Identification of Ascitic Fluid Bacterial Pathogens in Spontaneous Bacterial Peritonitis

Overview

Several studies have pointed out changes in the epidemiology of the causative bacteria in SBP and bacterascites and in their susceptibility to antibiotics. In particular, the development of beta-lactamase enzymes, which confer resistance to clavulanate, or extended spectrum beta-lactamases in Escherichia coli. The potential emergence of enterococci, methicillin-resistant S. aureus, or fluoroquinolone-resistant bacteria, following norfloxacin prophylaxis, is also a cause of concern since they may be associated with a higher risk of therapeutic failure. The microbial etiology of SBP remains relatively constant; however, the antibiotic resistance rate especially for third-generation cephalosporins (including cefotaxime and ceftazidime), ciprofloxacin, and ofloxacin increased dramatically

Spontaneous bacterial peritonitis (SBP), defined as an infection of ascites in the absence of a contiguous source of infection. Spontaneous bacterial peritonitis (SBP) is a common and potentially fatal bacterial infection in patients with cirrhosis and ascites, occurring in 10 to 30% of patients, with in-hospital mortality rates ranging from 20 to 30% . It is secondary to impaired humoral and cellular immune responses that result in indirect intestinal bacterial translocation into the ascitic fluid. SBP is also associated with a poor long-term prognosis for patients, as mortality rates can reach 50 to 70% at 1 year. Early diagnosis and early optimal treatment of these infections with appropriate antibiotics and the prevention of hepatorenal syndrome with albumin are required . Current European and most other international guidelines recommend the use of a third-generation cephalosporin as the first choice, or amoxicillin-clavulanate acid or fluoroquinolones as an alternative choice. These recommendations are based mainly on clinical trials that were very often conducted a decade or more ago, and on the assumption that E. coli would be involved in nearly half of the cases. Several studies have pointed out changes in the epidemiology of the causative bacteria in SBP and bacterascites and in their susceptibility to antibiotics. In particular, the development of beta-lactamase enzymes, which confer resistance to clavulanate, or extended spectrum beta-lactamases in Escherichia coli.The potential emergence of enterococci, methicillin-resistant S. aureus, or fluoroquinolone-resistant bacteria, following norfloxacin prophylaxis, is also a cause of concern since they may be associated with a higher risk of therapeutic failure.