Incidence, risk factors and outcomes of Escherichia coli bloodstream infections in a large Canadian region

Risk of myocardial infarction and stroke following bloodstream infection: a population-based self-controlled case series

BACKGROUND

Cardiovascular disease (CVD) events triggered by inflammation are an underappreciated and poorly quantified cause of morbidity and mortality in patients with bloodstream infections (BSIs). We aimed to determine the risk of myocardial infarction (MI) and stroke after BSI.

METHODS

This self-controlled case series study was conducted within the Secure Anonymised Information Linkage Databank, containing anonymised population-scale electronic health record data for Wales, UK. We included adults with community-acquired BSI between 2010 and 2020. MI and stroke were determined from International Classification of Disease Version 10 coded admissions. Predefined risk periods after BSI were compared with the baseline period using pseudo-Poisson regression adjusted for age. Maximum C-reactive protein (CRP), a proxy for the magnitude of the inflammatory response, was determined within the first 7 days after BSI.

RESULTS

We identified 50 450 individuals with MI and 56 890 with stroke, of whom 1000 and 1290, respectively, also had at least one community-associated BSI. The risk of MI was most elevated in the first 1-7 days after BSI (adjusted incidence rate ratio (IRR) (95% CI): 9.67 (6.54 to 14.3)) and returned to baseline after 28 days. The risk was similarly elevated for stroke.The largest magnitude of risk was observed for those with a maximal CRP>300 mg/L (MI IRR: 21.54 (9.57 to 48.52); stroke IRR: 6.94 (3.14 to 15.32)).

CONCLUSION

BSI is associated with an increased risk of CVD events in the first 2 weeks after infection. Greater systemic inflammation was associated with a higher risk of CVD events and suggests targeting the inflammatory response caused by BSI warrants further study.

Epidemiology of invasive Escherichia coli disease in adults in England, 2013-2017

Extraintestinal pathogenic Escherichia coli (ExPEC) causes invasive E. coli disease (IED), including bacteraemia and (uro)sepsis, resulting in a high disease burden, especially among older adults. This study describes the epidemiology of IED in England (2013-2017) by combining laboratory surveillance and clinical data. A total of 191 612 IED cases were identified. IED incidence increased annually by 4.4-8.2% across all ages and 2.8-7.6% among adults ≥60 years of age. When laboratory-confirmed urosepsis cases without a positive blood culture were included, IED incidence in 2017 reached 149.4/100 000 person-years among all adults and 368.4/100 000 person-years among adults ≥60 years of age. Laboratory-confirmed IED cases were identified through E. coli-positive blood samples (55.3%), other sterile site samples (26.3%), and urine samples (16.6%), with similar proportions observed among adults ≥60 years of age. IED-associated case fatality rates ranged between 11.8-13.2% among all adults and 13.1-14.7% among adults ≥60 years of age. This study reflects the findings of other published studies and demonstrates IED constitutes a major and growing global health concern disproportionately affecting the older adult population. The high case fatality rates observed despite available antibiotic treatments emphasize the growing urgency for effective intervention strategies. The burden of urosepsis due to E. coli is likely underestimated and requires additional investigation.

Prevalence of Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli in Humans, Food, and Environment in Kathmandu, Nepal: Findings From ESBL E. coli Tricycle Project

The need to address antimicrobial resistance (AMR) through a One Health (OH) approach is now well recognized. There is, however, limited guidance on how AMR surveillance should be implemented across sectors to generate meaningful AMR and AMU data for decision-making. Using a sympatric approach to cross-sector sample collection, Nepal adopted the WHO extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) Tricycle Project as a step toward OH surveillance for assessing the prevalence of ESBL-producing E. coli across human, veterinary, and environment sectors. This involved a three-stage approach: identification of human hotspots (Stage 1) and sample collection sites for poultry (Stage 2) and wastewater (Stage 3). A total of 53 blood cultures from patients with bloodstream infections (BSIs), 100 stool samples from healthy pregnant women, 220 poultry ceca from slaughterhouses and live markets, and 48 wastewater samples were processed for bacterial culture and analyzed for the presence of ESBL-producing E. coli. The prevalence of ESBL-producing E. coli among isolated E. coli was the highest in wastewater samples (91%) followed by human BSIs (49%), poultry (38.6%), and fecal carriage isolates from healthy pregnant females (15%). A statistically significant association was seen in the prevalence of multidrug resistance among ESBL producers (52%) and nonproducers (26%). ESBL-producing E. coli was detected in all wastewater samples tested except for the upstream river. The findings of the study showed a high prevalence of ESBL-producing E. coli in samples from all three sectors and provided baseline data based upon which strategies for the safe disposal of communal and hospital waste, integrated AMR surveillance, and control strategies could be planned and implemented.

Evaluating the costs of Escherichia coli bloodstream infections: a population-based cohort study in a large metropolitan Canadian region

Objectives

We evaluated the costs of susceptible and resistant Escherichia coli bloodstream infections (BSIs) in adults. Secondary outcomes were the impact of BSI on length of stay (LOS), readmissions and death.

Methods

We examined a population-based retrospective cohort of blood cultures from 2011 to 2018 in Calgary, Canada, linked to microcosting and gross costing data. Propensity score matching was completed, and costs were compared between no BSI and E. coli BSI over 90 days using linear regression.

Results

A total of 4581 BSIs in 89 673 adults experienced E. coli bacteraemia during the study period. The mean cost of an E. coli BSI at 90 days was $39 072 (SD: $95 747) in adults. Ceftriaxone-resistant (CRO-R) E. coli, resistant to fluoroquinolones (FQ) and trimethoprim/sulfamethoxazole, compared with susceptible E. coli BSI resulted in the greatest mean cost at $53 899 and the highest odds of readmission, increased LOS, and death.

Conclusions

E. coli BSI is associated with substantial costs. Total cost differences were highest in those with CRO-R E. coli with resistance to FQ and trimethoprim/sulfamethoxazole. Over the study period, bacteraemia secondary to these strains alone, added over $9 million to costs for healthcare in the Calgary Zone.

Frequency of antimicrobial-resistant bloodstream infections in 111 hospitals in Thailand, 2022

OBJECTIVES

To evaluate the frequency of antimicrobial-resistant bloodstream infections (AMR BSI) in Thailand.

METHODS

We analyzed data from 2022, generated by 111 public hospitals in health regions 1 to 12, using the AutoMated tool for Antimicrobial resistance Surveillance System (AMASS), and submitted to the Ministry of Public Health, Thailand. Multilevel Poisson regression models were used.

RESULTS

The most common cause of community-origin AMR BSI was third-generation cephalosporin-resistant Escherichia coli (3GCREC, 65.6%; 5101/7773 patients) and of hospital-origin AMR BSI was carbapenem-resistant Acinetobacter baumannii (CRAB, 51.2%, 4968/9747 patients). The percentage of patients tested for BSI was negatively associated with the frequency of community-origin 3GCREC BSI and hospital-origin CRAB BSI (per 100,000 tested patients). Hospitals in health regions 4 (lower central region) had the highest frequency of community-origin 3GCREC BSI (adjusted incidence rate ratio, 2.06; 95% confidence interval: 1.52-2.97). Health regions were not associated with the frequency of hospital-origin CRAB BSI, and between-hospital variation was high, even adjusting for hospital level and size.

CONCLUSION

The high between-hospital variation of hospital-origin CRAB BSI suggests the importance of hospital-specific factors. Our approach and findings highlight health regions and hospitals where actions against AMR infection, including antimicrobial stewardship and infection control, should be prioritized.

A microbiological and genomic perspective of globally collected Escherichia coli from adults hospitalized with invasive E. coli disease

OBJECTIVES

Escherichia coli can cause infections in the urinary tract and in normally sterile body sites leading to invasive E. coli disease (IED), including bacteraemia and sepsis, with older populations at increased risk. We aimed to estimate the theoretical coverage rate by the ExPEC4V and 9V vaccine candidates. In addition, we aimed at better understanding the diversity of E. coli isolates, including their genetic and phenotypic antimicrobial resistance (AMR), sequence types (STs), O-serotypes and the bacterial population structure.

METHODS

Blood and urine culture E. coli isolates (n = 304) were collected from hospitalized patients ≥60 years (n = 238) with IED during a multicentric, observational study across three continents. All isolates were tested for antimicrobial susceptibility, O-serotyped, whole-genome sequenced and bioinformatically analysed.

RESULTS

A large diversity of STs and of O-serotypes were identified across all centres, with O25b-ST131, O6-ST73 and O1-ST95 being the most prevalent types. A total of 45.4% and 64.7% of all isolates were found to have an O-serotype covered by the ExPEC4V and ExPEC9V vaccine candidates, respectively. The overall frequency of MDR was 37.4% and ST131 was predominant among MDR isolates. Low in-patient genetic variability was observed in cases where multiple isolates were collected from the same patient.

CONCLUSIONS

Our results highlight the predominance of MDR O25b-ST131 E. coli isolates across diverse geographic areas. These findings provide further baseline data on the theoretical coverage of novel vaccines targeting E. coli associated with IED in older adults and their associated AMR levels.

Presence of carbapenem resistance in hybrid Escherichia coli pathovars from ready-to-eat fresh-cut fruits in Accra, Ghana

AIM

This study reports the presence of carbapenem-resistant Escherichia coli hybrid pathovars and its prevalence in 200 fresh-cut fruits from Accra.

METHODS AND RESULTS

Standard culture methods were used to quantify microbial indicators and E. coli on fresh-cut fruits retailed in formal and informal outlets in Accra. The Kirby-Bauer disc diffusion method was used to determine the antibiotic resistance profile of E. coli, while multiplex PCR was employed to identify the virulence and carbapenem-resistance genes. Escherichia coli prevalence in cut fruits was 17%, with pawpaw, watermelon, and mixed fruit having higher prevalence than pineapple. Of the 34 E. coli isolates from fresh-cut fruits, 44% showed broad resistance to beta-lactam antibiotics, while 5.9% showed carbapenem resistance. The study identified virulence genes associated with all E. coli isolates, including stx1, stx2, escV, and ipaH, of which 97% were hybrid pathovars bearing genes for Shiga toxin-producing E. coli/enteropathogenic E. coli/enteroinvasive E. coli. The carbapenemase gene, blaIMP, was associated with both carbapenem-resistant E. coli phenotypes identified.

CONCLUSION

Despite a low-carbapenem-resistance prevalence observed among E. coli isolates, hypervirulent hybrid strains of E. coli is present in fresh-cut fruits in the sampling area, posing a potential public health risk to fresh-cut fruit consumers.

