Ceftolozane/tazobactam is a cephalosporin/beta-lactamase inhibitor with enhanced activity against P. aeruginosa, approved for the treatment of complicated intra-abdominal infection, and complicated UTIs including pyelonephritis with no restrictions of age, provided the patients are ≥ 7 days and ≥ 32 weeks of gestation, and for the treatment of hospital-acquired pneumonia in adults [48]. Here, LACTB is linked to pyelonephritis.