Point-counterpoint: Piperacillin-tazobactam should be used to treat infections with extended-spectrum-beta-lactamase-positive organisms

Points of agreement 1. The decision to use PTZ to treat an infection with an ESBL-GNR is complex and requires consideration of the source of the infection, the severity of the infection, the identity of the organism, the MIC of the organism, and the dosage of antibiotic used. 2. PTZ may be effective for treating invasive ESBL-GNR infections in patients who are not critically ill and who have a lower inoculum of infection and a lower MIC (2 g/ml). 3. The strongest data supporting the use of a BLBLI for treating infections caused by ESBL-GNR are those from urinary tract infections and possibly biliary tract infections. 4. Therapy using BLBLIs appears to be less effective than carbapenem therapy for bloodstream infections due to ESBL-GNR. 5. If PTZ is used for these infections, the laboratory should report MIC data and perform ESBL confirmatory testing to provide clinicians with optimal information for clinical decisions. 6. Laboratories that perform ESBL confirmatory testing should consider inclusion of a comment indicating that PTZ therapy may be inadequate for treating bloodstream infections or other serious infections. Points requiring further consideration 1. The efficacy of BLBLIs for bloodstream infections due to ESBL-producing organisms needs to be assessed in a large multicenter trial. The ongoing MERINO study, a randomized controlled trial of PTZ versus meropenem for the treatment of bloodstream infections due to these organisms, should provide much-needed data on appropriate treatment options. 2. Similar studies are needed for other types of infections, such as intra-abdominal infections. 3. Outcomes studies assessing the clinical utility of rapid molecular methods for detecting ESBL-producing organism are needed to assist clinical laboratories in determining the ideal approach for confirming identification of ESBL-producing organisms.