Genomic Dissection of an Enteroaggregative Escherichia coli Strain Isolated from Bacteremia Reveals Insights into Its Hybrid Pathogenic Potential

Escherichia coli is a frequent pathogen isolated from bloodstream infections. This study aimed to characterize the genetic features of EC092, an E. coli strain isolated from bacteremia that harbors enteroaggregative E. coli (EAEC) genetic markers, indicating its hybrid pathogenic potential. Whole-genome sequencing showed that EC092 belongs to phylogroup B1, ST278, and serotype O165:H4. Genes encoding virulence factors such as fimbriae, toxins, iron-uptake systems, autotransporter proteins (Pet, Pic, Sat, and SepA), and secretion systems were detected, as well as EAEC virulence genes (aggR, aatA, aaiC, and aap). EC092 was found to be closely related to the other EAEC prototype strains and highly similar in terms of virulence to three EAEC strains isolated from diarrhea. The genomic neighborhood of pet, pic, sat, sepA, and the EAEC virulence genes of EC092 and its three genetically related fecal EAEC strains showed an identical genomic organization and nucleotide sequences. Also, EC092 produced and secreted Pet, Pic, Sat, and SepA in the culture supernatant and resisted the bactericidal activity of normal human serum. Our results demonstrate that the strain EC092, isolated from bacteremia, is a hybrid pathogenic extraintestinal E. coli (ExPEC)/EAEC with virulence features that could mediate both extraintestinal and intestinal infections.

Global burden associated with 85 pathogens in 2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Despite a global epidemiological transition towards increased burden of non-communicable diseases, communicable diseases continue to cause substantial morbidity and mortality worldwide. Understanding the burden of a wide range of infectious diseases, and its variation by geography and age, is pivotal to research priority setting and resource mobilisation globally.

METHODS

We estimated disability-adjusted life-years (DALYs) associated with 85 pathogens in 2019, globally, regionally, and for 204 countries and territories. The term pathogen included causative agents, pathogen groups, infectious conditions, and aggregate categories. We applied a novel methodological approach to account for underlying, immediate, and intermediate causes of death, which counted every death for which a pathogen had a role in the pathway to death. We refer to this measure as the burden associated with infection, which was estimated by combining different sources of information. To compare the burden among all pathogens, we used pathogen-specific ratios to incorporate the burden of immediate and intermediate causes of death for pathogens modelled previously by the GBD. We created the ratios by using multiple cause of death data, hospital discharge data, linkage data, and minimally invasive tissue sampling data to estimate the fraction of deaths coming from the pathway to death chain. We multiplied the pathogen-specific ratios by age-specific years of life lost (YLLs), calculated with GBD 2019 methods, and then added the adjusted YLLs to age-specific years lived with disability (YLDs) from GBD 2019 to produce adjusted DALYs to account for deaths in the chain. We used standard GBD methods to calculate 95% uncertainty intervals (UIs) for final estimates of DALYs by taking the 2·5th and 97·5th percentiles across 1000 posterior draws for each quantity of interest. We provided burden estimates pertaining to all ages and specifically to the under 5 years age group.

FINDINGS

Globally in 2019, an estimated 704 million (95% UI 610-820) DALYs were associated with 85 different pathogens, including 309 million (250-377; 43·9% of the burden) in children younger than 5 years. This burden accounted for 27·7% (and 65·5% in those younger than 5 years) of the previously reported total DALYs from all causes in 2019. Comparing super-regions, considerable differences were observed in the estimated pathogen-associated burdens in relation to DALYs from all causes, with the highest burden observed in sub-Saharan Africa (314 million [270-368] DALYs; 61·5% of total regional burden) and the lowest in the high-income super-region (31·8 million [25·4-40·1] DALYs; 9·8%). Three leading pathogens were responsible for more than 50 million DALYs each in 2019: tuberculosis (65·1 million [59·0-71·2]), malaria (53·6 million [27·0-91·3]), and HIV or AIDS (52·1 million [46·6-60·9]). Malaria was the leading pathogen for DALYs in children younger than 5 years (37·2 million [17·8-64·2]). We also observed substantial burden associated with previously less recognised pathogens, including Staphylococcus aureus and specific Gram-negative bacterial species (ie, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Helicobacter pylori). Conversely, some pathogens had a burden that was smaller than anticipated.

INTERPRETATION

Our detailed breakdown of DALYs associated with a comprehensive list of pathogens on a global, regional, and country level has revealed the magnitude of the problem and helps to indicate where research funding mismatch might exist. Given the disproportionate impact of infection on low-income and middle-income countries, an essential next step is for countries and relevant stakeholders to address these gaps by making targeted investments.

FUNDING

Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care using UK aid funding managed by the Fleming Fund.

Modelling the implementation of narrow versus broader spectrum antibiotics in the empiric treatment of E. coli bacteraemia

The implementation of new antimicrobial resistance stewardship programs is crucial in optimizing antibiotic use. However, prescription choices can be difficult during empiric therapy; clinicians must balance the survival benefits of broader spectrum antibiotics with associated increases in resistance. The aim of this study was to evaluate the overall feasibility of switching to narrow spectrum antibiotics during the empiric treatment of E. coli bacteraemia by quantifying changes in resistance rates, antibiotic usage, and mortality using a deterministic state-transition model. Three unique model scenarios (A, B, and C), each representing a progressively broader spectrum empiric treatment regimen, were used to compare outcomes at 5 years. We show that the empiric use of the narrowest spectrum (first-line) antibiotics can lead to reductions in resistance to second-line antibiotics and the use of third-line antibiotics, but they also lead to increases in resistance to first-line therapy and higher mortality. Crucially, we find that shortening the duration of empiric and overall treatment, as well as reducing the baseline mortality rate, are important for increasing the feasibility of switching to narrow spectrum antibiotics in the empiric treatment of E. coli bacteraemia. We provide a flexible model design to investigate optimal treatment approaches for other bacterial infections.

Characterization and Antimicrobial Susceptibility Patterns of Enterococcus Species Isolated from Nosocomial Infections in a Saudi Tertiary Care Hospital over a Ten-Year Period (2012-2021)

INTRODUCTION

The Enterococcus genus is a common cause of nosocomial infections, with vancomycin-resistant enterococci (VRE) posing a significant treatment challenge.

METHOD

This retrospective study, spanning ten years (2012 to 2021), analyzes antimicrobial susceptibility patterns of Enterococcus species from clinical samples in a Saudi Arabian tertiary care hospital.

RESULT

A total of 1034 Enterococcus isolates were collected, 729 from general wards and 305 from intensive care unit (ICU) patients. VRE accounted for 15.9% of isolates. E. faecalis was the most common species (54.3% of isolates and 2.7% of VRE), followed by E. faecium (33.6% of isolates and 41.2% of VRE). E. faecium exhibited the highest resistance to ciprofloxacin (84.1%), ampicillin (81.6%), and rifampicin (80%), with daptomycin (0.6%) and linezolid (3.1%) showing the lowest resistance. In E. faecalis, ciprofloxacin resistance was highest (59.7%), followed by rifampicin (20.1%) and ampicillin (11.8%). Daptomycin (0%), linezolid (1.5%), and vancomycin (2.7%) had the lowest resistance. VRE cases had higher mortality rates compared to vancomycin-sensitive enterococci (VSE).

CONCLUSION

Eight different strains of Enterocci were identified. E. faecalis was the most commonly identified strain, while E. faecium had the highest percentage of VRE. VRE cases had a significantly higher mortality rate than VSE cases.

All-cause and Infection-attributable Mortality Amongst Adults With Bloodstream Infection-a Population-based Study

Background

Bloodstream infections (BSIs) are common, life-threatening infections. However, it remains unclear whether deaths following BSIs are primarily from uncontrolled infection or underlying comorbidities. We aimed to determine the overall mortality, infection-attributable mortality, and causes of death for four leading BSI pathogens.

Methods

This retrospective cohort study was conducted within the Secure Anonymized Information Linkage Databank, containing anonymized population-scale electronic health record data for Wales, UK. We included adults with Escherichia coli, Klebsiella spp, Pseudomonas aeruginosa, and Staphylococcus aureus BSI between 2010 and 2022 using linked data from Public Health Wales and the Office for National Statistics. Thirty-day all-cause and sepsis-specific mortality, as a proxy for infection-attributable mortality, were compared using Cox proportional hazards and competing risk regression, respectively.

Results

We identified 35 691 adults with BSI (59.6% E coli). Adjusted analyses revealed that all organisms had a higher 30-day mortality versus E coli with Pseudomonas aeruginosa the highest (hazard ratio, 1.96 [1.76-2.17], P < .001). Cancer was the leading cause of death following BSIs for all organisms, particularly deaths occurring between 30 and 90 days (35.9%). A total of 25.5% of deaths within 30 days involved sepsis. Methicillin-resistant Staphylococcus aureus was associated with the highest sepsis mortality versus E coli (hazard ratio, 2.56 [2.10-3.12], P < .001). Peak C-reactive protein was positively associated with increased sepsis mortality (P < .001).

Conclusions

This population-level study challenges the assumption that most deaths following BSIs are directly attributable to uncontrolled infection, particularly subacutely more than 30 days from BSI. Our findings underscore the need for reevaluating clinical trial design and developing better preventive strategies for BSIs.

Sex- and Gender-Based Analysis on Norepinephrine Use in Septic Shock: Why Is It Still a Male World?

Sex and gender are fundamental health determinants and their role as modifiers of treatment response is increasingly recognized. Norepinephrine is a cornerstone of septic shock management and its use is based on the highest level of evidence compared to dopamine. The related 2021 Surviving Sepsis Campaign (SCC) recommendation is presumably applicable to both females and males; however, a sex- and gender-based analysis is lacking, thus not allowing generalizable conclusions. This paper was aimed at exploring whether sex- and gender-disaggregated data are available in the evidence supporting this recommendation. For all the studies underpinning it, four pairs of authors, including a woman and a man, extracted data concerning sex and gender, according to the Sex and Gender Equity in Research guidelines. Nine manuscripts were included with an overall population of 2126 patients, of which 43.2% were females. No sex analysis was performed and gender was never reported. In conclusion, the present manuscript highlighted that the clinical studies underlying the SCC recommendation of NE administration in septic shock have neglected the likely role of sex and gender as modifiers of treatment response, thus missing the opportunity of sex- and gender-specific guidelines.

Population-based genomic surveillance of Pseudomonas aeruginosa causing bloodstream infections in a large Canadian health region

PURPOSE

Population-based surveillance was undertaken to determine clinical factors, susceptibility patterns, and incidence rates (IR) of Pseudomonas aeruginosa causing bloodstream infections (BSIs) in a Canadian region (2010-2018).

METHODS

We combined clinical data with genomics to characterize P. aeruginosa (BSIs) (n = 167) in a well-defined Canadian (Calgary) human population over a 9-year period (2010-2018).

