Objectives: To characterise urinary tract infections (UTIs) caused by Pseudomonas aeruginosa in hospitalised adults and identify risk factors for those caused by multidrug-resistant (MDR) strains. Methods: A retrospective case-case-control study was conducted in two teaching hospitals. Results: 242 monomicrobial P. aeruginosa UTIs were analysed, 65 (26.8%) of which were caused by MDR strains. Clinical treatment failure at 72 h was more frequent in MDR cases (38/65 [58.4%] vs. 45/177 (25.4%) in non-MDR cases, p=<0.001), particularly when a β-lactam-β-lactamase inhibitor combination or fluoroquinolone was initially prescribed. By day 7 (when all treatment regimens were consistent with antimicrobial susceptibility testing (AST) results), treatment failure rates were similar (MDR 15/65 [23.1%] vs. non-MDR 25/177 [14.1%], p=0.09). In-hospital mortality rates remained low in both groups (6/65 [9.2%] vs. 22/177 (12.3%), p=0.49), but median hospital stays for the MDR cases were longer (48 vs. 22 days in non-MDR, p=<0.001). The models for predicting MDR and non-MDR P. aeruginosa UTIs displayed good discriminatory power. The presence of ≥3 risk factors for MDR P. aeruginosa UTI was associated with an OR for this outcome of 7.44 (95% CI 3,24-17.57, P<0.001; specificity 91%, accuracy 75%). The model for predicting non-MDR P. aeruginosa UTI displayed similar accuracy (74%) with a risk-factor burden threshold of ≥2 (OR 7.02 [95% CI 4.61-10.70], P<0.001). Conclusions: Risk-factor assessment can identify UTIs in hospitalised patients likely to be caused by MDR P. aeruginosa strains, thereby facilitating targeted infection-control and timelier, effective treatment of these infections.
Tumbarello, M., Raffaelli, F., Peghin, M., Losito, A. R., Chirico, L., Giuliano, G., Spanu, T., Sartor, A., Fiori, B., Bassetti, M., Characterisation and risk-factor profiling of P. aeruginosa urinary tract infections: pinpointing those likely to be caused by multidrug-resistant strains, <<INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS>>, 2020; (NA): N/A-N/A. [doi:10.1016/j.ijantimicag.2020.105900] [http://hdl.handle.net/10807/148216]
Characterisation and risk-factor profiling of P. aeruginosa urinary tract infections: pinpointing those likely to be caused by multidrug-resistant strains
Tumbarello, Mario;Raffaelli, Francesca;Losito, Angela Raffaella;Giuliano, Gabriele;Spanu, Teresa;Fiori, Barbara;
2020
Abstract
Objectives: To characterise urinary tract infections (UTIs) caused by Pseudomonas aeruginosa in hospitalised adults and identify risk factors for those caused by multidrug-resistant (MDR) strains. Methods: A retrospective case-case-control study was conducted in two teaching hospitals. Results: 242 monomicrobial P. aeruginosa UTIs were analysed, 65 (26.8%) of which were caused by MDR strains. Clinical treatment failure at 72 h was more frequent in MDR cases (38/65 [58.4%] vs. 45/177 (25.4%) in non-MDR cases, p=<0.001), particularly when a β-lactam-β-lactamase inhibitor combination or fluoroquinolone was initially prescribed. By day 7 (when all treatment regimens were consistent with antimicrobial susceptibility testing (AST) results), treatment failure rates were similar (MDR 15/65 [23.1%] vs. non-MDR 25/177 [14.1%], p=0.09). In-hospital mortality rates remained low in both groups (6/65 [9.2%] vs. 22/177 (12.3%), p=0.49), but median hospital stays for the MDR cases were longer (48 vs. 22 days in non-MDR, p=<0.001). The models for predicting MDR and non-MDR P. aeruginosa UTIs displayed good discriminatory power. The presence of ≥3 risk factors for MDR P. aeruginosa UTI was associated with an OR for this outcome of 7.44 (95% CI 3,24-17.57, P<0.001; specificity 91%, accuracy 75%). The model for predicting non-MDR P. aeruginosa UTI displayed similar accuracy (74%) with a risk-factor burden threshold of ≥2 (OR 7.02 [95% CI 4.61-10.70], P<0.001). Conclusions: Risk-factor assessment can identify UTIs in hospitalised patients likely to be caused by MDR P. aeruginosa strains, thereby facilitating targeted infection-control and timelier, effective treatment of these infections.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.