The epidemiology of bloodstream infections and antimicrobial susceptibility patterns in Thuringia, Germany: a five-year prospective, state-wide surveillance study (AlertsNet)

Long versus short course anti-MICROBIAL therapy of uncomplicated STAPHYLOCOCCUS aureus bacteraemia: a systematic review

BACKGROUND

Current guidelines recommend at least two weeks duration of antibiotic therapy (DOT) for patients with uncomplicated Staphylococcus aureus bacteraemia (SAB) but the evidence for this recommendation is unclear.

OBJECTIVES

To perform a systematic literature review assessing current evidence for recommended DOT for patients with SAB.

METHODS

Data sources: We searched MEDLINE, ISI Web of Science, the Cochrane Database and clinicaltrials.gov from inception to March 30, 2024. References of eligible studies were screened and experts in the field contacted for additional articles.

STUDY ELIGIBILITY CRITERIA

All clinical studies, regardless of design, publication status and language.

PARTICIPANTS

Adult patients with uncomplicated SAB.

INTERVENTIONS

Long (>14; >18; 11-16 days) vs. short (≤14; 10-18; 6-10 days, respectively) DOT with the DOT being defined as the first until the last day of antibiotic therapy.

ASSESSMENT OF RISK OF BIAS

Risk of bias was assessed using the ROBINS-I-tool.

METHODS OF DATA SYNTHESIS

The primary outcome was 90-day all-cause mortality. Only studies presenting results of adjusted analyses for mortality were included. Data synthesis could not be performed.

RESULTS

Eleven non-randomized studies were identified that fulfilled the predefined inclusion criteria, of which three studies reported adjusted effect ratios. Only these were included in the final analysis. We did not find any RCT. Two studies with 1,230 patients reported the primary endpoint 90-day all-cause mortality. Neither found a statistically significant superiority for longer (>14; 11-16 days) or shorter DOT (≤14; 6-10 days, respectively) for patients with uncomplicated SAB. Two studies investigated the secondary endpoint 30-day all-cause mortality (>18; 11-16 days vs. 10-18; 6-10 days, respectively) and did not find a statistically significant difference. All included studies had a moderate risk of bias.

CONCLUSIONS

Sound evidence that supports any duration of antibiotic treatment for patients with uncomplicated SAB is lacking.

Early treatment response to piperacillin/tazobactam in patients with bloodstream infections caused by non-ESBL ampicillin/sulbactam-resistant Escherichia coli: a binational cohort study

PURPOSE

This study aimed to compare treatment outcomes for bloodstream infections (BSI) caused by a piperacillin/tazobactam (PIP/TAZ)-susceptible E. coli among three patient groups: BSI caused by ampicillin/sulbactam (AMP/SLB)-resistant isolates treated with PIP/TAZ, BSI caused by AMP/SLB-sensitive isolates treated with PIP/TAZ, and BSI caused by AMP/SLB-resistant isolates treated with another monotherapy.

METHODS

This retrospective study was conducted in two academic centres in Europe. Adult patients with E. coli BSI were screened from 2014 to 2020. Inclusion criteria were non-ESBL BSI and initial monotherapy for ≥ 72 h. To reduce the expected bias between the patient groups, propensity score matching was performed. The primary outcome was early treatment response after 72 h and required absence of SOFA score increase in ICU/IMC patients, as well as resolution of fever, leukocytosis, and bacteraemia.

RESULTS

Of the 1707 patients screened, 315 (18.5%) were included in the final analysis. Urinary tract infection was the most common source of BSI (54.9%). Monotherapies other than PIP/TAZ were cephalosporins (48.6%), carbapenems (34.3%), and quinolones (17.1%). Enhanced early treatment response rate was detected (p = 0.04) in patients with BSI caused by AMP/SLB-resistant isolates treated with another monotherapy (74.3%) compared to those treated with PIP/TAZ (57.1%), and was mainly driven by the use of cephalosporins and quinolones (p ≤ 0.03). Clinical success, 28-day mortality, and rate of relapsing BSI did not significantly differ between the groups.

CONCLUSIONS

Our study suggests that initial use of PIP/TAZ may be associated with reduced early treatment response in E. coli BSI caused by AMP/SLB-resistant isolates compared to alternative monotherapies.