RESULTS

The annual population IR per 100,000 patient years increased from 3.4/100,000 in 2010 to 5.9/100,000 in 2018, with the highest IRs in elderly males from the hospital setting. Over a quarter of patients presented with febrile neutropenia, followed by urinary tract infections and pneumonia. Antimicrobial resistance (AMR) rates and determinants were rare. The P. aeruginosa population was polyclonal consisting of three dominant sequence types (STs), namely ST244, ST111, and ST17. Antimicrobial-susceptible ST244 was the most common clone and belonged to three clades (A, B, C). The ST244 IR/100,000 increased over time due to the expansion of clade C. Multidrug-resistant ST111 was the second most common clone and IR/100,000 decreased over time. ST111 belonged to three clades (A, B, C) with clade C containing blaVIM-2. Different serotypes were linked to various STs. The IR/100,000 of P. aeruginosa that belonged to serotypes O6 increased significantly over time.

CONCLUSION

An effective multivalent vaccine consisting of five serotypes (O1, O3, O5, O6, O11) would confer protection to > 70% of Calgary residents with P. aeruginosa BSIs. This study has provided a unique perspective of the population dynamics over time of P. aeruginosa STs, clades, and serotypes responsible for BSIs.

Rapid Phenotypic Antibiotic Susceptibility Profiling of Clinical Escherichia coli and Klebsiella pneumoniae Blood Cultures

Bloodstream infections (BSI) are defined by the presence of viable bacteria or fungi, accompanied by systemic signs of infection. Choosing empirical therapy based solely on patient risk factors and prior antibiotic susceptibility test (AST) may lead to either ineffective treatment or unnecessarily broad-spectrum antibiotic exposure. In general, Clinical & Laboratory Standards Institute guideline-approved ASTs have a turnaround time of 48-72 h from sample to answer, a period that may result in a critical delay in the appropriate selection of therapy. Therefore, reducing the time required for AST is highly advantageous. We have previously shown that our novel rapid AST method, MAPt (Micro-Agar-PCR-test), accurately identifies susceptibility profiles for spiked bioterrorism agents like Bacillus anthracis, Yersinia pestis and Francisella tularensis directly from whole-blood and blood culture samples, even at low bacterial levels (500 CFU/mL). This study evaluated the performance of MAPt on routine bloodstream infection (BSI), focusing on Escherichia coli and Klebsiella pneumoniae isolates from clinical cultures, including resistant strains to some of the six tested antibiotics. Notably, MAPt yielded results exceeding 95% agreement with the standard hospital method within a significantly shorter timeframe of 6 h. These findings suggest significant potential for MAPt as a rapid and reliable BSI management tool.

Multidrug-Resistant Sepsis: A Critical Healthcare Challenge

Sepsis globally accounts for an alarming annual toll of 48.9 million cases, resulting in 11 million deaths, and inflicts an economic burden of approximately USD 38 billion on the United States healthcare system. The rise of multidrug-resistant organisms (MDROs) has elevated the urgency surrounding the management of multidrug-resistant (MDR) sepsis, evolving into a critical global health concern. This review aims to provide a comprehensive overview of the current epidemiology of (MDR) sepsis and its associated healthcare challenges, particularly in critically ill hospitalized patients. Highlighted findings demonstrated the complex nature of (MDR) sepsis pathophysiology and the resulting immune responses, which significantly hinder sepsis treatment. Studies also revealed that aging, antibiotic overuse or abuse, inadequate empiric antibiotic therapy, and underlying comorbidities contribute significantly to recurrent sepsis, thereby leading to septic shock, multi-organ failure, and ultimately immune paralysis, which all contribute to high mortality rates among sepsis patients. Moreover, studies confirmed a correlation between elevated readmission rates and an increased risk of cognitive and organ dysfunction among sepsis patients, amplifying hospital-associated costs. To mitigate the impact of sepsis burden, researchers have directed their efforts towards innovative diagnostic methods like point-of-care testing (POCT) devices for rapid, accurate, and particularly bedside detection of sepsis; however, these methods are currently limited to detecting only a few resistance biomarkers, thus warranting further exploration. Numerous interventions have also been introduced to treat MDR sepsis, including combination therapy with antibiotics from two different classes and precision therapy, which involves personalized treatment strategies tailored to individual needs. Finally, addressing MDR-associated healthcare challenges at regional levels based on local pathogen resistance patterns emerges as a critical strategy for effective sepsis treatment and minimizing adverse effects.

Mortality and length of hospital stay after bloodstream infections caused by ESBL-producing compared to non-ESBL-producing E. coli

OBJECTIVE

To compare mortality and length of hospital stay between patients with ESBL-producing E. coli bloodstream infections (BSIs) and patients with non-ESBL E. coli BSIs. We also aimed at describing risk factors for ESBL-producing E. coli BSIs and time to effective antibiotic treatment for the two groups.

METHODS

A retrospective case-control study among adults admitted between 2014 and 2021 to a Norwegian University Hospital.

RESULTS

A total of 468 E. coli BSI episodes from 441 patients were included (234 BSIs each in the ESBL- and non-ESBL group). Among the ESBL-producing E. coli BSIs, 10.9% (25/230) deaths occurred within 30 days compared to 9.0% (21/234) in the non-ESBL group. The adjusted 30-day mortality OR was 1.6 (95% CI 0.7-3.7, p = 0.248). Effective antibiotic treatment was administered within 24 hours to 55.2% (129/234) in the ESBL-group compared to 86.8% (203/234) in the non-ESBL group. Among BSIs of urinary tract origin (n = 317), the median length of hospital stay increased by two days in the ESBL group (six versus four days, p < 0.001). No significant difference in the length of hospital stay was found for other sources of infection (n = 151), with a median of seven versus six days (p = 0.550) in the ESBL- and non-ESBL groups, respectively.

CONCLUSION

There was no statistically significant difference in 30-day mortality in ESBL-producing E. coli compared to non-ESBL E. coli BSI, despite a delay in the administration of an effective antibiotic in the former group. ESBL-production was associated with an increased length of stay in BSIs of urinary tract origin.

The bacterial genetic determinants of Escherichia coli capacity to cause bloodstream infections in humans

Escherichia coli is both a highly prevalent commensal and a major opportunistic pathogen causing bloodstream infections (BSI). A systematic analysis characterizing the genomic determinants of extra-intestinal pathogenic vs. commensal isolates in human populations, which could inform mechanisms of pathogenesis, diagnostic, prevention and treatment is still lacking. We used a collection of 912 BSI and 370 commensal E. coli isolates collected in France over a 17-year period (2000-2017). We compared their pangenomes, genetic backgrounds (phylogroups, STs, O groups), presence of virulence-associated genes (VAGs) and antimicrobial resistance genes, finding significant differences in all comparisons between commensal and BSI isolates. A machine learning linear model trained on all the genetic variants derived from the pangenome and controlling for population structure reveals similar differences in VAGs, discovers new variants associated with pathogenicity (capacity to cause BSI), and accurately classifies BSI vs. commensal strains. Pathogenicity is a highly heritable trait, with up to 69% of the variance explained by bacterial genetic variants. Lastly, complementing our commensal collection with an older collection from 1980, we predict that pathogenicity continuously increased through 1980, 2000, to 2010. Together our findings imply that E. coli exhibit substantial genetic variation contributing to the transition between commensalism and pathogenicity and that this species evolved towards higher pathogenicity.

Acquired susceptibility to autoimmune diseases in pediatric patients with Escherichia coli infection: A population-matched retrospective cohort study

BACKGROUND

Escherichia coli (E.coli) infection has been proposed to play an important role as an initial trigger in the development of autoimmunity via molecular mimicry. However, there has been no preliminary cohort study to establish the association of E.coli infection with autoimmune diseases. Therefore, we conducted a large scale, population-matched cohort study to determine the risk of autoimmune disease among patients with exposure to E.coli.

METHODS

Utilizing the National Health Insurance Service database, we retrospectively analyzed a total of 259,875 Korean children that consisted of 23,625 exposed and 236,250 unexposed persons from January 1, 2002 to December 31, 2017. The exposed cohort was defined as patients diagnosed with E.coli infection. Unexposed controls were matched by birth year and sex at a 1:10 ratio for each exposed patient, using incidence density sampling. The primary outcome was autoimmune disease development. We used the Cox model to estimate the risks of autoimmune diseases among patients diagnosed with E.coli infection.

RESULTS

Over a mean follow-up of 10 years, there were 1455 autoimmune disease cases among exposed patients (incidence rate, 63.6 per 10,000 person-years) and 11,646 autoimmune disease cases among unexposed persons (incidence rate, 50.4 per 10,000 person-years), with an adjusted hazard ratio (HR) of 1.254 (95% CI 1.187-1.325). E.coli infection was associated with increased risks of autoimmune diseases; Reactive arthritis, HR 1.487, 95% CI 1.131-1.956; Henoch Schönlein purpura, HR 1.265, 95% CI 1.050-1.524; Systemic lupus erythematosus, HR 1.838, 95% CI 1.165-2.898; Sjögren's syndrome, HR 2.002, 95% CI 1.342-2.987; IgA nephropathy, HR 1.613, 95% CI 1.388-1.874. Kaplan-Meier cumulative incidence curves also showed a significant association between E.coli infection and incident autoimmune disease (p < 0.0001). This relationship was not only independent of demographic variables, but also remained consistent across various sensitivity analyses. On the other hand, patients with longer hospital stay for E.coli infection were at a higher risk of autoimmune disease (p = 0.0003), and the risk of autoimmune disease also tended to increase, as the frequency of E.coli infection was higher. Moreover, the relative risk of autoimmune disease seemed to be attenuated by use of antibiotics and a history of intestinal infectious disease, but elevated by coexistence of other autoimmune diseases.

CONCLUSIONS

Our cohort study indicates that E.coli infection was significantly associated with increased susceptibility to autoimmune diseases, even after adjusting for different factors. Thus, among environmental factors, a previous history of E.coli infection could be a predisposing risk factor in the development of autoimmune diseases.

Interactions between Gender and Sepsis—Implications for the Future

Sex and gender dimorphisms are found in a large variety of diseases, including sepsis and septic shock which are more prevalent in men than in women. Animal models show that the host response to pathogens differs in females and males. This difference is partially explained by sex polarization of the intracellular pathways responding to pathogen–cell receptor interactions. Sex hormones seem to be responsible for this polarization, although other factors, such as chromosomal effects, have yet to be investigated. In brief, females are less susceptible to sepsis and seem to recover more effectively than males. Clinical observations produce more nuanced findings, but men consistently have a higher incidence of sepsis, and some reports also claim higher mortality rates. However, variables other than hormonal differences complicate the interaction between sex and sepsis, including comorbidities as well as social and cultural differences between men and women. Conflicting data have also been reported regarding sepsis-attributable mortality rates among pregnant women, compared with non-pregnant females. We believe that unraveling sex differences in the host response to sepsis and its treatment could be the first step in personalized, phenotype-based management of patients with sepsis and septic shock.

