Multidrug-Resistant Proteus mirabilis Infections and Clinical Outcome at Tertiary Hospital in Riyadh, Saudi Arabia

Abstract

Background: Proteus mirabilis ( P. mirabilis ) is known to cause various infections, most commonly urinary tract infections, and is a threat to hospitalized patients, especially in long-stay departments that utilize invasive devices. This study aims to fill the knowledge gap regarding P. mirabilis epidemiology and antimicrobial resistance in Saudi Arabia. It investigates epidemiological patterns, resistance characteristics, and clinical outcomes among P. mirabilis patients at King Fahad Medical City in Riyadh from 2019 to 2021. Methods: A total of 598 P. mirabilis isolated from diverse clinical specimens, including the clinical information of 78 intensive care unit (ICU) patients, were included in the current study. The Phoenix BD instrument was used for complete identification and sensitivity testing of Proteus spp. Demographic, clinical, and outcome data were reported and compared using statistical analysis. Results: Pan-drug-resistant isolates were identified in 2019 (n = 6), although multi- and extensively drug-resistant isolate frequencies were greatest among all patients in 2019. The highest susceptibility levels were observed for piperacillin-tazobactam, carbapenems, and cephalosporins antibiotics. In contrast, Cephalothin, trimethoprim-sulfamethoxazole, and ampicillin had the lowest susceptibilities. Urine infections with a positive culture of P. mirabilis were significantly higher in females and non-ICU patients ( p < 0.001), but respiratory infections were significantly higher in ICU patients ( p < 0.001). Moreover, ICU patients infected with P. mirabilis and undergoing renal dialysis have a 7.2-fold ( P 0.034) higher risk of death than those not receiving dialysis. Conclusion: Hospitalized patients are at risk of fatal consequences due to P. mirabilis infection. It is crucial to conduct further investigation to fully understand the severity of this issue and take necessary measures to prevent it. Keywords: Proteus mirabilis , ICU, nosocomial infection, multidrug-resistant, extensively drug-resistant, pan-drug-resistant, risk factors, mortality