Pathogens In Bloodstream Infections Research Articles

Evaluation of XGEN Multi Sepsis Flow Chip Molecular Assay for Early Diagnosis of Bloodstream Infection.

Among healthcare-associated infections that can affect a critically ill patient, bloodstream infections are one of the most frequent causes of mortality, especially in hospitalized patients. The objective of this work is to evaluate the performance of the XGEN Multi Sepsis Flow Chip for the rapid diagnosis of bloodstream infections compared with conventional tests. In total, 101 positive blood culture samples were included, and the results obtained by the phenotypic conventional method (culture with susceptibility profile) were compared with results obtained by the XGEN Multi Sepsis Flow Chip. This molecular assay allows the simultaneous detection of the main bloodstream infection pathogens, and their most common antibiotic resistance markers in a short period of time. It was possible to observe substantial agreement between the methods for identifying the genus of pathogens. Considering species, the agreement was excellent. In relation to susceptibility, excellent agreement was noted between the detected resistance genes and susceptibility profile obtained through conventional antibiograms. The evaluated assay presented very early and satisfactory results for identification and detection of resistance genes of the main pathogens involved in bloodstream infections.

Effect of appropriate empirical antimicrobial therapy on mortality of patients with Gram-negative bloodstream infections: a retrospective cohort study

BackgroundLittle evidence exists regarding the prevalence of pathogens in bloodstream infections (BSIs), the mortality risk, and the benefit of combination therapy over monotherapy. This study aims to describe patterns of empiric antimicrobial therapy, and the epidemiology of Gram-negative pathogens, and to investigate the effect of appropriate therapy and appropriate combination therapy on the mortality of patients with BSIs.MethodsThis was a retrospective cohort study including all patients with BSIs of Gram-negative pathogens from January 2017 to December 2022 in a Chinese general hospital. The in-hospital mortality was compared between appropriate and inappropriate therapy, and between monotherapy and combination therapy for patients receiving appropriate therapy. We used Cox regression analysis to identify factors independently associated with in-hospital mortality.ResultsWe included 205 patients in the study, of whom 147 (71.71%) patients received appropriate therapy compared with 58 (28.29%) who received inappropriate therapy. The most common Gram-negative pathogen was Escherichia coli (37.56%). 131 (63.90%) patients received monotherapy and 74 (36.10%) patients received combination therapy. The in-hospital mortality was significantly lower in patients administered appropriate therapy than inappropriate therapy (16.33% vs. 48.28%, p = 0.004); adjusted hazard ratio [HR] 0.55 [95% CI 0.35–0.84], p = 0.006). In-hospital mortality was also not different in combination therapy and monotherapy in the multivariate Cox regression analyses (adjusted HR 0.42 [95% CI 0.15–1.17], p = 0.096). However, combination therapy was associated with lower mortality than monotherapy in patients with sepsis or septic shock (adjusted HR 0.94 [95% CI 0.86–1.02], p = 0.047).ConclusionsAppropriate therapy was associated with a protective effect on mortality among patients with BSIs due to Gram-negative pathogens. Combination therapy was associated with improved survival in patients with sepsis or septic shock. Clinicians need to choose optical empirical antimicrobials to improve survival outcomes in patients with BSIs.

Enter Enterococcus: should we add it to the list of bloodstream infection pathogens for which infectious diseases consultation improves mortality?

Enter Enterococcus: should we add it to the list of bloodstream infection pathogens for which infectious diseases consultation improves mortality?

Time-series prediction and detection of potential pathogens in bloodstream infection using mcfDNA sequencing.

Next-generation sequencing of microbial cell free DNA (mcfDNA-seq) has emerged as a promising diagnostic method for blood stream infection (BSI) and offers the potential to detect pathogens before blood culture. However, its application is limited by a lack of clinical validation. We conducted sequential mcfDNA-seq on blood samples from ICU participants at high risk of BSI due to pneumonia, or intravascular catheterization; and explored whether mcfDNA-seq could diagnose and detect pathogens in advance of blood culture positivity. Blood culture results were used as evaluation criteria. A total of 111 blood samples were collected during the seven days preceding and on the day of onset of 16 BSI episodes from 13 participants. The diagnostic and total predictive sensitivity of mcfDNA-seq were 90% and 87.5%, respectively. The proportion of pathogenic bacteria was relatively high in terms of both diagnosis and prediction. The reads per million of etiologic agents trended upwards in the days approaching the onset of BSI. Our work found that mcfDNA-seq has high diagnostic sensitivity and could be used to identify pathogens before the onset of BSI, which could help expand the clinical application of mcfDNA-seq.

