title: Changes in the aerobic faecal flora of patients treated with antibiotics for acute intra-abdominal infection.
abstract: BACKGROUND
  An open observational study was performed to investigate changes in the rectal flora and antibiotic susceptibility among faecal bacteria in patients treated with antibiotics for acute intra-abdominal infection.
  
  
  METHODS
  One hundred and forty patients with acute intra-abdominal infection requiring antibiotic treatment and hospitalization were included. Eight surgical units from the southern part of Sweden participated, between January 2006 and November 2007. Antibiotic treatments were according to local guidelines. Rectal swabs were obtained on admission (sample 1) and 2-14 days after the end of antibiotic treatment (sample 2). Aerobic bacteria and yeasts were analysed. The material was divided into 2 groups: 1 group with Enterobacteriaceae and 1 group with non-fermentative Gram-negative bacteria. The susceptibility to antibiotics in each group was compared between samples 1 and 2.
  
  
  RESULTS
  The main finding of this study on patients with severe intra-abdominal infections was a shift in the aerobic faecal flora following antibiotic treatment, from Escherichia coli to other more resistant Enterobacteriaceae, Enterococcus faecium, and yeasts. The susceptibility to cephalosporins and piperacillin-tazobactam decreased in Enterobacteriaceae.
  
  
  CONCLUSIONS
  Following antibiotic treatment, a shift in the aerobic rectal flora to species with intrinsic antibiotic resistance was observed. This indicates that the emergence of resistance is not due to new mutations, but rather to selection of more resistant species. This should be taken into account when designing treatments for secondary intra-abdominal infections.
authors: Department of Infection Control, University Hospital Linköping, Linköping, Sweden. annika.samuelsson@lio.se
authors: Annika
authors: A
authors: Samuelsson
authors: Barbro
authors: B
authors: Isaksson
authors: Abbas
authors: A
authors: Chabok
authors: Jon
authors: J
authors: Jonasson
authors: Lennart E
authors: LE
authors: Nilsson
authors: Olle
authors: O
authors: Eriksson
authors: Håkan
authors: H
authors: Hanberger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001420:Bacteria, Aerobic / Q000187:drug effects* / Q000302:isolation & purification; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D059413:Intraabdominal Infections / Q000188:drug therapy* / Q000382:microbiology*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D013548:Sweden / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents