Bacteremia Research Articles

Evaluation of Direct Antimicrobial Susceptibility Testing of Gram-Negative Bacilli and Staphylococcus aureus from Positive Pediatric Blood Culture Bottles Using BD Phoenix M50.

Bloodstream infections (BSIs) are life-threatening infections for which a timely initiation of appropriate antimicrobial therapy is critical. Antibiotic susceptibility testing (AST) directly performed on positive blood culture broths can help initiate targeted antibiotic therapy sooner than the standard AST performed on colonies isolated on solid media after overnight incubation. Faster antimicrobial susceptibility testing (AST) results can improve clinical outcomes, and reduce broad-spectrum antimicrobial consumption and healthcare-associated costs in sepsis. In this study, we evaluated the accuracy of a direct AST inoculation method on the BD Phoenix M50 system using serum separator tubes to harvest bacteria from positive pediatric blood culture bottles. Direct AST was performed on 132 monomicrobial pediatric blood culture bottles that were positive for Enterobacterales (65; 49.2%), Staphylococcus aureus (46; 34.8%), and non-fermenting Gram-negative bacilli (21; 16%). Overall, the categorical and essential agreements between the direct method and standard method were 99.6% and 99.8%, respectively. Very major, major, and minor error rates were 0.1%, 0.09%, and 0.20% respectively. Direct AST performed on pediatric blood culture bottles using BD Phoenix M50 can quickly provide accurate susceptibility information to guide antimicrobial therapy in patients with BSI.

Induction of biofilm in extended-spectrum beta-lactamase Staphylococcus aureus with drugs commonly used in pharmacotherapy

Staphylococcus aureus is a bacterial pathogen that causes bloodstream infections, pneumonia, and skin abscesses and is the primary pathogen responsible for medical devices associated with biofilm infections, accounting for approximately 70 % of cases. Therefore, the World Health Organization (WHO) has designated this microorganism as a top priority due to its role in causing over 20,000 bacteremia-related deaths in the US each year. The issue of pathogen resistance to antibiotics, mainly by a biofilm, further complicates these infections since biofilms render the bacterial colony impervious to antibiotics. However, many natural and synthetic substances also induce bacterial biofilm formation. Therefore, we investigated whether the most common active pharmaceutical ingredients (APIs) could induce biofilm formation in two clinical isolates of extended-spectrum beta-lactamase Staphylococcus aureus, one of them also methicillin-resistant (A2M) and two medical devices.We detected biofilm inducers, inhibitors, and destabilizers. Microbial strain, medical devices, API structure, and concentration influenced the modulatory effects of biofilm. In all devices tested, including microplates, FR18 duodenal probe, and respiratory probe, the clinic isolate methicillin-resistant S. aureus A2M exhibited lower susceptibility to biofilm formation than S. aureus A1. The anti-inflammatory acetaminophen, the hypocholesterolemic lovastatin, and the diuretic hydrochlorothiazide all induced biofilm. However, verapamil, an antihypertensive, and cetirizine, an antihistamine, inhibited biofilm on S. aureus A2M, while propranolol, another antihypertensive, inhibited biofilm on S. aureus A1. Additionally, diclofenac, an analgesic, and cetirizine destabilized the biofilm, resulting in more free bacteria and possibly making them more susceptible to external agents such as antibiotics. Nonetheless, further epidemiologic analyses and in vivo assays are needed to confirm these findings and to establish a correlation between drug use, the onset of bacterial infections in patients, and the use of medical devices.This work provides information about the probable clinical implications of drugs in patients using medical devices or undergoing surgical procedures. Inhibitory APIs could also be used as drug repurposing or templates to design new, more potent biofilm inhibitors.

Antibacterial Activity of Ag+ on ESKAPEE Pathogens In Vitro and in Blood.

Bloodstream infections are a significant threat to soldiers wounded in combat and contribute to preventable deaths. Novel and combination therapies that can be delivered on the battlefield or in lower roles of care are urgently needed to address the threat of bloodstream infection among military personnel. In this manuscript, we tested the antibacterial capability of silver ions (Ag+), with long-appreciated antibacterial properties, against ESKAPEE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species, and Escherichia coli) pathogens. We used the GENESYS (RAIN LLC) device to deliver Ag+ to Gram-positive and Gram-negative ESKAPEE organisms grown in broth, human blood, and serum. Following the Ag+ treatment, we quantified the antibacterial effects by quantifying colony-forming units. We found that Ag+ was bactericidal against 5 Gram-negative organisms, K pneumoniae, A baumannii, P aeruginosa, E cloacae, and E coli, and bacteriostatic against 2 Gram-positive organisms, E faecium and S aureus. The whole blood and serum inhibited the bactericidal activity of Ag+ against a common agent of bloodstream infection, P aeruginosa. Finally, when Ag+ was added in conjunction with antibiotic in the presence of whole blood, there was no significant effect of Ag+ over antibiotic alone. Our results confirmed that Ag+ has broad-spectrum antibacterial properties. However, the therapeutic value of Ag+ may not extend to the treatment of bloodstream infections because of the inhibition of Ag+ activity in blood and serum.

A case report of iliopsoas abscess and literature review.

Iliopsoas abscess is a rare acute medical condition. It usually occurs because of the spread of infection from adjacent structures and hematogenous spread. Clinical features include fever, backache, radiating nerve root pain, and leg weakness. When sepsis occurs, prompt recognition is required to initiate appropriate antimicrobial therapy and surgical drainage. A 65-year-old male presented to the outpatient department with a 2-day history of lower back, hip, and leg pain, for which analgesics were administered. During hospitalization, he experienced deterioration, becoming febrile, hypoxic, hypotensive, tachycardiac, and delirious. The patient was then intubated and ventilated. His family reported an additional history of acupuncture for back pain, which sustained an inflamed wound on his right forearm. Abdominal computed tomography was performed, which confirmed bilateral iliopsoas abscess without involvement of intra-abdominal organs. A preliminary report of blood culture revealed Gram-positive cocci. Echocardiography showed vegetation on the aortic valve, and moderate aortic regurgitation was sustained. He was started on vancomycin along with piperacillin-tazobactam. Ultrasound-guided percutaneous drainage was inserted into the bilateral abscess. Pus and blood yielded methicillin-sensitive Staphylococcus aureus. He remained septic. The repeat computed tomography showed the right abscess enlarged. A repeated echocardiogram showed that the vegetation increased. Further incision and surgical drainage were performed with continuous wash-out. His condition improved after management and he was discharged to a regional hospital for ongoing care. Prompt diagnosis and surgical treatment are essential to improve patient outcomes. The unique aspect of this case is the persistence of the methicillin-sensitive Staphylococcus aureus infection. Centralized surgical services are pivotal in conjunction with robust antimicrobial regimens. This case reinforces the importance of high clinical suspicion of an unknown source of sepsis.

Intestinal mucositis, systemic inflammation and bloodstream infections following high-dose methotrexate treatment in childhood acute lymphoblastic leukaemia: Comparison between the NOPHO ALL 2008 protocol and the ALLTogether1 protocol.

