A biosensor equipped with a nanochip can detect diarrhea bacteria in piglets and reduce antimicrobial use.

A new type of nanotechnology-based biosensor can capture particles from diarrhea-inducing bacteria which claim the lives of more than one million piglets every year. A team of DTU researchers have developed the new biosensor which will be further developed in the new upcoming DTU spin-out, Enterogate, and in collaboration with pig producers, veterinarians, advisory clinics, and Bactolife ApS.

“We’re seeing a great interest from pig producers, who, with the help of the new biosensor technology, can quickly and inexpensively tell whether or not diarrhea in their piglets is caused by an infection with diarrhea bacteria. The new technology could lead to a significant improvement in animal welfare and a reduction in financial losses for pig producers. Furthermore, the quick test method can help reduce antimicrobial consumption and ensure a more focused use of antimicrobial agents on pig farms. This is very important in the fight against multi-resistant bacteria,” says Professor Winnie E. Svendsen from DTU Bioengineering, who has developed the new biosensor in collaboration with Associate Professor Andreas Hougaard Laustsen from DTU Bioengineering.

Nano and chip technology

The new biosensor has yielded positive results in detecting diarrhea-inducing E. coli bacteria in laboratory tests conducted at DTU. The sensor is based on a combination of nano and chip technologies, where a chip with a gold surface treated with particularly stable antibodies is able to capture and hold some of the so-called virulence factors in E. coli bacteria that cause diarrhea in piglets.

The market for piglet diarrhea treatment amounts to around DKK 110 million a year in Denmark alone, and Winnie E. Svendsen estimates that the new biosensor will be able to take over 40 per cent of the current Danish market for diagnostics and treatment. The technology can subsequently be marketed globally and be developed for diagnostics for a number of other diseases in both animals and humans.

Mapping frequent outbreaks

The biosensor is currently under further development in dialogue with pig producers who will help determine where the biosensor can used most effectively and with the best results.

“Through nanotechnology, we obtain a highly sensitive signal that enables us to measure the bacteria, but the big challenge will be to design the right system for these tests. The question is whether we should measure on each pig, or whether we should measure on one section at a time. What is most efficient for the farmer? Is it to isolate a section and administer antimicrobial agents to that section only, or do we need to treat each pig individually? And does it even make sense to separate the individual samples from the piglets in the pen?” says Winnie E. Svendsen.

In the long term, she expects to be able to supplement the biosensor with artificial intelligence which can use the large data volumes to produce a map of a pigpen showing the areas with the most frequent outbreaks.

“The question is whether there is a pattern to where the infections typically break out in the pigpen. This information would be of great value to the farmers, so that they can reduce the number of infections and diarrhea in the long term. And our equipment enables them to do that,” says Winnie E. Svendsen.

Facts about diarrhea in piglets

Every year, approximately 32 million pigs are produced in Denmark – one of the world’s biggest exporters of both piglets and pork. One of the major challenges in pig production is diarrhea in piglets, the so-called post-weaning diarrhea, which often occurs when they are weaned from the sow’s milk at four weeks old. This leads to significant financial losses for pig producers as well as reduced animal welfare.

The current treatment for post-weaning diarrhea is to administer antimicrobial agents to the entire litter, often without farmers knowing the exact cause of the diarrhea. Antimicrobial treatment in piglets is often based on observations of their health in the pigpen, rather than diagnostics, as sending samples to a laboratory and having them analysed is a long and costly process. The end result is a large and unnecessary antimicrobial consumption in pig production. Up to a third of the Danish antimicrobial consumption is treatment of piglets.

Every year, Danish pig producers use 35 tonnes of antimicrobial agents and 400 tonnes of zinc oxide for treating post-weaning diarrhea in piglets, and in a global perspective, the consumption levels among US pig producers are seven times higher than among Danish pig producers.