title: [Spectrum of microbial colonisation and resistance of a surgical ICU in a systematic comparison of the 10-year time period 1996-2005 using routine microbiological testing].
abstract: BACKGROUND
  Knowledge on potentially pathogenic microbes including characteristics of their antibiotic resistance in septic patients as well as on the ward- and department-specific microbial spectrum can be considered essential for an efficient initiation of an adequate antimicrobial treatment, which turns out to become pivotal for patient outcome. Permanent changes in microbial patterns and antibiotic resistance can only be identified by a continuous investigation of various microbiological specimens.
  
  
  OBJECTIVE
  Based on the retrospective evaluation of prospectively collected data on microbiological investigations of the surgical ICU in 1996, 2002, 2004 and 2005, the short- and long-term changes by trend of microbial spectrum and antibiotic resistance following reorganisation and restructuring of the University Hospital from the more traditional pavillon-based system to a multidisciplinary complex building in 2003 were investigated.
  
  
  METHODS
  Twice a week, routine microbiological testing of blood and urinary cultures as well as swabs from wound areas and endotracheal swabs were initiated in septic patients (suspect, manifestation) or in case of their clinical impairment. The microbial spectrum was sub-divided according to Gram-staining (Gram-positive/ -negative), various species and fungi with descriptive absolute and relative data values. -Various groups and time periods were statistically compared using χ² test as appropriate. P values < 0.05 were considered statistically significant.
  
  
  RESULTS
  In total (n (Total) = 4 899), microbiological testing resulted in the detection of microbes in 699 and 833 blood and urinary cultures (14.3 % and 17 %, respectively) as well as 1 232 wound swabs (25.1 %) together with 2 135 samples from the endotracheal sites (43.6 %). During the short- (2002 vs. 2004) and long-term analyses (1996 vs. 2005), the proportion of Gram-positive microbes increased. Al-though Gram-positive bacteria can be considered the most frequent microbes for bacteriemia, there was a shift onto urinary and wound infections as well as pneumonias through the observation period. Despite the decreasing incidence of Enterococcus and the consistent proportion of MRSA, the increase of resistant Enterococcus strains (0 % vs. 43.2 %; P < 0.05) is critical. However, in the Gram-negative microbial spectrum there was an increase of the bacteraemia rate but a fall of the detection rate in wound and endotracheal swabs. In parallel, an increase of the detection rate of E. coli in blood (6.5 % vs. 45.5 %; P < 0.05) and endotracheal swabs (9.2 % vs. 16.2 %; P < 0.05) is associated with an increase of multiresistant Enterobacteriaceae strains (0 % vs. 30.7 %; P < 0.05). The portion of multiresistant strains of Pseudomonas with 31 % stayed the same through the 10-year time period. While Candida-based colonisation showed a decreased incidence (25 % vs. 15 %; P < 0.05) during the whole investigation period, there was a relative rise in the frequency of candidemia.
  
  
  CONCLUSIONS
  ICU relocation from the pavillon-based system to a new complex clinic building was not associated with any significant alteration of the microbial spectrum on the surgical ICU. Increasing incidences of resistant Enterococcus and Gram-negative problematic microbes may indicate a general spread of multi-resistant microbes under the steady selecting pressure of a not always adequately initiated antibiotic / antimicrobial therapeutic regimen and underline the required but specific and selected microbiological screening.
authors.affiliation: Universitätsklinikum Magdeburg A. ö. R., Klinik für Allgemein-, Viszeral- und Gefässchirurgie, Magdeburg, Deutschland. stephan.arndt@med.ovgu.de
authors.forename: S
authors.initials: S
authors.lastname: Arndt
authors.forename: H
authors.initials: H
authors.lastname: Lauf
authors.forename: G
authors.initials: G
authors.lastname: Weiss
authors.forename: U
authors.initials: U
authors.lastname: Lodes
authors.forename: P
authors.initials: P
authors.lastname: Mroczkowski
authors.forename: H-U
authors.initials: HU
authors.lastname: Schulz
authors.forename: H
authors.initials: H
authors.lastname: Lippert
authors.forename: W
authors.initials: W
authors.lastname: König
authors.forename: F
authors.initials: F
authors.lastname: Meyer
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000935:Antifungal Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D001424:Bacterial Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology*; D001437:Bacteriuria / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D003422:Critical Care; D003428:Cross Infection / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology*; D003430:Cross-Sectional Studies; D004352:Drug Resistance, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D005858:Germany; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D009181:Mycoses / Q000188:drug therapy / Q000382:microbiology; D012189:Retrospective Studies; D018805:Sepsis / Q000188:drug therapy / Q000382:microbiology; D013530:Surgical Wound Infection / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D014132:Trachea / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents