Cross contamination of food by pathogens via surfaces increases the risk of the propagation of infectious diseases. E.Coli and Listeria species are the predominant bacterium that causes fouling on food processing surfaces, chutes, cutting tables, tube systems, pipes and conveyor belts. The knowledge of the ability of the material surface for bacterial colonization is essential for selecting and designing surfaces for food processing. Characterization and optimization of surface pre-treatment with anti-microbial coatings will prevent the biofilm formation, and thereby will ensure food safety. Silver zeolite (SZ) acts as a smart surface coating. Upon contact with moisture, silver and highly reactive oxygen ions are released from the crystalline structure. The silver ions interact with the bacteria’s proteins and DNA. The oxygen acts as a free radical oxidizing components within the bacteria. The objectives of this project are (i) To investigate the interaction of the food pathogenic bacteria with various surfaces, and (ii) To assess the rate of antimicrobial activity of selected disinfectants against the pathogenic bacteria.
Microstructure of food matrix determines the physical, textural and sensory properties of end products. For predicting moisture transport and viscoelastic stresses during sorption and drying of wheat grains it is crucial to determine the precise internal structure of wheat. Lack of 3-dimensional morphology of the internal features of wheat kernel at the micro-nano scale is a constraint to understand the structure-function relationship, and the coupling between the heat and the mass-transfer processes during drying, cooking and processing. Micro X-ray computed tomography (X-ray CT) is a powerful tool for non-invasive high resolution 3-D visualisation and characterization of the internal micro-structure of cellular food products.
The goals of this study are:(i) to accurately investigate the 3-dimensional spatial distribution of the internal microstructure of insect and sprout damaged wheat kernels using X-ray micro CT images, and (ii) to determine the morphometric parameters such as porosity, anisotropy (3D symmetry) and absolute permeability of the matrix structures inside the insect and sprout damaged wheat kernels.
Collaborators: Ameet Singh and Scott Weese - Ontario Veterinary College
Surgical site infections (SSIs) are an inherent risk of any surgical procedure and SSIs caused by Staphylococcus pseudintermedius are becoming the most common nosocomial infections in canines at the Ontario Veterinary College. An important underlying pathogenic factor for the development of SSIs is the ability of the bacteria to form a biofilm. Bacterial biofilms are complex communities of bacteria embedded within a self-produced carbohydrate matrix attached to biological or non-biological surfaces that can greatly impact the ability to treat infections. Clarithromycin eliminates biofilms formed by a wide variety of bacteria and has an effective break-point of 8mg/l on methicillin-susceptible S.pseudintermedius strains. In this study, we investigated the in-vitro efficacy of clarithromycin on 20 methicillin-resistant S.pseudintermedius (MRSP) isolates in-order to test eradication therapies against SSI related infections. MRSP isolates were sub-cultured and inoculated into tryptic soy-broth before addition to microtiter plates. Biofilm formation was quantified first through removal of planktonic bacteria followed by staining, then heat fixing, and finally with elution of biofilm-embedded bacteria before completion of an OD570 reading. To characterize the adhesion, MRSP isolates were grown on stainless steel orthopaedic screws exposed to antibiotics at various time points using Scanning Electron Microscopy (SEM). Visual and image processing evaluation of the SEM images revealed the ability of the MRSPs to form biofilm on the surface and between the screw threads. The quantitative assay results (P > 0.5126) suggest that the influence of clarithromycin in the remediation of MRSP biofilms was insignificant after a 24h growth period. The results of our study indicate that the MRSP biofilms exhibits higher resistance to clarithromycin in therapeutic doses.
Nanomedicine is the technology that uses nanoscale or nanostructured materials such as bionanorobots in medicine that according to their structure have unique medical effects. A Nanorobot is defined as any smart structure which is capable of actuation, sensing, signaling, information processing, intelligence, manipulation and swarm behaviour at the nano scale. Bio-nanorobots are nanorobots designed and inspired by harnessing properties of biological materials such as DNAs and peptides. Bionanorobots made using bio-instrumentation have several clinical advantages including targeted drug delivery, nano sized hybrid therapeutics (low dosage) and early diagnosis at cellular level. Realizing Bionanorobots for biomedical applications raises several challenges. The objective of this project is to design an intelligent system using fuzzy logic and neural networks for diagnosis and treatment of tumours in humans using bionanorobots.
Bacterial biofilms have garnered much attention in recent years due to their importance in a wide range of both natural and engineered processes such as infection, water treatment, food processing, and oil pipelining. Here, we use a microfluidic device to quantify the effects of fluid shear force on the biofilm morphology of Shewanella oneidensis, a metal reducing bacteria of interest for several bioremediation and energy applications.
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Bionanotechnology LaboratorySuresh Neethirajan
School of EngineeringUniversity of GuelphGuelph, OntarioCanada N1G 2W1
Office: Room 2340, Tower OfficeThornbrough Building50 Stone Road East
Lab: OVC VMI building
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