Risk factors and outcome due to extended-spectrum ß-lactamase-producing uropathogenic Escherichia coli in community-onset bloodstream infections: A ten-year cohort study in Sweden.

OBJECTIVE: To study clinical outcome and risk factors associated with extended-spectrum ß-lactamase (ESBL)-producing uropathogenic Escherichia coli (UPEC) in community-onset bloodstream infections (CO-BSI). METHODS: This was a population-based cohort study including patients with pheno- and genotype-matched ESBL-producing E. coli and non-ESBL- E. coli in urine and blood samples collected in 2009-2018 in southeast Sweden. Seventy-seven episodes of ESBL-UPEC satisfying the inclusion criteria were matched 1:1 with 77 non-ESBL-UPEC for age, gender, and year of culture. RESULTS: The most common ST-type and ESBL gene was ST131 (55%), and blaCTX-M-15 (47%), respectively. Risk factors for ESBL-UPEC were: previous genitourinary invasive procedure (RR 4.66; p = 0.005) or history of ESBL-producing E. coli (RR 12.14; p = 0.024). There was significant difference between ESBL-UPEC and non-ESBL-UPEC regarding time to microbiologically appropriate antibiotic therapy (27:15 h vs. 02:14 h; p = <0.001) and hospital days (9 vs. 5; p = <0.001), but no difference in 30-day mortality (3% vs. 3%; p = >0.999) or sepsis within 36 hours (51% vs. 62%; p = 0.623) was observed. CONCLUSION: The predominant risk factors for ESBL-UPEC were history of ESBL-Ec infection and history of genitourinary invasive procedure. The overall mortality was low and the delay in appropriate antibiotic therapy did not increase the risk for 30-day mortality or risk for sepsis within 36 hours among patients infected with ESBL UPEC. However, these results must be regarded with some degree of caution due to the small sample size.

Antibiotic resistance among major pathogens compared to hospital treatment guidelines and antibiotic use in Nordic hospitals 2010-2018.

BACKGROUND: The Nordic countries have comparable nationwide antibiotic resistance surveillance systems and individual antibiotic stewardship programmes. The aim of this study was to assess antibiotic resistance among major pathogens in relation to practice guidelines for hospital antibiotic treatment and antibiotic use in Nordic countries 2010-2018. METHODS: Antibiotic resistance among invasive isolates from 2010-2018 and aggregated antibiotic use were obtained from the European Centre for Disease Prevention and Control. Hospital practice guidelines were obtained from national or regional guidelines. RESULTS: Antibiotic resistance levels among Escherichia coli and Klebsiella pneumoniae were similar in all Nordic countries in 2018 and low compared to the European mean. Guidelines for acute pyelonephritis varied; 2nd generation cephalosporin (Finland), 3rd generation cephalosporins (Sweden, Norway), ampicillin with an aminoglycoside or aminoglycoside monotherapy (Denmark, Iceland and Norway). Corresponding guidelines for sepsis of unknown origin were 2nd (Finland) or 3rd (Sweden, Norway, Iceland) generation cephalosporins, carbapenems, (Sweden) combinations of penicillin with an aminoglycoside (Norway, Denmark), or piperacillin-tazobactam (all Nordic countries). Methicillin-resistant Staphylococcus aureus rates were 0-2% and empirical treatment with anti-MRSA antibiotics was not recommended in any country. Rates of penicillin non-susceptibility among Streptococcus pneumoniae were low (<10%) except in Finland and Iceland (<15%), but benzylpenicillin was recommended for community-acquired pneumonia in all countries. CONCLUSION: Despite similar resistance rates among Enterobacteriaceae there were differences in practice guidelines for pyelonephritis and sepsis. National surveillance of antibiotic resistance can be used for comparison and optimization of guidelines and stewardship interventions to preserve the low levels of antibiotic resistance in Nordic countries.

Low incidence of antibiotic-resistant bacteria in south-east Sweden: An epidemiologic study on 9268 cases of bloodstream infection.

OBJECTIVES: The aim of this study was to investigate the epidemiology of bloodstream infections (BSI) in a Swedish setting, with focus on risk factors for BSI-associated mortality. METHODS: A 9-year (2008-2016) retrospective cohort study from electronic records of episodes of bacteremia amongst hospitalized patients in the county of Östergötland, Sweden was conducted. Data on episodes of BSI including microorganisms, antibiotic susceptibility, gender, age, hospital admissions, comorbidity, mortality and aggregated antimicrobial consumption (DDD /1,000 inhabitants/day) were collected and analyzed. Multidrug resistance (MDR) was defined as resistance to at least three groups of antibiotics. MDR bacteria and MRSA, ESBL-producing Enterobacteriaceae, vancomycin-resistant enterococci not fulfilling the MDR criteria were all defined as antimicrobial-resistant (AMR) bacteria and included in the statistical analysis of risk factors for mortality. RESULTS: In all, 9,268 cases of BSI were found. The overall 30-day all-cause mortality in the group of patients with BSI was 13%. The incidence of BSI and associated 30-day all-cause mortality per 100,000 hospital admissions increased by 66% and 17% respectively during the nine-year study period. The most common species were Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae and Enterococcus faecalis. Independent risk factors for 30-day mortality were age (RR: 1.02 (CI: 1.02-1.03)) and 1, 2 or ≥3 comorbidities RR: 2.06 (CI: 1.68-2.52), 2.79 (CI: 2.27-3.42) and 2.82 (CI: 2.31-3.45) respectively. Almost 3% (n = 245) of all BSIs were caused by AMR bacteria increasing from 12 to 47 per 100,000 hospital admissions 2008-2016 (p = 0.01), but this was not associated with a corresponding increase in mortality risk (RR: 0.89 (CI: 0.81-0.97)). CONCLUSION: Comorbidity was the predominant risk factor for 30-day all-cause mortality associated with BSI in this study. The burden of AMR was low and not associated with increased mortality. Patients with BSIs caused by AMR bacteria (MDR, MRSA, ESBL and VRE) were younger, had fewer comorbidities, and the 30-day all-cause mortality was lower in this group.