Premium
Secreted single‐stranded DNA is involved in the initial phase of biofilm formation by N eisseria gonorrhoeae
Author(s) -
Zweig Maria,
Schork Sabine,
Koerdt Andrea,
Siewering Katja,
Sternberg Claus,
Thormann Kai,
Albers SonjaVerena,
Molin Søren,
Does Chris
Publication year - 2014
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12291
Subject(s) - biofilm , biology , dna , microbiology and biotechnology , neisseria gonorrhoeae , strain (injury) , secretion , extracellular polymeric substance , recombinant dna , bacteria , gene , biochemistry , genetics , anatomy
Summary N eisseria gonorrhoeae is an obligate human pathogen that colonizes the genital tract and causes gonorrhoea. N eisseria gonorrhoeae can form biofilms during natural cervical infections, on glass and in continuous flow‐chamber systems. These biofilms contain large amounts of extracellular DNA , which plays an important role in biofilm formation. Many clinical isolates contain a gonococcal genetic island that encodes a type IV secretion system ( T 4 SS ). The T 4 SS of N . gonorrhoeae strain MS 11 secretes ss DNA directly into the medium. Biofilm formation, studied in continuous flow‐chamber systems by confocal laser scanning microscopy ( CLSM ), was strongly reduced, especially in the initial phases of biofilm formation, in the presence of E xonuclease I, which specifically degrades ss DNA or in a Δ tra B strain that does not secrete ss DNA . To specifically detect ss DNA in biofilms using CLSM , a novel method was developed in which thermostable fluorescently labelled ss DNA ‐ and ss/ds DNA ‐binding proteins were used to visualize ss DNA and total DNA in biofilms and planktonic cultures. Remarkably, mainly ds DNA was detected in biofilms of the ss DNA secreting strain. We conclude that the secreted ss DNA facilitates initial biofilm formation, but that the secreted ss DNA is not retained in mature biofilms.