Risk factors for antimicrobial resistance in patients with Escherichia coli bacteraemia related to urinary tract infection

Introduction

NHS Lothian policy has recently changed to avoid first-line use of trimethoprim for uncomplicated urinary tract infections (UTI) in patients with risk factors for trimethoprim resistance, in line with national guidance. This study aimed to identify risk factors for antimicrobial resistance in Escherichia coli bacteraemia related to UTI.

Methods

A retrospective cohort study of 687 patients with E. coli bacteraemia related to UTI in NHS Lothian from 01/02/18 to 29/02/20 was undertaken. Demographics and comorbidities were collected from electronic patient records. Community prescribing and microbiology data were collected from the prescribing information system and Apex. Univariate and multivariate analysis was undertaken using RStudio to analyse trimethoprim, gentamicin and multi-drug resistance (MDR).

Results

Trimethoprim resistance was present in 282/687(41%) of blood culture isolates. MDR was present in 278/687(40.5%) isolates. Previous urinary trimethoprim resistant E. coli was a significant risk factor for both trimethoprim resistance (OR 9.44, 95%CI 5.83-15.9) and MDR (OR 4.81, 95%CI 3.17-7.43) on multivariate modelling. Trimethoprim prescription (OR 2.10, 95% CI 1.33-3.34) and the number of community antibiotic courses (OR 1.19, 95%CI 1.06-1.35) were additional risk factors for trimethoprim resistance. Multiple independent risk factors were also identified for trimethoprim resistance, MDR and gentamicin resistance.

Discussion

This study showed a high prevalence of trimethoprim resistance and MDR in patients with E. coli bacteraemia related to UTI. This supports the withdrawal of trimethoprim from first-line treatment of UTIs in patients with risk factors for trimethoprim resistance. It has also identified risk factors for MDR in E. coli bacteraemia.

Distribution of extraintestinal pathogenic Escherichia coli O-serotypes and antibiotic resistance in blood isolates collected from patients in a surveillance study in Japan

INTRODUCTION

Invasive extraintestinal pathogenic Escherichia coli (ExPEC) disease (IED), characterised by sepsis and bacteraemia, is a major global healthcare concern worsened by emerging multidrug resistant (MDR) strains. The development of multivalent prophylactic vaccines targeting E. coli strains of IED-associated O-serotypes could address this. A better understanding of O-serotype distribution is required for this purpose. Here, we characterised O-serotype prevalence and drug resistance among ExPEC bacteraemia isolates in Japan.

METHODS

E. coli blood isolates from patients aged ≥60 years with bacteraemia were obtained from a retrospective surveillance study in Japan (2015-2017). O-serotyping was performed by agglutination; for isolates non-typeable by agglutination, O-genotyping was performed. Antimicrobial susceptibility was evaluated by broth microdilution using a 21-antibiotic panel. The frequency of drug resistant (DR) isolates was evaluated by antimicrobial susceptibility testing.

RESULTS

Of 401 ExPEC bacteraemia isolates evaluated, the most prevalent O-serotype (≥1%) was O25 (28.7% [n = 115]), followed by O1 (14.2% [n = 57]), O2 (8.5% n = 34]), O6 (5.5% [n = 22]), O75, O18, O13, O16, O15, O4, O46/O134, O86, O8 and O83 (each <5% prevalence). These 14 O-serotypes accounted for 81.5% of isolates collected. In total, 19% (n = 77) of isolates were DR ≥ 3, of which 59.7% were O25. Fluoroquinolone-resistance among all and O25 isolates was most prevalent (35.7% and 84.3%, respectively). Almost all (98%) isolates identified as O25 were of subtype O25B.

CONCLUSIONS

E. coli serotype O25B showed the highest prevalence and highest multidrug resistance among ExPEC bacteraemia isolates from patients ≥60 years in Japan. Our data may inform development of multivalent glycoconjugate vaccines to prevent IED.

Development and performance characteristics of novel code-based algorithms to identify invasive Escherichia coli disease

PURPOSE

Evaluation of novel code-based algorithms to identify invasive Escherichia coli disease (IED) among patients in healthcare databases.

METHODS

Inpatient visits with microbiological evidence of invasive bacterial disease were extracted from the Optum^© electronic health record database between 01 January 2016 and 30 June 2020. Six algorithms, derived from diagnosis and drug exposure codes associated to infectious diseases and Escherichia coli, were developed to identify IED. The performance characteristics of algorithms were assessed using a reference standard derived from microbiology data.

RESULTS

Among 97,194 eligible records, 25,310 (26.0%) were classified as IED. Algorithm 1 (diagnosis code for infectious invasive disease due to E. coli) had the highest positive predictive value (PPV; 96.0%) and lowest sensitivity (60.4%). Algorithm 2, which additionally included patients with diagnosis codes for infectious invasive disease due to an unspecified organism, had the highest sensitivity (95.5%) and lowest PPV (27.8%). Algorithm 4, which required patients with a diagnosis code for infectious invasive disease due to unspecified organism to have no diagnosis code for non-E. coli infections, achieved the most balanced performance characteristics (PPV, 93.6%; sensitivity, 78.1%; F₁ score, 85.1%). Finally, adding exposure to antibiotics in the treatment of E. coli had limited impact on performance algorithms 5 and 6.

CONCLUSION

Algorithm 4, which achieved the most balanced performance characteristics, offers a useful tool to identify patients with IED and assess the burden of IED in healthcare databases. This article is protected by copyright. All rights reserved.

Global Distribution of O Serotypes and Antibiotic Resistance in Extraintestinal Pathogenic Escherichia coli Collected From the Blood of Patients With Bacteremia Across Multiple Surveillance Studies

BACKGROUND

Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of bacteremia worldwide, with older populations having increased risk of invasive bacterial disease. Increasing resistance to first-line antibiotics and emergence of multidrug-resistant (MDR) strains represent major treatment challenges. ExPEC O serotypes are key targets for potential multivalent conjugate vaccine development. Therefore, we evaluated the O serotype distribution and antibiotic resistance profiles of ExPEC strains causing bloodstream infections across 4 regions.

METHODS

Blood culture isolates from patients aged ≥60 years collected during 5 retrospective E. coli surveillance studies in Europe, North America, Asia-Pacific, and South America (2011-2017) were analyzed. Isolates were O serotyped by agglutination; O genotyping was performed for nontypeable isolates. Antimicrobial susceptibility testing was also conducted.

RESULTS

Among 3217 ExPEC blood culture isolates, the most ubiquitous O serotype was O25 (n = 737 [22.9%]), followed by O2, O6, O1, O75, O15, O8, O16, O4, O18, O77 group, O153, O9, O101/O162, O86, and O13 (prevalence of ≥1%). The prevalence of these O serotypes was generally consistent across regions, apart from South America; together, these 16 O serotypes represented 77.6% of all ExPEC bacteremia isolates analyzed. The overall MDR frequency was 10.7%, with limited variation between regions. Within the MDR subset (n = 345), O25 showed a dominant prevalence of 63.2% (n = 218).

CONCLUSIONS

Predominant O serotypes among ExPEC bacteremia isolates are widespread across different regions. O25 was the most prevalent O serotype overall and particularly dominant among MDR isolates. These findings may inform the design of multivalent conjugate vaccines that can target the predominant O serotypes associated with invasive ExPEC disease in older adults.

Outpatient transperineal prostate biopsy under local anaesthesia is safe, well tolerated and feasible

BACKGROUND

Transperineal biopsy (TPB) of the prostate has been increasingly utilized as it has reduced infection risks. Traditionally however, it is performed under general anaesthesia, thus it carries a differing set of risks. Recently, new studies have performed TPB under local anaesthesia with success. In the present study, we explored our experience of performing TPB under local anaesthesia in an Australian cohort.

METHODS

In this prospective study based at a metropolitan outpatient clinic, patients were provided with TPB under local anaesthesia. We assessed prostate cancer detection rates, complication rates and patient tolerability. Pain tolerability was assess using patient reported pain score on the visual analogue scale. Follow up data was collected at days 7 and 30 post-biopsy via telephone interview.

RESULTS

A total of 48 patients were enrolled in this study between June 2020 and March 2021. Median age was 65.5 years and median PSA was 6.95 ng/mL. Clinically significant prostate cancer was detected in 58% of patients. During the procedure, pain scores were rated the highest during infiltration of local anaesthetic agent with a median score of 5. By the conclusion of the procedure, median pain score was 1. Vast majority of patients (85.4%) would opt for a repeat TPB under local anaesthesia should the need for prostate biopsy arise again. Two of our patients experienced infectious complications, and one experienced urinary retention.

CONCLUSION

Our data is in line with currently available data and confirms that TPB under local anaesthesia can be achieved in a safe and tolerable manner.

Evaluating the diagnostic role of in-bore magnetic resonance imaging guided prostate biopsy: a single-centre study

Background

To evaluate the role of in‐bore MRI‐guided biopsy (IB‐MRGB) in the diagnosis of clinically significant prostate cancer (csPCa).

Methods

In this tertiary single centre study, a total of 125 consecutive patients receiving IB‐MRGB over a three‐year period were evaluated, including 73 patients who had prior biopsies and 52 biopsy‐naïve patients. We assessed cancer detection rate of patients according to the degree of suspicion based on mpMRI findings. Histopathological data were reviewed by experienced uropathologists.

Results

The mpMRI was suspicious for PCa (PI‐RADS 4/5) in 77% (96/125) and equivocal (PI‐RADS 3) in 23% (29/125). The detection rate for csPCa was 54.2% (52/96) and 20.7% (6/29) for suspicious lesions (PI‐RADS 4/5) and equivocal lesions (PI‐RADS 3), respectively. In subgroup analysis, patients with previous negative biopsy, overall positive biopsy rate and csPCa detection rate were 48.3% (19/35) and 34.5% (13/35), respectively. In patients on AS, 36/44 (81.8%) and 21/44 (47.8%) had PCa and csPCa respectively. In biopsy‐naïve patients 34/52 (65.4%) and 27/52 (51.92%) had PCa and csPCa respectively. Of the patients on AS, 18/44 (41.6%) upgraded from ISUP 1 to ISUP 2 PCa, and 4/44 (9.1%) upgraded from ISUP 1 to ISUP 3 PCa on IB‐MRGB. A total of 14 Clavien‐Dindo≤2 complications occurred in 14 patients (11.2%) that were directly related to the biopsy. No Clavien‐Dindo≥3 complications occurred.

