[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]. / Erreger- und Resistenzspektrum einer chirurgischen ITS im systematischen 10-Jahres-Vergleich 1996-2005 im Rahmen des mikrobiologischen Routinemonitorings.

INTRODUCTION: 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. AIM: 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. MATERIAL AND 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. CONCLUSION: 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.

[Microbial spectrum in surgical infections based on a microbiological routine monitoring over the 10-year period from 1995 to 2004]. / Erregerspektrum chirurgischer Infektionen im 10-Jahres-Vergleich 1995-2004 eines mikrobiologischen Routinemonitorings.

INTRODUCTION: Infections belong to the most frequent and dangerous complications in surgery. In addition to the medical aspects, these infections may have a significant impact on the costs and the overall economic efficacy of medical treatment under the present circumstances of DRG. AIM: A systematic, prospective collection and retrospective evaluation of all consecutive microbiological analyses in specimens from the 3 medical floors (except the ICU) of the Department of Surgery at the University Hospital, Magdeburg (Germany) was performed in 1995, 2002 and 2004 to characterise i) the 10-year course (1995 vs. 2004) and ii) possible alterations due to changes in the previously existing pavillon system (2002 vs. 2004). PATIENTS AND METHODS: The microbial spectrum was determined in the 3 most frequent specimen types (blood culture, urine sample, wound swab) including number and percentage of the single microbial groups such as gram-positive and gram-negative Enterobacteriae, pseudomonades and fungi. In addition, the antibiotic resistance of selected microbes was analysed. The primary data were registered in a database and evaluated according to the various questions. RESULTS: Overall, 2 979 microbes were identified in 1995 (2002, 1 338; 2004, 915). On comparing 1995 with 2004, the percentage of gram-positive microbes did not change (50.5 vs. 50.3 %), whereas the percentage of gram-negative enterobacteriae increased: 37.4 vs. 29.1 %. The percentage of detected fungi was only half of that in 1995: 6.2 vs. 12.2 %. In blood cultures, the Klebsiella spp. portion in the group of gram-negative enterobacteriae distinctly increased: 29.6 vs. 18.8 %. While in 2004, MRSA was found in 24.4 % of all detected Staphylococcus aureus strains in swab specimens amounting to a considerable increase compared to 2002 (17.6 %), in 1995, MRSA was not isolated at all in this material. In the fungi group, there was a decrease of the Candida albicans portion vs. the non-C. albicans strains, which was associated with an increasing resistance against fluconazol. This requires treatment with caspofungin, resulting in increased costs vs. those necessary for fluconazol treatment. CONCLUSION: A systematic, microbiological, long-term monitoring is indispensable since i) microbial detection plays a growing role to include the various types of infections in the spectrum of diagnosis for DRG, ii) alterations of the microbial spectrum can only be detected through a long-term observation period (MRSA, fungi) and iii) simultaneously developing antibiotic resistances can be determined (MRSA, ESBL strains in Enterobacteriae, fluconazol-resistant fungi). This can have an infectious, biological, hygienic and cost-determining as well as a health policy relevance among others, with considerable additional costs (e. g., isolation of patients, cost-intensive substitutional medication) with necessary reimbursement.

[Analysis and conclusions regarding the epidemic spread of methicillin resistant S. aureus]. / Analysen und Schlussfolgerungen zur epidemischen Verbreitung von Methicillin-resistenten S. aureus.

Increasing dissemination of Methicillin-resistant S. aureus (MRSA) calls for a more consequent examination of the causal mechanisms. Experiences and results of analysis of three different outbreaks caused by MRSA are described. In summary it is shown that MRSA are especially epidemic virulent and persist over a long range of time in a care unit. Main reasons for these outbreaks obviously were mistakes in hospital hygiene and an inappropriate antibiotic prophylaxis. Predisposed inpatients suffer from severe infections. Interregional dissemination of MRSA observed is mainly due to the transfer of patients between hospitals. Optimization of hospital hygiene especially isolated or cohort nursing of affected patients as well as restriction of antibiotic prophylaxis and therapy are crucial measures against the dissemination of MRSA. For success of these measures information and motivation of staff are necessary.