The biofilm formation by Klebsiella strains isolated from various infections on chemically different catheters
Abstract number: 1134_03_424
Maczyñska B.M., Smutnicka D.S., Przondo-Mordarska A.P.M., Bartoszewicz M.B., Kasprzykowska U.K.
Klebsiella bacilli are frequently cases of nosocomial infections associates with usage urinary (CAUTI) and intravenous catheters (CR-BSI) due to its ability to biofilm formation on biomaterials. The aim of our study was the correlation between pathogenic properties in clinical Klebsiella strains (the capsule, the types of adhesins), the type of using biomaterials and degree of in vitro formation the biofilm structure on the catheters.
Material and Methods:
The 69 clinical Klebsiella strains producing several distinct types of fimbria were tested (30 isolated from UTI, 23 from blood and 16 from other clinical samples). Influence of capsule on ability of the biofilm formation was estimated using uncapsulated mutants and their capsulated variants. In the investigations the urinary catheters-polyvinyl chloride Nelaton, latex Foley, all-silicone Foley and venous catheter-polyurethan Cavafix were tested. In vitro biofilm formation was evaluated by Richard method. In this assay, soluble colourless TTC is reduced to insoluble red formazan by electron transfer associated with active oxidative bacterial metabolism and is precipitated intracellulary. This assay were validated by electron microscopy.
All investigated strains showed the ability of formation of the biofilm on the catheters after 24 hours incubation. For most of strains the value of fomazan reduction were evaluated like as intermediate or strong. The highest level of biofilm formation showed the strains to venous catheters from polyurethan and urinary catheters from polyvinyl chloride. The lowest adhesion rate was observed in case of all-silicone Foley catheters. The capsulated strains made the biofilm weaker then the uncapsulated strains. The presence of the characteristic biofilm structure on catheters was confirmed in electron microscopy.
The level of adhesion in clinical Klebsiella bacilli to biomaterials was associated with the chemical type of catheters. The capsule absence leads in case of investigated strains to the stronger biofilm formation on the surface of biomaterials. The various Kebsiella strains showed in electron microskopy various structures of biofilms The correlation between the type of expressed fimbria and degree of biofilm formation was not observed in this investigation.
This study was supported by the Polish Committee of Scientific Studies (KBN Grant No 4 P05A 064 24).
|Session name:||XXIst ISTH Congress|
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