Antibiotic residue lights up bacteria

Large numbers of antibiotics are used in cattle production, fuelling fears of the emergence of antibiotic-resistant bacteria and their subsequent transferral to humans. The use of antibiotics in livestock is regulated to prevent the spread of antibiotic-resistant strains and reduce the amount of antibiotic residues in food.

The European Union requires its member states to monitor residues and contaminants in food.

“The conventional screening methods are inexpensive and simple to use. However, the methods are based on the prevention of microbial growth and are not particularly sensitive or precise”, says Virolainen.

Bacterial biosensors are genetically engineered to produce a measurable signal in response to a specific chemical or substance in their environment. Virolainen developed bioluminescent biosensors that glow in the presence of antibiotic molecules.

“Bioluminescent biosensors allow for more accurate results than conventional screening methods, because they only respond to a certain group of antibiotics. They represent an inexpensive and fast method for screening large numbers of samples”, says Virolainen.

In addition, Virolainen developed a biosensor that responds to nisin, which is widely used as a food preservative. The biosensor is capable of determining the amount of nisin in food samples and identify nisinogenic bacteria.

Public defence of a doctoral dissertation on Friday, 7 September

The doctoral dissertation of MA Nina Virolainen in the field of biotechnology ”Antimicrobial detection illuminated: developing bioluminescent antibiotic biosensors based on bacterial gene regulatory elements ” will be publicly examined at the Faculty of Science and Environmental Engineering of Tampere University of Technology (TUT) in room Pieni Sali 1 in the Festia building (address: Korkeakoulunkatu 8, Tampere) on Friday, 7 September 2012 at 12:00.

The opponent will be Professor Sylvia Daunert (University of Miami). Professor Matti Karp from the Department of Chemistry and Bioengineering will act as Chairman.

Nina Virolainen (34) comes from Turku, Finland, and works as a biochemist at Ductor Ltd in Helsinki.

Further information:
Nina Virolainen, tel. +358 50 303 5068, nina.virolainen@tut.fi