Noninvasive screening identifies patients at risk for spontaneous bacterial peritonitis caused by multidrug-resistant organisms

Abstract

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: antibiotic therapy; ascites; liver cirrhosis; multidrug resistance; screening routine.

Figure 1

Competing risk analysis of 22 patients with MDRO-SBP compared to 111 patients without MDRO-SBP. Notes: Patients were included from the day of first SBP detection, and death due to sepsis and death due to other reasons were defined as competing risks. Lethal sepsis was significantly increased in patients with MDRO-SBP (HR =5.67, P<0.001). Of note, MDRO-SBP was included as a time-dependent variable in this analysis. Therefore, the number at risk cannot be displayed in this plot, since the time-dependent calculation has been performed with censored data. MDRO-SBP, SBP with the evidence of MDROs or S. maltophilia in ascitic culture. Abbreviations: MDRO, multidrug-resistant organism; SBP, spontaneous bacterial peritonitis; S. maltophilia, Stenotrophomonas maltophilia.

Figure 2

(A) Time of first in-house MDRO screening in relation to time of study inclusion. Ticks at the bottom represent first rectal swab. Screening was performed before or within 28 days upon study inclusion in 123 patients (92.5%), and later than 28 days upon inclusion in 10 patients (7.5%). (B) Time of first MDRO detection in relation to time of study inclusion. First overall diagnosis of MDRO had been made before study inclusion in 24/72 patients (33.3%) and was made upon or after study inclusion in 48/72 patients (66.7%). Abbreviations: E. coli, Escherichia coli; ESBL, extended-spectrum ß-lactamase; ICU, intensive care unit; IMU, intermediate care unit; MDRO, multidrug-resistant organism; QR, fluoroquinolone resistance; SBP, spontaneous bacterial peritonitis; S. maltophilia, Stenotrophomonas maltophilia.