Noninvasive screening identifies patients at risk for spontaneous bacterial peritonitis caused by multidrug-resistant organisms Philip G Ferstl,1,2 Mona Müller,1 Natalie Filmann,3 Michael Hogardt,2,4,5 Volkhard AJ Kempf,2,4,5 Thomas A Wichelhaus,2,4,5 Christian M Lange,1,2 Johannes Vermehren,1,2 Stefan Zeuzem,1,2 Claudia Reinheimer,2,4,5 Oliver Waidmann1,2 1Department for Internal Medicine I/Gastroenterology and Hepatology, University Hospital Frankfurt, Frankfurt am Main, Germany; 2University Center for Infectious Diseases (UCI), University Hospital Frankfurt, Frankfurt am Main, Germany; 3Institute of Biostatistics and Mathematical Modeling, University Hospital Frankfurt, Frankfurt am Main, Germany; 4Institute of Medical Microbiology and Infection Control, University Hospital Frankfurt, Frankfurt am Main, Germany; 5University Center of Competence for Infection Control at the Universities Frankfurt, Giessen, and Marburg, Frankfurt am Main, State of Hesse, Germany Background and aims: Spontaneous bacterial peritonitis (SBP) is a severe complication of decompensated cirrhosis. The prevalence of multidrug-resistant organisms (MDROs) in patients with cirrhosis is increasing. Identification of patients at risk for SBP due to MDROs (ie, SBP with the evidence of MDROs or Stenotrophomonas maltophilia in ascitic culture, MDRO-SBP) is crucial to the early adaptation of antibiotic treatment in such patients. We therefore investigated whether MDROs found in ascitic cultures can also be found in specimens determined by noninvasive screening procedures.Patients and methods: This retrospective study was conducted at the liver center of the University Hospital Frankfurt, Germany. Between 2011 and 2016, patients with cirrhosis were included upon diagnosis of SBP and sample collection of aerobic/anaerobic ascitic cultures. Furthermore, the performance of at least one complete MDRO screening was mandatory for study inclusion.Results: Of 133 patients diagnosed with SBP, 75 (56.4%) had culture-positive SBP and 22 (16.5%) had MDRO-SBP. Multidrug-resistant Escherichia coli (10/22; 45.5%) and vancomycin-resistant enterococci (7/22; 36.4%) resembled the major causatives of MDRO-SBP. Rectal swabs identified MDROs in 17 of 22 patients (77.3%) who developed MDRO-SBP with a time-dependent sensitivity of 77% and 87% after 30 and 90 days upon testing, while negative predictive value was 83% and 76%, respectively. The majority of patients were included from intensive care unit or intermediate care unit.Conclusion: MDRO screening may serve as a noninvasive diagnostic tool to identify patients at risk for MDRO-SBP. Patients with decompensated cirrhosis should be screened for MDROs from the first day of inpatient treatment onward. Keywords: multidrug resistance, liver cirrhosis, ascites, screening routine, antibiotic therapy