Research
Streptococcus pyogenes (StrepA)
StrepA causes a wide array of diseases ranging from sore throat to severe invasive disease such as necrotizing fasciitis and toxic shock. Our lab has been interested in exploring the epidemiology of invasive StrepA disease with a focus changes on emm types in Alberta. StrepA can possess a wide collection of emm types numbering over 250 worldwide. We are exploring why various emm types come into a region and predominate and sometimes cause outbreaks whereas others do not. This work is currently being undertaken using tools such as whole genome sequencing, emm typing and epidemiological/clinical analysis of invasive cases. In addition, we collaborate with the Dr. Michael Good research group in Australia with respect to a StrepA vaccine and potential immunotherapies for invasive StrepA.
Streptococcus agalactiae (GBS)
GBS are pathogens of both adults and neonates causing invasive disease in both groups. Our laboratory has been focused on both understanding the epidemiology of invasive GBS disease as well as exploring mechanisms GBS uses to invade host cells. GBS possess a polysaccharide capsule which can be expressed as 10 different types. Whole genome sequencing of invasive cases of GBS in Alberta has shown the presence of novel GBS capsule types and lead to the development of a molecular GBS capsule typing assay currently in place in the public health laboratory in Alberta. We have also been working towards understanding how GBS surface proteins interact with their environment and in turn activate specific virulence factors such as beta hemolytic toxins. This work has lead us to determine the effect sugar alcohols (polyols) have in activating various virulence phenotypes of GBS.
Streptococcus pneumoniae
S. pneumonaie are primarily bacterial pathogens causing community acquired pneumonia however, this clinical condition can lead to more severe invasive pneumococcal disease. Our work has centered on serotyping pneumococci in Alberta over the last 20 years as all invasive S. pneumonaie in Alberta come to our laboratory for serotyping. S. pneumonaie possess a polysaccharide capsule of which there are over 90 different types (serotypes). Understanding circulating capsule types has become more important with the introduction of conjugate pneumococcal vaccines. Our work has been targeted towards understanding serotype changes for invasive S. pneumoniae in Alberta especially as to how these changes relate to vaccine introductions and specific populations affected by this pathogen.
Mycobacteria
As the Program Lead for the Public Health mycobacteriology program in Public Health, Dr. Tyrrell also oversees mycobacterial diagnostics in Alberta. All laboratory aspects of mycobacterial investigations in Alberta are centralized in this single location. This allows us to perform diagnostic and epidemiological investigations for both M. tuberculosis as well as non-TB mycobacteria species such as Mycobacterium chimaera for the province.