Projects / Programmes source: ARIS

Virulentnost bakterij Campylobacter v modelu: okoljski stres - celične linije (Slovene)

Research activity

Code Science Field Subfield
1.03.00  Natural sciences and mathematics  Biology   

Code Science Field
1.06  Natural Sciences  Biological sciences 
Evaluation (rules)
source: COBISS
Researchers (1)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  22491  PhD Anja Klančnik  Animal production  Head  2009 - 2013  333 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0481  University of Ljubljana, Biotechnical Faculty  Ljubljana  1626914  65,900 
Significance for science
Campylobacter jejuni is currently recognized as a leading cause of foodborne illness worldwide, which is usually transmitted by eating and/or handling undercooked meat and other food. Unlike most other bacterial foodborne pathogens, campylobacters are not normally capable of multiplication in food during processing or storage, but they are capable to survive and cause human infection. During food chain they are exposed to variety of stresses. Often they are able to tolerate these stresses, survive in extraintestinal environment. Thus we clarify of Campylobacter spp. survival potential in food production/supply chain. We also tested additives that have can be used in food processing. Additional problem during food chain is also increasing antimicrobial resistance of C. jejuni¸ what gives additional impact on the use of alternative natural antimicrobials. We also established new microdilution method based on metabolic activit (using reagent ATP or INT) measurement as useful and rapid technique also for determining efficiency of plant extract and pure phenolics, and clarified the determination of the impact of natural antimicrobials on bacterial cells and develop better diagnostics of samples. Using establised food microdilution method and real food system (chicken and minced meat) we obtained real risk assessment and efficiecy of natural antimicrobial agents. Since their mechanism of influence is very complex and unknown for campylobacters we focus also on their complex activity on cell level. For the first time we demonstrated that complex efflux mechanisms are involved in the resistance of C. jejuni to phenolic compounds and extracts of plant phenolics. These findings represent the first comprehensive evaluationof the anti-Campylobacter and modulatory activities of natural phenolics and suggest that alternative compounds can be further developed to control Campylobacter contamination in food production and processing, or as therapeutics for clinical treatment of campylobacteriosis. We transfer the environmental impact also on virulence level of campylobacters and thus better increase quantitative microbial risk assessment (QMRA). We determined the connection between bacterial environmental stress response and their virulence properties and oxidative stress seems to make a lot of concern since does not influence campylobacter survival and even increase their virulence properties. However, the reduction in virulence activity of campylobacters and decreased of their capacity for infection in more resistant VBNC state are more encourage for accurate determination of quantitative microbial risk assessment (QMRA). We also introduce several cell lines in vitro and mouse in vivo models, which will allow the additional studies needed to determine the exact mechanism by which campylobacters establish human intestinal infection. According to better understanding of Campylobacter virulence determinants we can determine immune mechanisms of their infection and novel insights into the systemic disease by this pathogen. However, we clarify knowledge on the nature, regulation, and mechanism of action of virulence determinants what is indispensable in formulating new strategies for food safety management and potentially for the development of novel control strategies.
Significance for the country
Food quality and food safety have become an important topic in last years. Food safety is connected with different good practices and thus production of microbiologically safe food is of national importance. Obtained results are important for appropriate food handling (preparation, storage) and thus fill up some gaps of food handlers' knowledge on microbiological hazards. With the help of national health policy this may contribute to better understanding of the consumer about their behavior and attitudes toward food safety. Food safety point of view should be focused on knowledge, constant education and exchange of information. Consequently this will decrease consumption of contaminated food, illness of people / animals and thus also decrease drug consumption. Additionally, new insights will directly contribute to food safety management schemes in food supply chains in particular in primary and secondary production and knowledge transfer into HACCP and ISO 22000 systems. Using mildly processed food products we can increase microbial resistance and their survival and in some cases also cause a disease of consumer. But including obtained knowledge and also natural antimicrobials like plant phenolic extracts with biological activity we can reduce microbial growth and thus represent a new and consumerfriendly concept in safe food supply.
Most important scientific results Annual report 2009, 2011, 2012, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2009, 2011, 2012, final report, complete report on dLib.si
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