Prevalence of bloodstream infection pathogens in hemato-oncological patients and predictors of carbapenem-resistant gram-negative bacterial infections during febrile neutropenia.

Carbapenem-Resistant Gram-Negative (CRGN) Bloodstream Infections (BSI) represent a therapeutic challenge, especially in the context of Febrile Neutropenia (FN) in cancer patients. We characterized pathogens causing BSI in patients aged ≥18 years who had undergone systemic chemotherapy for solid or hematological cancers between 2012 and 2021 in Porto Alegre, Brazil. Predictors of CRGN were evaluated through a case-control analysis. Each case was matched to two controls from whom CRGN were not isolated and had the same sex and year of inclusion in the study. From 6094 blood cultures evaluated, 1512 (24.8%) showed positive results. Gram-negative bacteria accounted for 537 (35.5%) of the isolated bacteria, of which 93 (17.3%) were carbapenem-resistant. From 105 patients included in the case-control analysis, all cases had baseline hematological malignancies (60% acute myeloid leukemia). Variables related to CRGN BSI in Cox regression analysis were the first chemotherapy session (p<0.01), chemotherapy performed in the hospital setting (p=0.03), intensive care unit admission (p<0.01), and CRGN isolation in the previous year (p<0.01). Patients with CRGN BSI received 75% less empirical active antibiotics and had 27.2% higher 30-day mortality rates than controls. A CRGN risk-guided approach should be considered for empirical antibiotic therapy in patients with FN.

A Comparative Study of Conventional and Automated Blood Culture System in Adult Patients

Introduction: Blood culture is considered as the gold standard for the diagnosis of bloodstream infection. Conventional blood culture system is less sensitive and takes longer duration for the detection of bloodstream infections whereas automated blood culture system is more sensitive and rapid in detecting causative organisms of bloodstream infections. This prospective study was undertaken to compare the automated blood culture system with the conventional blood culture system for the identification of microbial pathogens in bloodstream infections. Method: This prospective study was done in Department of Microbiology, Silchar Medical College &amp; Hospital, Silchar for a period of 7 months from November 2021 to May 2022. Blood samples from the patients were inoculated into BD BACTEC Plus Aerobic culture vials for automated blood culture system and Brain Heart Infusion broth for conventional blood culture system. Positive bottles flagged by the automated machine were isolated and identified by doing routine subcultures on Blood agar and MacConkey agar and necessary biochemical tests. The conventional blood culture bottles were processed as per standard protocols. Result: Out of 123 samples, 21(17.09%) showed culture positivity by automated blood culture method and 15(12.19%) showed culture positivity by conventional blood culture method. The most common isolate was Staphylococcus aureus followed by Escherichia coli in automated method whereas the most common isolate in conventional method was Staphylococcus aureus followed by Klebsiella pneumoniae. Conclusion: This study concluded that automated blood culture method is more sensitive than conventional method and detects the presence of microorganisms rapidly causing bloodstream infections. Keywords: Bloodstream infection, Automated blood culture, Conventional blood culture

Bacterial bloodstream infection in critically ill patients with COVID-19: a retrospective cohort study.

Intensive care unit (ICU) patients with coronavirus disease 2019 (COVID-19), have a high risk of developing bloodstream infections (BSIs). However, the characteristics of and risk factors for BSIs in these patients remain unclear. We aimed to identify prevalent causative pathogens of BSI and related factors in critically ill patients with COVID-19. This was a single-center, retrospective cohort study. We analyzed the clinical characteristics and outcomes of 201 ICU patients with COVID-19. Logistic regression analysis was conducted to identify factors associated with BSI occurrence. Furthermore, we identified the primary causative pathogens of BSIs. The study outcomes were death or ICU discharge. Among the 201 included patients, 43 (21.4%) patients developed BSI. The mortality rate was non-significantly higher in the BSI group than in the BSI group (65.1% versus 58.9%, p = 0.487). There were significant between-group differences in the obesity prevalence and sex distribution, but not corticosteroid usage. BSI occurrence was significantly associated with duration of mechanical ventilation (MV), presence of ventilator-associated pneumonia, use of neuromuscular blocking agents, length of stay in ICU (ICU LOS), high body mass index (BMI), and male sex. The main causative pathogens were Klebsiella pneumoniae, Acinetobacter baumannii, and Enterococcus faecalis. Multi-drug-resistant pathogens were found in 87% of cases. Regardless of the origin, the common risk factors for BSI were ICU LOS and MV duration. All BSIs were acquired within the hospital setting, with ≈60% of the cases being primary BSIs. A small proportion of the BSI cases were catheter-related (four cases, 6.2%). Ventilator-associated pneumonia and urinary tract infections were present in 25% and 9.4% of the BSI cases, respectively. On average, the first positive blood culture appeared ≈11.4 (±9.7) days after ICU admission. Elucidating the risk factors for and common pathogens of BSI can inform prompt management and prevention of BSIs.

