The article “The CLO3403/CLO3404 Two-Component System of Clostridium botulinum E1 Beluga Is Important for Cold Shock Response and Growth at Low Temperatures” published by Mascher et al. was selected as spotlight in the current issue (January 2014, volume 80, issue 1) of Applied and Environmental Microbiology.

Applied and Environmental Microbiology highlighted the article as shown below:

“A Two-Component System Responsible for Cold Tolerance of Clostridium botulinum Type E

Type E botulism outbreaks are mainly associated with consumption of contaminated, minimally processed, anaerobically packaged fish products, for which thermal control is not sufficient to prevent outgrowth from Clostridium botulinum type E spores. Mascher et al. (p. 399–407) demonstrate a two-component system that is important for the cold-shock response in C. botulinum type E and its growth at low temperatures. Understanding the mechanisms behind the cold tolerance of this life-threatening pathogen may reveal novel insights into the prevention of botulism outbreaks and is thus important for the development of control measures.”
“Copyright © 2014, American Society for Microbiology. All Rights Reserved.”

C. botulinum type E is mainly found in cold regions of the world and highly prevalent in the Baltic Sea and Finnish freshwaters. The authors (Gerald Mascher, Yağmur Derman, David G. Kirk, Eveliina Palonen, Miia Lindström and Hannu Korkeala) were focusing on the cold tolerance of C. botulinum E1 Beluga which allows the organism to grow and produce the life-threatening botulinum neurotoxin at temperatures as low as 3°C. Constructing the first knock-out mutants of C. botulinum type E allowed them to study this organism in more detail and they could show the important role of the CLO3403/CLO3404 TCS in cold tolerance of C. botulinum type E. The group is now investigating the mechanisms regulated by the TCS.

The work was performed in the Finnish Centre of Excellence in Microbial Food Safety Research and supported by the Academy of Finland (grants 141140, 118602), the Finnish Graduate School on Applied Bioscience, the Finnish Foundation of Veterinary Research, the European Community’s Seventh Framework Program FP7/2007-2013 (grant 237942), and the Doctoral Program of the Faculty of Veterinary Medicine of the University of Helsinki.

Link to the article: http://aem.asm.org/content/80/1/1.full

Programme

The course contains lectures, demonstrations, laboratory practice, presentations and writing tasks. The preliminary programme can be seen on NOVA webpage.

Course fee and accommodation

For PhD students registered at any of the NOVA member institutions, NOVA PhD courses are free of charge and includes accommodation and meals. Travel costs are not covered by NOVA.

For PhD or MSc students registered at any of the BOVA member institutions, NOVA PhD courses are free of charge. For the non-PhD/MSc students at BOVA member institution and for other Baltic PhD/MSc students course fee is 200 €. Accommodation and meals are charged by the course organisation. Travel arrangements should be made and travel costs should be covered by the participants.

Read more about course fees.

Registration

Registration for the course by https://elomake.helsinki.fi/lomakkeet/47156/lomake.html. The deadline for the registration is February 17^th, 2014. Course attendance is limited to 25 participants.

Additional information

Course leader, Dr. Leena Maunula, leena.maunula@helsinki.fi.

DVM Elias Dahlsten will defend his doctoral dissertation entitled
“Genetic mechanisms of stress response and sporulation in Clostridium botulinum” in the Faculty of Veterinary Medicine, University of Helsinki, on Friday 20th December 2013 at 12. The public examination will take place at the EE Building, Agnes Sjöbergin katu 2, Helsinki, Lecture room Walter.

Professor Martti Vaara, will serve as the opponent, and Professor Hannu Korkeala as the custos.

MSc Pradeep Kumar Kondadi will defend his doctoral dissertation entitled “Genomics and functional genetics of the zoonotic pathogen Helicobacter bizzozeronii” in the Faculty of Veterinary Medicine, University of Helsinki, on Friday 25th October 2013 at 12. The public examination will take place at the University Main Building, Fabianinkatu 33, Lecture room 5.

Assistant Professor Annmieke Smet, Ghent University, will serve as the opponent, and Professor Marja-Liisa Hänninen as the custos.

Encrine disrupting chemicals, foremost substances eliciting effects similar to estrogen (dubbed xenoestrogens), are common in our environment. However, the extent to which they exist in foodstuffs and industrially processed foods is still poorly known. In this study, professor Raimo Pohjanvirta and his group examined three batches each of 15 popular processed foods, purchased from a local supermarket, for their estrogenic activity. “In addition, we included 3 x 5 ready-to-eat snacks acquired from a hamburger place for comparison. The assay system consisted of yeast cells transfected with a luciferase reporter gene that became activated by estrogen receptor-alpha-mediated signal transduction.” says Pohjanvirta.

Industrially processed chicken and beef burgers exhibited high estrogenic activity

In the majority of the samples analyzed, estrogenic activity was low. An exception to this rule were industrially processed chicken and beef burgers and, in particular, pepper salami, in which they consistently found quite high activities in all three batches. A fact common to these three food items was that they all contained soy protein as an ingredient. In the great majority of other samples, soy had not been used in their manufacture. Because soy has been shown to contain isoflavones with potential for estrogenic activity such as genistein, they further analyzed two soy sauces by their assay system; both proved highly positive.

An intriguing finding was that chicken, beef or cheese burgers bought from a hamburger restaurant were devoid of estrogenic activity, despite the fact that they were also informed to contain soy. The reason for the discrepancy may lie in a quantitative difference or, in the case of supermarket burgers, antioxidants might conceivably have potentiated the activity. Since the health impacts of soy are arguable, from the health risk point of view it would be advisable to avoid frequent exposure to it; this is especially true for children whose endocrine system can be more vulnerable to endocrine disrupters than that of adults. Finally, they also examined the wrapping materials of food products because there is a suspicion that certain estrogenic plasticizers such as phthalates and bisphenol-A might leach from the wrappings into food. However, all these samples were negative in their assay.

