University of Helsinki has its research and doctoral training evaluated every sixth year. In the recent evaluation covering the years 2005-2010, the research groups of the Department of Food Hygiene and Environmental Health formed a research community (CoE-MiFiSaPLUS) together with the microbiological groups of the Department of Veterinary Biosciences.

CoE-MiFiSaPLUS was an extended research community based on the Center of Excellence in Microbiological Food Safety Research led by Professor Palva. Research in CoE-MiFiSaPLUS was evaluated outstanding (scores 24/25) by the international scientific panel. University of Helsinki allocated 390000 € for CoE-MiFoSaPLUS during 2013-2016. In the last evaluation the Department of Food Hygiene and Environmental Health got maximum scores (7/).

The evaluation report concerning CoE-MiFiSaPLUS

The summary report on the evaluation of University of Helsinki

A recent study by DVM Annukka Markkula and colleagues showed that three DEAD-box RNA helicases are needed for cold-temperature growth of Listeria monocytogenes. Deletion of single DEAD-box RNA helicase genes increased the minimum growth temperature and dramatically decreased the growth rate of L. monocytogenes at 3˚C. In addition, deletion of helicase genes reduced the motility of L. monocytogenes. The study was published in valued Environmental Microbiology journal.

Environ Microbiol 2012, Early View, doi:10.1111/j.1462-2920.2012.02761.x

Markkula A, Mattila M, Lindström M, and Korkeala H.

Department of Food Hygiene and Environmental Health, University of Helsinki

Genes encoding putative DEAD-box RNA helicases in Listeria monocytogenes EGD-e are needed for growth and motility at 3˚C

The study showed that the relative expression of all four DEAD-box RNA helicase-encoding genes of L. monocytogenes EGD-e was increased at 3˚C. The growth rate of three deletion mutant strains was decreased at 25˚C compared to that of the wild type L. monocytogenes EGD-e. At 3˚C the growth of three mutant strains was virtually impaired. Deletion of the genes increased the minimum growth temperature of strains by 4.9-8.8˚C. A total of two cold sensitive deletion mutant strains were impaired in motility. Motility of a cold-sensitive strain was decreased approximately by half compared to the wild type EGD-e.

The study shows that three DEAD-box RNA helicases have an important role in cold tolerance and motility of L. monocytogenes EGD-e. The role of one DEAD-box RNA in cold tolerance and motility is negligible.

DEAD-box RNA helicases are found in most living organisms and are involved in various aspects of RNA metabolism from transcription to RNA decay. DEAD-box RNA helicases have recently been linked to cold tolerance of some bacteria. At cold temperatures stability of RNA secondary structures, like RNA duplexes increases. DEAD-box proteins function as helicases that separate short duplex regions of RNA.

The research was carried out at the Finnish Centre of Excellence in Microbial Food Safety Research and supported by the Finnish Graduate School on Applied Bioscience and the Walter Ehrström Foundation.

Academy of Finland granted funding 240 000€ for the research project ‘The Pathogenic Mechanisms of Clostridium botulinum type E ‘. The project leader is DVM, PhD, Professor Miia Lindström from the Department of Food Hygiene and Environmental Health. The main collaborators are Professor Yukako Fujinaga and Dr. Yo Sugawara from Osaka University, Japan.

Botulinum neurotoxin, the most potent natural poison, is produced by the spore-forming soil and food bacterium Clostridium botulinum. The toxin causes life-threatening paralysis, botulism. Countries with type E toxin causing a serious public health risk via traditional fish products include Finland and Japan. Cases of intestinal botulism due to toxigenic growth in the gut of small babies are also reported. At the same time, types A and B neurotoxins are applied in therapeutics to treat spastic muscular disorders from torticollis to genitourinary disorders and migraine. Due to unfavourable immunity development, interest towards alternative toxin types is increasing. However, the structure and function of types E and F neurotoxins are poorly known. This project will characterize neurotoxin type E protein complex. This helps to prevent human botulism and develop novel therapeutic toxins. Multiple medical applications and thus highly beneficial impacts on public health are expected.