Conclusion

MRI‐targeted biopsy is suitable for assessment of csPCa. Given the favourable complications profile, its use may be considered in both the initial biopsy and re‐biopsy settings.

A 21-Year Survey of Escherichia coli from Bloodstream Infections (BSI) in a Tertiary Hospital Reveals How Community-Hospital Dynamics of B2 Phylogroup Clones Influence Local BSI Rates

This is a longitudinal study comprising 649 Escherichia coli isolates representing all 7,165 E. coli bloodstream infection (BSI) episodes recorded in a hospital (1996 to 2016). Strain analysis included clonal identification (phylogenetic groups/subgroups, STc131 subclades, pulsed-field gel electrophoresis [PFGE], and whole-genome sequencing [WGS]), antibiotic susceptibility (13 antibiotics), and virulence-associated genes (VAGs; 29 genes). The incidence of E. coli BSI increased from 1996 to 2016 (5.5 to 10.8 BSI episodes/1,000 hospitalizations, average 7 to 8/1,000). B2 isolates predominate (53%), with subgroups B2-I (STc131), B2-II, B2-IX, and B2-VI representing 25%, 25%, 14%, and 9%, respectively. Intertwined waves of community-acquired (CA) plus health care-associated and community-onset health care-associated (HCA) and hospital-acquired (HA) episodes of both B2 and non-B2 phylogroups occurred. A remarkable increase was observed only for B2-I-STc131 (C1/C2 subclades), with oscillations for other B2 subgroups and phylogroups throughout the years. Epidemic and persistent clones (comprising isolates with highly similar/identical PFGE types and genomes differing in 6 to 173 single nucleotide polymorphisms [SNPs]) of B2-I (STc131), B2-II (STc73), B2-III (STc127), B2-IX (STc95), and B2-VI (STc12) were recovered from different patients, most at hospital admission, for long periods (2 to 17 years), and extended-spectrum beta-lactamase (ESBL) producers or resistance to ciprofloxacin in B2 isolates was almost restricted to B2-I (STc131) subclade C. STc131 contributed to increasing the B2 rates but only transiently altered the E. coli population structure. The increase of E. coli BSI was determined by waves of CA+HCA BSI episodes that predate the waves of HA BSI. Besides the risk of hospital transmission that led to temporal increases in BSI, this study suggests that E. coli populations/clones from community-based healthy individuals may occasionally have an epidemic structure and provide a source of transmissible strains influencing the HA BSI incidence.

IMPORTANCE Sepsis is the third leading cause of mortality in Western countries and one of the Global Health Threats recognized by the WHO since 2017. Despite Escherichia coli constituting the most common cause of bloodstream infections (BSI), its epidemiology is not fully understood, in part due to the scarcity of local and longitudinal studies. Our work analyzes the long-term dynamics of E. coli causing bacteremia in a single institution and reveals waves of different clonal lineages that emerge periodically and successfully spread afterward in both the community and hospitals. Because the origin of E. coli bloodstream infections is the gut, the microbiota of healthy individuals might occasionally have an epidemic structure, providing a source of E. coli strains to influence the incidence of hospital BSI. The study complements previous fractionated observations focusing on specific E. coli lineages or antibiotic-resistant isolates in the last decades and helps to understand the epidemiology of E. coli BSI and the dynamics of pandemic clones.

Exploring temporal trends and risk factors for resistance in Escherichia coli-causing bacteraemia in England between 2013 and 2018: an ecological study

BACKGROUND

Escherichia coli are Gram-negative bacteria associated with an increasing burden of antimicrobial resistance (AMR) in England.

OBJECTIVES

To create a comprehensive epidemiological picture of E. coli bacteraemia resistance trends and risk factors in England by linking national microbiology data sources and performing a longitudinal analysis of rates.

METHODS

A retrospective observational study was conducted on all national records for antimicrobial susceptibility testing on E. coli bacteraemia in England from 1 January 2013 to 31 December 2018 from the UK Health Security Agency (UKHSA) and the BSAC Resistance Surveillance Programme (BSAC-RSP). Trends in AMR and MDR were estimated using iterative sequential regression. Logistic regression analyses were performed on UKHSA data to estimate the relationship between risk factors and AMR or MDR in E. coli bacteraemia isolates.

RESULTS

An increase in resistance rates was observed in community- and hospital-onset bacteraemia for third-generation cephalosporins, co-amoxiclav, gentamicin and ciprofloxacin. Among community-acquired cases, and after adjustment for other factors, patients aged >65 years were more likely to be infected by E. coli isolates resistant to at least one of 11 antibiotics than those aged 18-64 years (OR: 1.21, 95% CI: 1.18-1.25; P < 0.05). In hospital-onset cases, E. coli isolates from those aged 1-17 years were more likely to be resistant than those aged 18-64 years (OR: 1.33, 95% CI: 1.02-1.73; P < 0.05).

CONCLUSIONS

Antibiotic resistance rates in E. coli-causing bacteraemia increased between 2013 and 2018 in England for key antimicrobial agents. Findings of this study have implications for guiding future policies on a prescribing of antimicrobial agents, for specific patient populations in particular.

A nationwide population-based study of Escherichia coli bloodstream infections: incidence, antimicrobial resistance and mortality

OBJECTIVES

Escherichia coli is the leading cause of bloodstream infection (BSI). The incidence of E. coli BSI caused by antibiotic-resistant strains is increasing. We aimed to describe the nationwide incidence and resistance profile of E. coli BSI in Israel and its impact on mortality, to compare E. coli BSI mortality to all-cause mortality, and community-onset to hospital-onset E. coli BSI.

METHODS

We used mandatory BSI surveillance reports submitted by all Israeli hospitals to the Ministry of Health and the national death registry. All E. coli BSI from January 1, 2018, to December 31, 2019 in patients ages 18 and over were included.

RESULTS

A total of 11 113 E. coli BSI occurred in 10 218 patients; 85% (9012/10 583) were community onset. Median age was 76 (IQR 65-85), and 57% (6304/11 113) of cases occurred in women. The annual incidence was 92.5 per 100,000 population. Antibiotic resistance was frequent and significantly more common in hospital-onset than in community-onset BSI; 65% (1021/1571) vs 45% (4049/9012) were multidrug-resistant (MDR) (p<0.001). The case-fatality rate (CFR) was higher following hospital-onset BSI than community-onset: 23% (276/1214) vs 12% (926/7620) at 14 days, 31% (378/1214) vs 16% (1244/7620) at 30 days, and 55% (418/766) vs 34% (1645/4903) at 1 year (p<0.001 for all comparisons). The 1-year-CFR was 47% (1258/2707) for MDR vs 28% (928/3281) for non-MDR (p<0.001). The annual mortality rate was 31.0 per 100,000 population, comprising 4.2% (31.0/734.8) of all causes of deaths.

CONCLUSIONS

E. coli BSI carries a high burden, with a large proportion of MDR isolates, which are associated with increased incidence and CFR.

Mathematical model of the cost-effectiveness of the BioFire FilmArray Blood Culture Identification (BCID) Panel molecular rapid diagnostic test compared with conventional methods for identification of Escherichia coli bloodstream infections

BACKGROUND

Gram-negative pathogens, such as Escherichia coli, are common causes of bloodstream infections (BSIs) and increasingly demonstrate antimicrobial resistance. Molecular rapid diagnostic tests (mRDTs) offer faster pathogen identification and susceptibility results, but higher costs compared with conventional methods. We determined the cost-effectiveness of the BioFire FilmArray Blood Culture Identification (BCID) Panel, as a type of mRDT, compared with conventional methods in the identification of E. coli BSIs.

METHODS

We constructed a decision analytic model comparing BCID with conventional methods in the identification and susceptibility testing of hospitalized patients with E. coli BSIs from the perspective of the public healthcare payer. Model inputs were obtained from published literature. Cost-effectiveness was calculated by determining the per-patient admission cost, the QALYs garnered and the incremental cost-effectiveness ratios (ICERs) where applicable. Monte Carlo probabilistic sensitivity analyses and one-way sensitivity analyses were conducted to assess the robustness of the model. All costs reflect 2019 Canadian dollars.

RESULTS

The Monte Carlo probabilistic analyses resulted in cost savings ($27 070.83 versus $35 649.81) and improved QALYs (8.65 versus 7.10) in favour of BCID. At a willingness to pay up to $100 000, BCID had a 72.6%-83.8% chance of being cost-effective. One-way sensitivity analyses revealed length of stay and cost per day of hospitalization to have the most substantial impact on costs and QALYs.

CONCLUSIONS

BCID was found to be cost-saving when used to diagnose E. coli BSI compared with conventional testing. Cost savings were most influenced by length of stay and cost per day of hospitalization.

Cost-effectiveness of rapid laboratory-based mass-spectrometry diagnosis of bloodstream infection: evidence from the RAPIDO randomised controlled trial

OBJECTIVES AND INTERVENTION

Bloodstream infection, the presence of viable micro-organisms in the blood, is a prevalent clinical event associated with substantial mortality. Patient outcomes may be improved when the causative micro-organism is identified quickly. We assessed the cost-effectiveness of rapid microbial identification by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry.

DESIGN

Economic evaluation alongside a randomised multicentre trial (RAPIDO: RAPId Diagnosis on Outcome) assessing the impact of rapid identification by MALDI-TOF spectrometry.

SETTING

Adult inpatients with bloodstream infections at seven National Health Service hospital trusts in England and Wales.

PRIMARY OUTCOME

Net monetary benefit, estimated as incremental costs compared with incremental 28-day survival, of rapid identification by MALDI-TOF spectrometry compared with conventional identification.

METHODS

Patients were randomised (1:1) to receive diagnosis by conventional methods of microbial identification (conventional arm) only or by MALDI-TOF spectrometry in addition to conventional identification (RAPIDO arm).

RESULTS

Data from 5550 patients were included in primary analysis. Mean imputed costs in 2018/2019 prices per patient were lower by £126 in the RAPIDO arm (95% CI -£784 to £532) but the proportion of patients alive at day 28 was lower (81.4% vs 82.3%). The probability of cost-effectiveness of MALDI-TOF was <0.5 at cost-effectiveness thresholds between £20 000 and £50 000.

CONCLUSIONS

Adjunctive MALDI-TOF diagnosis was unlikely to be cost-effective when measured as cost per death avoided at 28 days. However, the differences between arms in cost and effect were modest, associated with uncertainty and may not accurately reflect 'real-world' routine use of MALDI-TOF technology in this patient group.

TRIAL REGISTRATION NUMBERS

ISRCTN97107018/UKCRN 11978.