Severe intestinal mucositis (IM) increases the risk of bloodstream infections (BSI) and inflammatory toxicity during acute lymphoblastic leukaemia (ALL) induction treatment. However, the implications of IM in subsequent ALL therapy phases after achieving remission remain unknown. This study investigated the relationship between IM (measured by plasma citrulline and the chemokine CCL20) and the development of BSI and systemic inflammation (reflected by C-reactive protein, CRP) in children with ALL during high-dose methotrexate (HDMTX) treatment, an important part of ALL consolidation therapy. The study compared patients treated according to the NOPHO ALL 2008 protocol (n = 52) and the ALLTogether1 protocol (n = 42), both with identical HDMTX procedures but different scheduling. One week post-HDMTX, citrulline dropped to median levels of 14.5 and 16.9 μM for patients treated according to the NOPHO ALL 2008 and ALLTogether1 protocols, respectively (p = 0.11). In a protocol and neutrophil count-adjusted analysis, hypocitrullinaemia (<10 μmol/L) was associated with increased odds of BSI within 3 weeks from HDMTX (OR = 26.2, p = 0.0074). Patients treated according to the NOPHO ALL 2008 protocol exhibited increased mucosal- and systemic inflammation post-HDMTX compared to patients treated according to ALLTogether1, with increased CCL20 (14.6 vs. 3.7 pg/mL, p < 0.0001) and CRP levels (10.0 vs. 1.0 mg/L, p < 0.0001). Both citrulline and CCL20 correlated with CRP for these patients (rs = -0.44, p = 0.0016 and rs = 0.35, p = 0.016, respectively). These results suggest that hypocitrullinaemia following HDMTX increases the risk of BSI, confirming previous observations from more intensive treatments. Moreover, these data indicate that the patients' vulnerability to mucositis and inflammatory toxicity after chemotherapy varies with treatment protocol.

COVID-19 Pandemic Increases in Nursing-Sensitive Quality Indicators.

The pandemic profoundly stressed practicing nurses and could have thereby affected trends in nursing-sensitive quality indicators (NSIs), measures that detect changes in patient health status directly affected by nursing care. The aim of the study was to determine if NSIs have worsened in response to the pandemic and then returned to prepandemic levels using data from 2019 through 2022. We conducted a cross-sectional descriptive study of annual trends, examining unit data from the National Database of Nursing Quality Indicators (NDNQI) from 2019 through 2022 for five indicators: rates of falls, central line-associated bloodstream infections (CLABSI), catheter-associated urinary tract infections (CAUTI), hospital-acquired pressure injuries (HAPI), and ventilator-associated events (VAE). The NDNQI is the largest repository of nursing quality indicators, which are derived from patient-level events, reported at the nursing unit level, and submitted quarterly by over 2,000 member hospitals. Adult medical-surgical or critical care inpatient nursing units with complete data for the 4 years were included, with samples ranging from 456 to 5,818 nursing units in 2,346 hospitals. Analysis of variance was conducted by comparing the 2019 rates to each subsequent year. In decreasing order of prevalence, the mean prepandemic rates were 6.58 VAE per 1,000 ventilator days (critical care only), 2.41 HAPI per 1,000 device days, 2.20 falls per 1,000 patient days, 0.96 CAUTI per 1,000 catheter days, and 0.68 CLABSI per 1,000 central line days for medical-surgical and critical care units combined. The rates for all five nurse-sensitive indicators increased significantly beginning in 2020 and have begun to decline but have not returned to baseline by 2022. The maximum rate was observed in 2020 for falls and 2021 for the remaining indicators. These increases to the maximum ranged from a 12% increase in CAUTI to 49% for CLABSI. NSIs increased during the pandemic and are now returning to baseline. The pandemic underscored the importance of nursing practice. The pandemic's enduring negative effects on the nursing workforce must be addressed to preserve patient safety.

Usefulness of central venous catheter replacement with a guidewire in patients with intestinal failure: a single-center study.

Patients with intestinal failure (IF) require long-term parenteral nutrition using central venous catheters (CVCs), which often require replacement. We adopted a less fallible guidewire replacement (GWR) method and verified its effectiveness and validity. We enrolled 108 cases that underwent a CVC replacement with "GWR" method with IF at our department between 2013 and 2023. We retrospectively reviewed patients' clinical details with tunneled CVC (Hickman/Broviac catheter). For the analysis, we compared for the same time period the catheter exchange method "Primary placement"; newly inserted catheter by venipuncture. The success rate of catheter replacement using GWR was 94.4%. There were six unsuccessful cases. A log-rank test showed no significant difference in catheter survival between primary placement and the GWR, and the time to first infection was significantly longer in the GWR (p = 0.001). Furthermore, no significant differences were observed between the two methods until the first infection, when the exchange indication was limited to infections. In the same way, when the indication was restricted to catheter-related bloodstream infection, there was no significant difference in catheter survival between the two approaches. Our GWR procedure was easy to perform and stable, with a high success rate and almost no complications. Moreover, using a guidewire did not increase the frequency of catheter replacement and the infection rate.

