A scoring system to predict resistance to ceftolozane/tazobactam in respiratory isolates of Pseudomonas aeruginosa

• Published in: Journal of antimicrobial chemotherapy 2025-01
• Main Authors: Karadogan, Eda, Sertcelik, Ahmet, Dizman, Gulcin Telli, Uzar, Hanife, Hazirolan, Gulsen, Cakir, Banu, Metan, Gokhan
• Format: Article
• Language: English
• ISSN: 1460-2091; 1460-2091
• DOI: 10.1093/jac/dkae476

To develop a scoring system to predict resistance to ceftolozane/tazobactam in Pseudomonas aeruginosa strains isolated from respiratory specimens.OBJECTIVESTo develop a scoring system to predict resistance to ceftolozane/tazobactam in Pseudomonas aeruginosa strains isolated from respiratory specimens.A case-control study was conducted to evaluate the risk factors associated with resistance to ceftolozane/tazobactam. Patients with P. aeruginosa were defined as cases if they had ceftolozane/tazobactam-resistant strains, whereas those with ceftolozane/tazobactam-susceptible strains were defined as test-negative controls. A predictive scoring system based on binary logistic regression coefficients was formulated to predict resistance to ceftolozane/tazobactam. The score's performance was assessed using ROC curves and AUC. The sensitivity, specificity and predictive values of the score were determined on the basis of a cut-off point, using the Youden index.METHODSA case-control study was conducted to evaluate the risk factors associated with resistance to ceftolozane/tazobactam. Patients with P. aeruginosa were defined as cases if they had ceftolozane/tazobactam-resistant strains, whereas those with ceftolozane/tazobactam-susceptible strains were defined as test-negative controls. A predictive scoring system based on binary logistic regression coefficients was formulated to predict resistance to ceftolozane/tazobactam. The score's performance was assessed using ROC curves and AUC. The sensitivity, specificity and predictive values of the score were determined on the basis of a cut-off point, using the Youden index.Ceftolozane/tazobactam resistance was detected in 18.4% of P. aeruginosa isolates from 473 patients. In multivariate analysis, a history of bronchoscopy [OR (95% CI) = 2.1 (1.1-4.3), P = 0.035], invasive mechanical ventilation [OR (95% CI) = 2.4 (1.2-4.5), P = 0.009], colistin/polymyxin B use [OR (95% CI) = 3.2 (1.8-5.7), P