MALDI-TOF MS-Based Approaches for Direct Identification of Gram-Negative Bacteria and BlaKPC-Carrying Plasmid Detection from Blood Cultures: A Three-Year Single-Centre Study and Proposal of a Diagnostic Algorithm.

The rapid identification of pathogens of bloodstream infections (BSIs) and the detection of antibiotic resistance markers are critically important for optimizing antibiotic therapy and infection control. The purpose of this study was to evaluate two approaches based on MALDI-TOF MS technology for direct identification of Gram-negative bacteria and automatic detection of Klebsiella pneumoniae carbapenemase (KPC) producers using the Bruker MBT Subtyping IVD Module in a large routine laboratory over a three-year period. MALDI-TOF MS analysis was performed directly from blood culture (BC) bottles following bacterial pellet recovery by Rapid MBT Sepsityper® Kit and on blood agar 4-h subcultures. Automated detection of blaKPC-carrying pKpQIL-plasmid by Bruker MBT Subtyping Module was evaluated in BCs tested positive to K. pneumoniae or E. coli. The results were compared with those obtained with conventional reference methods. Among the 2858 (93.4%) monomicrobial BCs, the overall species identification rates of the Rapid Sepsityper and the short-term subculture protocols were 84.5% (n = 2416) and 90.8% (n = 2595), respectively (p < 0.01). Excellent specificity for KPC-producers identification were observed for both MALDI-TOF MS protocols. The pKpQIL plasmid-related peak was detected in overall 91 of the 120 (75.8%) KPC-producing isolates. Notably, 14 out of the 17 (82.3%) K. pneumoniae isolates carrying blaKPC variants associated with ceftazidime/avibactam resistance and tested negative by the immunocromatography assay, were correctly identified as KPC-producers by MALDI-TOF MS. In conclusion, combination of both Rapid Sepsityper and short-term subculture protocols may represent an optimal solution to promptly identify more than 95% of Gram-negative bacteria causing BSIs. MALDI Biotyper® platform enabled a reliable and robust automated detection of KPC producers in parallel with species identification. However, integration of molecular or immunocromatographic assays are recommended according to local epidemiology.

737. Oral Antibiotic Stepdown Therapy for Uncomplicated Streptococcal

Abstract Background Streptococcus species are known pathogens in bloodstream infections (BSIs). Traditionally, BSIs are managed with intravenous (IV) antibiotics, however there is growing literature supporting oral (PO) antibiotics in BSIs as well as other invasive infections. Advantages to PO therapies include shortened hospital stay, reduced treatment costs, and avoidance of line-related complications. Currently, there is a paucity of data supporting the use of PO antibiotics in streptococcal BSIs. Methods This retrospective cohort study evaluated patients with streptococcal bacteremia between September 2019 to September 2021. Patients 18 and older were included if they had at least one positive blood culture for any Streptococcus species and excluded if BSI was polymicrobial, or treatment was for complicated BSI, identified by receipt of targeted therapy for ≥ 16 days, or source being endocarditis, osteomyelitis, or meningitis. Clinical outcomes were compared between patients who completed treatment with IV antibiotics verses those who completed with an PO stepdown regimen. The primary endpoint was clinical failure, which was a composite endpoint defined as BSI recurrence with the same pathogen and infection-related readmission within 30 days from completion of antibiotics. Results A total of 158 patients were included, with 77 (49%) receiving a full course of IV antibiotics and 81 (51%) receiving an PO antibiotic stepdown regimen. Clinical failure was not different between the IV antibiotics group versus the PO stepdown group, respectively (16% vs. 15%, odds ratio [OR] = 0.94; 95% confidence interval [CI], 0.40 to 2.25). No differences were observed in 30-day all-cause mortality. Patients that received PO antibiotic stepdown therapy had a significantly shorter hospital length of stay by 6 days (6 versus 12 days, p&amp;lt; 0.01). Conclusion Our results suggest that clinical cure with an PO stepdown regimen for uncomplicated streptococcal BSIs is comparable to IV antibiotics. The benefit of comparable efficacy in the setting of reduced length of stay and avoidance of central line placement for outpatient IV antibiotics should be considered when making treatment plans for patients with uncomplicated streptococcal BSIs. Disclosures All Authors: No reported disclosures.

