This study is to investigate the recent epidemiological trends and the treatment outcome in terms of the length of hospital stay, the relevant renal and neurological side effects, risk factors for developing these side effects, the selection of more resistant pathogens under therapy as well as the incidence of Clostridium difficile infections under treatment.

Increasing resistance among Enterobacterales to beta-lactam antibiotics is globally a major concern in the antibiotic resistance crisis. In gram-negative bacteria it evolves primarily through the production of beta-lactamases that allow the rapid hydrolysis of common antibiotics - most notably 3rd generation cephalosporins. Particularly, the production of Ambler class C beta-lactamase (AmpC) is a very concerning and unique resistance mechanism as so called derepressed mutants can be induced during treatment. Information on recent epidemiological trends as well as comparative information about the treatment strategies (cefepime versus piperacillin/tazobactam versus carbapenems) for infections with AmpC-producing Enterobacterales in Switzerland is still lacking. This study is to investigate the recent epidemiological trends and the treatment outcome in terms of the length of hospital stay, the relevant renal and neurological side effects, risk factors for developing these side effects, the selection of more resistant pathogens under therapy as well as the incidence of Clostridium difficile infections under treatment.

Inclusion Criteria:

• Patients with detection of AmpC beta-lactamase producing Enterobacterales

  1. In a blood culture (any ward)
  2. In a clinical sample of the lower respiratory tract (only intensive care unit)

Exclusion Criteria:

• Patients with documented refusal of subsequent use of their data

Patients treated in the inpatient setting at the University Hospital Basel from January 1st, 2015 until July 31st, 2020 with detection of AmpC beta-lactamase producing Enterobacterales