Randomised, open-label, non-inferiority clinical trial on the efficacy and safety of a 7-day vs 14-day course of antibiotic treatment for uncomplicated enterococcal bacteraemia: the INTENSE trial protocol

INTRODUCTION

Enterococcus spp is responsible for 8%-15% of total bacteraemias with an associated global mortality around 23%-30%. Regarding the clinical management of enterococcal bacteraemia, the evidence on the duration of antibiotic treatment is scarce and the studies do not discriminate between complicated and uncomplicated bacteraemia.

METHODS

The INTENSE study is a multicentre, open-label, randomised, pragmatic, phase-IV clinical trial to demonstrate the non-inferiority of a 7-day vs 14-day course for the treatment of uncomplicated enterococcal bacteraemia and incorporating the early switching to oral antibiotics when feasible. The primary efficacy endpoint is the clinical cure at day 30±2 after the end of the treatment. Secondary endpoints will include the rate of relapse or infective endocarditis, length of stay, duration of intravenous therapy, Clostridioides difficile infection and the evaluation of the safety of both treatment arms through the recording and analysis of adverse events. For a 6% non-inferiority margin and considering a 5% withdrawal rate, 284 patients will be included.

ANALYSIS

The difference in proportions with one-sided 95% CIs will be calculated for the clinical cure rate using the control group as reference. For secondary categorical endpoints, a similar analysis will be performed and Mann-Whitney U-test will be used to compare median values of quantitative variables. A superiority analysis applying the response adjusted for days of antibiotic risk will be performed if there were incidents in recruitment; will allow obtaining results with 194 patients recruited.

ETHICS AND DISSEMINATION

The study has obtained the authorisation from the Spanish Regulatory Authority, the approval of the ethics committee and the agreement of the directors of each centre. Data will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05394298.

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

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.

Clinical epidemiology and case fatality due to antimicrobial resistance in Germany: a systematic review and meta-analysis, 1 January 2010 to 31 December 2021

BackgroundAntimicrobial resistance (AMR) is of public health concern worldwide.AimWe aimed to summarise the German AMR situation for clinicians and microbiologists.MethodsWe conducted a systematic review and meta-analysis of 60 published studies and data from the German Antibiotic-Resistance-Surveillance (ARS). Primary outcomes were AMR proportions in bacterial isolates from infected patients in Germany (2016-2021) and the case fatality rates (2010-2021). Random and fixed (common) effect models were used to calculate pooled proportions and pooled case fatality odds ratios, respectively.ResultsThe pooled proportion of meticillin resistance in Staphylococcus aureus infections (MRSA) was 7.9% with a declining trend between 2014 and 2020 (odds ratio (OR) = 0.89; 95% CI: 0.886-0.891; p < 0.0001), while vancomycin resistance in Enterococcus faecium (VRE) bloodstream infections increased (OR = 1.18; (95% CI: 1.16-1.21); p < 0.0001) with a pooled proportion of 34.9%. Case fatality rates for MRSA and VRE were higher than for their susceptible strains (OR = 2.29; 95% CI: 1.91-2.75 and 1.69; 95% CI: 1.22-2.33, respectively). Carbapenem resistance in Gram-negative pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Enterobacter spp. and Escherichia coli) was low to moderate (< 9%), but resistance against third-generation cephalosporins and fluoroquinolones was moderate to high (5-25%). Pseudomonas aeruginosa exhibited high resistance against carbapenems (17.0%; 95% CI: 11.9-22.8), third-generation cephalosporins (10.1%; 95% CI: 6.6-14.2) and fluoroquinolones (24.9%; 95% CI: 19.3-30.9). Statistical heterogeneity was high (I2 > 70%) across studies reporting resistance proportions.ConclusionContinuous efforts in AMR surveillance and infection prevention and control as well as antibiotic stewardship are needed to limit the spread of AMR in Germany.