Increasing incidence and antimicrobial resistance in Escherichia coli bloodstream infections: a multinational population-based cohort study

BACKGROUND

Escherichia coli is an important pathogen in humans and is the most common cause of bacterial bloodstream infections (BSIs). The objectives of our study were to determine factors associated with E. coli BSI incidence rate and third-generation cephalosporin resistance in a multinational population-based cohort.

METHODS

We included all incident E. coli BSIs (2014-2018) from national (Finland) and regional (Australia [Canberra], Sweden [Skaraborg], and Canada [Calgary, Sherbrooke, and western interior]) surveillance. Incidence rates were directly age and sex standardized to the European Union 28-country 2018 population. Multivariable negative binomial and logistic regression models estimated factors significantly associated with E. coli BSI incidence rate and third-generation cephalosporin resistance, respectively. The explanatory variables considered for inclusion in both models were year (2014-2018), region (six areas), age (< 70-years-old and ≥ 70-years-old), and sex (female and male).

RESULTS

We identified 31,889 E. coli BSIs from 40.7 million person-years of surveillance. Overall and third-generation cephalosporin-resistant standardized rates were 87.1 and 6.6 cases/100,000 person-years, respectively, and increased 14.0% and 40.1% over the five-year study. Overall, 7.8% (2483/31889) of E. coli BSIs were third-generation cephalosporin-resistant. Calgary, Canberra, Sherbrooke, and western interior had significantly lower E. coli BSI rates compared to Finland. The significant association between age and E. coli BSI rate varied with sex. Calgary, Canberra, and western interior had significantly greater odds of third-generation cephalosporin-resistant E. coli BSIs compared to Finland. Compared to 2014, the odds of third-generation cephalosporin-resistant E. coli BSIs were significantly increased in 2016, 2017, and 2018. The significant association between age and the odds of having a third-generation cephalosporin-resistant E. coli BSI varied with sex.

CONCLUSIONS

Increases in overall and third-generation cephalosporin-resistant standardized E. coli BSI rates were clinically important. Overall, E. coli BSI incidence rates were 40-104% greater than previous investigations from the same study areas. Region, sex, and age are important variables when analyzing E. coli BSI rates and third-generation cephalosporin resistance in E. coli BSIs. Considering E. coli is the most common cause of BSIs, this increasing burden and evolving third-generation cephalosporin resistance will have an important impact on human health, especially in aging populations.

Escherichia coli bloodstream infections in the western interior of British Columbia, Canada: a population-based cohort study

Our population-based study objectives were to describe characteristics and outcomes of Escherichia coli bloodstream infections (BSIs), and to evaluate factors associated with outcomes. We included incident E. coli BSIs from western interior residents (British Columbia, Canada; 04/2010–03/2020). We obtained data including patient demographics, location of onset, infection focus, Charlson comorbidity index (CCI), antimicrobial resistance, 30-day all-cause mortality and length of hospital stay (LOS). Using multivariable logistic regression models fitted with generalised estimating equations, we estimated factors associated with 30-day mortality and long post-infection LOS (>75th percentile). We identified 1080 incident E. coli BSIs in 1009 patients. The crude incidence and 30-day mortality rates were 59.1 BSIs and 6.8 deaths/100 000 person-years, respectively. The 30-day case fatality risk was 11.5%. Compared to community-acquired E. coli BSIs, either healthcare-associated or nosocomial cases had higher odds of 30-day mortality. Older cases, non-urogenital BSI foci and CCI ⩾ 3 had higher odds of 30-day mortality compared to younger cases, urogenital foci and CCI < 3. In patients that survived to discharge, those with extended-spectrum β-lactamase (ESBL)-producing E. coli BSIs, nosocomial BSIs, and CCI ⩾ 3 had higher odds of long post-infection LOS compared to those with non-ESBL-producing, community-acquired and healthcare-associated, and CCI < 3. There is a substantial disease burden from E. coli BSIs.

Surviving serum - the E. coli iss gene (increased serum survival) of extraintestinal pathogenic E. coli (ExPEC) is required for the synthesis of group 4 capsule

Extra-intestinal pathogenic E. coli strains - ExPEC - constitute a serious and emerging clinical problem, as they cause a variety of infections and are usually highly antibiotic resistant. Many ExPEC - are capable of evading the bactericidal effects of serum and causing sepsis. One critical factor for the development of septicemia is the gene iss, increased serum survival, which is highly correlated with complement resistance and lethality. Although it is very important, the function of the iss gene has not been elucidated so far. We have been studying the serum survival of a septicemic strain of E. coli serotype O78, which has a group 4 capsule. Here we show that the iss gene is required for the synthesis of capsules, which protect the bacteria from the bactericidal effect of complement. Moreover, we show that the deletion of the iss gene results in significantly increased binding of the complement proteins that constitute the membrane attack complex to the bacterial surface.

Mortality in Escherichia coli bloodstream infections: a multinational population-based cohort study

Background

Escherichia coli is the most common cause of bloodstream infections (BSIs) and mortality is an important aspect of burden of disease. Using a multinational population-based cohort of E. coli BSIs, our objectives were to evaluate 30-day case fatality risk and mortality rate, and determine factors associated with each.

Methods

During 2014–2018, we identified 30-day deaths from all incident E. coli BSIs from surveillance nationally in Finland, and regionally in Sweden (Skaraborg) and Canada (Calgary, Sherbrooke, western interior). We used a multivariable logistic regression model to estimate factors associated with 30-day case fatality risk. The explanatory variables considered for inclusion were year (2014–2018), region (five areas), age (< 70-years-old, ≥70-years-old), sex (female, male), third-generation cephalosporin (3GC) resistance (susceptible, resistant), and location of onset (community-onset, hospital-onset). The European Union 28-country 2018 population was used to directly age and sex standardize mortality rates. We used a multivariable Poisson model to estimate factors associated with mortality rate, and year, region, age and sex were considered for inclusion.

Results

From 38.7 million person-years of surveillance, we identified 2961 30-day deaths in 30,923 incident E. coli BSIs. The overall 30-day case fatality risk was 9.6% (2961/30923). Calgary, Skaraborg, and western interior had significantly increased odds of 30-day mortality compared to Finland. Hospital-onset and 3GC-resistant E. coli BSIs had significantly increased odds of mortality compared to community-onset and 3GC-susceptible. The significant association between age and odds of mortality varied with sex, and contrasts were used to interpret this interaction relationship. The overall standardized 30-day mortality rate was 8.5 deaths/100,000 person-years. Sherbrooke had a significantly lower 30-day mortality rate compared to Finland. Patients that were either ≥70-years-old or male both experienced significantly higher mortality rates than those < 70-years-old or female.

Conclusions

In our study populations, region, age, and sex were significantly associated with both 30-day case fatality risk and mortality rate. Additionally, 3GC resistance and location of onset were significantly associated with 30-day case fatality risk. Escherichia coli BSIs caused a considerable burden of disease from 30-day mortality. When analyzing population-based mortality data, it is important to explore mortality through two lenses, mortality rate and case fatality risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06326-x.

Outcome of community-onset ESBL-producing Escherichia coli and Klebsiella pneumoniae bacteraemia and urinary tract infection: a population-based cohort study in Denmark

OBJECTIVES

To assess the impact of ESBL production on mortality and length of hospital stay (LOS) of community-onset infections due to Escherichia coli or Klebsiella pneumoniae.

METHODS

A population-based cohort study including all adult patients hospitalized with a first-time community-onset E. coli or K. pneumoniae bacteraemia or urinary tract infection in the North Denmark Region between 2007 and 2017. For each bacterial agent, we computed 1 year Kaplan-Meier survival curves and cumulative incidence functions of LOS, and by use of Cox proportional hazard regression we computed HRs as estimates of 30 day and 1 year mortality rate ratios (MRRs) and LOS among patients with and without ESBL-producing infections.

RESULTS

We included 24 518 cases (among 22350 unique patients), of whom 1018 (4.2%) were infected by an ESBL-producing bacterium. The 30 day cumulative mortality and adjusted MRR (aMRR) in patients with and without ESBL-producing isolates was as follows: E. coli bacteraemia (n = 3831), 15.8% versus 14.0%, aMRR = 1.01 (95% CI = 0.70-1.45); E. coli urinary tract infection (n = 17151), 9.5% versus 8.7%, aMRR = 0.97 (95% CI = 0.75-1.26); K. pneumoniae bacteraemia (n = 734), 0% versus 17.2%, aMRR = not applicable; and K. pneumoniae urinary tract infection (n = 2802), 13.8% versus 10.7%, aMRR = 1.13 (95% CI = 0.73-1.75). The 1 year aMRR remained roughly unchanged. ESBL-producing E. coli bacteraemia was associated with an increased LOS compared with non-ESBL production.

CONCLUSIONS

ESBL production was not associated with an increased short- or long-term mortality in community-onset infections due to E. coli or K. pneumoniae, yet ESBL-producing E. coli bacteraemia was associated with an increased LOS.

A prospective study of Escherichia coli bloodstream infection among adolescents and adults in northern Tanzania

Background

Characterization of the epidemiology of Escherichia coli bloodstream infection (BSI) in sub-Saharan Africa is lacking. We studied patients with E. coli BSI in northern Tanzania to describe host risk factors for infection and to describe the antimicrobial susceptibility of isolates.

Methods

Within 24 h of admission, patients presenting with a fever at two hospitals in Moshi, Tanzania, were screened and enrolled. Cases were patients with at least one blood culture yielding E. coli and controls were those without E. coli isolated from any blood culture. Logistic regression was used to identify host risk factors for E. coli BSI.

Results

We analyzed data from 33 cases and 1615 controls enrolled from 2007 through 2018. The median (IQR) age of cases was 47 (34–57) y and 24 (72.7%) were female. E. coli BSI was associated with (adjusted OR [aOR], 95% CI) increasing years of age (1.03, 1.01 to 1.05), female gender (2.20, 1.01 to 4.80), abdominal tenderness (2.24, 1.06 to 4.72) and urinary tract infection as a discharge diagnosis (3.71, 1.61 to 8.52). Of 31 isolates with antimicrobial susceptibility results, the prevalence of resistance was ampicillin 29 (93.6%), ceftriaxone three (9.7%), ciprofloxacin five (16.1%), gentamicin seven (22.6%) and trimethoprim-sulfamethoxazole 31 (100.0%).

Conclusions

In Tanzania, host risk factors for E. coli BSI were similar to those reported in high-resource settings and resistance to key antimicrobials was common.