Clonal background and routes of plasmid transmission underlie antimicrobial resistance features of bloodstream Klebsiella pneumoniae

Bloodstream infections caused by the opportunistic pathogen Klebsiella pneumoniae are associated with adverse health complications and high mortality rates. Antimicrobial resistance (AMR) limits available treatment options, thus exacerbating its public health and clinical burden. Here, we aim to elucidate the population structure of K. pneumoniae in bloodstream infections from a single medical center and the drivers that facilitate the dissemination of AMR. Analysis of 136 short-read genome sequences complemented with 12 long-read sequences shows the population consisting of 94 sequence types (STs) and 99 clonal groups, including globally distributed multidrug resistant and hypervirulent clones. In vitro antimicrobial susceptibility testing and in silico identification of AMR determinants reveal high concordance (90.44–100%) for aminoglycosides, beta-lactams, carbapenems, cephalosporins, quinolones, and sulfonamides. IncF plasmids mediate the clonal (within the same lineage) and horizontal (between lineages) transmission of the extended-spectrum beta-lactamase gene blaCTX-M-15. Nearly identical plasmids are recovered from isolates over a span of two years indicating long-term persistence. The genetic determinants for hypervirulence are carried on plasmids exhibiting genomic rearrangement, loss, and/or truncation. Our findings highlight the importance of considering both the genetic background of host strains and the routes of plasmid transmission in understanding the spread of AMR in bloodstream infections.

Outcomes of older adults undergoing allogeneic hematopoietic cell transplantation with post-transplant cyclophosphamide based prophylaxis.

This study evaluates the feasibility of using post-transplant cyclophosphamide (PTCY) prophylaxis in allo-hematopoietic cell transplantation (HCT) for adults aged 65 and older. PTCY is increasingly used to prevent graft-versus-host disease (GVHD) across all donor types, but concerns remain about potential risks, especially in older patients. Fifty-seven adults aged 65 or older with hematological malignancies, undergoing their first allo-HCT with PTCY prophylaxis between January 2011 and January 2023 were included. Overall, 94.8% of patients achieved primary engraftment. The median durations for neutrophil and platelet engraftments were 19 and 21 days. The day +30 cumulative incidence of bacterial bloodstream infection was 43.9%. No CMV reactivations occurred within the first 100 days after letermovir implementation. The day +180 cumulative incidences of grade II-IV and III-IV acute GVHD, and the 2-year cumulative incidence of moderate/severe chronic GVHD were 26.3%, 10.5%, and 4.8%. Eighteen patients (31.6%) relapsed, and 30 (52.6%) died, with relapse (16.4%) and infection (11.5%) being the main causes of death. The estimated 2-year overall survival, non-relapse mortality, cumulative incidence of relapse, and GVHD-free relapse-free survival rates were 45.5%, 27.1%, 33.9%, and 37.0%. Adults aged 70 or older had similar outcomes to those aged 65-69. This study confirms the safety and feasibility of PTCY-based allo-HCT in older adults.

Microbial cell-free DNA-sequencing as an addition to conventional diagnostics in neonatal sepsis.