Staphylococcus aureus induces tolerance in human monocytes accompanied with expression changes of cell surface markers

Exposure of human monocytes to lipopolysaccharide (LPS) or other pathogen-associated molecular pattern (PAMPs) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance (ET), associated with the pathogenesis of sepsis. In this study, we aimed to characterize the cellular state of human monocytes from healthy donors stimulated with Staphylococcus aureus in comparison to TLR2-specific ligands. We analyzed S. aureus induced gene expression changes after 2 and 24 hours by amplicon sequencing (RNA-AmpliSeq) and compared the pro-inflammatory response after 2 hours with the response in re-stimulation experiments. In parallel, glycoprotein expression changes in human monocytes after 24 hours of S. aureus stimulation were analyzed by proteomics and compared to stimulation experiments with TLR2 ligands Malp-2 and Pam3Cys and TLR4 ligand LPS. Finally, we analyzed peripheral blood monocytes of patients with S. aureus bloodstream infection for their ex vivo inflammatory responses towards S. aureus stimulation and their glycoprotein expression profiles. Our results demonstrate that monocytes from healthy donors stimulated with S. aureus and TLR ligands of Gram-positive bacteria entered the tolerant cell state after activation similar to LPS treatment. In particular reduced gene expression of pro-inflammatory cytokines (TNF, IL1β) and chemokines (CCL20, CCL3, CCL4, CXCL2, CXCL3 and CXCL8) could be demonstrated. Glycoprotein expression changes in monocytes tolerized by the different TLR agonists were highly similar while S. aureus-stimulated monocytes shared some of the PAMP-induced changes but also exhibited a distinct expression profile. 11 glycoproteins (CD44, CD274, DSC2, ICAM1, LAMP3, LILRB1, PTGS2, SLC1A3, CR1, FGL2, and HP) were similarly up- or downregulated in all four comparisons in the tolerant cell state. Monocytes from patients with S. aureus bacteremia revealed preserved pro-inflammatory responsiveness to S. aureus stimulation ex vivo, expressed increased CD44 mRNA but no other glycoprotein of the tolerance signature was differentially expressed.

Antimicrobial resistance prevalence of Escherichia coli and Staphylococcus aureus amongst bacteremic patients in Africa: a systematic review

OBJECTIVES

Antimicrobial resistance (AMR) is a global concern among infectious diseases. Bloodstream infections can potentially become life-threatening if they become untreatable with conventional antimicrobials. This review aims to provide an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the World Health Organization (WHO) Africa region.

METHODS

PubMed and Google Scholar were searched using relevant keywords for published human studies (excluding case reports and reviews) reporting bacteremic AMR data on the pathogens of interest between 2008 and 2019. Two reviewers independently screened the articles against a pre-defined eligibility criterion. Data extraction and analysis were achieved with different platforms: Covidence, Excel, R version 3.6.3, and QGIS v3.4.5. The pooled prevalence, 95% confidence intervals, and I² index (a measure of heterogeneity) were calculated for the various pathogen-antibiotic combinations.

RESULTS

Five hundred sixty-two papers were retrieved, with 27 papers included in the final analysis. Only 23.4% (11/47) of member states of the WHO African region had reports on AMR in bacteremia. The Clinical and Laboratory Standards Institute (CLSI) (78.5%) was the most common standard used in the region. For E. coli, the pooled resistance was: cefotaxime (42%), imipenem (4%), meropenem (0%), and colistin (0%). For S. aureus, the calculated pooled resistance was cloxacillin (34%), oxacillin (12%), and vancomycin (0%). There was a high degree of variation across studies (I² > 90%).

CONCLUSION

The pooled resistance rates indicate a concerning degree of methicillin-resistant and Extended Spectrum-ß-lactamase-producing pathogens. The paucity of AMR data also presents challenges for a comprehensive understanding of the situation in the region. Continent-wide and standardized surveillance efforts therefore need strengthening.

Short-course versus long-course antibiotic treatment for uncomplicated vancomycin-resistant enterococcal bacteraemia: a retrospective multicentre cohort study

OBJECTIVES

The optimal treatment duration for vancomycin-resistant enterococcal (VRE) bacteraemia is still a matter of debate. The aim of the present study was to compare short-course (≤9 days) and long-course (≥10 days) antibiotic treatments in hospitalized adult patients with uncomplicated VRE bacteraemia.

METHODS

This retrospective study was conducted in four university hospitals in Germany. Adult patients with a positive blood culture for a VRE were screened from 1 January 2016 to 31 December 2018. Only patients who received a VRE-active antibiotic for at least 48 hours were included. The exclusion criteria were a survival of <10 days and a deep-seated source of infection requiring prolonged treatment. To compare the outcome of short-course therapy with that of long-course therapy, 30-day and 90-day overall mortality, relapse within 90 days, duration of hospitalization, and potential antibiotic-related adverse events were analysed by inverse probability of treatment weighting using the propensity score and by additional covariate adjustment.

