Researchers Use Serotyping to Categorize Streptococcus suis According to Virulence

Researchers with the Western College of Veterinary Medicine are using serotyping to categorise the virulence of Streptococcus suis.Researchers with the Western College of Veterinary Medicine have been investigating the implications of multiple Streptococcus suis serotype infections.

Dr. Matheus Costa, an Assistant Professor with the Western College of Veterinary Medicine and an Adjunct Professor at Utrecht University, explains dealing with Streptococcus suis associated disease is especially challenging because the bacteria is commonly found in the microbiome of the pig, however only certain serotypes will cause disease.

Quote-Dr. Matheus Costa-Western College of Veterinary Medicine:

Serotypes are a way of grouping bacteria.Bacteria, if you think about it, they are a very diverse population.Just like humans, every single bacteria is different from each other but not every Strep suis causes disease so, grouping them may make it easier for us to identify groups that are more aggressive and cause disease versus those groups that are not so aggressive and can not be ignored but they do not require a quick response.

The way we establish serotypes is by looking at their capsule.Many Streptococcus suis will produce a capsule that protects the cell from any damage, including from an immune response.We can determine what capsule types by using a physical test.

We would expose this Streptococcus isolate to an antibody and that antibody may or may not react but that is a very costly and time-consuming test so now laboratories have PCRs or even whole genome sequencing.So that all can be used to establish what serotype is present in the clinical sample.

Again, that helps us say this may be a problematic strain or this may just be a normal strain that is not going to cause a lot of disease so we don't need to address it immediately, let's look for another pathogen.

Dr. Costa says, so far, 25 different serotypes have been identified and they seem to be very diverse but there is also a lot of similarities.
He says by establishing serotyping, the goal is to determine if there is a difference in virulence between the serotypes.