Over 3 million PLN for research on Salmonella

Salmonella is responsible for infections found in nearly 200 million people a year. In developing countries, especially in Africa, it is responsible for a high number of deaths from dehydration caused by diarrhoea among children. In the European Union alone, financial losses caused by salmonellosis are estimated at nearly 3 billion EUR a year. In compliance with sanitary service recommendations, birds or other farm animals diagnosed with Salmonella should be put down. Bacteriologists distinguish two main groups of these bacteria – one causes typhus, also known as typhoid fever, a dangerous disease that can lead to death, the other are non-typhoidal Salmonella, responsible for most human and animal food poisonings.

- The infection’s symptoms are prolonged diarrhoea, vomiting and dehydration which lead to the body's water and electrolyte level imbalance. In our part of the world, it is usually necessary to hospitalize Salmonella patients, especially children and the elderly. In developing countries, poisonings caused by this group of Salmonella are as dangerous as those caused by the other group, which causes typhus – explains professor Krzysztof Grzymajło, who has just won 3,101,200 PLN in the National Science Centre’s Sonata Bis 10 competition.

The project carried out by professor Grzymajło involves research on the interaction between the host, the pathogen and the microbiome in the early stages of a Salmonella infection.

- Most research on the early stages of an infection has focused on host – pathogen interactions. But we know that a third important player in this process is the host's intestinal microbiome, which has a huge impact on the entire body. These billions of microorganisms living in symbiosis with the human body are one of the barriers faced by pathogenic bacteria. We want to check how this barrier opens up to pathogens, what interactions take place between the microbiome and Salmonella, because this will allow us to develop a complete model of infection – explains professor Grzymajło, adding that the idea for the winning project was to join the general research model of the microbiome studied from two perspectives: its changes under the influence of infection, but also its impact on the pathogen.

At the UPWr Department of Biochemistry and Molecular Biology, research on Salmonella infections has been conducted for years, but so far scientists have focused on analyzing the first stages of the infection, i.e. the attachment of bacteria to the host cells. Extending the research spectrum to the microbiome means that the studies will be conducted on three models: simple cell lines, on organoids that have not been used in such research so far, and on an animal model. Organoids are three-dimensional structures that simulate the structure of the intestine, and thus a natural habitat of the intestine microbiome.

- This triad, with experiments on mice being the last stage of the research, will hopefully show us how a Salmonella infection proceeds in a comprehensive way – emphasizes professor Krzysztof Grzymajło, adding that the project carried out as part of the Sonata Bis 10 competition is still basic research, but it may become a starting point for work on pre- and probiotics that strengthen the host's microbiome so that it will be able to protect the body against infections.

Research conducted by prof. Grzymajło is going to define the composition of the microbiome before, during and after the infection, as well as describe the course of the infection in the presence of modified probiotic bacteria, which may initiate new strategies for preventing and treating Salmonella infections in humans and animals.

In 2007, the Human Microbiome Project (HMP) research program was launched, showing the complexity of the human microbiome. With the use of genetics the researchers studied microorganisms found on the skin, in the mouth, lungs and in the gastrointestinal tract – mainly in the large intestine. The differences in human microflora depending on the population, genotype, age, environment, diet and social factors were also analysed. Separate databases were developed for a specific microbiome, e.g. the mouth – the Human Oral Microbiome Database (HOMD). Collaboration on projects related to analyzing the human microbiome have demonstrated its importance for human health.