[Complicated intra-abdominal infections: pathogens, resistance. Recommendations of the Infectliga on antbiotic therapy].

Intra-abdominal infections are generally the result of invasion and multiplication of enteric bacteria in the wall of a hollow viscus within the abdomen to produce peritonitis or abscess. When the infection extends into the peritoneal cavity or another normally sterile region of the abdominal cavity, the infection is described as a "complicated" intra-abdominal infection. Treatment of patients with complicated intra-abdominal infections involves antimicrobial therapy, generally in conjunction with an appropriate and timely surgical source control. Nearly all intra-abdominal infections are caused by multiple microorganisms that constitute the intestinal flora (aerobes and facultative and obligate anaerobes, with Enterobacteriaceae, enterococci and Bacteroides fragilis isolated most frequently). The emergence of drug resistance (e.g. ESBL-producing Enterobacteriaceae or resistant enterococci and staphylococci) poses a substantial threat to patients with surgical infections. Especially in patients with nosocomially acquired infections inadequate empiric antibiotic treatment is associated with treatment failure and death. In patients at risk broader spectrum antibiotic regimens with coverage of resistant Gram-negative bacilli and anaerobes and Gram-positive bacteria such as enterococci (including VRE) and staphylococci should be considered.