Bloodstream infections remain a challenge for neonatologists, as traditional culture-based methods are time-consuming and rely on adequate blood volume. Next-generation sequencing (NGS) offers an alternative, as it can identify microbial cell-free DNA (mcfDNA) in a small blood sample, providing rapid pathogen detection. This study aimed to assess the diagnostic performance of DISQVER®-NGS compared to blood cultures in neonatal patients with suspected sepsis. In neonates with suspected sepsis, blood cultures and samples for NGS were prospectively collected. Patients were divided into four categories: 1) sepsis, blood culture positive, 2) clinical sepsis, culture negative, 3) suspected sepsis, 4) validation cohort. NGS detected bacterial, viral or fungal mcfDNA in 24 of 82 samples. Blood cultures were collected in 46 of 84 patients (15/46 positive). DISQVER® correctly identified pathogens in 9/15 patients with a positive blood culture, two with intrinsic resistance to their antibiotic regimen. In seven samples NGS reported the mcfDNA of bacteria that could have theoretically grown in culture but did not. NGS may enhance sensitivity in sepsis diagnostics by detecting mcfDNA in neonates with suspected sepsis. Interpreting NGS results requires correlation with clinical data, laboratory values, and routine microbiological tests for a comprehensive understanding of the patient's condition. Conventional blood culture methods have limitations in accuracy and turnaround time. The study aimed to investigate the diagnostic performance of the Next-Generation Sequencing method DISQVER® compared to traditional blood cultures in neonatal patients with suspected sepsis. Our findings suggest that NGS has the potential to augment the precision of conventional diagnostic techniques, can lead to improved detection of pathogens and targeted treatment approaches in neonatal sepsis. It is emphasized that further validation and integration with clinical and microbiological data are required to ensure optimal clinical utility.

A Local Experience of Antibiotic Lock Therapy as an Adjunctive Treatment for Central Venous Catheter-Related Bloodstream Infections in Pediatric Oncology and Hematology Patients.

One of the main drawbacks of tunneled central venous catheters (CVCs) is catheter-related bloodstream infections (CRBSIs). Antibiotic lock therapy (ALT) can be combined with systemic antibiotics to achieve catheter salvage. Our objectives are to describe cases of CRBSI and our experience with ALT in a pediatric oncology-hematology ward. a retrospective descriptive study of pediatric CRBSI cases in a Spanish oncology-hematology unit from 2007 to 2017 was conducted. We collected demographic, clinical, and microbiological data from all patients. fifty-eight CRBSIs were diagnosed in thirty-nine patients; 72.9% of these patients were male, with a median age of 42.1 months. The main underlying diseases were leukemia/lymphoma (51.7%) and solid tumors (32.7%). Thirty-five (60.3%) CRBSIs were caused by Gram-positive cocci, of which 70.6% were coagulase-negative Staphylococci, and sixteen (27.6%) were caused by Gram-negative bacilli. We treated 41/58 (71%) cases with ALT. A total of 12/17 (71%) CVCs that were not treated with adjunctive ALT were removed, compared with 13/41 (32%) that were treated with ALT (relative risk (RR), 0.449; confidence interval (CI), 95%: 0.259-0.778, p = 0.004). Major reasons to remove the CVC in the CRBSI-ALT group were local insertion/pocket site infection (23%), persistent symptoms (23%), and infectious' relapses (15%). ALT was shown to be an effective approach to keeping the CVC in place, with no added adverse effects.

Infections after musculoskeletal injuries in earthquake survivors.

This study aimed to investigate the infections following musculoskeletal injuries in earthquake survivors, offering a future clinical point of reference for the handling of musculoskeletal injuries resulting from earthquakes. In this single-center retrospective observational study, 225 earthquake survivors (120 females, 105 males; median: 39 years; range, 18 to 94 years) admitted between February 2023 and April 2023 were evaluated. Patients with musculoskeletal injuries and patients who had at least one month of follow-up data were included in the study. Diagnosis of healthcare-associated infections was verified by an infection control physician in accordance with the Centers for Disease Control and Prevention. Among all cultures, the most isolated pathogen was Acinetobacter baumannii (49.4%), followed by enterococci (28.6%). Colistin sensitivity of A. baumannii was 36 (94.7%). However, sensitivity rate was 5.3% for ciprofloxacin, 10.5% for piperacillin-tazobactam, and 26.4% for carbapenems, which are frequently used for skin and soft tissue infections. Among all, 76% of the microorganisms isolated from wound culture and 58% of the microorganisms isolated from deep tissue culture were found to be multidrug-resistant pathogens. During the follow-up, 12 (5.3%) patients had hospital-acquired urinary tract infections, 13 (5.7%) patients had hospitalacquired bloodstream infections, one (0.4%) patient had hospital-acquired pneumonia, and 74 (32.8%) patients had surgical site infections. Eighty (35.6%) of the patients were followed up in the intensive care unit, and the overall mortality rate was 2.7%. While gram-positive microorganisms are frequently the causative microorganisms in infections after traumatic injuries, this study revealed that gram-negative microorganisms could be observed more frequently in postearthquake traumatic injuries. Most causative microorganisms are resistant to commonly prescribed antibiotics in clinical settings, which makes them more challenging to treat.

