[Impact of reporting gram stain results from blood culture bottles on the selection of antimicrobial agents].

We assessed the utility of reporting direct blood Gram stain results compared with the results of positive blood cultures in 482 episodes, and monitored the impact on the selection of antimicrobial treatment. We found that the groups: "Staphylococcus species (spp.)", "Pseudomonas spp. and related organisms", and "Yeasts" identified in this way perfectly matched those on later culture identification. When the report indicated "Staphylococcus spp." or "Pseudomonas spp. and related organisms", the physicians started or changed antimicrobials suitable for these bacteria more frequently than "Other streptococci" and "family Enterobacteriaceae" (p < 0.05). The incorrect recognition of Acinetobacter spp. and Pseudomonas spp. as "family Enterobacteriaceae" is still the most challenging problem in this context, but these microorganisms seemed to be cultured from patients in some special departments and clinical conditions, including malignant diseases and chemotherapy. In conclusion, Gram-stain results that definitively identify "Staphylococcus spp.", "Pseudomonas spp. and related organisms", and "Yeasts" can be reliably and rapidly provided by clinical laboratories, and this has a significant impact on the early selection of effective antimicrobials. In case of patients at a high risk of non-fermentative gram-negative rod infection, we have to consider the selection of anti-pseudomonal agents while awaiting culture identification and susceptibility tests. Further investigation is needed to assess the clinical impact of reporting Gram-stain results in the presence of bacteremia.