Changing epidemiology and prognosis of nosocomial bloodstream infection: A single-center retrospective study in Taiwan.

Nosocomial bloodstream infection (BSI) remains a significant cause of mortality and morbidity. We evaluate the trend of the pathogens of nosocomial BSI and investigate the distribution of the pathogens to demonstrate the risk factors of mortality. In this retrospective study, we collected data from a 2076-bed tertiary referral center that offers a full range of clinical services in central Taiwan during January, 2016 to December, 2017. Five hundred and eighty-four patients were identified with nosocomial BSI. Among the comorbidities of nosocomial BSI patients with, the most frequent were hypertension, in 294 patients (50.3%), malignancy, in 279 patients (47.8%); diabetes, in 278 patients (47.6%); chronic kidney disease, in 171 patients (29.3%); and liver cirrhosis, in 132 patients (22.6%). Gram-positive organisms caused 22.9% of these nosocomial BSIs, gram-negative organisms caused 69.2%, and fungi caused 6.8%. The most common organism causing nosocomial BSIs were Klebsiella spp. (14%), E coli. (14%), and Enterococcus spp. (11%). Multivariate analysis of risk factors for mortality displayed that comorbidity with low body weight, liver cirrhosis, and malignancy, high CRP level, high Charlson Comorbidity Index and internal medicine and hematology/oncology distribution were strikingly associated with mortality (P=0.0222, 0.0352, 0.0008, 0.0122, <0.001, and 0.041; [OR]=1.8097, 1.9268, 2.7156, 2.7585, 3.5431, and 2.2449, respectively). K. spp. and E coli. became the most common pathogens of nosocomial BSI in recent years. Comorbidities could be important roles to predictive the outcome of nosocomial BSI. The modifiable risk factors of nosocomial BSI may be investigated further to improve the outcome.

Rapid detection of four pathogens in bloodstream infection by antimicrobial peptide capture combined with multiplex PCR and capillary electrophoresis

Bloodstream infection (BSI) is a common and serious infection that threatens the life of patients. In this study, a rapid method combining magnetic separation techniques and multiplex PCR-based capillary electrophoresis (mPCR-CE) was developed to detect four pathogens causing BSI. Taking advantage of the binding capacity with the cell membrane, the antimicrobial peptides melittin was connected to magnetic beads as a broad-spectrum bacterial capture element, which was used to capture pathogenic bacteria in whole blood. The detection limit of this proposed method was significantly lower than that of the common PCR method, reaching 101 CFU/mL with excellent specificity. The overall clinical sensitivity was 90 %, and the clinical specificity was 100 %. There were no false positives for testing another 100 clinical samples suspected of bloodstream infections. The detection platform took only 3–4 h, which is obviously shorter than the identification time of the traditional methods. Our method possesses tremendous clinical application potential for its advantages in detecting mixed bacterial infections.

Establishment of Mortality Risk Prediction Model for Bloodstream Infections in Patients with Hematological Diseases

