Microbiological Characteristics and Antibiotic Sensitivity in Patients with Nosocomial Spontaneous Bacterial Peritonitis Caused by Escherichia coli: A Multicenter Study

Escherichia coli is a prevalent causative pathogen of spontaneous bacterial peritonitis (SBP). In this retrospective study, we investigated the microbiological characteristics and antibiotic susceptibility of E. coli clinical isolates obtained from liver cirrhosis patients suffering from nosocomial SBP. Our results showed that extended-spectrum β-lactamase (ESBL)-producing E. coli accounted for 47% of the cases, while 62% of the isolates were multi-drug resistant (MDR) pathogens. ESBL-producing and MDR isolates showed high incidences of resistance to third-generation cephalosporins, but they displayed susceptibility to carbapenems, β-lactamase inhibitors, and aminoglycosides. Importantly, liver cirrhosis patients with MDR E. coli SBP showed a significantly higher death rate than patients with non-MDR infections (P = 0.021). The 30-day mortality of nosocomial SBP was independently correlated with female gender [odds ratio (OR) = 5.200, 95% confidence interval (CI) = 1.194-22.642], liver failure (OR = 9.609, 95% CI = 1.914-48.225), hepatocellular carcinoma (OR = 8.176, 95% CI = 2.065-32.364), hepatic encephalopathy (OR = 8.176, 95% CI = 2.065-32.364), model of end-stage liver disease score (OR = 1.191, 95% CI = 1.053-1.346), white blood cell count (OR = 0.847, 95% CI = 0.737-0.973), and ascites polymorphonuclear (OR = 95.903, 95% CI = 3.410-2697.356). In conclusion, third-generation cephalosporins may be inappropriate for empiric treatment of nosocomial SBP caused by E. coli, due to the widespread presence of ESBLs and high incidence of MDR pathogens.