New test for distinguishing virulent strains of bacteria in pigs

Research lead | Development opportunity

Scientists at Universitat Autonoma de Barcelona have used genome sequencing to identify virulent strains of the bacteria Haemophilus parasuis, the cause of Glässer’s disease in pigs. The research has provided the basis of a diagnostic test and could used to develop a vaccine against the disease.

Although H. parasuis is frequently found in the upper respiratory tract of pigs, not all the strains are capable of inducing the disease.

The researchers sequenced 98 per cent of the genome of the highly pathogenic Nagasaki strain, identifying thirteen genes coding for trimeric autotransporters (AT-2), proteins that are considered as essential virulence factors.

AT-2 proteins on the cell surface of bacteria allow it to adhere to the wall of the respiratory tract. All the pathogenic strains of H. parasuis tested by the researchers possess AT-2 molecules that are homologous with those found in the Nagasaki strain, while the non-pathogenic strains have none of these genes.

From these results, the researchers have developed a test that distinguishes pathogenic strains of H. parasuis, and say the AT-2 protein could form the basis of a new vaccine.