Sarah Morin

Supervisor: Linda Chui

Project: Investigating the accuracy of multiplex molecular panels in detecting gut pathogens in children


Edmonton, AB

Degree program:

Doctor of Medicine

Why did you choose this program?

I view medicine as the culmination of applying scientific knowledge, caring for those who are vulnerable and advocating for communities. I love being involved in the scientific process, from the conception of an idea to testing that idea to refining our knowledge and eventually applying that knowledge in a practical manner. I want to understand medicine from its basic scientific core, all the way up to its clinical application, which is why I hope to remain involved in research during my medical training.

How was your studentship impacted by COVID-19?

My project is primarily composed of wet lab work, and so the bulk of my project was delayed until I could physically enter the laboratory in mid-June, which was a month and a half past the original start date. Once restrictions were lifted, however, I was able to make up for most of the lost time.

What did you get to work on throughout your studentship?

My project is very hands-on. I am involved in every step of my project, from organizing specimens to extracting DNA to estimating bacterial load (measurable quantity of bacteria) based on the amount of different bacterial genes present in stool samples. I have the opportunity to use a diverse array of research techniques such as quantitative polymerase chain reaction (qPCR), bacterial culture and ribotyping via capillary electrophoresis.

What interested you in the summer studentship program?

The project aligns with my interests in medicine and pediatrics, and gives me the opportunity to apply and build upon my existing knowledge while learning many novel concepts and techniques. It’s especially fascinating and educational for me because of its clinical relevance regarding children in Alberta. I love the hands-on aspects of my project and find it very exciting to be handling real clinical samples and analyzing patient data.

What has the support from WCHRI and the Stollery Children's Hospital Foundation meant to you?

I am very grateful to be supported by an organization whose values align with mine as I hope to advocate for children's health one day as a pediatrician. I believe that my research will have an impact in the ever expanding area of child-centered research and I am honoured that this organization has recognized the relevance of my project. This support reminds me of the importance of my efforts and encourages me to work harder, especially through the minor setbacks and troubleshooting.

Lay abstract:

Bacterial pathogens in the gut remain an important cause of child mortality. Due to their underdeveloped immune systems, newborns and young children can get sick easily. Fortunately, they can respond quickly to appropriate treatment in a timely manner. Therefore, the need for a rapid diagnostic method has catalyzed a shift from laborious and time-consuming conventional culture methods to multiplex molecular panels targeting multiple different pathogens within hours. The Luminex xTAG Gastrointestinal Pathogen Panel (GPP) can simultaneously identify nine different bacterial targets, including some important enteric—occurring in the intestines—pathogens such as Salmonella, Shiga toxin-producing Escherichia coli including O157 and non O157, Campylobacter and Shigella. However, this particular panel has a potential major drawback for generating false-positives and false-negative results for the Salmonella target as shown in one recent publication. This type of data can have great impact leading to inappropriate treatment which can have devastating effects on young children.

My project's purpose is to evaluate the sensitivity and specificity of the Luminex xTAG GPP (PCR) assay on stools collected by the Alberta Provincial Pediatric EnTeric Infection Team (APPETITE). A standard curve based on the bacterial cell number and crossing point of our in-house quantitative polymerase chain reaction (qPCR) will be determined. We will include samples with discordant results (Luminex positive and culture negative) and concordant results (Luminex positive and culture positive) in our study. The results generated will reveal approximately the bacteria number present in the patient's stools.

This study could help to identify the potential limitations of multiplex molecular panels in accurately identifying bacteria in children experiencing diarrhea. It is paramount that diagnostic laboratories are made aware of these limitations.