Associate Professor

Jennie Johnstone

Department of Medicine


Mount Sinai Hospital: Sinai Health
600 University Ave., Rm 210, Toronto, Ontario Canada M5G 1X5
Research Interests
Infectious Diseases & Immunopathology
Clinical Interests
Infectious Disease
Appointment Status

Dr. Johnstone obtained her medical degree from Dalhousie University. She then moved to Edmonton, Alberta where she completed her Internal Medicine and Infectious Disease training at the University of Alberta. Following her residency she completed a clinical research fellowship in Edmonton. She moved to Hamilton in July 2008 where she practiced Infectious Diseases at McMaster University and completed her PhD in Health Research Methodology (Epidemiology).

Following her PhD, she joined Public Health Ontario as an Infection Prevention and Control physician where she continues to lead research focused on Infection Prevention and Control in the areas of vancomycin resistant enterococci, ventilator associated pneumonia and Clostridium difficile. She worked at St. Joseph's Health Center in Toronto for 5 years, where she practiced Infectious Diseases and ran the Infection Prevention and Control program.

In 2018 she left St. Joseph's to become the Physician Lead of Infection Prevention and Control at Sinai Health System in Toronto where she is also an Assistant Professor in the Laboratory Medicine and Pathobiology and Dalla Lana School of Public Health, University of Toronto.

Research Synopsis

As a practicing Infectious Diseases and Infection Prevention and Control physician and scientist, I am highly motivated to find better ways to prevent healthcare associated infections. My research interest and focus is therefore the prevention of healthcare associated infections.

My first program of research aims to determine ways to prevent transmission of vancomycin resistant Enterococci (VRE), antibiotic resistant organisms that primarily spread in hospitals. Historically, there was no consensus among hospitals within Canada (and worldwide) on how to best prevent the spread of VRE. This was mainly due to a paucity of high quality studies on the issue. Accordingly, VRE control programs were heterogeneous and there was disagreement over best practice.

Given the controversy, and the need to have a more standardized approach to VRE control in Ontario hospitals, Public Health Ontario invested in a series of studies aimed to inform future guidance. I therefore developed a program of research to inform VRE control best practices by answering four questions:

  1. does discontinuing VRE infection control practices lead to an associated change in rate of VRE bacteremia
  2. are outcomes different between patients with VRE bacteremia versus vancomycin susceptible Enterococci
  3. what are risk factors for VRE bacteremia
  4. what health service costs are associated with VRE bacteremia.

My second program of research is focused on the prevention of ventilator associated pneumonia and other healthcare associated infections in the critically ill.

I currently co-lead the PROSPECT Trial, a multi-center, multi-national trial testing whether administration of probiotics reduce ventilator associated pneumonia and other healthcare infections in critically ill, mechanically ventilated patients. This large trial involving 44 intensive care units in Canada, the United States and Saudi Arabia completed enrolment of the targeted 2650 patients in March 2019.

We aim to complete terminal statistical analyses, manuscript preparation and submission to a high impact journal by Winter 2020. I am mentored by the co-lead of the trial, Dr. Deborah Cook (Critical Care physician and veteran trialist, McMaster University).

Once the trial is complete, and the primary paper published, we will have a robust dataset that captures detailed clinical data on a cohort of 2650 critically ill patients including comorbidities, antimicrobials used, infections during their intensive care unit stay (and associated microbiology and susceptibility patterns), and outcomes. Additional cohort studies are already planned, including predictors of ventilator associated pneumonia and predictors of Clostridium difficile infection.

In terms of future research direction, in addition to completing my two programs of research, I am part of the Public Health Ontario - Institute for Clinical Evaluative Sciences (ICES) team of physicians and scientists that are cleaning the microbiology results within the Ontario Laboratory Information System (OLIS).

OLIS is a dataset that captures all routinely collected microbiology specimens in the province of Ontario, and the OLIS dataset has recently been integrated into ICES, which allows the linkage of OLIS to all ICES databases. Once cleaned, we will be uniquely poised to capitalize on linkable Ontario-wide laboratory and healthcare administrative datasets.

There are very few jurisdictions in the world which have access to population-wide microbiology test results. Once complete, this powerful dataset will allow researchers to determine the population-level prevalence and incidence of any microbe, including antibiotic resistant organisms and emerging pathogens, as well as describe their clinical characteristics and attributable mortality in an efficient, comprehensive way. We have recently secured CIHR funding and have hired a full time epidemiologist to begin cleaning the data; we estimate the full dataset will be ready for use in 2-3 years.

