In 2001, Coulthart teamed up with
Neil Cashman to write a paper on "Variant Creutzfeldt-Jakob disease: A summary of current scientific knowledge in relation to public health".[8]
As early as December 2003, Coulthart worked at the
National Microbiology Laboratory (NML) in
Winnipeg, where he reported that "In May 2003, Canada became the 22nd country outside of the
United Kingdom to report a case of
bovine spongiform encephalopathy (BSE) in an animal not known to be imported from a country with cattle previously affected by this fatal, transmissible
prion disease."[9]
In November 2004, Coulthart was co-author of a study on
scrapie of
mice. At the time he worked in the Division of Host Genetics and Prion Diseases of the NML.[10][11]
In 2013, Coulthart Cashman et al described at an academic conference Creutzfeldt-Jakob disease reporting in Canada.[15]
In 2014, Coulthart et al studied the
RT-QuIC assay, which is "able to detect low levels of the disease-inducing
isoform of the prion protein (PrP(d)) in
brain tissue biopsies and (CSF)," and "has great potential to become a method for diagnosing prion disease
ante mortem."[16]
In 2019, Coulthart was concerned with a girl from Ontario who died of sCJD "with initially rapid neurocognitive decline followed by a prolonged (~10 years) clinical course. Neuropathological findings at
autopsy included generalized
cerebral and
cerebellaratrophy with relative sparing of the
hippocampi, cerebral and cerebellar
white matter and
gray matter involvement, minimal spongiform change, PrP deposits in the
neocortex,
striatum and cerebellum by
immunohistochemistry, and
protease-resistant PrP by
Western immunoblot. With its longer disease duration and atypical manifestations of white matter loss, CJD-LS can be clinically mistaken for other
neurodegenerative diseases, or in the
pediatric setting for
metabolic or
genetic conditions. This case clearly demonstrates that with rapid-onset encephalopathy,
prion disease should be carefully considered, even in younger patients with slower disease progression."[17]
In June 2019, Coulthart was the lead interviewee who was called to answer the question: "Why did deer meat from an infected herd end up in Canada's food chain?" when "scientists, indigenous leaders and wildlife advocates signed a letter to Prime Minister
Justin Trudeau urging immediate action to stop the spread" of CWD in Canada, and "to recognize the dire nature of this
epidemic." Amongst the signatories of this letter was Coulthart's colleague Cashman. The catalyst was the plague of CWD that
was discovered on or around certain deer farms in southern Quebec.[18] Coulthart had on 15 March 2019 made a presentation to the
Ontario Federation of Anglers and Hunters (who are an intimately concerned party because they eat the meat from the deer which they kill) about the problem of CWD.[19]
Coulthart was the federal lead on the 2021 investigation into the
New Brunswick neurological syndrome of unknown cause (NSUC) cluster, which was first identified in 2019. The existence of the
disease cluster was published in a provincial government memo which was leaked to the Radio-Canada through a whistleblower.[20] By 26 March 2021, Coulthart as CJDSS director, had ruled out "a prion disease such as Creutzfeldt-Jakob disease (CJD)" even though there were many similarities. At that time, early on in their research, a "top priority" was to investigate possible exposure to toxins.[21]
^Doherty, JA (1 October 2006). "Final report and recommendations from the National Notifiable Diseases Working Group". Canada Communicable Disease Report. 32 (19): 211–25.
PMID17076030.
^Hardy, Isabelle; Li, Yan; Coulthart, Michael B; Goyette, Nathalie; Boivin, Guy (August 2001). "Molecular evolution of influenza A/H3N2 viruses in the province of Québec (Canada) during the 1997–2000 period". Virus Research. 77 (1): 89–96.
doi:
10.1016/s0168-1702(01)00269-6.
PMID11451491.
^Abed, Yacine; Coulthart, Michael B.; Li, Yan; Boivin, Guy (2003). "Evolution of Surface and Nonstructural-1 Genes of Influenza B Viruses Isolated in the Province of Québec, Canada, during the 1998–2001 Period". Virus Genes. 27 (2): 125–135.
doi:
10.1023/a:1025768308631.
PMID14501190.
S2CID6022963.
^Kwok, Anita Y. C.; Wilson, Jason T.; Coulthart, Michael; Ng, Lai-King; Mutharia, Lucy; Chow, Anthony W. (10 February 2011). "Phylogenetic study and identification of human pathogenic Vibrio species based on partial hsp60 gene sequences". Canadian Journal of Microbiology. 48 (10): 903–910.
doi:
10.1139/w02-089.
PMID12489780.
^Coulthart, Michael B; Mogk, Rhonda; Rancourt, Jason M; Godal, Deborah L; Czub, Stefanie (1 December 2003). "Prion protein gene sequence of Canada's first non-imported case of bovine spongiform encephalopathy (BSE)". Genome. 46 (6): 1005–1009.
doi:
10.1139/g03-124.
PMID14663519.
^Li, Li; Coulthart, Michael B.; Balachandran, Aru; Chakrabartty, Avi; Cashman, Neil R. (December 2007). "Species barriers for chronic wasting disease by in vitro conversion of prion protein". Biochemical and Biophysical Research Communications. 364 (4): 796–800.
doi:
10.1016/j.bbrc.2007.10.087.
PMID17964288.