Pathogenesis of Gram-Negative Bacteremia

Gram-negative bacteremia is a devastating public health threat, with high mortality in vulnerable populations and significant costs to the global economy. Concerningly, rates of both Gram-negative bacteremia and antimicrobial resistance in the causative species are increasing. Gram-negative bacteremia develops in three phases. First, bacteria invade or colonize initial sites of infection. Second, bacteria overcome host barriers, such as immune responses, and disseminate from initial body sites to the bloodstream. Third, bacteria adapt to survive in the blood and blood-filtering organs. To develop new therapies, it is critical to define species-specific and multispecies fitness factors required for bacteremia in model systems that are relevant to human infection. A small subset of species is responsible for the majority of Gram-negative bacteremia cases, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii The few bacteremia fitness factors identified in these prominent Gram-negative species demonstrate shared and unique pathogenic mechanisms at each phase of bacteremia progression. Capsule production, adhesins, and metabolic flexibility are common mediators, whereas only some species utilize toxins. This review provides an overview of Gram-negative bacteremia, compares animal models for bacteremia, and discusses prevalent Gram-negative bacteremia species.

Sex differences in vancomycin-resistant enterococci bloodstream infections-a systematic review and meta-analysis

Background

Vancomycin-resistant enterococci (VRE) have emerged in the healthcare setting worldwide. Infections with these pathogens, i.e., bloodstream infections (BSI), are accompanied with an impaired patient outcome. Diverse factors comprising patient characteristics, therapeutic strategies, and infection control measures are positively or negatively associated with VRE BSI occurrence. However, whether sex-specific differences influence the frequency of VRE BSI is yet unknown.

The aim of this systematic review was to comprehensively summarize and analyze sex prevalence in VRE BSI patients.

Main text

A systematic search for relevant articles was conducted in PubMed and Web of Science. After screening for eligibility, data extraction from included articles and risk of bias assessment were processed. The prevalence of male/female sex in VRE BSI patients and 95% CI were calculated for each study and summarized as pooled estimated effect.

In total, nine articles met the inclusion criteria. Risk of bias assessment resulted in low (six studies) to moderate bias (three studies). The pooled prevalence of male patients suffering from VRE BSI was 59% resulting in a 1.4 male/female prevalence ratio.

Conclusions

Current literature suggests sex differences with male preference (59%) in the distribution of VRE BSI cases. Further primary studies should address the question of male-specific factors favoring the enhanced frequency of VRE BSI.

Epidemiology of Escherichia coli Bacteremia: A Systematic Literature Review

BACKGROUND

Escherichia coli is the most common cause of bacteremia in high-income countries. To enable the development and implementation of effective prevention strategies, a better understanding of the current epidemiology of invasive E. coli infections is needed.

METHODS

A systematic review of literature published between 1 January 2007 and 31 March 2018 on the burden and epidemiology of E. coli bacteremia in populations that include adults in high-income countries was conducted. Meta-analysis was performed for descriptive purposes.

RESULTS

During the studied time interval, the estimated incidence rate of E. coli bacteremia was 48 per 100 000 person-years, but this increased considerably with age: rates per 100 000 person-years were >100 in 55-to-75-year-olds and >300 in 75-to-85-year-olds. Overall, E. coli accounted for 27% of documented bacteremia episodes: 18% if hospital acquired, 32% if community-onset healthcare associated, and 33% if community acquired. The estimated case fatality rate was 12%. Approximately 44% of episodes were community acquired, 27% community-onset healthcare associated, and 27% hospital acquired. Urinary tract infection (UTI) was the primary source for 53% of episodes.

CONCLUSIONS

This systematic review confirms the substantial burden of E. coli bacteremia in older adults and justifies the implementation of community-level programs to prevent E. coli bacteremia and ideally UTI in this age group.

Comparison of antimicrobial resistances and clinical features in community-onset Escherichia coli and Klebsiella pneumoniae bacteremia

BACKGROUND/AIMS

The aim of this study was to compare antimicrobial resistance, clinical features, and outcomes of community-onset Escherichia coli (COEC) and Klebsiella pneumoniae (COKP) bacteremia.

METHODS

The medical records of patients diagnosed with E. coli or K. pneumoniae bacteremia in the emergency department of a 750-bed secondary care hospital in Daegu, Korea from January 2010 to December 2016 were retrospectively reviewed.

RESULTS

A total of 866 patients with COEC bacteremia and 299 with COKP bacteremia were enrolled. COEC bacteremia, compared to COKP bacteremia, had higher rates of 3rd generation cephalosporin (3GC) (18.8% vs. 8.4%, p < 0.001) and f luoroquinolone (FQ) (30.4% vs. 8.0%, p < 0.001) resistance. The patients with COKP bacteremia had higher Charlson comorbidity indices (CCI) (1.8 ± 2.0 vs. 1.5 ± 1.8, p = 0.035), Pittsburgh bacteremia scores (PBS) (2.0 ± 2.6 vs. 1.3 ± 1.8, p < 0.001), and 30-day mortality (14.44% vs. 8.8%, p = 0.008) than the patients with COEC bacteremia. Age younger than 70 years, male sex, polymicrobial infections, pneumonia, intra-abdominal infection, PBS ≥ 2, and Foley catheter insertion were independent predictive factors for COKP bacteremia compared to COEC bacteremia in the multivariate analysis. CCI, PBS, and intensive care unit admission were independent risk factors for 30-day mortality in the multivariate analysis.

CONCLUSION

3GCs and FQs are still useful for the empirical treatment of patients with probable COKP bacteremia. The patients with COKP bacteremia had worse outcomes because of its greater severity and more frequent underlying comorbidities.

O-serotype distribution of Escherichia coli bloodstream infection isolates in critically ill patients in The Netherlands

OBJECTIVES

Invasive infections by extra-intestinal pathogenic Escherichia coli (ExPEC) strains are increasing. We determined O-serogroups of E. coli isolates from ICU patients having bloodstream infections (BSI) and the potential coverage of a 10-valent O-polysaccharide conjugate vaccine currently in development for the prevention of invasive ExPEC disease.

METHODS

We studied E. coli BSI among patients admitted to a tertiary ICU in the Netherlands between April 2011 and November 2016. O-serogroups were determined in vitro by agglutination and whole genome sequencing.

RESULTS

Among 714 ICU patients having BSI, 70 (10%) had an E. coli BSI. Among 68 (97%) isolates serogrouped, the most common serogroups were O25 (n = 11; 16%), O8 (n = 5; 7%), O2 (n = 4; 6%), O6 (n = 4; 6%), and O15 (n = 4; 6%). The theoretical coverage of a 10-valent ExPEC vaccine was 54% (n = 37).

CONCLUSIONS

A multi-valent ExPEC O-polysaccharide conjugate vaccine in development could potentially aid in the prevention of E. coli BSI in Dutch ICU patients.

Evaluation of the health and healthcare system burden due to antimicrobial-resistant Escherichia coli infections in humans: a systematic review and meta-analysis

BACKGROUND

Assessment of the burden of disease due to antimicrobial-resistant Escherichia coli infections facilitates understanding the scale of the problem and potential impacts, and comparison to other diseases, which allows prioritization of research, surveillance, and funding. Using systematic review and meta-analysis methodology, the objectives were to evaluate whether humans with antimicrobial-resistant E. coli infections experience increases in measures of health or healthcare system burden when compared to susceptible E. coli infections.

METHODS

Comprehensive literature searches were performed in four primary and seven grey literature databases. Analytic observational studies of human E. coli infections that assessed the impact of resistance to third/fourth/fifth-generation cephalosporins, resistance to quinolones, and/or multidrug resistance on mortality, treatment failure, length of hospital stay and/or healthcare costs were included. Two researchers independently performed screening, data extraction, and risk of bias assessment. When possible, random effect meta-analyses followed by assessment of the confidence in the cumulative evidence were performed for mortality and length of hospital stay outcomes, and narrative syntheses were performed for treatment failure and healthcare costs.

RESULTS

Literature searches identified 14,759 de-duplicated records and 76 articles were included. Based on 30-day and all-cause mortality meta-analyses, regardless of the type of resistance, there was a significant increase in the odds of dying with resistant E. coli infections compared to susceptible infections. A summary mean difference was not presented for total length of hospital stay meta-analyses due to substantial to considerable heterogeneity. Since small numbers of studies contributed to meta-analyses for bacterium-attributable mortality and post-infection length of hospital stay, the summary results should be considered with caution. Studies contributing results for treatment failure and healthcare costs had considerable variability in definitions and reporting.

CONCLUSIONS

Overall, resistant E. coli infections were associated with significant 30-day and all-cause mortality burden. More research and/or improved reporting are necessary to facilitate quantitative syntheses of bacterium-attributable mortality, length of hospital stay, and hospital costs. Protocol Registration PROSPERO CRD42018111197.

Community-Acquired Escherichia coli Bacteremia after Age 50 and Subsequent Incidence of a Cancer Diagnosis: A Danish Population-Based Cohort Study

BACKGROUND

Community-acquired bacteremia (CAB) with Escherichia coli may signal occult cancer. This might differ between phylogenetic groups.

METHODS

We conducted a population-based cohort study in northern Denmark (1994-2013) to examine whether E. coli CAB after age 50 is associated with incident cancer. We followed patients from their bacteremia diagnosis date to identify subsequent gastrointestinal, hepatobiliary, and urinary tract cancer diagnoses. We calculated 1- and 5-year cumulative cancer incidence. We compared the observed incidence with that expected based on national cancer incidence rates, and computed standardized incidence ratios (SIR) at 0-<1 year and ≥1 year. In a subcohort, we assessed the prevalence of phylogenetic groups.

RESULTS

Among 2,735 patients with E. coli CAB, 173 later were diagnosed with cancer. The 1-year cumulative incidence of a gastrointestinal or hepatobiliary tract cancer was 1.9%, and the 0-<1-year SIR was 5.44 [95% confidence interval (CI), 4.06-7.14]. For urinary tract cancer, the corresponding estimates were 1.0% and 3.41 (95% CI, 2.27-4.93). All individual cancers occurred more often than expected during the first year following E. coli CAB, but thereafter the relative risks declined toward unity. Still, the ≥1-year SIR for colorectal cancer remained 1.4-fold elevated, and the SIR for liver, pancreas, gallbladder, and biliary tract cancer was 2-fold elevated. The prevalence of phylogenetic groups was similar among patients with and without cancer.

CONCLUSIONS

Gastrointestinal, hepatobiliary, and urinary tract cancer may debut with E. coli CAB.

IMPACT

Owing to the high incidence of E. coli bacteremia, cancers missed at the time of bacteremia diagnosis represent a clinically significant problem.

