Email: lmuthari@uoguelph.ca

Office: SCIE 3253
Ext: 56349
Lab: SCIE 3206
Ext: 54385

 

Profile

My research interests are in the field of Bacterial Pathogenesis and specifically in the study of intracellularly growing bacteria, how these parasites interact with host cells and development of diagnostic assays. I completed B.Sc. and M.Sc. studies in Biochemistry at the University of Nairobi, and a PhD in Microbiology at the University of British Columbia. As a PhD student I studied the immunochemistry of bacterial lipopolyshaccharides and it was then I became interested in Microbial pathogenesis and immunology. My interests in bacterial pathogenesis were strongly influenced by my PhD advisor Dr. REW Hancock. My current research focuses on Mycobacterium avium subspecies paratuberculosis to understand at the molecular level, the genes and properties that enable this bacterium to growth within the mammalian macrophage cells.

I am a member of several scientific associations including, the International Association for Paratuberculosis and currently is on the Board of the IAP, the American Society of Microbiology (ASM) and the Canadian Society for Microbiology. I am on the Editorial Board for Journal of Clinical Microbiology, and a Member of the ASM Task Force for Africa.

Education

B.Sc. Nairobi
M.Sc. Nairobi
Ph.D. British Columbia

Research

Mycobacterium avium subspecies paratuberculosis or MAP is the causative agent of Johne's disease and the bacterium is implicated in some cases of human Crohn's disease. Johne's disease is a chronic and fatal inflammatory disease of the intestinal tract and which affects many animal species.

The current areas of research focus in the lab are:

  1. To study the molecular basis for MAP ability to invade, parasitize, and grow within the macrophage defense cells of the host animal. To survive within the macrophage, MAP bacteria regulate the expression of essential genes and proteins that allow the bacterium to overcome innate defenses of the macrophage cells and to survive within these cells. We use molecular approaches to identify and study the properties and functions of specific two-component signal transduction genes required for intracellular growth. We use mammalian cell lines and environmental protozoa as model systems to study expression of specific genes associated with the parasitic lifestyle.
  2. Current vaccines do not protect animals against infection vaccines, and worse, they do not prevent shedding of MAP bacteria in feces and animals milk. These vaccines do not prevent transmission of the disease or contamination of the environment. We are applying proteomic and molecular tools to identify MAP components which induce MAP-specific cellular and antibody responses. These components can be used to develop diagnostic reagents and for development of vaccines.
  3. Because MAP is extremely slow growing detection of contamination can be a protracted process taking weeks to months before growth become evident. We are developing new or improved diagnostic assays for detecting live MAP bacterial contamination of animal products and environmental samples.

Selected Publications

Mutharia LM, MD Klassen, Fairles J, S Barbut and CO Gill. 2010. Mycobacterium avium subsp. paratuberculosis in muscle and lymphatic tissues from cattle with advanced Johne's disease. Int J Food Microbiol. 2010 Jan 1;136(3):340-4.

Gao AL, J Odumeru, M Raymond, S Hendrick, T Duffield and L Mutharia. 2009. Comparison of milk culture, direct and nested polymerase chain reaction (PCR) with fecal culture based on samples from dairy herds infected with Mycobacterium avium subsp. paratuberculosis Can. J Vet Res. 73:58-64

Gao A, L Mutharia, M Raymond, J Odumeru. 2007.  Improved Template DNA Preparation Procedure for Detection of Mycobacterium avium subsp. paratuberculosis in Milk by PCR. J Microbiol Methods.

Gao, A., J Odumeru, M Raymond, and L Mutharia. 2005. Development of improved method for isolation of Mycobacterium avium subsp. paratuberculosis from bulk tank milk: effect of age of milk, centrifugation, and decontamination. Can J Vet Res. 69:81-7.

Teaching

At the undergraduate level I teach Introduction to Microbiology (MICR*2420) and Microbiology Methods I (MICR*2430, and have taught Pathogenic Bacteriology (MICR*4010), and Immunology I (MICR*3230). At the Graduate level I have participated in the teaching of Bacterial Pathogenesis (PABI*6000).

Graduate Students

Antonio Facciuolo (PhD)
John McLean (MSc)

Current and recent undergraduate research students  include : Mitchell Harding, John McLean, Brittany Dunbar, Jonathan Samson

Links

Publications in PubMed

International Association for Paratuberculosis

MAP K10 genome project
http://www.ncbi.nlm.nih.gov/genomes/framik.cgi?db=genome&gi=380
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=genomeprj&cmd=Retrieve&dopt=Overview&list_uids=91

Johne's Disease

Crohn's Disease:
http://www.ccfc.ca/English/index.html
http://www.crohnscanada.org/

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