Fig 1.
Laboratory workflow of positive blood culture bottles according to time of positivity detection during pre-intervention and intervention periods.
AST, antimicrobial susceptibility testing; BC, blood culture; βLT, βLACTA test; EB, Enterobacteriaceae; ID, identification; MALDI-TOF MS, matrix-assisted laser desorption ionization time-of-flight mass spectrometry; PBP2a, PBP2a Culture Colony Test. *: AST was directly performed from positive blood culture fluid when Gram staining identified a Gram-negative rod. Grey squares highlight the accelerated identification and susceptibility tests applied in the modified workflow.
Fig 2.
Flowchart of adult monomicrobial blood culture episodes included during pre-intervention and intervention periods.
BC, blood culture; BSI, bloodstream infections.
Table 1.
Distribution of microorganisms and main resistances of all bloodstream infections across the three study periods.
3GC, third generation cephalosporin (cefotaxime, ceftriaxone, ceftazidime); AST, antimicrobial susceptibility testing; BSI, bloodstream infection; carbapenem (imipenem, meropenem); ID, identification; P0, pre-intervention period; P1, intervention period 1; P2, intervention period 2. Natural AmpC producers identified during the study periods: Citrobacter freundii, Enterobacter aerogenes, Enterobacter cloacae, Hafnia alvei, Serratia marcescens. Non-natural AmpC producers identified during the study periods: Citrobacter koseri, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Salmonella spp.
Table 2.
Time to identification and time to partial/complete susceptibility results of all bloodstream infections during pre-intervention and intervention period 1 and 2.
Fig 3.
Distribution of the bloodstream infections over time in the three study periods according to their microbiological and clinical outcomes.
(A) Distribution of the bloodstream infections identified within defined time lapses. (B) Distribution of the bloodstream infections according to the time of complete susceptibility result availability. (C) Distribution of the bloodstream infections benefitting from the optimal antimicrobial treatment within defined time lapses. The “No change” category defines bloodstream infections optimally treated before the detection of positive blood culture. BSI, bloodstream infection.
Table 3.
Effective antibiotic treatment tailoring of bloodstream infections in both intervention periods following accelerated laboratory results.