Diagnosis and Management of UTI in Primary Care Settings-A Qualitative Study to Inform a Diagnostic Quick Reference Tool for Women Under 65 Years

Background: To inform interventions to improve antimicrobial use in urinary tract infections (UTIs) and contribute to a reduction in Escherichia coli bloodstream infection, we explored factors influencing the diagnosis and management of UTIs in primary care. Design: Semi-structured focus groups informed by the Theoretical Domains Framework. Setting: General practice (GP) surgeries in two English clinical commissioning groups (CCGs), June 2017 to March 2018. Participants: A total of 57 GP staff within 8 focus groups. Results: Staff were very aware of common UTI symptoms and nitrofurantoin as first-line treatment, but some were less aware about when to send a urine culture, second-line and non-antibiotic management, and did not probe for signs and symptoms to specifically exclude vaginal causes or pyelonephritis before prescribing. Many consultations were undertaken over the phone, many by nurse practitioners, and followed established protocols that often included urine dipsticks and receptionists. Patient expectations increased use of urine dipsticks, and immediate and 5 days courses of antibiotics. Management decisions were also influenced by patient co-morbidities. No participants had undertaken recent UTI audits. Patient discussions around antibiotic resistance and back-up antibiotics were uncommon compared to consultations for respiratory infections. Conclusions: Knowledge and skill gaps could be addressed with education and clear, accessible, UTI diagnostic and management guidance and protocols that are also appropriate for phone consultations. Public antibiotic campaigns and patient-facing information should cover UTIs, non-pharmaceutical recommendations for "self-care", prevention and rationale for 3 days antibiotic courses. Practices should be encouraged to audit UTI management.

Prevalence and recurrence of bacteraemia in hospitalised people who inject drugs - a single Centre retrospective cohort study in Denmark

Background

People who inject drugs (PWID) have increased risk of acquiring blood-transmitted chronic viral infections such as Hepatitis B (HBV), Hepatitis C (HCV) and Human Immunodeficiency Virus (HIV) as well as increased risk of acquiring bacterial infections. We aimed to identify and describe bacteraemic episodes, their recurrence rates, predictive and prognostic factors amongst hospitalised PWID.

Methods

In this retrospective cohort study, we included 257 hospitalised PWID during 2000–2006 with follow up at the Department of Infectious Diseases, Hvidovre Hospital, Denmark. Data collection included comorbidity (HBV-, HCV-, HIV-, and psychiatric comorbidities), social information (contact to an addiction treatment centre, homelessness), opioid substitution treatment (OST), treatment completion and microbiology findings. There was a 10-years follow-up regarding mortality.

Results

The study identified 257 patients classified as PWID. Of these, 58 (22.6%) had at least one episode of bacteraemia during their first hospital admission. Recurrence was found in 29 (50.0%) of the bacteraemia cases. Staphylococcus aureus was the dominant microorganism of both first and recurrent episodes with 24 (41.4%) and nine (31.4%) of cases, respectively. A psychiatric diagnose was significantly associated with a lower risk of bacteraemia in the multivariate analysis (OR: 0.29, [95%CI: 0.11–0.77], P = 0.01). Mortality was significantly higher in patients with bacteraemia (17.2% vs. 3.0%, P < 0.01, OR: 6.67 [95%CI: 2.33–20], P < 0.01).

Conclusions

In hospitalised PWID, bacteraemia was found in 22.6% and was associated with at higher mortality. The most common microorganism of bacteraemia was S. aureus. Psychiatric comorbidity was significantly associated with a lower risk of bacteraemia.

Prospective multi-center evaluation on risk factors, clinical characteristics and outcomes due to carbapenem resistance in Acinetobacter baumannii complex bacteraemia: experience from the Chinese Antimicrobial Resistance Surveillance of Nosocomial Infections (CARES) Network

Introduction. Increasing evidence demonstrates unfavourable outcomes in bloodstream infections (BSI) due to the carbapenem-resistant Acinetobacter baumannii complex (CRAB).Aim. To investigate the differences in risk factors, clinical characteristics and outcomes in patients with A. baumannii complex BSI stratified by carbapenem resistance, a prospective multi-center study was conducted.Methodology. Information was collected in a predefined form. A total of 317 cases was included for comparison between CRAB BSI vs. carbapenem-susceptible A. baumannii complex (CSAB) BSI. Among these cases, 229 cases were defined as CRAB BSI and 88 cases as CSAB BSI.Results. Univariable analysis showed that male gender, underlying neurologic disease, prior carbapenems exposure, intensive care unit (ICU) stay, presence of central venous catheter, endotracheal intubation, tracheotomy, Foley catheter, nasogastric intubation, lower respiratory tract infections and catheter-related infections were more prevalent in CRAB BSI. Only male gender, prior carbapenems exposure and presence of endotracheal intubation persisted as independent risk factors for acquiring CRAB BSI. Patients with CRAB BSI displayed unfavourable outcomes characterized by failure of pathogen clearance, continuous fever, disease aggravation and higher incidence of 30-day all-cause mortality. Multivariate analysis demonstrated carbapenem resistance as an independent risk factor for 30-day all-cause mortality.Conclusion. Our findings reveal the epidemiological differences between CRAB BSI and CSAB BSI in a Chinese cohort. Our data suggest that carbapenem resistance has a significant impact on mortality for patients with A. baumannii complex BSI, further strengthening the importance of active prevention and control strategies for the spread of CRAB in Chinese hospitals.

A retrospective study on Escherichia coli bacteremia in immunocompromised patients: Microbiological features, clinical characteristics, and risk factors for shock and death

Background

To evaluate clinical features, bacterial characteristics, and risk factors for shock and mortality of immunocompromised patients with Escherichia coli bacteremia.

Methods

A nearly 6‐year retrospective study of E coli bacteremia in 188 immunocompromised patients at Xiangya Hospital was conducted. Demographic, clinical, and laboratory data were documented. Phylogenetic background and virulence factors of E coli isolates were detected by polymerase chain reaction. Risk factors for shock and mortality were also investigated.

Results

Of all 188 E coli isolates, most prevalent virulence factors were fimH (91.0%), followed by traT (68.6%) and iutA (67.0%), while papG allele I, gafD, and cdtB were not detected. Phylogenetic group D was dominant (42.0%) among all isolates, and group B2 accounted for 17.6%, while group A and B1 accounted for 28.2% and 12.2%, respectively. In univariate analysis, ibeA and cnf1 were associated with mortality, which were not found in multivariate regression analysis. 22.3% of patients suffered shock, and 30‐day mortality rate was 21.3%. MDR (HR 2.956; 95% CI, 1.091‐8.012) was the only risk factor for shock, while adult (HR 0.239; 95% CI, 0.108‐0.527) was a protective factor. Multivariate analysis revealed that shock (HR 4.268; 95% CI, 2.208‐8.248; P < .001) and Charlson index > 2 (HR 2.073; 95% CI, 1.087‐3.952; P = .027) were associated with fatal outcome.

Conclusions

Escherichia coli bacteremia was highly lethal in immunocompromised patients, and host‐related factors played major roles in poor prognosis, while bacterial determinants had little effect on outcome. This study also provided additional information about the virulence and phylogenetic group characteristics of E coli bacteremia.

Antimicrobial resistance of Escherichia coli isolated from retail foods in northern Xinjiang, China

To determine antimicrobial resistance, 431 samples of retail foods purchased at different supermarkets in Northern Xinjiang were examined in this study. There were 112 Escherichia coli strains that were isolated, with approximately 26% of the samples contaminated by E. coli. The detection rate of E. coli isolated from pork was the highest (59.6%), followed by mutton (52.6%), retail fresh milk (52.4%), duck (36.4%), beef (35.3%), chicken (33.3%), and ready-to-eat food (12.9%); the E. coli detection rate for fish and vegetables was <11%. The result showed that the 112 isolates were mostly resistant to tetracycline (52%), followed by ampicillin (42%), compound trimethoprim/sulfamethoxazole (37%), amoxicillin (33%), and nalidixic acid (32%), imipenem resistance was not detected. One hundred isolates carried at least one antimicrobial resistance gene. The detection rate of resistance genes of our study was as follows: tetA (38%), tetB (27%), bla OXA (40%), bla TEM (20%), floR (20%), sul1 (16%), sul2 (27%), aad Ala (19%), aadB (11%), strA (28%), and strB (24%); tetC and bla PSE were not detected. Virulence genes fimC, agg, stx2, fimA, fyuA, papA, stx1, and eaeA were found in 52, 34, 21, 19, 6, 3, 2, and 2 isolates, respectively; papC was not detected. There was a statistically significant association between fimC and resistance to ciprofloxacin (p = .001), gentamicin (p = .001), amikacin (p = .001), levofloxacin (p = .001), and streptomycin (p = .001); between fimA and resistance to tetracycline (p = .001), ampicillin (p = .001), compound trimethoprim/sulfamethoxazole (p = .001), and amoxicillin (p = .003); between agg and resistance to gentamicin (p = .001), tetracycline (p = .001), ciprofloxacin (p = .017), and levofloxacin (p = .001); and between stx2 and resistance to ampicillin (p = .001), tetracycline (p = .001), compound trimethoprim/sulfamethoxazole (p = .002), and amoxicillin (p = .015).

Impact of rapid microbial identification on clinical outcomes in bloodstream infection: the RAPIDO randomized trial

OBJECTIVES

Bloodstream infection has a high mortality rate. It is not clear whether laboratory-based rapid identification of the organisms involved would improve outcome.

METHODS

The RAPIDO trial was an open parallel-group multicentre randomized controlled trial. We tested all positive blood cultures from hospitalized adults by conventional methods of microbial identification and those from patients randomized (1:1) to rapid diagnosis in addition to matrix-assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) performed directly on positive blood cultures. The only primary outcome was 28-day mortality. Clinical advice on patient management was provided to members of both groups by infection specialists.

RESULTS

First positive blood culture samples from 8628 patients were randomized, 4312 into rapid diagnosis and 4136 into conventional diagnosis. After prespecified postrandomization exclusions, 2740 in the rapid diagnosis arm and 2810 in the conventional arm were included in the mortality analysis. There was no significant difference in 28-day survival (81.5% 2233/2740 rapid vs. 82.3% 2313/2810 conventional; hazard ratio 1.05, 95% confidence interval 0.93-1.19, p 0.42). Microbial identification was quicker in the rapid diagnosis group (median (interquartile range) 38.5 (26.7-50.3) hours after blood sampling vs. 50.3 (47.1-72.9) hours after blood sampling, p < 0.01), but times to effective antimicrobial therapy were no shorter (respectively median (interquartile range) 24 (2-78) hours vs. 13 (2-69) hours). There were no significant differences in 7-day mortality or total antibiotic consumption; times to resolution of fever, discharge from hospital or de-escalation of broad-spectrum therapy or 28-day Clostridioides difficile incidence.

CONCLUSIONS

Rapid identification of bloodstream pathogens by MALDI-TOF MS in this trial did not reduce patient mortality despite delivering laboratory data to clinicians sooner.