Backgrounds: In recent years, with the continuous development of treatment for hematological diseases, the remission rate and survival rate of patients have been significantly improved. However, due to the progression of the hematological disease and immunosuppression, the incidence of bloodstream infection was greatly increased in patients with hematological disease. The occurrence of bloodstream infection had many negative effects on patients with hematological diseases, including the increase in mortality, the adding of medical bills, the prolongation of hospitalization period, and so on. West China Hospital is a national center for diagnosing and treating difficult and critical diseases in Western China. In our center, we found that the incidence of bloodstream infection in hematological patients was not low, and it was often one of the common causes of death. So, our purpose was to explore the risk factors for the 30-day death and establish a mortality risk prediction model in patients with bloodstream infections in hematological diseases, to provide evidence for the prevention and treatment of bloodstream infection in hematological diseases. Methods: The clinical data of 412 strains of pathogens of bloodstream infection from patients with hematological diseases were retrospectively collected from June 2015 to June 2020 in the Department of Hematology, West China Hospital, Sichuan University. Statistical analysis was conducted with IBM SPSS Statistics (version 26.0). 70% of the patients were randomly selected as the development group and 30% as the validation group. Results: A total of 338 patients with hematological diseases with positive blood culture were collected and 412 strains of pathogens of bloodstream infection were isolated. The most common primary hematological disease was acute myeloid leukemia, accounting for 44.2%. Among the included cases, the 7-day and 30-day mortality rates of all patients were 5.6% and 32.0%, respectively. All cases were randomly divided into the development group (n = 289) and validation group (n = 123) by 7:3. Univariate and multivariate logistic regression analysis revealed that septic shock [P = 0.001, OR = 4.126], albumin < 30g/L [P < 0.001, OR = 3.622], platelets < 30×109/L before infection [P = 0.002, OR = 4.202], bleeding [P = 0.029, OR = 2.308], placement of urinary ducts [P = 0.008, OR = 3.769], and inappropriate empiric antibiotic treatment [P = 0.007, OR = 2.523] were independent risk factors for 30-day death after bloodstream infection in patients with hematological diseases. In the light of the results of multivariate analysis, the equation of risk prediction model of 30-day death for bloodstream infections in patients with hematological diseases was established as follows: P = ea/ (1 + ea), a=-4.172 + (1.417 × septic shock) + (1.287 × albumin < 30g/L) + (1.436 × platelets < 30×109/L before infection) + (0.836 × bleeding) + (1.327 × placement of urinary ducts) + (0.925 × inappropriate empiric antibiotic treatment). The Hosmer-Lemeshow Chi-square test showed P = 0.582, and the area under ROC curve was 0.863±0.022 [95%CI (0.820-0.906)], indicating that the model had a good prediction coincidence and discriminant validity. The model was verified using the data of the validation group, and the results exhibited that the sensitivity, specificity, positive predictive value, negative predictive value, and coincidence rate were 97.3%, 86.0%, 75.0%, 98.7%, and 89.4%, respectively. Discussion and Conclusions: This study showed that about 32.0% of patients with bloodstream infections died within 30 days, which was consistent with other data reported at home and abroad. In the mortality risk prediction model established in this study, the four risk factors for death included septic shock, albumin < 30g/L, placement of urinary ducts, and inappropriate empirical antibiotic treatment, which have also been reported in other studies. A notable finding in this study was the identification of previously unnoted risk factors for death, including platelets < 30×109/L before infection and bleeding. The prediction model in our study was verified that the model had a good prediction coincidence, discriminant validity, and clinical predictive value, which can provide evidence for clinicians to evaluate the death risk and make individualized treatment plans for patients.

Rapid Etiological Detection Value of Metagenomic Next-Generation Sequencing for Bloodstream Infections in Patients with High-Risk Hematologic Malignancies

Background: Patients with hematological malignancies often suffer from infectious fever, rapid and accurate diagnosis of pathogens facilitates optimal and precise treatment of infectious diseases. In recent years, metagenomic next-generation sequencing (mNGS) technology has been widely used in the etiological detection of patients with respiratory tract infection, sepsis, etc, due to its advantages of rapid detection.However, at present, the clinical diagnosis of mNGS in patients with hematological malignancies in secondary bloodstream infections remains scarce. Objective: In this study, the application value of mNGS in the rapid etiological detection of bloodstream infection pathogens in patients with high-risk hematological malignancies was explored by comparing two etiological detection methods of mNGS and traditional pathogen culture. Methods: This study retrospectively analyzed 66 peripheral blood samples of patients with high-risk hematologic malignancies in our hospital from May 2020 to January 2022. SPSS 20.0 software was used to analyze the positive rate, species distribution and consistency of pathogens between mNGS and traditional pathogen culture method. The diagnostic efficiency of the two etiological detection methods was compared, and the risk factors affecting the positive rate of mNGS were investigated. Results: A total of 66 patients were enrolled in this study, including 38 males and 28 females, with an average age of (43.39±14.427) years. Among the 66 patients, 48 cases were acute myeloid leukemia (48/66, 72.7%), the rest included 2 cases of acute lymphoblastic leukemia (2/66, 3.0%), 3 cases of chronic myeloid leukemia (3/66, 4.5%), 3 cases of myelodysplastic syndrome (3/66, 4.5%), 4 cases of non-Hodgkin lymphoma (4/66, 6.0%), 4 cases of malignant tumor after autologous hematopoietic stem cell transplantation (4/66, 6.0%), and Hemophagocytic syndrome was found in 2 cases (2/66, 3.0%). Peripheral blood samples from 66 patients were both tested for mNGS and traditional pathogen culture. The positive rate of mNGS was 54.5% (36/66), while the traditional culture was 18.1% (12/66). There was a significant statistical difference between the two methods (P=0.000). Multivariate analysis was conducted on the influence of factors such as patient age, gender, disease diagnosis, and time from fever to the mNGS detection, and no statistical difference was found. Among the 36 mNGS-positive patients, a total of 64 pathogens were detected, including 19 bacteria (19/64, 29.7%), 12 fungus (12/64, 18.8%), 31 virus (31/64, 48.4%), and 2 special pathogens (2/64, 3.1%). Six drug-resistant bacteria were detected by mNGS in 5 patients .Among the 12 patients with positive traditional culture, 15 pathogens were detected, including 14 bacteria (14/15, 93.3%) and 1 fungus (1/12, 3.7%). In this study, 8 patients (8/66, 36.4%) were both positive for mNGS and traditional culture tests, and 5 of them (5/8, 62.5%) developed the same type of clinical infection with all or part identical detected pathogens. The time for positive and negative blood culture report was 72h and 7 days respectively, and 24h for mNGS. Among the 54 patients with negative results of traditional culture, 28 cases (28/54, 51.9%) were positive for mNGS, of which 15 cases (15/28, 53.6%) were made corresponding anti-infection regimens according to the positive results of mNGS, and the clinical efficacy was significantly improved. Seven of the 26 patients with both negative traditional culture and mNGS results were considered to have fungal infection based on chest imaging. After empirical antifungal treatment, the imaging results and clinical symptoms were improved; while only 4 of the remaining 19 patients (4/19, 21.5%) had clinical benefit from empirical anti-infective therapy. It demonstrated that pathogen-oriented therapy was significantly better than empirical anti-infective therapy (P=0.000). Conclusions: mNGS enhanced the positive rate of bloodstream pathogens detection and provided more accurate pathogen species in patients with high-risk hematologic malignancies.It could effectively detect multidrug-resistant bacteria and special pathogens,which provide an important reference for clinical antimicrobial treatment and improved their prognosis.

