A well-balanced immune system in the gut and the correct choice and dosage of antibiotics can reduce the spread of resistance to antibiotics amongst gut microbiota.

Picture: Synchronized delivery and immediate separation of the piglets from the sows to avoid colostrum intake (Photo by Leon Cantas, 2013)

Blood sampling from newborn piglets. (Photo by Leon Cantas) An increasing resistance to antibiotics, which are in daily use for the treatment of infections in both humans and animals, is well documented. Many bacteria have become resistant to several types of antibiotics and there are hardly any new antibiotics available to combat multiresistant bacteria of this kind. It is important to make sure that antibiotics continue to be an effective treatment for the generations to come, but incorrect and excessive use of antibiotics can increase the occurrence of resistant microorganisms.

Cantas used zebra fish, Atlantic salmon and pigs as models to study the immune system’s role in the development of resistance to antibiotics. He discovered that immune response was a key factor. The use of probiotics (immune-stimulating bacteria) during treatment increased the development of resistance in the gut microbiota, whereas treatment with immune-inhibiting medicines such as steroids or NSAID (Non-steroidal Anti-Inflammatory Drugs) lowered the development of resistance.

A well-balanced immune system in the gut appears to reduce the transmission of resistance to antibiotics between gut microbiota, but this balance may be affected by intestinal infections, sudden changes in diet or stress. Controlling so-called production stress (especially in intensive, livestock industries), improving routine procedures in order to ensure good animal health and increasing the focus on animal welfare are all factors that will help to promote an optimal immune response in the gut to harmful bacteria.

Intestinal microbiota culturing from triploid and diploid juvenile Atlantic salmon (Photo by Leon Cantas)The use of probiotics is thought to be advantageous in combating infections, but can – due to their stimulation of the immune system – paradoxically increase the development of resistance to antibiotics in the animal’s normal gut bacteria. In contrast, the use of medicines which inhibit the immune system, combined with a restrictive choice of antibiotics, can lead to a reduction in the spreading of antimicrobial drug resistance.

By following up and developing the results of this doctoral project through further research, we will learn more about the effect of medicines used by doctors and veterinary surgeons to combat infections and this will help to ensure that effective antibiotics will still be available in the future.

DVM Leon Cantas defended his doctoral research on 6th June with a thesis entitled “Development of antimicrobial drug resistance – impact of the bacterial infection treatment”.

Cantas carried out his research at the Department of Food Safety and Infection Biology (MatInf), the Department of Production Animal Clinical Sciences (ProdMed) and the Department of Basic Sciences and Aquatic Medicine (BasAM) at the Norwegian School of Veterinary Science, in collaboration with the Pasteur Institute in Paris and the Faculty of Medicine at the University of Tromsø.

Leon Cantas (born 1987) comes originally from Cyprus and has worked as an authorised veterinary surgeon in Norway since 2010. For the last three years, he has held a research fellowship at the Norwegian School of Veterinary Science, studying the antibiotic treatment of bacterial infections in animals. He has published 6 scientific papers in international/national medical and veterinary journals, been responsible for 1 conference proceeding and 1 academic paper at a conference and has given an oral presentation at a conference on the theme of infectious diseases and resistance to antibiotics. Cantas has also acted as a reviewer for several international journals. He carried out a research internship at the Pasteur Institute in Paris from October 2010 to February 2011. He is a member of the EU-COST action network “Detecting antibiotic resistance in Europe” (TD0803 DARE) at the Norwegian School of Veterinary Science.

Cantas has had internships at the ambulatory and stationary clinic at the Norwegian School of Veterinary Science and has worked as a veterinary surgeon at the Norwegian Food Safety Authority, at Trollheimen Animal Clinic and at a combined practice in Lista. He currently works at Grim Torv VeterinærHus and runs MegaVet.no in his capacity as a clinical veterinary in Southern Norway.

Contact information:
Leon Cantas
Mobile: +47 406 83 725
Email: [email protected] and [email protected]

Magnhild Jenssen, Information Officer at NVH
Tel.: +47 77 66 54 01
Mobile: +47 957 94 830
Email: [email protected]

 Leon Cantas