Association of microbiological factors with mortality in Escherichia coli bacteraemia presenting with sepsis/septic shock: a prospective cohort study.

OBJECTIVES: This study aimed to determine the association of Escherichia coli microbiological factors with 30-day mortality in patients with bloodstream infection (BSI) presenting with a dysregulated response to infection (i.e. sepsis or septic shock). METHODS: Whole-genome sequencing was performed on 224 E coli isolates of patients with sepsis/septic shock, from 22 Spanish hospitals. Phylogroup, sequence type, virulence, antibiotic resistance, and pathogenicity islands were assessed. A multivariable model for 30-day mortality including clinical and epidemiological variables was built, to which microbiological variables were hierarchically added. The predictive capacity of the models was estimated by the area under the receiver operating characteristic curve (AUROC) with 95% confidence intervals (CI). RESULTS: Mortality at day 30 was 31% (69 patients). The clinical model for mortality included (adjusted OR; 95% CI) age (1.04; 1.02-1.07), Charlson index ≥3 (1.78; 0.95-3.32), urinary BSI source (0.30; 0.16-0.57), and active empirical treatment (0.36; 0.11-1.14) with an AUROC of 0.73 (95% CI, 0.67-0.80). Addition of microbiological factors selected clone ST95 (3.64; 0.94-14.04), eilA gene (2.62; 1.14-6.02), and astA gene (2.39; 0.87-6.59) as associated with mortality, with an AUROC of 0.76 (0.69-0.82). DISCUSSION: Despite having a modest overall contribution, some microbiological factors were associated with increased odds of death and deserve to be studied as potential therapeutic or preventive targets.

Whole-genome characterisation of Escherichia coli isolates from patients with bacteraemia presenting with sepsis or septic shock in Spain: a multicentre cross-sectional study.

BACKGROUND: Escherichia coli is the most frequent cause of bloodstream infections (BSIs). About one-third of patients with BSIs due to E coli develop sepsis or shock. The objective of this study is to characterise the microbiological features of E coli blood isolates causing sepsis or septic shock to provide exploratory information for future diagnostic, preventive, or therapeutic interventions. METHODS: E coli blood isolates from a multicentre cross-sectional study of patients older than 14 years presenting with sepsis or septic shock (according to the Third International Consensus Definitions for Sepsis and Septic Shock criteria) from hospitals in Spain between Oct 4, 2016, and Oct 15, 2017, were studied by whole-genome sequencing. Phylogroups, sequence types (STs), serotype, FimH types, antimicrobial resistance (AMR) genes, pathogenicity islands, and virulence factors were identified. Susceptibility testing was performed by broth microdilution. The main outcome of this study was the characterisation of the E coli blood isolates in terms of population structure by phylogroups, groups (group 1: phylogroups B2, F, and G; group 2: A, B1, and C; group 3: D), and STs and distribution by geographical location and bloodstream infection source. Other outcomes were virulence score and prevalence of virulence-associated genes, pathogenicity islands, AMR, and AMR-associated genes. Frequencies were compared using χ² or Fisher's exact tests, and continuous variables using the Mann-Whitney test, with Bonferroni correction for multiple comparisons. FINDINGS: We analysed 224 isolates: 140 isolates (63%) were included in phylogenetic group 1, 52 (23%) in group 2, and 32 (14%) in group 3. 85 STs were identified, with four comprising 44% (n=98) of the isolates: ST131 (38 [17%]), ST73 (25 [11%]), ST69 (23 [10%]), and ST95 (12 [5%]). No significant differences in phylogroup or ST distribution were found according to geographical areas or source of bloodstream infection, except for ST95, which was more frequent in urinary tract infections than in other sources (11 [9%] of 116 vs 1 [1%] of 108, p=0·0045). Median virulence score was higher in group 1 (median 25·0 [IQR 20·5-29·0) than in group 2 (median 14·5 [9·0-20·0]; p<0·0001) and group 3 (median 21 [16·5-23·0]; p<0·0001); prevalence of several pathogenicity islands was higher in group 1. No significant differences were found between phylogenetic groups in proportions of resistance to antibiotics. ST73 had higher median virulence score (32 [IQR 29-35]) than the other predominant clones (median range 21-28). Some virulence genes and pathogenicity islands were significantly associated with each ST. ST131 isolates had higher prevalence of AMR and a higher proportion of AMR genes, notably blaCTX-M-15 and blaOXA-1. INTERPRETATION: In this exploratory study, the population structure of E coli causing sepsis or shock was similar to previous studies that included all bacteraemic isolates. Virulence genes, pathogenicity islands, and AMR genes were not randomly distributed among phylogroups or STs. These results provide a comprehensive characterisation of invasive E coli isolates causing severe response syndrome. Future studies are required to determine the contribution of these microbiological factors to severe clinical presentation and worse outcomes in patients with E coli bloodstream infection. FUNDING: Instituto de Salud Carlos III.