RESULTS

Of the 363 patients screened, 219 (60.3%) patients were included in the final analysis. Among them, 48 (21.9%) patients had underlying haematological diseases. Seventy-eight (35.6%) patients received short-course treatment (median, 7 days; interquartile range, 5-8 days) and 141 (64.4%) patients received long-course treatment (median, 15 days; interquartile range, 12-23.5 days). Thirty-day mortality was similar in both groups (19.2% vs. 22.0%; adjusted OR, 1.15; p 0.773). Duration of hospitalization (in total and after onset of bacteraemia) was significantly shorter (p < 0.05) in the short-course treatment group, whereas other secondary outcome parameters did not differ between both groups.

DISCUSSION

Our study suggests that short-course treatment might not be associated with a worse outcome in patients with uncomplicated VRE bacteraemia.

Distribution and Antibiotic Resistance Characteristics of Bacteria Isolated from Blood Culture in a Teaching Hospital in Vietnam During 2014-2021

Purpose

Studies on the epidemiology of bloodstream infection (BSI) and antimicrobial resistance (AMR) are limited in Vietnam. Thus, the present study aimed to elucidate the epidemiology of BSI and AMR of BSI-causing bacteria in Vietnam.

Methods

Data regarding blood cultures from 2014 to 2021 were collected and analyzed using the chi-square test, Cochran-Armitage test, and binomial logistic regression model.

Results

Overall, 2405 (14.15%) blood cultures were positive during the study period. In total, 55.76% of BSIs occurred in patients aged ≥60 years. The male-to-female ratio of patients with BSI was 1.87:1. Escherichia coli (26.11%), Staphylococcus aureus (15.79%), Klebsiella pneumoniae (10.44%), Acinetobacter baumannii (4.70%), and Pseudomonas aeruginosa (3.45%) were the leading bacterial species causing BSI. The AMR rate of these bacteria isolated in the intensive care unit (ICU) was significantly higher compared with that of those in other wards. E. coli was the least resistant to carbapenems (2.39%-4.14%), amikacin (3.85%), and colistin (11.54%) and most resistant to penicillins (>80.0%). S. aureus was the least resistant to glycopeptides (0%-3.38%), quinupristin-dalfopristin (0.59%), and linezolid (1.02%) and most resistant to clindamycin (71.57%). K. pneumoniae was the least resistant to ertapenem (8.86%), amikacin (9.39%), and colistin (15.38%) and most resistant to aztreonam (83.33%). A. baumannii was the least resistant to amikacin (16.67%) and colistin (16.67%) and highly resistant to other antibiotics (≥50.0%). P. aeruginosa was the least resistant to colistin (16.33%) and piperacillin (28.17%) and highly resistant to other antibiotics (≥50.0%). Notably, the multidrug resistance rate of E. coli (76.41%) was the highest among common pathogens, followed by A. baumannii (71.57%), P. aeruginosa (64.56%), S. aureus (56.99%), and K. pneumoniae (43.72%).

Conclusion

The AMR rate of BSI-causing bacteria, particularly strains isolated from ICU, was alarmingly high. There is a need for new antibiotics, therapeutic strategies, as well as prevention and control to combat BSI and AMR.

Trends of Bloodstream Infections in a University Hospital During 12 Years

This study aims to investigate trends in bloodstream infections and their antimicrobial susceptibility profiles over 12 years in our hospital. This retrospective study was carried out in the Bursa Uludag University Hospital, Turkey, during 2008–2019. Blood cultures from patients were performed using BACTEC System. Isolates were identified with Phoenix System until 2018 and “matrix-assisted laser desorption ionization time-of-flight mass spectrometry” (MALDI-TOF MS) in 2019. Antibiotic susceptibility testing was performed with Phoenix System. Patient data came from the BD EpiCenter™ data management system. Escherichia coli was found to be the most common Gram-negative (11.6%), and coagulase-negative staphylococci were the most common Gram-positive (10.1%) monomicrobial growth. Overall, there was a significant increase in rates of extended-spectrum β-lactamase positive E. coli (p = 0.014) and Klebsiella pneumonia (p < 0.001), carbapenem-resistant E. coli (p < 0.001), and K. pneumoniae (p < 0.001) and colistin-resistant K. pneumoniae (p < 0.001) and Acinetobacter baumannii (p < 0.001) over 12 years. Carbapenem and colistin resistance has increased dramatically in recent years. We believe that regular monitoring of the distribution of pathogens and antibiotic susceptibility profiles, especially in intensive care units, can contribute to evidence for the increase in resistant microorganisms and help prevent their spread with antimicrobial stewardship and infection control policies.

