Elucidation of the AI-2 communication system in the food-borne pathogen Campylobacter jejuni by whole-cell-based biosensor quantification

Ramić, Dina (author), Klančnik, Anja (author), Smole Možina, Sonja (author), Dogša, Iztok (author)

The food-borne pathogen Campylobacter jejuni produces autoinducer-2 (AI-2) as an interspecies signalling molecule. AI-2 can trigger enhanced colonisation and biofilm formation, and this poses a serious risk to public health. To date, this communication system of C. jejuni is only partially understood, as detection and quantifi- cation of such autoinducer signalling molecules in complex media is hard to achieve. We have developed a whole-cell Vibrio harveyi-based biosensor assay to accurately quantify and follow production of AI-2 by C. jejuni 81–176 in a defined growth medium and in a model food system. Several V. harveyi strains were tested, but the most sensitive bioluminescent response to C. jejuni AI-2 was achieved with V. harveyi MM30, likely due to its ability to self-amplify the response to AI-2. The AI-2 concentrations measured by this biosensor were confirmed using an independent analytical method, HPLC-FLD, which we introduced for Campylobacter analytics for the first time. The AI-2 concentration produced by C. jejuni 81–176 in the model food system was ~5-fold that in the defined growth medium, at the same cell density. Together with the linear increments in AI-2 concentrations with cell density, this suggests that in C. jejuni, AI-2 represents a metabolic by-product rather than a true quorum- sensing molecule. This biosensor method is highly sensitive, as shown by the reduction in the limit of detection (by a factor of 100) compared to HPLC-FLD, and it enables quantification of AI-2 in complex matrices, such as food, which will help to improve the quality and safety of food production.

• Language: English
• Keywords: Campylobacter jejuni, AI-2 quantification, biosensor method, HPLC-FLD
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: 8 str.
• Numbering: Vol. 212, art. 114439
• PID: 20.500.12556/RUL-139598
• UDC: 579.24/.26:53.082.9
• ISSN on article: 0956-5663
• DOI: 10.1016/j.bios.2022.114439
• COBISS.SI-ID: 110249219
• Publication date in RUL: 05.09.2022

Record is a part of a journal

• Title: Biosensors & bioelectronics
• Shortened title: Biosens. bioelectron.
• Publisher: Elsevier
• ISSN: 0956-5663
• COBISS.SI-ID: 15321605

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: patogeni mikroorganizmi, Campylobacter jejuni, medcelično signaliziranje, biosenzorji, kvantifikacija, varnost živil