Researchers Under the Scope

That's So Metal: Dr. Jessica Sheldon Targets Acinetobacter BaumanniiJessica Sheldon (PhD) is on a mission to starve out Acinetobacter baumannii —one of the world's most virulent hospital-borne pathogens. Notorious for its speedy evolution and multi-drug resistance, the hospital-borne bacteria lingers on dry surfaces and infects critically-ill patients, leading to sepsis, pneumonia and high mortality rates. In this episode, Sheldon delves into the real-life events that drove her to investigate histamine, and its role in bacterial survival and immune response. In 2022, Sheldon joined the University of Saskatchewan's College of Medicine as an assistant professor of Biochemistry, Microbiology & Immunology -- something she now laughs about after an ill-fated high school placement in an immunology laboratory. "Cytokine cascades, pathways, the signaling just got way over my head real fast," said Sheldon. "I didn't really know what I was doing." Sheldon enrolled at Lakehead University, drawn to the tiny pathogens with outsized roles in movies like Outbreak. She estimates she read the book The Hot Zone 20 times. Her persistence paid off. "One of my second year microbiology teachers said, 'you know, I think you're kind of good at this. Maybe you should try it as a career.' Sheldon zeroed in on metals and wrote her doctoral dissertation on the role iron plays in the proliferation of bacteria such as Methicillin-resistant staphylococcus aureus (MRSA). Today, she studies both Morganella morganii and Acinetobacter baumannii — the multi-drug-resistant bacteria singled out twice in the last decade by the World Health Organization as a 'priority 1-critical pathogen'. "I'm perpetually fascinated by the idea that something so small can change the course of history," said Sheldon. "And we've seen that recently with COVID." Sheldon was already studying the metal uptake and signalling systems that grow and sustain A. baumannii when the bacteria ripped through hospitals during the pandemic, attacking Covid-infected patients on ventilators. By 2023, Sheldon landed a five-year CIHR grant of $900,000 to study A. Baumannii and the way it turns histidine into histamine. Her goal is to pinpoint the way the pathogen uses histamine to evade its host, as it sends out siderophores to steal iron and other nutrients. The compound appears to serve as a signalling mechanism for both the host and the invading pathogen, she said. "We know the bacteria are using histamine in the synthesis of these molecules to get iron, but they're also secreting it into the environment. We're not really sure why," Sheldon said. Her laboratory is working to trace and target those pathways, so researchers can identify and potentially develop new treatments — small molecules or antibody inhibitors that could disrupt multi-drug resistant pathogens. Beyond A. baumannii, histamine may hold the key to how some of the world's most notorious bacteria grow, spread, and evade immune defences, Sheldon said. "We're running out of drugs, but there's really not a full appreciation for the fact that we're losing the ability to treat bacterial infections," Sheldon said. "We need to develop supplementary therapies or alternative therapies."

18 min

Dr. Stu Skinner & Mobile Medicine: Halting Syphilis & HIVStuart Skinner (MD) knew something was wrong three years ago, when patients started coming to him with vision loss, fever, rashes, and meningitis. Almost every case could be traced back to untreated syphilis — a sexually transmitted infection with caseloads exploding 1,200 per cent from 2017. Saskatchewan saw this spike just as Covid-19 entered the picture. "With the pandemic, testing dropped dramatically," Skinner said, noting this wave of syphilis entered north-western Saskatchewan from Alberta, often travelling alongside HIV. Syphilis often spreads through sores, and can remain unnoticed for months or years on end, making early detection difficult. "If you don't see it, you won't be seeking care for it." When the infectious diseases physician and the Wellness Wheel team began treating mothers with severely ill newborns, stillbirths and birth defects, Skinner knew he had to act. Treating syphilis usually means a series of clinic and laboratory appointments, followed by intramuscular Bicillin injections, and intense contact tracing. Instead, Skinner, Dr. Sean Rourke, Cara Spence and their teams pared that down to a one-hour stop. They approached tribal councils and Indigenous-led health organizations, asking for help setting up mobile locations where anyone could be tested, diagnosed, and offered treatment. Nursing teams drove vans to powwows, festivals, even pharmacies, offering quick, confidential finger-prick tests and results. "The whole concept was to be flexible and mobile and adaptable . . . . so that we weren't the barrier," said Skinner. "It wasn't easy for the nurses to set up and read the results or draw the blood in a less comfortable environment, but they did an amazing job." In Saskatchewan, a total of 1,797 people agreed to be tested, uptake Skinner calls 'phenomenal'. Roughly three per cent were infected with HIV; 16% had syphilis. "The majority were willing to get treated right then and there," Skinner said. Those teams have now visited more than 50 locations across the prairies, through a $4M national partnership called the 'Ayaangwaamiziwin' Centre — which translates to 'be careful, be prepared' in Anishinaabe. Health officials and private donors recently extended those grants for an additional year. Skinner's colleagues keep fielding requests for the point-of-care service, which in turn has created a network of trusted Indigenous health leaders. This web, he said, could create the backbone of targeted outreach and screening for other diseases, such as diabetes or cancer. But it only works with mutual respect, he warned. "This isn't going to First Nations just to help them," Skinner said. "I've learned so much from the cultural values that are built on what happens in First Nations. We have a lot to learn." Skinner said mutual respect also means predictable paycheques — not just the odd grant. He said health budgets need to pay for health promotion workers employed at Indigenous-run organizations and non-profits, the ones who stick around after the testing van leaves. Patients are more likely to stay in touch with familiar faces and staff, he said. "It's about respect, kindness, and building trust," he said. "That is really critical."

31 min

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