Factors Associated with Poor Clinical and Microbiologic Outcomes in C. auris Bloodstream Infection: A Multicenter Retrospective Cohort Study.

C. auris has become a growing concern worldwide due to increases in incidence of colonization and reports of invasive infections. There are limited data on clinical factors associated with poor outcomes in patients with C. auris bloodstream infection (BSI). We assembled a multicenter retrospective cohort of patients with C. auris BSI from two geographics areas in US healthcare settings. We collected data on demographic, clinical, and microbiologic characteristics to describe the cohort and constructed multivariate logistic regression models to understand risk factors for two clinical outcomes, all-cause mortality during facility admission, and blood culture clearance. Our cohort consisted of 187 patients with C. auris BSI (56.1% male, 55.6% age >65 years); 54.6% died by facility discharge and 66.9% (of 142 with available data) experienced blood culture clearance. Pitt bacteremia score at infection onset was associated with mortality (odds-ratio [95% confidence interval]: 1.19 [1.01,1.40] per 1-point increase). Hemodialysis was associated with a reduced odds of microbiologic clearance (0.15 [0.05,0.43]) and with mortality (3.08 [1.27,7.50]). The Pitt bacteremia score at the onset of C. auris BSI may be a useful tool in identifying patients at risk for mortality. Targeted infection prevention practices in patients receiving hemodialysis may be useful to limit poor outcomes.

Rapid diagnosis of herpes simplex virus 1 and 2 bloodstream infections utilizing a sample-to-answer platform.

Rapid, accurate, and definitive diagnosis of herpes simplex virus (HSV) infections is crucial in clinical settings for patient management. The absence of FDA-authorized molecular assays for HSV-1/2 detection in blood, coupled with a lack of consensus on the optimal sample type, underscores the need for improved diagnostic methods. Furthermore, rapid diagnosis of HSV bloodstream infections enables timely administration of antiviral treatment, influences patient management decisions for those at high risk, and can contribute to shorter hospital stays, thereby reducing healthcare costs.

The bacteriological profile and antimicrobial susceptibility patterns of central line-associated blood stream infections in surgical intensive care unit in Tanta University Hospital

The bacteriological profile and antimicrobial susceptibility patterns of central line-associated blood stream infections in surgical intensive care unit in Tanta University Hospital

Clinical profile and risk factors associated with Elizabethkingia anophelis infection in neonates born in a tertiary care hospital-a case-control study and outbreak investigation.

The objective of this study was to determine the risk factors associated with Elizabethkingia anophelis infection in neonates admitted to a tertiary care neonatal intensive care unit (NICU). A case-control study was undertaken as part of the outbreak investigation for E. anophelis sepsis in a tertiary care NICU in South India. Thirty-eight neonates with E. anophelis bloodstream infection (BSI) between January 2021 and February 2022 were enrolled as cases, and 38 neonates symptomatic with other BSIs, were selected as controls, and risk factors analysed. The 38 cases were relatively stable neonates, likely to be admitted to level 1 and level 2 NICU, unlike the controls, who were sicker and required level 3 NICU care. Only a third of neonates with Elizabethkingia sepsis had traditional risk factors like central lines, need for respiratory support or perinatal risk factors. Multiple logistic regression analysis revealed that neonates with E. anophelis infection were more likely to be stable and on only enteral feeds, cared in level 1 or 2 of the NICU. This observation, combined with isolation of Elizabethkingia meningosepticum from breast pumps earlier, led us to autoclave the feeding vessels and milk containers along with provision of hot water for cleaning breast pumps, and adoption of general infection control measures, after which incident cases declined. Sanger sequencing of 10 representative isolates obtained from the neonates showed 100% sequence identity to E. anophelis. Infection due to E. anophelis affects relatively stable neonates without traditional risk factors for sepsis. Adherence to asepsis routines and housekeeping protocols helps to prevent the spread of infection.

