Remarkable Antimicrobial Resistance in Nosocomial Spontaneous Bacterial Peritonitis

Abstract

Introduction: The aim of this prospective observational study was to investigate the causative agents and their susceptibility to antimicrobial drugs in patients with nosocomial spontaneous bacterial peritonitis (SBP) in order to clarify empirical antimicrobial treatment. Materials and Methods: Patients who were admitted to the Gastroenterology Department of Antalya Training and Research Hospital with prediagnosis of SBP during the period of January 2011 to December 2014 were enrolled in the study. Spontaneous bacterial peritonitis was defined as ascitic fluid with polymorphonuclear leukocyte count ≥250 cells/mm³. Spontaneous bacterial peritonitis was considered to be nosocomial if diagnosed after >48 hours of hospitalization. During the study period, cefotaxime was the preferred empirical antimicrobial therapy in our center. If there was no clinical recovery after 48 hours or cefotaxime-resistant bacteria was identified in culture, antimicrobial therapy was switched. Results: The proportion of culture-positive SBP was 13% (57/439). In total, 46% (202/439) of the cases were neutrocytic ascites and 52.6% (30/57) were evaluated as nosocomial SBP. Candida spp. was the causative agent in one case, which was not included in the calculation. The overall natural/acquired cefotaxime resistance was 51.8% (29/56). The rate of cefotaxime resistance was 66.7% (20/30) in nosocomial SBP, significantly higher than in non-nosocomial infections (34.6%; 9/26, p=0.04). Resistance to gentamicin, trimethoprim-sulfamethoxazole, and carbapenems were also significantly higher in nosocomial infections (p=0.04, p=0.04, p=0.02). Conclusion: Cefotaxime resistance was found to be higher in nosocomial SBP than non-nosocomial cases. Therefore, determining whether an infection is nosocomial is beneficial when selecting empirical antibiotic therapy.

Keywords

• extended-spectrum beta-lactamases
• antimicrobial resistance
• surveillance
• community-acquired infections
• culture-negative neutrocytic ascites