Further studies are warranted

Based on their results, they concluded that the majority of Finnish commercial food products do not contain xenoestrogens in concentrations that could be detrimental to health. The researchers remind, however, that their sample composition was fairly confined and therefore further studies are warranted regarding, for example, dietary supplements.

Link to the article

Iyekhoetin Matthew Omoruyi, Grit Kabiersch & Raimo Pohjanvirta , Food Additives & Contaminants: Part A (2013): Commercial processed food may have endocrine-disrupting potential: soy-based ingredients making the difference, Food Additives & Contaminants: Part A, DOI: 10.1080/19440049.2013.817025

Iyekhoetin Matthew Omoruyi  & Raimo Pohjanvirta, Department of Food and Environmental Hygiene (Food and Environmental Toxicology Unit), Faculty of Veterinary Medicine, University of Helsinki, F-00014 Helsinki, Finland
Grit Kabiersch, Division of Microbiology, Department of Food and Environmental Sciences, Faculty of Agriculture and Forestry, University of Helsinki, F-00014 Helsinki, Finland

Professor, Vice-Rector Johanna Björkroth has been nominated as Scientific Editor of the Applied and Environmental Microbiology (AEM) published by the American Society for Microbiology (ASM).

The American Society for Microbiology (ASM) is the world’s oldest and largest life science membership organization. Society has been established in 1899, nowadays there are more than 39.000 members worldwide.

The Society publishes journals, of which Applied and Environmental Microbiology (AEM) is the most cited journal in the fields of microbiology, biotechnology and applied microbiology, with more than 86.000 citations. It has an Impact Factor of 3.678 according to the 2012 Journal Citation Reports®.

The term of the Scientific Editor is for 5 years. AEM emphasized professor Björkroth’s wide expertise not only in the area of food microbiology, but also tangential areas such as microbial physiology or the molecular microbiology. Björkroth’s preceding job as an Editorial Board Member was highly acknowledged, she started as an Editorial Board Member in 2002.

Professor Björkroth is leading a research group focusing on cold-tolerant lactic acid bacteria and enterobacteria causing food spoilage. The research group belongs to the Centre of Excellence in Microbial Food Safety Research (MiFoSa). She has published more than 100 articles in peer-reviewed scientific series and several book chapters, and supervised several postgraduate studies (PhD Thesis). Since 2008, she has served as a Vice-Rector of the University of Helsinki in charge of research, researcher training and innovation affairs.

A study by DVM Elias Dahlsten and colleagues under Prof. Hannu Korkeala’s supervision suggests a previously unidentified role for the alternative sigma factor SigK in response and adaptation to low temperature and high salt conditions in Clostridium botulinum. The study was published in Applied and Environmental Microbiology.

C. botulinum ATCC 3502 wild type strain was
evaluated for relative sigK expression levels after cold shock, exposure to hyperosmotic conditions, exposure to acidity, or in optimal growth conditions, using quantitative reverse transcription PCR. Significant induction of sigK expression was observed upon temperature downshift and in hyperosmotic shock, but not in pH downshift or in optimal growth. Insertional inactivation of sigK with the ClosTron system resulted in a phenotype with impaired growth at low temperature and in high salt concentration, but with no difference in growth at optimal temperature or low pH conditions.

To date, SigK of clostridia has been strictly sporulation-associated. In this study, the researchers suggest a hitherto unidentified role for this alternative sigma factor in stress tolerance. Study of mechanisms by which the feared foodborne pathogen C. botulinum senses and responds to various environmental stresses it might encounter as hurdles applied in food preservation is of key importance. Identification of stress-activated genetic machineries of foodborne pathogens might provide biomarkers to exploit in detection of potentially stress-adapted cells, allowing targeted control methods.

The research was carried out at the Finnish Centre of Excellence in Microbial Food Safety Research and supported by the Academy of Finland, the Finnish Graduate School on Applied Bioscience, the European Community’s Seventh Framework Programme FP7/2007-2013 “CLOSTNET”, and the Walter Ehrström Foundation.

The Department of Food Hygiene and Environmental Health and Professor Hannu Korkeala hosted the AntiBotABE meeting on 17-18^th June in Helsinki. Centre Recherche Service Santé Armée supported by VITAMIB coordinates an international consortium on the development of neutralizing antibodies against botulinum toxins A, B, E.

It is a collaborative project under the EU’s 7^th Research Framework Programme in the security research area. The AntiBotABE consortium contains of academic and industrial partners with the expertise to carry out highly innovative research and development in this exciting domain.

Participants from Centre Recherche Service Santé Armée, France, Ministère de la Défense, France, Technische Universität Braunschweig, Germany, Institut Pasteur, France, Health Protection Agency HPA, United Kingdom, Centre National de la Recherche Scientifique, France, LFB Biotechnologies, France, University of Helsinki, Finland and VITAMIB, France shared and evaluated the recent developments in the AntiBotABE project and also experienced the Finnish summer.

>> Read more AntiBotABE

Jere Lindén, DVM will defend the doctoral dissertation entitled “TCDD-induced changes in the expression of selected hypothalamic feeding-regulatory genes and mRNA quantification using reverse transcription–qPCR” in the Faculty of Veterinary Medicine, University of Helsinki, on 8 June 2013 at 12:00. The public examination will take place at the EE building, Walter hall, Agnes Sjöbergin katu 2, Helsinki.

Docent Risto Juvonen, University of Eastern Finland, will serve as the opponent, and Professor Raimo Pohjanvirta as the custos.

The dissertation is also available in electronic form through the E-thesis service.

Contact information:
Jere Lindén
jere.linden@helsinki.fi