The Etiology of Bloodstream Infections at an Italian Pediatric Tertiary Care Hospital: A 17-Year-Long Series.

Knowledge of epidemiology is essential for guiding correct antibiotic prescription, reducing bacteremia-associated mortality, and implementing targeted infection control programs. However, only a few studies have reported on the epidemiology of bloodstream infections (BSIs) in pediatrics. We performed a retrospective analysis of all BSIs (excluding those caused by common skin contaminants) diagnosed from 2006 to 2022 in patients younger than 18 years who were treated at an Italian pediatric tertiary care hospital. Overall, 2395 BSIs were recorded, including 2207 (92.15%) due to bacteria and 188 (7.85%) due to fungi. The incidence rate (BSIs/10,000 hospital discharges, IR) of bacterial BSIs significantly increased during the study period. In particular, BSIs caused by S. aureus (including MRSA), Enterobacterales (including ESBL and AmpC producers), Enterococcus spp., and P. aeruginosa became more common. The frequency of carbapenem-resistant strains was <1% and stable over time. Conversely, there was a significant reduction in the incidence of BSIs due to S. pneumoniae. The BSIs were stratified by patient age, and S. aureus was the most frequent cause of BSIs in all age groups, while E. coli was the most frequent in the Enterobacterales family. S. agalactiae was the third most frequent cause of neonatal early-onset BSIs. The prevalence of Enterococcus spp. increased in the subgroups from 8 days to 5 years of age, while P. aeruginosa became more prevalent in children over 5 years of age. S. aureus was also the most frequent isolate in both community- and hospital-onset BSIs, followed by E. coli. The prevalence of multidrug-resistant (MDR) pathogens was very low. It was <5% for both Gram-positive (i.e., MRSA and VRE) and Gram-negative (ESBL, AmpC, and carbapenem-resistant) pathogens, and MDR pathogens were almost exclusively detected in hospital-onset BSIs. Fungi accounted for just under 8% of BSIs. C. albicans was the most frequently isolated strain, followed by C. parapsilosis. Notably, the IR of fungemia did not change significantly during the study period, in spite of an increase in the absolute number of events. The continuous monitoring of local epidemiology is essential to identify changes in the IRs of pathogens and antibiotic susceptibility and to guide antibiotic treatments, especially in the phase when antibiograms are not yet available.

Patterns, Outcomes and Economic Burden of Primary vs. Secondary Bloodstream Infections: A Single Center, Cross-Sectional Study.

Bloodstream infections (BSIs) can be primary or secondary, with significant associated morbidity and mortality. Primary bloodstream infections (BSIs) are defined as infections where no clear infection source is identified, while secondary BSIs originate from a localized infection site. This study aims to compare patterns, outcomes, and medical costs between primary and secondary BSIs and identify associated factors. Conducted at the University Hospital of Patras, Greece, from May 2016 to May 2018, this single-center retrospective cohort study included 201 patients with confirmed BSIs based on positive blood cultures. Data on patient characteristics, clinical outcomes, hospitalization costs, and laboratory parameters were analyzed using appropriate statistical methods. Primary BSIs occurred in 22.89% (46 patients), while secondary BSIs occurred in 77.11% (155 patients). Primary BSI patients were younger and predominantly nosocomial, whereas secondary BSI was mostly community-acquired. Clinical severity scores (SOFA, APACHE II, SAPS, and qPitt) were significantly higher in primary compared to secondary BSI. The median hospital stay was longer for primary BSI (21 vs. 12 days, p < 0.001). Although not statistically significant, mortality rates were higher in primary BSI (43.24% vs. 26.09%). Total care costs were significantly higher for primary BSI (EUR 4388.3 vs. EUR 2530.25, p = 0.016), driven by longer hospital stays and increased antibiotic costs. This study underscores the distinct clinical and economic challenges of primary versus secondary BSI and emphasizes the need for prompt diagnosis and tailored antimicrobial therapy. Further research should focus on developing specific management guidelines for primary BSI and exploring interventions to reduce BSI burden across healthcare settings.