The association of ESBL Escherichia coli with mortality in patients with Escherichia coli bacteremia at the emergency department.

Background: Escherichia coli is a common bloodstream infection pathogen in the emergency department (ED). Patients with extended-spectrum beta-lactamase (ESBL) E. coli have a higher risk of morbidity. However, there is still debate surrounding ESBL E. coli-associated mortality in community, intensive care unit, and tertiary care settings. In addition, there have been few studies regarding mortality in ESBL E. coli in ED settings, and results have been contradictory. Methods: This was a retrospective cohort study conducted at the Department of Emergency Medicine, Faculty of Medicine, Khon Kaen University in Thailand aimed at evaluating the possible association between ESBL E. coli bacteremia and mortality in the ED. The inclusion criteria were age 18 years or over, clinical presentation suspicious of infection, and positive blood culture for E. coli. Predictors for mortality were analyzed by logistic regression analysis. Results: During the study period, 273 patients presented at the ED with hemoculture positive for E. coli. Of those, 27 (9.89%) died. Five factors remained in the final model, of which plasma glucose levels, serum lactate levels, and ESBL E. coliwere significantly associated with 28-day mortality in the ED with adjusted odds ratios of 0.970, 1.258, and 12.885, respectively. Plasma glucose of less than 113 mg/dL yielded a sensitivity of 80.95% and specificity of 64.29%, while serum lactate over 2.4 mmol/L had a sensitivity of 81.48% and specificity of 45.50%. Conclusion: ESBL E. coli, plasma glucose, and serum lactate levels were associated with 28-day mortality in patients with E. coli bacteremia presenting at the ED.

Bloodstream infections and antibiotic resistance patterns: a six-year surveillance study from southern Italy

ABSTRACT Bloodstream infections (BSI) are associated with high morbidity and mortality. This study aimed to describe the epidemiology of BSI and antimicrobial resistance patterns amongst its common bacterial causes. We conducted a retrospective record review of blood culture results of patients hospitalized with BSI at University Hospital ‘L. Vanvitelli’ from 2016 to 2021. For each patient records were obtained from the database using microbiological information. Gram-positive bacteria were the most predominant pathogens followed by Gram-negative bacteria. Among all isolates, bacterial pathogens most frequently identified included coagulase-negative Staphylococci (CoNS), Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and enterococci. We noted a general decrease in antimicrobial resistance amongst BSI pathogens in the latter years of the study. High levels of macrolide and aminoglycoside resistance amongst CoNS were reported. Carbapenem resistance amongst E. coli was barely reported, while resistance rates amongst K. pneumoniae declined considerably between 2018 and 2021. The prevalence of methicillin-resistant S. aureus decreased during the study period while that of methicillin-resistant CoNS remained relatively high throughout. The prevalence of extended spectrum ß-lactamase – producing E. coli increased considerably between 2016 and 2018 but showed a slight decrease thereafter. Conversely, there was a general decline in the resistant rates of extended spectrum ß-lactamase – producing K. pneumoniae between 2016 and 2018 with a similar trend being noted for carbapenem resistance in K. pneumoniae. Continuously monitoring the changes in the trends in BSI microbiological profiles, including pathogen profiles and the associated antibiotic resistance patterns, can help diagnostic approaches, treatment strategies and prevention programs.

