Quinolone and Multidrug Resistance Predicts Failure of Antibiotic Prophylaxis of Spontaneous Bacterial Peritonitis

Background. The efficacy of antibiotic prophylaxis to prevent spontaneous bacterial peritonitis (SBP) in patients colonized with multidrug-resistant organisms (MDROs) is unknown. We evaluated the effectiveness of fluoroquinolone-based SBP prophylaxis in an era and area of frequent antibiotic resistance. Methods. This is a prospective observational study in patients with liver cirrhosis and an indication for fluoroquinolone-based prophylaxis of SBP. Patients were recruited and followed in a large German tertiary reference center with comprehensive microbiological and clinical monitoring performed at baseline and after 30, 60, 90, and 180 days of prophylaxis. Results. Overall, 77 patients received antibiotic prophylaxis for an average of 93 days. Baseline prevalence of colonization with MDROs was high (N = 39, 50.6%). At least one de novo MDRO was detected in 27 patients (35.1%) during antibiotic prophylaxis; 33 patients (42.9%) developed secondary infections, including 14 cases (17.9%) of infections with MDROs, and 13 cases (16.9%) of de novo/recurrent SBP. Thirty patients (39.0%) died during follow-up. Significantly higher risks of SBP development during antibiotic prophylaxis were observed for patients with versus without any apparent MDROs (P = .009), vancomycin-resistant enterococci (P = .008), multidrug-resistant gram-negative bacteria (P = .016), or quinolone-resistant gram-negative bacteria (QR-GNB) (P = .015). In competing risk analysis, QR-GNB were independently associated with prophylaxis failure (hazard ratio, 3.39; P = .045) and infections with QR-GNB were independently associated with death before SBP (subdistribution hazard risk, 6.47; P = .034). Conclusions. Antibiotic prophylaxis of SBP appears to be less efficient in patients with known MDROs. Regular MDRO screening seems to be useful to tailor treatment of secondary infections and re-evaluate antibiotic prophylaxis in case of selection of quinolone resistance.