[A prospective, controlled, non-randomized study of three cohorts to test the effectiveness of two antibiotics levofloxacin and cotrimoxazol on antibacterial prophylaxis in neutropenic patients]. / Estudio prospectivo y controlado, no aleatorizado, de tres cohortes sobre la efectividad de dos pautas antibióticas, levofloxacino y contrimoxazol, en profilaxis antibacteriana de pacientes neutropénicos.

BACKGROUND AND OBJECTIVE: At present, there is strong concern about the efficacy of current antimicrobial prophylaxis for the management of neutropenic patients. The purpose of this study was to test the effectiveness of levofloxacin, a new quinolone with expanded activity against grampositive bacteria, versus cotrimoxazol as a prophylactic treatment for granulocytopenic patients. PATIENTS AND METHOD: In this prospective and controlled study, we included 249 consecutive episodes of neutropenia, such as those resulting from lymphoma and leukemia treatment, during 28 months (from November 1999 to February 2002). These episodes were divided into 3 cohorts: the first was treated with levofloxacin, the second with cotrimoxazol and the third was a subgroup without antibiotic prophylaxis (control group). The incidence of infection, rate of mortality, and reduction of hospitalization rate for treatment with parenteral antibiotics were tested. RESULTS: There was a reduction in documented infections (clinically or microbiologically) when comparing the levofloxacin cohort with the control cohort (p < 0.0001) and the levofloxacin cohort with the cotrimoxazol group (p < 0.01). The reduction in the hospitalization rate for treatment with parenteral antibiotics reached statistical significance when comparing the levofloxacin group with the control cohort (p < 0.001) and levofloxacin group with the cotrimoxazol group (p < 0.05). Although the rate of global mortality was lower in the levofloxacin group than in the other two groups, no statistical significance was observed. CONCLUSIONS: Our results show that levofloxacin effectively reduces the incidence of infection, the rate of hospitalization and the requirement for parenteral antibiotics. Although we found a reduction in the overall mortality and in the infection-related mortality, the corresponding data did not reach statistical significance.

Estudio prospectivo y controlado, no aleatorizado, de tres cohortes sobre la efectividad de dos pautas antibióticas, levofloxacino y contrimoxazol, en profilaxis antibacteriana de pacientes neutropénicos / A prospective, controlled, non-randomized study of three cohorts to test the effectiveness of two antibiotics levofloxacin and cotrimoxazol on antibacterial prophylaxis in neutropenic patients

FUNDAMENTO Y OBJETIVO: En el momento actual existe una honda preocupación sobre la eficacia de la profilaxis antimicrobiana en pacientes neutropénicos. Se plantea como objetivo el estudio de la efectividad del levofloxacino, una nueva quinolona con mayor actividad sobre microorganismos grampositivos, comparado con cotrimoxazol y con la ausencia de tratamiento antimicrobiano (grupo control), como tratamiento profiláctico en pacientes granulocitopénicos. PACIENTES Y MÉTODO: En este estudio, prospectivo y controlado, se han incluido 249 episodios consecutivos de neutropenia en pacientes sometidos a regímenes de poliquimioterapia, durante 28 meses (desde noviembre de 1999 a febrero de 2002). Estos episodios se han distribuido en tres cohortes: según recibieran levofloxacino, cotrimoxazol, o sin tratamiento antibiótico profiláctico (grupo control). Se han estudiado la tasa de infecciones, el índice de mortalidad y la necesidad de ingreso hospitalario para tratamiento antibiótico intravenoso. RESULTADOS: Los datos de este estudio evidencian una reducción de la tasa de infecciones documentadas (clínica o bacteriológicamente) entre el grupo de levofloxacino y el grupo control (p < 0,0001), así como entre el grupo de levofloxacino y el de cotrimoxazol (p < 0,01). La reducción de la necesidad de hospitalización para tratamiento antibiótico por vía intravenosa alcanzó significación estadística entre la cohorte de levofloxacino y la de control (p < 0,001) y entre levofloxacino y cotrimoxazol (p < 0,05). Aunque la tasa de mortalidad global fue inferior en el grupo de levofloxacino que en los otros dos grupos, no llegó a alcanzar valor estadístico significativo. Además, sólo hubo dos casos de mortalidad en pacientes en remisión en el momento de recibir la poliquimioterapia (uno en el grupo control y otro en el de cotrimoxazol). Por otro lado, los datos de la mortalidad asociada a infección, aunque también fueron mejores en el grupo de levofloxacino, tampoco alcanzaron significación estadística. CONCLUSIONES: Los resultados ponen de manifiesto que el levofloxacino es efectivo en la reducción de la incidencia de infección y del índice de hospitalización para tratamiento con antibioticos por vía intravenosa. Aunque se ha observado una reducción en la mortalidad global y en la mortalidad relacionada con infección, estos valores no llegaron a alcanzar significación estadística. Según las bases de datos consultadas, éste es el primer estudio controlado en el cual esta nueva quinolona se ha ensayado en pacientes neutropénicos sometidos a regímenes poliquimioterápicos para tratar enfermedades oncohematológicas (AU)