Catheter-related bloodstream infections: predictive factors for Gram-negative bacteria aetiology and 30 day mortality in a multicentre prospective cohort.

BACKGROUND: Catheter-related bloodstream infections (CRBSIs) increase morbidity and mortality, prolong hospitalization and generate considerable medical costs. Recent guidelines for CRBSI recommend empirical therapy against Gram-positive bacteria (GPB) and restrict coverage for Gram-negative bacteria (GNB) only to specific circumstances. OBJECTIVES: To investigate predictors of GNB aetiology in CRBSI and to assess the predictors of outcome in patients with CRBSI. METHODS: Patients with CRBSI were selected from the PROBAC cohort, a prospective, observational, multicentre national cohort study including patients with bloodstream infections consecutively admitted to 26 Spanish hospitals in a 6 month period (October 2016-March 2017). Outcome variables were GNB aetiology and 30 day mortality. Adjusted analyses were performed by logistic regression. RESULTS: Six hundred and thirty-one episodes of CRBSI were included in the study. Risk factors independently related to GNB aetiology were central venous catheter (CVC) [OR 1.60 (95% CI: 1.05-2.44), P = 0.028], sepsis/septic shock [OR: 1.76 (95% CI: 1.11-2.80), P = 0.016], antibiotic therapy in the previous 30 days [OR: 1.56 (95% CI: 1.02-2.36), P = 0.037], neutropenia <500/µL [OR: 2.01 (95% CI: 1.04-3.87), P = 0.037] and peripheral vascular disease [OR: 2.04 (95% CI: 1.13-3.68), P = 0.018]. GNB were not associated with increased mortality in adjusted analysis, while removal of catheter [OR: 0.24 (95% CI: 0.09-0.61), P = 0.002] and adequate empirical treatment [OR: 0.37 (95% CI: 0.18-0.77), P = 0.008] were strong protective factors. CONCLUSIONS: Our study reinforces the recommendation that empirical coverage should cover GNB in patients presenting with sepsis/septic shock and in neutropenic patients. Catheter removal and adequate empirical treatment were both protective factors against mortality in patients with CRBSI.

Utility of an immunocapture-agglutination test and an enzyme-linked immunosorbent assay test against cytosolic proteins from Brucella melitensis B115 in the diagnosis and follow-up of human acute brucellosis.

The utility of an immunocapture-agglutination (Brucellacapt, Vircell SL, Granada, Spain) test and an enzyme-linked immunosorbent assay IgG, IgA, and IgM (ELISA-IgG, ELISA-IgA, ELISA-IgM) against cytosolic proteins from Brucella melitensis B115 (R) was compared with ELISA-IgG, ELISA-IgA, and ELISA-IgM against smooth lipopolysaccharide (S-LPS) from B. melitensis 16M (S), serum agglutination test (SAT), and Coombs test in the diagnosis and follow-up for 10 months of 51 patients with acute brucellosis. The sensitivities of ELISA tests against cytosolic proteins varied from 49.0 % for ELISA-IgG to 64.7% for ELISA-IgM and were lower than the sensitivities showed by ELISA S-LPS (from 88.2% to 92.2%), SAT (88.2%), Coombs (96.1%), and Brucellacapt (98.0%) tests. Specificity was over 93% in all cases. The evolutionary behavior of the SAT, Coombs, and Brucellacapt tests was similar. There was a decrease of between 20% and 40% in antibody titer in the 10th month of evolution after treatment. The evolutional curves of IgG, IgA, and IgM against cytosolic protein increased slightly till the eighth month. The specific IgM and IgA antibodies against protein fractions began to show a drop from the eighth month on, showing levels slightly lower than the initial sera values by the end of the 10th month. In this month, titers of specific IgG against proteins fractions remained higher than the titers showed by the initial sera.