Highly versus less bioavailable oral antibiotics in the treatment of gram-negative bloodstream infections: a propensity-matched cohort analysis

ObjectivesIn this study, we evaluated the clinical outcomes associated with the use of highly bioavailable oral antibiotics (fluoroquinolones and trimethoprim-sulfamethoxazole) compared with the less-bioavailable oral antibiotics (β-lactams) in gram-negative bloodstream infections (BSIs). MethodsAmong hospitalized older adult patients in Ontario, Canada, discharged home on oral treatment for gram-negative BSI between 1 January 2017 and 31 December 2019, we used a matched cohort design to compare outcomes among those receiving highly versus less-bioavailable agents; hard-matching 1:1 on sex, BSI pathogen (Escherichia coli vs. non–E. coli), and infection source (urinary vs. non-urinary/unknown source) along with a propensity score, incorporating specific pathogen, patient, and infection characteristics. The primary outcome was the composite of 90-day all-cause mortality, recurrent BSI with the same pathogen (genus and species), and re-admission to any Ontario hospital. ResultsA total of 2012 patients were included in the study (1006 in each bioavailability category). Those who received highly (compared with less) bioavailable antibiotics at discharge had lower rates of the composite outcome (171/1006 [17.0%] vs. 216/1006 [21.5%]), adjusted odds ratio being 0.74 (95% CI, 0.60–0.92). Recurrent BSI at 90 days was the main driver for the composite outcome occurring in 64 (5.4%) and 107 (9.4%) patients of the highly and less-bioavailable groups, respectively (p < 0.001) (adjusted odds ratio, 0.56; 95% CI, 0.40–0.78). DiscussionUse of highly (compared with less) bioavailable antibiotics at discharge was associated with significantly better clinical outcomes among patients with gram-negative BSIs.

Adoptive immunotherapy overcomes genetic susceptibility to bloodstream infections due to fc-gamma receptor polymorphisms after liver transplantation

Single nucleotide polymorphisms (SNPs) in FCGR3A can predict the susceptibility of liver transplant (LT) recipients to bloodstream infections (BSI) and clinical outcomes following living-donor LT (LDLT). Here, we retrospectively analyzed the relationship of adoptive immunotherapy with activated natural killer (NK) cells from perfusate effluents of liver allografts against BSI following LDLT. Higher BSI incidence and lower survival were observed in LT recipients with FcγRIIIa (158F/F or F/V) (n=81) who did not receive adoptive immunotherapy (n=55) than in those who did (n=26) (BSI frequency, 36.4% vs. 11.5%; p =.033; log-rank p =.047). After matching patient background using propensity score, similar results were obtained (BSI ratio, 41.7% vs. 12.5%; p =.049; log-rank p=.039). The predominant BSI pathogens in patients who did and did not receive adoptive immunotherapy were gram-negative rods (n=3, 100%) and gram-positive cocci (GPC) (n=15, 65.2%), respectively. The proportion of NK cells administered to patients with BSI was significantly lower than that administered to patients without BSI (Number: 80.3 (29.9-239.2)× 106 cells vs. 37.1 (35.6-50.4)× 106 ; p=.033, percentage; 14.1 (13.3-17.8)% vs. 34.6 (16.5-47)%, p=.0078). Therefore, adoptive immunotherapy with NK cells was associated with the reduced post-transplant BSI related to GPCs due to FcγRIIIa SNP in LT recipients.

