QseC controls biofilm formation of non-typeable Haemophilus influenzae in addition to an AI-2-dependent mechanism.

Summary, in English

Non-typeable Haemophilus influenzae (NTHi) is a common pathogen associated with diseases such as acute otitis media or exacerbations in patients with chronic obstructive pulmonary disease. The biofilm-forming capability substantially contributes to the persistence of NTHi. However, the regulation of biofilm formation is not completely understood. Quorum sensing regulated by autoinducer-2 produced by luxS is until now the only described regulatory mechanism. In this study, we show that the two-component signalling system QseB/C is involved in the biofilm formation of NTHi in vitro. An isogenic NTHi mutant of qseC (Hi3655KR2) showed a significant decrease in biofilm formation under static and semi-static conditions as assessed by crystal violet staining. In addition, under constant flow conditions, Hi3655KR2 formed less biofilm after 48h. The biofilm defects were irrespective of autoinducer-2 levels. Hence, here we suggest for the first time a regulatory circuit in NTHi, which controls biofilm formation by mechanisms other than or in addition to luxS-dependent factors.

• Author: Can Ünal; Birendra Singh; Christophe Fleury; Kalpana Singh; Luis Chávez de Paz; Gunnel Svensäter; Kristian Riesbeck
• Department/s: Clinical Microbiology, Malmö
• Publishing year: 2012
• Language: English
• Pages: 261-269
• Publication/Series: International Journal of Medical Microbiology
• Volume: 302
• Issue: 6
• Full text: - 1 MB; Download statistics
• Links: http://www.ncbi.nlm.nih.gov/pubmed/22954413?dopt=Abstract; http://dx.doi.org/10.1016/j.ijmm.2012.07.013
• Document type: Journal article
• Publisher: Elsevier
• Topic: Microbiology in the medical area
• Status: Published
• Research group: Clinical Microbiology, Malmö
• ISBN/ISSN/Other: ISSN: 1618-0607