Selected Publications

Ling R, Achonu C, Li Y, Katz K, Garber G, Johnstone J. Investigating the relationship between vancomycin-resistant Enterococcus control practices and the incidence of health care-associated Clostridioides difficile infections in Ontario. Am J Infect Control 2019, In Press.

Johnstone J, Heels-Ansdell D, Thabane L, Meade MO, Marshall JC, Lauzier F, Duan E, Zytaruk N, Lamarche D, Surette M, Cook DJ for the PROSPECT Investigators and the Canadian Critical Care Trials Group. Evaluating probiotics for the prevention of ventilator associated pneumonia: A randomized placebo controlled multicenter trial protocol and statistical analysis plan for PROSPECT. BMJ Open 2019; 9:e025228.

Lamarche D, Johnstone J, Zytaruk N, Clarke F, Hand L, Rossi L, Szamosi JC, McDonald E, Meade MO, Marshall JC, Bowdish DME, Karachi T, Heels-Ansdell D, Cook DJ, Surette MG for the PROSPECT Investigators, Canadian Critical Care Trials Group & Canadian Critical Care Translational Biology Group. Microbial dysbiosis and mortality during mechanical ventilation: a prospective observational study. Respir Res 2018; 19:245.

Salaripour M, Johnstone J, Broukhanski G, Gardam, M. A spatial, temporal, and molecular epidemiological study of hospitalized patients infected with community-acquired or healthcare-associated Clostridium difficile in the Niagara Region, Ontario, Canada, between September 2011 and December 2013. Can J of Infect Control 2018; 33: 146-157.

Johnstone J, Chen C, Rosella L, Adomako K, Policarpio M, Lam F, Prematunge C, Garber G, on behalf of the Ontario VRE Investigators. Patient- and hospital-level predictors of vancomycin-resistant Enterococcus (VRE) bacteremia in Ontario, Canada. Am J Infect Control 2018; 46(11):1266-1271.

Salaripour M, Johnstone, J, Gardam, M. Epidemiology of patients hospitalized with Clostridium difficile infection: A comparative analysis of community-associated and healthcare-associated Clostridium difficile infections. Can J Infect Control 2018; 33(2): 96 – 101.

Prematunge C, Policarpio M, Johnstone J, Adomako K, Nadolny E, Lam F, Li Y, Brown K and Garber G. Impact of an independent quarterly audit on publicly reported vancomycin-resistant Enterocococi (VRE) bacteremia data in Ontario, Canada. American Journal of Infection Control. Am J Infect Control 2018; 46(9):1036-1040. doi: 10.1016/j.ajic.2018.02.016. Epub 2018 Apr 13.

Johnstone J, Policarpio M, Lam F, Adomako K, Prematunge C, Nadolny E, Li Y, Brown K, Kerr E, Garber G. Rates of blood cultures positive for vancomycin-resistant Enterococcus in Ontario: a quasi-experimental study. CMAJ Open 2017; 5: E273-E280.

Cook D, Johnstone J, Marshall J, Lauzier F, Thabane L, Mehta S, Dodek P, McIntyre L, Pagliarello J, Henderson W, Taylor R, Carten-Cebo R, Golan E, Herridge M, Wood G, Ovakim D, Karachi T, Surette M, Bowdish D, Lamarche D, Verschoor C, Duan E, Heels-Ansdell D, Arabi Y, Meade M.  Probiotics: Prevention of Severe Pneumonia and Endotracheal Colonization Trial - PROSPECT: A Pilot Trial. Trials 2016;17: 377.

Prematunge C, MacDougall, Johnstone J, Adomako K, Lam F, Robertson J, Garber G.  VRE and VSE bacteremia outcomes in the era of effective VRE therapy:  A systematic review and meta-analysis. Infect Control Hosp Epidemiol 2015; 37(1): 26-35.

Johnstone J, Meade M, Marshall J, Heyland DK, Surette M, Bowdish D, Lauzier F, Thabane L, Cook DJ. Probiotics: Prevention of Severe Pneumonia and Endotracheal Colonization Trial: PROSPECT: Protocol for a feasibility randomized pilot trial. Pilot Feasibility Stud 2015; 1:19.