Causative agents of bloodstream infections in two Croatian hospitals and their resistance mechanisms

Blood samples were collected alongside with routine blood cultures (BC) from patients with suspected sepsis, to evaluate the prevalence of different causative agents in patients with bacteraemia. Among 667 blood samples, there were 122 positive BC (18%). Haemoglobin content, platelet number, and systolic blood pressure values were significantly lower in patients with positive BC, whereas serum lactate levels, CRP, creatinine and urea content were significantly higher in patients with positive BC. The rate of multidrug (MDR) or extensively drug resistant (XDR) bacteria was 24% (n = 29): Klebsiella pneumoniae (9), Pseudomonas aeruginosa (9), Acinetobacter baumannii (4), Escherichia coli (1), vancomycin resistant Enterococcus spp (VRE) (3), and methicillin-resistant Staphylococcus aureus MRSA (3). The dominant resistance mechanisms were the production of extended-spectrum β-lactamases, OXA-48 carbapenemase, and colistin resistance in K. pneumoniae, VIM metallo-β-lactamases in P. aeruginosa and OXA-23-like oxacillinases in A. baumannii. The study revealed high rate of MDR strains among positive BCs in Zagreb, Croatia.

Effect of Automated Telephone Infectious Disease Consultations to Nonacademic Hospitals on 30-Day Mortality Among Patients With Staphylococcus aureus Bacteremia: The SUPPORT Cluster Randomized Clinical Trial

IMPORTANCE

Staphylococcus aureus bacteremia (SAB) is a common and potentially severe infectious disease (ID). Retrospective studies and derived meta-analyses suggest that bedside infectious disease consultation (IDC) for SAB is associated with improved survival; however, such IDCs might not always be possible because of the lack of ID specialists, particularly at nonacademic hospitals.

OBJECTIVES

To investigate whether unsolicited telephone IDCs (triggered by an automated blood stream infection reporting system) to nonacademic hospitals improved 30-day all-cause mortality in patients with SAB.

DESIGN, SETTING, AND PARTICIPANTS

This patient-blinded, multicenter, interventional, cluster randomized, controlled, crossover clinical trial was conducted in 21 rural, nonacademic hospitals in Thuringia, Germany. From July 1, 2016, to December 31, 2018, 1029 blood culture reports were assessed for eligibility. A total of 386 patients were enrolled, whereas 643 patients were not enrolled for the following reasons: death before enrollment (n = 59); palliative care (n = 41); recurrence of SAB (n = 9); discharge from the hospital before enrollment (n = 77); age younger than 18 years (n = 5); duplicate report from a single patient (n = 26); late report (n = 17); blood culture reported during the washout phase (n = 48); and no signed informed consent for other or unknown reasons (n = 361).

INTERVENTIONS

During the ID intervention phase, ID specialists from Jena University Hospital provided unsolicited telephone IDCs to physicians treating patients with SAB. During the control phase, patients were treated according to local standards. Crossover was performed after including 15 patients or, at the latest, 1 year after the first patient was included.

MAIN OUTCOMES AND MEASURES

Thirty-day all-cause mortality.

RESULTS

A total of 386 patients (median [IQR] age, 75 [63-82] years; 261 [67.6%] male) were included, with 177 randomized to the IDC group and 209 to the control group. The 30-day all-cause mortality rate did not differ between the IDC and control groups (relative risk reduction [RRR], 0.12; 95% CI, -2.17 to 0.76; P = .81). No evidence was found of a difference in secondary outcomes, including 90-day mortality (RRR, 0.17; 95% CI, -0.59 to 0.57; P = .62), 90-day recurrence (RRR, 0.10; 95% CI, -2.51 to 0.89; P = .89), and hospital readmission (RRR, 0.04; 95% CI, -0.63 to 0.48; P = .90). Exploratory evidence suggested that indicators of quality of care were potentially realized more often in the IDC group than in the control group (relative quality improvement, 0.16; 95% CI, 0.08-0.26; P = .01).

