Volume 5, Issue 10 p. 859-866

Leitbakteria of microbial biofilm communities causing occlusion of biliary stents

Dirk F. Wenderoth

Corresponding Author

Dirk F. Wenderoth

Division of Microbiology, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany.

*E-mail [email protected]; Tel. (+49) 531 6181 449; Fax (+49) 531 6181411. Search for more papers by this author
Björn Ferslev

Björn Ferslev

Surgery Clinic, Braunschweig General Hospital, Klinikum Salzdahlumer Strasse, Salzdahlumer Str. 90, 38126 Braunschweig, Germany.

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Giampiero Macarri

Giampiero Macarri

Department of Gastroenterology, University of Ancona, Hospital Torrette, via Conca, 60100 Ancona, Italy.

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Gabriella Molinari

Gabriella Molinari

Division of Microbiology, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany.

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Heinrich Lünsdorf

Heinrich Lünsdorf

Division of Microbiology, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany.

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Kenneth N. Timmis

Kenneth N. Timmis

Division of Microbiology, GBF-German Research Centre for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany.

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First published: 01 September 2003
Citations: 11

We propose here the term Leitbakteria (as in Leitmotif: dominant recurring thematic element, etc.) here to indicate specific abundant bacteria common to, and thus characteristic of, a given niche or community; in this case, biliary stent biofilm communities.

Summary

Biliary stents inserted to relieve obstructive jaundice caused by biliary or pancreatic malignancies inevitably become occluded by microbial growth in the form of diverse microbial community biofilms. The scarce information available on these communities is based on cultivation methods, but such methods usually provide distorted overviews of community composition, so commonalities and differences in biliary stent communities are uncertain. We extracted DNA and RNA from the microbial communities of 11 biliary stents explanted from nine patients in hospitals from two different countries, amplified 16S rRNA and rDNA sequences, analysed the amplicons by the single-strand conformation polymorphism (SSCP) method, and sequenced and deduced phylogenetic assignments of the major amplicons representing the major biofilm community members. We used a Modified Robbins Device (MRD) to study de novo development of a stent biofilm from a patient stent microbial community. Single-strand conformation polymorphism fingerprinting revealed the same six abundant bacterial species, here designated Leitbakteria, namely Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Enterobacter aerogenes, and two unculturable bacteria distantly related to E. coli and Shigella sonnei, in all of the stent biofilm communities. In the experimental biliary stent system, a sequential colonization of the stent surface was observed, with P. aeruginosa being the pioneer colonizer, followed by K. pneumoniae and one of the unculturable Leitbakteria, followed by the remainder of the community. The overview of microbial biofilm communities of biliary stents gained by the use of culture-independent methods revealed new unculturable bacteria as major members of biliary stent biofilms, and the diversity of the abundant members of the stent biofilms is considerably lower than suggested from earlier studies based on cultivation methods, and that communities from different stents from different patients in different countries are remarkably similar and have similar major members, the stent Leitbakteria.