A diagnostic test of real-time PCR detection in the diagnosis of clinical bloodstream infection

Blood culture remains the standard for diagnosing bloodstream infections, but it is difficult to identify bacteria directly and timeliness. The real-time polymerase chain reaction (PCR) has the potential to fill this diagnostic gap. This study intends to explore the sensitivity and specificity of PCR in detecting bloodstream infection pathogens and to compare it with routine blood culture to explore its clinical application value. A total of 126 patients with bloodstream infections collected from various clinical departments of The First Hospital of Hebei Medical University. The patient's sample was divided into two parts. The one for multiplex PCR detection was performed using the Pathogeno Elite Multiplex PCR kit. Another blood culture was a fully automatic blood culture system from Autobio company. Among the 126 patients, a total of 17 pathogens were detected by PCR and blood culture both methods. PCR detected a total of 43 positive samples and 83 negative samples. Five samples were positive with blood culture, and 81 were negative. The negative predictive value of PCR was 0.98, with a sensitivity of 0.71 and a specificity of 0.68. A total of 38 specimens were positive for PCR but negative for blood culture, and 2 samples were positive for blood culture but negative for PCR. The top 5 pathogens with PCR detection were Epstein-Barr virus (27 cases), Human herpes virus 5 (9 cases), Klebsiella pneumoniae (5 cases), Staphylococcus (5 cases), and Stenotrophomonas maltophilia (4 cases). PCR detection can rapidly identify more pathogens and even multi-pathogen infections. Therefore, PCR testing may improve pathogen detection in patients with suspected bloodstream infections, enabling targeted treatment of patients.

Identification of selected primary bloodstream infection pathogens in patients attending Kisii level five and Homa Bay county hospitals

Background: Bloodstream infection (BSI) contributes to a substantial proportion of mortality in sub-Saharan Africa and is marked by the presence of bacterial and/or fungal microorganisms in the blood. Because BSI can be life threatening, it requires a timely, reliable and accurate diagnosis. This study retrospectively analyzed data of identified BSI pathogens and compared the performance of the different diagnostic technologies used in terms of accuracy, sensitivity, turnaround time (TAT) and cost. Methods: Currently, culture followed by analytical profile index biochemical strips (API), (BioMerieux) are used as the conventional standard diagnostics in Kenyan public hospitals and labs. We compared the results of this standard to that of the BioFire FilmArray (FA) (BioFire Diagnostics) and MicroScan WalkAway-40 plus System (MS) (Beckman Coulter) used in diagnosis of BSI. The FA technology was able to identify 150/152 bacterial and yeast isolates with an overall accuracy of 99.04% (95% CI: 96.59-99.88%), sensitivity of 98.68% (95% CI: 95.33-99.84%), mean TAT of 8 hours 40 minutes per eight samples and running cost per sample of USD 140.11. The MS identified 150/152 isolates with an overall accuracy of 98.56% (95% CI: 95.86-99.70%), sensitivity of 98.68% (95% CI: 95.30-99.84%), mean TAT per sample was 42 hours and running cost per sample of USD 28.05. API detected 150/152 isolates, with an overall accuracy of 99.04% (95% CI: 96.59-99.88%), sensitivity of 98.68% (95% CI: 95.33-99.84%) and the mean TAT per sample was 53 and 103 hours for bacterial and yeast samples, respectively, with a running cost per sample of USD 28.05.Conclusions: The findings in this paper suggest that the FA and MS platforms should be able to perform adequately in Kenya referral hospitals and medical clinics as a rapid diagnostic tool.

Effective Rapid Diagnosis of Bacterial and Fungal Bloodstream Infections by T2 Magnetic Resonance Technology in the Pediatric Population.

Children are prone to bloodstream infections (BSIs), the rapid and accurate diagnosis of which is an unmet clinical need. The T2MR technology is a direct molecular assay for identification of BSI pathogens, which can help to overcome the limits of blood culture (BC) such as diagnostic accuracy, blood volumes required, and turnaround time. We analyzed results obtained with the T2Bacteria (648) and T2Candida (106) panels in pediatric patients of the Bambino Gesù Children's Hospital between May 2018 and September 2020 in order to evaluate the performance of the T2Dx instrument with respect to BC. T2Bacteria and T2Candida panels showed 84.2% and 100% sensitivity with 85.9% and 94.1% specificity, respectively. The sensitivity and specificity of the T2Bacteria panel increased to 94.9% and 98.7%, respectively, when BC was negative but other laboratory data supported the molecular result. T2Bacteria sensitivity was 100% with blood volumes <2 mL in neonates and infants. T2Bacteria and T2Candida provided definitive microorganism identification in a mean time of 4.4 and 3.7 h, respectively, versus 65.7 and 125.5 h for BCs (P < 0.001). T2 panels rapidly and accurately enable a diagnosis of a pediatric BSI, even in children under 1 year of age and for very small blood volumes. These findings support their clinical use in life-threatening pediatric infections, where the time to diagnosis is of utmost importance, in order to improve survival and minimize the long-term sequalae of sepsis. The T2 technology could be further developed to include more bacteria and fungi species that are involved in the etiology of sepsis.