CONCLUSIONS AND RELEVANCE

In this cluster randomized clinical trial, unsolicited telephone IDC, although potentially enhancing quality of care, did not improve 30-day all-cause mortality in patients with SAB.

TRIAL REGISTRATION

drks.de Identifier: DRKS00010135.

In Vitro Synergy of Isavuconazole Combined With Colistin Against Common Candida Species

Interactions of isavuconazole and colistin were evaluated against 57 common Candida strains belonging to the species Candida albicans (n = 10), Candida glabrata (n = 10), Candida kefyr (n = 8), Candida krusei (n = 10), Candida parapsilosis (n = 9), and Candida tropicalis (n = 10) by a broth microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference methodology for antifungal susceptibility testing. Results were analyzed with the fractional inhibitory concentration index and by the response surface analysis. Interpretation by the fractional inhibitory concentration index showed synergy for 50%, 80%, 90%, and 90% of the C. kefyr, C. krusei, C. glabrata, and C. tropicalis strains, respectively. Combination of isavuconazole with colistin against C. albicans and C. parapsilosis exhibited only indifference for 100% and 90% of the strains, respectively. The results were confirmed by response surface analysis for all species except for C. glabrata, for which an indifferent interaction was found for the majority of strains. Antagonistic interaction was never seen regardless of the interpretation model was used.

Clinical and microbiological characteristics of polymicrobial bacteremia: a retrospective, multicenter study

PURPOSE

To clarify the clinical and microbial characteristics of polymicrobial bacteremia (PMB) to contribute to improvements in clinical diagnosis and effective early treatment.

METHODS

This retrospective multicenter study used data from three acute-care hospitals in Okayama Prefecture, Japan, collected between January 2014 and March 2019. We reviewed the demographics, comorbidities, organisms isolated, infectious focus, and 30-day mortality of patients with PMB.

RESULTS

Of the 7233 positive blood cultures, 808 (11.2%) were positive for more than one organism. Of the patients with bacteremia, 507 (7.0%) had PMB, of whom 65.3% were male. Infectious foci were identified in 78.3% of the cases, of which intra-abdominal infections accounted for 47.1%. A combination of Gram-positive cocci (GPC) (chain form) and Gram-negative rods (GNR) accounted for 32.9% of the cases, and GPC/GNR and GNR/GNR patterns were significantly associated with intra-abdominal infections. The 30-day mortality rate of patients with PMB was 18.1%, with a median of 7.5 days from diagnosis to death. The mortality in patients with an infectious focus identified was significantly lower than that in patients with an unknown focus (16.3% vs. 24.5%; p = 0.031).

CONCLUSIONS

Intra-abdominal infections were the most common source of PMB, and were strongly associated with a Gram-staining combination pattern of GPC (chain form)/GNR. PMB cases with an unknown focus had a poorer prognosis, highlighting the importance of early diagnosis and appropriate treatment.

Single-site sampling versus multi-site sampling for blood cultures; A retrospective clinical study

Objectives The performance of blood cultures (BC) relies on optimal sampling. Sepsis guidelines do not specify which sampling protocol to use, but recommend two sets of BC bottles, each set containing one aerobic and one anaerobic bottle. For the single-site sampling (SSS) protocol, only one venipuncture is performed for all four bottles. The predominating multi-site sampling (MSS) protocol implies that BC bottles are collected from two separate venipuncture sites. The aim of this study was to compare SSS and MSS. Primary outcomes were number of BC sets collected, sample volume and diagnostic performance. Methods This was a retrospective clinical study comparing BC results in an emergency department before and after changing the sampling protocol to SSS from MSS. All BC samples were incubated in the BacT/ALERT BC system. Results The analysis included 5,248 patients before and 5,364 patients after the implementation of SSS. There was a significantly higher proportion of positive BCs sampled with SSS compared to MSS, 1,049/5,364 (19.56%) and 932/5,248 (17.76%) respectively (P=0.018). This difference was due to a higher proportion of solitary BC sets (two BC bottles) in MSS. Analyzing only patients with the recommended four BC bottles, there was no difference in positivity. SSS had a higher proportion of BC bottles with the recommended sample volumes of 8-12 ml than MSS (P<0.001). Conclusions Changing the sampling protocol to SSS from MSS resulted in higher positivity rates, higher sample volume and fewer solitary BC sets. These advantages of SSS should be considered in future sepsis guidelines.