Rapid Detection of Staphylococcus Epidermidis Using Electric-Double-Layer (EDL) Field-Effect Transistor (FET) Biosensors with Loop-Mediated Isothermal Amplification

Staphylococcus epidermidis is a Gram-positive bacterium which commonly grows in human skin, nasal passages, respiratory tract, intestinal tract, air, and water. Although it is harmless to healthy individuals, immunocompromised patients are at risk of infection, which can lead to severe symptoms. With the increased reliance on antibiotics in hospitals, the antimicrobial resistance of Staphylococcus epidermidis has also risen, pointing out a challenge in clinical treatment.Therefore, the diagnosis of this bacterium has gained significant attention. The aim of this experiment is to detect bloodstream infections (BSIs) in the shortest possible time. The study is intended to be implemented in hospitals to provide a more convenient method for medical professionals to conduct screenings. The approach involves screening for the most common disease sequence, ssDNA, followed by sequential detection of corresponding cDNA, plasmids, and bacteria. To detect bacteria with the least amount of bacteerial load, a novel isothermal amplification method called Loop-mediated isothermal amplification (LAMP) is employed to increase the concentration of DNA of BSIs bacteria before measurement. The overall time required for this process doesn’t exceed one day, significantly increasing speed for the detection of blood-borne bacteria in hospitals. The core mechanism of this platform involves the use of electric-double-layer-gated field-effect-transistors (EDL-gated FETs) to amplify the gate voltage changes generated when the ssDNA binds with complementary DNA. These voltage changes are then converted into numerical values for analysis and interpretation.Currently, the research results show that this biomedical sensor can detect concentrations ranging from 1fM to 1pM. With the assistance of LAMP, it has successfully achieved a concentration of approximately 1yM (10-24 M) and detected with EDL-gated FETs. The experiment was also carried out step by step on simulated clinical specimens. The experiments have found successful serum nucleic acid amplification methods that provide excellent detection limits. Compared with other biomedical sensors in the past, it not only has lower detection limits but also brings features such as faster, more convenient, and more portable.Keywords: EDL, FET, Staphylococcus epidermidis, Biosensor, LAMP Figure 1

Prevalence and risk factors for haematogenous periprosthetic joint infection during Staphylococcus aureus bacteraemia

Background Staphylococcus aureus bacteraemia (SAB) may lead to periprosthetic joint infections (PJI) via haematogenous spread of bacteria to the joint. Due to the risk of PJI, patients with SAB and prosthetic joint are recommended prolonged antibiotic treatment. The aim of the study was to assess the risk of PJI during SAB, and to evaluate if short treatment duration affects outcomes in patients with uncomplicated SAB and prosthetic joints without clinical signs of PJI. Methods Patients with growth of S. aureus in blood cultures were cross-referenced against the Swedish Arthroplasty register to identify patients with prosthetic hip or knee joints at the time of SAB. Medical records were reviewed to identify PJI at the time of SAB and during a 6-month follow-up period. Results Out of 400 patients with SAB and a prosthetic joint, 281 met all eligibility criteria and were included in the study. Of the included participants, 35 (12%) had a haematogenous PJI. Younger age and presence of multiple prosthetic joints were associated with an increased risk of PJI. Of the 247 patients without signs of PJI at the initial SAB episode, 118 patients (48%) had an uncomplicated infection and received short total antibiotic treatment (median 15 days, IQR 13-17). The risk of PJI during the follow-up period was low (<1%) and similar in the uncomplicated group compared to patients with complicated SAB that received longer antibiotic treatment (median 29 days, IQR 15-70). Conclusion The prevalence of haematogenous PJI was lower than previously reported. Our data do not support prolonged antibiotic treatment in patients with SAB and prosthetic joints without clinical signs of PJI.