacteremia, Gram-negative bacteremia, and fungemia. Furthermore, presepsin levels did not differ significantly among bloodstream infections caused by bacteria that were isolated from at least three different patients. In particular, Gram-positive bacteria such as Staphylococcus aureus and Enterococcus faecalis were able to induce presepsin levels comparable to those induced by Gram-negative bacteria. We demonstrated that there were no significant differences in plasma presepsin levels according to microbial isolates in blood culture. The major cause of the variability in presepsin levels during bloodstream infection might be the immunogenicity of each microorganism rather than the presence of LPS in the microorganism.