Temocillin vs Meropenem for the Targeted Treatment of Bacteraemia Resistant to Third Gen Cephalosporins

Inclusion Criteria: * Adult patients with monomicrobial bacteremia due to Enterobacteriaceae showing resistance to cefotaxime, ceftriaxone (MIC \>2 mg/L) and/or ceftazidime (MIC \>4 mg/L), and sensible to temocillin (MIC ≤8 mg/L, except in bacteremia only of urinary origin, for which the criterion is MIC ≤16 mg/L ) and meropenem (MIC ≤2 mg/L). Patients with polymicrobial bacteremia caused by more than one Enterobacteriaceae species may also be included, provided at least one of them is resistant to third-generation cephalosporins, and both are susceptible to meropenem and temocillin. * Duration of intravenous treatment is planned to be at least 4 days from randomization, or 3 days if the empirical treatment prior to randomization was active. * The patient signed informed consent form. * Potentially fertile patients must have a negative pregnancy test. Exclusion Criteria: * \<18 years * Pregnancy * Breastfeeding * Terminal condition, with life expectancy of less than 30 days, or palliative care , such that no actions will be taken to control the source of infection if necessary. Patients receiving palliative care with a life expectancy greater than 30 days may be included if source control is not necessary or, if necessary, will be carried out. * Allergy to betalactams * Polymicrobial bacteraemia (except when the other microorganism is considered a contaminant, (e.g. coagulase-negative staphylococci or diphtheroids in a single blood culture, or in cases where more than one Enterobacteriaceae species is isolated, provided that at least one isolate is resistant to third-generation cephalosporins and both are susceptible to meropenem and temocillin). * Infections typically needing prolonged \>14 days of therapy (e.g., endocarditis, prosthetic joint infection, vascular graft infection, empyema, chronic prostatitis) or meningitis. Patients who initially do not have a confirmed diagnosis of these infections may be included; if the diagnosis is made subsequently, the patient may be kept in the trial at the discretion of the investigator, establishing the duration of treatment that he considers necessary. * Active empirical treatment\> 96 hours after initial blood culture extraction * Delay in inclusion\> 48 h * Recruited in another clinical trial with active treatment * Peritoneal dialysis or continuous hemofiltration