415. Epidemiological Evaluation of Antibiotic Resistance and Subsequent Effect on Healthcare Resource Utilization among Subjects with Pseudomonas aeruginosa Infections in Italy
Authors: Bassetti Matteo , Cascio Antonio , Cattelan Annamaria , Cauda Roberto , Menichetti Francesco , Petrosillo Nicola , Rescigno Carolina , Tascini Carlo , Vena Antonio , Viale Pierluigi 
Published: December 2022

Abstract

Background
The aims of the study were to 1) evaluate the prevalence of multidrug resistant (MDR) /Extensively drug resistant (XDR) strains among hospitalized adults with Pseudomonas aeruginosa (PA) infections, and 2) examine whether antimicrobial resistance in PA infections is associated with worsening functional status and higher health care resource utilization (HCRU).

Methods
This multicenter prospective study was conducted in 9 large Italian teaching hospitals between June 2018-February 2020. We included patients aged ≥18 years with a diagnosis of nosocomial pneumonia (NP), complicated urinary tract infections (cUTI) or complicated intra-abdominal infections (cIAI) due to PA as confirmed by local evaluation of microbiological results. MDR PA was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories. XDR PA was defined as acquired non-susceptibility to at least one agent in all but two or fewer antimicrobial categories. HCRU metrics evaluated included hospital length of stay (LOS) and intensive care unit (ICU) LOS.

Results
A total of 95 patients with a nosocomial infection due to PA were enrolled. The main baseline characteristics of overall patients were reported in Table 1. Almost one-third of patients (28.4%) reported either MDR or XDR PA infection, with more patients experiencing MDR (Table 1). Health care resource use stratified by patients with and without MDR/XDR status are reported in Table 2. Overall, in our study population, median hospital LOS and ICU LOS were 42.0 (IQR=39.0) and 15.5 (IQR=37.0) days, respectively. There was a statistically significant longer median hospital LOS for patients with MDR/XDR infections compared to non MDR/XDR PA infections (53.0 vs. 36.5 days, p=0.04). ICU LOS also trended towards being longer for patients with MDR/XDR infections compared to those with non-MDR/XDR infections (25.5 vs. 13.5 days, p=0.10).

Conclusion
MDR/XDR isolates were prevalent among patients with nosocomial infections due to PA, particularly in those with cIAI. Overall, the present study may suggest a positive correlation between having MDR-XDR PA nosocomial infections (NP, cUTI, and cIAI) and increased HCRU that require further attention from a disease management perspective.

Disclosures
Matteo Bassetti, PhD, Angelini: Advisor/Consultant|Astellas: Grant/Research Support|Bayer: Advisor/Consultant|Bayer: Honoraria|BioMe ́ rieux: Advisor/Consultant|BioMe ́ rieux: Honoraria|Cidara: Advisor/Consultant|Cidara: Honoraria|Cipla: Advisor/Consultant|Cipla: Honoraria|Gilead: Advisor/Consultant|Gilead: Honoraria|Menarini: Advisor/Consultant|Menarini: Honoraria|MSD: Advisor/Consultant|MSD: Honoraria|Nabriva: Advisor/Consultant|Pfizer: Advisor/Consultant|Pfizer: Board Member|Pfizer: Grant/Research Support|Pfizer: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|Tetraphase: Advisor/Consultant Francesco Menichetti, n/a, Aneglini: Advisor/Consultant|Aneglini: Board Member|Aneglini: Grant/Research Support|Aneglini: Honoraria|Astellas: Advisor/Consultant|Astellas: Honoraria|Becton: Advisor/Consultant|Becton: Honoraria|bioMérieux: Advisor/Consultant|bioMérieux: Honoraria|Biotest: Advisor/Consultant|Biotest: Board Member|Biotest: Honoraria|Bristol-Myers Squibb: Advisor/Consultant|Bristol-Myers Squibb: Honoraria|Correvio: Advisor/Consultant|Correvio: Speaker honoraria|Dickinson: Advisor/Consultant|Dickinson: Honoraria|Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Janssen: Advisor/Consultant|Janssen: Honoraria|MSD: Advisor/Consultant|MSD: Speaker honoraria|Nordic pharma: Board Member|Nordic pharma: Honoraria|Pfizer: Advisor/Consultant|Pfizer: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|ViiV: Advisor/Consultant|ViiV: Honoraria Nicola Petrosillo, n/a, Becton & Dickinson,: Honoraria|MSD: Honoraria|ohnson & Johnson: Honoraria|Pfizer: Honoraria|Shionogi: Honoraria.