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.
- B.Sc. Nairobi
- M.Sc. Nairobi
- Ph.D. British Columbia
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:
- 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.
- 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.
- 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.
- Novel secreted antigens of Mycobacterium paratuberculosis as serodiagnostic biomarkers for Johne's disease in cattle. Facciuolo A, Kelton DF, Mutharia LM. 2013. Clin Vaccine Immunol. ;20(12):1783-91. doi: 10.1128/CVI.00380-13.
- Antibody and cell-mediated immune responses to Staphylococcus aureus small colony variants and their parental strains associated with bovine mastitis. Atalla H, Wilkie B, Gyles C, Leslie K, Mutharia L, Mallard B. 2010. Dev Comp Immunol. 34(12):1283-90. doi: 10.1016/j.dci.2010.07.005.
- The sensor kinase MprB is required for Rhodococcus equi virulence. MacArthur I, Parreira VR, Lepp D, Mutharia LM, Vazquez-Boland JA, Prescott JF. 2011. Vet Microbiol. 147(1-2):133-41. doi: 10.1016/j.vetmic.2010.06.018.
- Mycobacterium avium subsp. paratuberculosis in muscle, lymphatic and organ tissues from cows with advanced Johne's disease. Mutharia LM, Klassen MD, Fairles J, Barbut S, Gill CO. 2010. Int J Food Microbiol. 136(3):340-4. doi: 10.1016/j.ijfoodmicro.2009.10.026.
- 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. Gao A, Odumeru J, Raymond M, Hendrick S, Duffield T, Mutharia L. 2009. Can J Vet Res. 73(1):58-64.
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).
- Antonio Facciuolo, PhD student
- Will Martin, MSc student
- Ziad Marroushi, MSc student
MAP K10 genome project: