Bactec 9240 system

After disinfection of the skin and the connector, 8 to 10 mL of blood (one aerobic and one anaerobic BC bottle) was collected by sterile venepuncture or from a central venous catheter, if one was present. Blood was inoculated in BC bottles and incubated for up to 7 days at 36 °C (BACTEC 9240 system; Becton-Dickinson, Heidelberg, Germany). If BC results were positive, aliquots were drawn for Gram staining and culturing on solid media. Microorganisms were identified with VITEK MS mass spectrometry (bioMerieux, Nürtingen, Germany) or the MicroScan Walk-Away system (Beckmann Coulter, Krefeld, Germany).

Blood samples were processed using the Bactec 9240 system or Bactec FX system (Becton, Dickinson Microbiology Systems), with a 5-day incubation period. Isolates were identified by standard techniques. Antimicrobial susceptibility testing was performed using either a microdilution system (Microscan WalkAway Dade Behring, West Sacramento, CA or Phoenix system, Becton, Dickinson, Franklin Lakes, NJ) or the Etest (AB Biodisk, Solna, Sweden/bioMérieux, Mercy l’Etoile, France).
To define susceptibility or resistance to these antimicrobial agents, EUCAST version 9.0 of the EUCAST clinical breakpoint tables was used (35 ).

Blood samples were processed using the BACTEC 9240 system or Bactec FX system (Becton-Dickinson Microbiology Systems), with an incubation period of 5 d. Isolates were identified using MALDI-TOF mass spectrometry, which was supplemented with biochemical reactions during the first 2 yr for additional confirmation. Antimicrobial susceptibility testing was performed using a microdilution system (Phoenix system, Becton Dickinson, Franklin Lakes, NJ) or the Etest (AB Biodisk, Solna, Sweden/bioMérieux, Mercy l’Etoile, France). ESBL-producing bacteria were suspected by MIC results and confirmed by a double-disc synergy test (15 (link)). Carbapenemase-producing Enterobacterales were phenotypically detected by the modified carbapenem inactivation method (mCIM) (16 (link)), in combination with the NG-Test CARBA 5 lateral flow immunoassay (NG Biotech, France) to detect the five most prevalent carbapenemases (KPC, OXA-48-like, VIM, IMP, and NDM) (17 (link)). Current EUCAST breakpoints for each year were used to define susceptibility or resistance to these antimicrobial agents, and intermediate susceptibility was considered as resistance.

An episode of candidemia was defined as the isolation of a Candida spp. from blood culture [3 (link)]. If there was more than 1 candidemia episode in the same patient, only the first episode was considered for the study.
Two blood culture sets from peripheral sites were obtained from patients with fever (≥38 °C) or clinical presentation suggestive of infection and sent off to the clinical laboratory of the Microbiology Department. The blood samples were analyzed using a BACTEC 9240 system (Becton-Dickinson Microbiology Systems, Franklin Lakes, NJ, USA) or BacT/Alert (BioMérieux SA, Marcy L’Etoile, France).
We defined septic shock using the international consensus definition for sepsis and septic shock as a subset of sepsis in which the underlying abnormalities of cellular and circulatory metabolism are profound enough to substantially increase mortality, in which vasopressor therapy is needed to elevate the mean arterial pressure ≥65 mmHg despite adequate fluid resuscitation [26 (link),27 (link)]. PMV was considered greater than 48 h [28 (link)]. RRT was considered in case of potassium derangements, acid-base disbalance, fluid overload, or pronounced azotemia [29 (link)].

To detect the presence of Brucella, about 8–10 mL milk or whole blood samples from seropositive animals were inoculated into BACTEC bottles (Lytic/10 aerobic/F culture vials) and incubated for about 7 days in a BACTEC 9240 system (Becton Dickinson, USA). When a positive bottle was detected, a Gram stain for the broth was performed, and a portion of the fluid was subcultured onto 5% sheep blood agar and incubated for 3–4 days at 37°C. Bottles with negative growth index were kept for three more weeks. Cultures were considered negative if no Brucella was detected during the fourth week of incubation.