Devices, Methods, and Systems for Fluorescence-Based Imaging and Collection of Data for Food Safety Purposes

Abstract

A method of screening for contamination during food production is disclosed. The method includes applying an exogenous, bacteria-specific contrast agent to a surface to be screened, wherein the surface to be screened is one or more of a food product, a food-preparation surface, a food-handling surface, and a food-equipment surface. The surface is illuminated with excitation light emitted by at least one light excitation light source of a handheld device and optical signals responsive to illumination of the surface are filtered with at least one optical filter of the handheld device. Bacterial fluorescence data regarding the illuminated surface is collected with an image sensor of the handheld device and, in real-time, based on the collected bacterial fluorescence data, the presence and/or location of bacteria on the illuminated surface is determined

We claim: 
     
         1 . A method of screening for contamination during food production, comprising:
 applying an exogenous, bacteria-specific contrast agent to a surface to be screened, wherein the surface to be screened is one or more of a food product, a food-preparation surface, a food-handling surface, and a food-equipment surface;   illuminating the surface on which the contrast agent has been applied with excitation light emitted by at least one light excitation light source of a handheld imaging device;   filtering, with at least one optical filter of the handheld device, optical signals responsive to illumination of the surface including the contrast agent with the excitation light, the at least one optical filter being configured to enable optical signals having a wavelength corresponding to bacterial fluorescence to pass through the filter;   collecting bacterial fluorescence data regarding the illuminated surface with an image sensor of the handheld imaging device, wherein the collected bacterial fluorescence data comprises at least one image containing data relating to exogenous fluorescence of bacteria responsive to illumination of the surface; and   in real-time, based on the collected bacterial fluorescence data, determining the presence and/or location of bacteria on the illuminated surface.   
     
     
         2 . The method of  claim 1 , wherein applying an exogenous, bacteria-specific contrast agent to the surface to be screened includes applying a mixture of two or more contrast agents. 
     
     
         3 . The method of  claim 1 , wherein the exogenous, bacteria-specific contrast agent is configured to make visible only specific strains of bacteria. 
     
     
         4 . The method of  claim 1 , wherein the exogenous, bacteria-specific contrast agent is configured to make visible only viable  Listeria monocytogenes.    
     
     
         5 . The method of  claim 1 , wherein the exogenous, bacteria-specific contrast agent is configured to make visible one or more of  Listeria monocytogenes, Enterobacter sakazakii, Campylobacter coli, Campylobacter jejuni, Campylobacter lari,  coliform bacteria, all bacteria of the  E. coli  species,  Salmonella,  all bacteria of the  Staphylococcus aureus  species, all bacteria of the  Staphylococcus  genus, and  Pseudomonas aeruginosa.    
     
     
         6 . The method of  claim 1 , further comprising displaying an image of bacteria detected on the illuminated surface on a display of the handheld imaging device or on a display configured to receive transmissions from the handheld imaging device. 
     
     
         7 . The method of  claim 1 , further comprising, when bacteria are determined to be present on the illuminated surface, identifying one or more strains of bacteria present. 
     
     
         8 . The method of  claim 1 , further comprising, when bacteria are determined to be present on the illuminated surface, differentiating between strains of bacteria present on the illuminated surface. 
     
     
         9 . A method for fluorescence-based imaging of a target to detect contamination comprising:
 labelling a selected biomarker at the target with at least one fluorescing contrast agent;   illuminating the target with excitation light emitted by an excitation light source and having at least one wavelength or wavelength band causing at least the selected biomarker to fluoresce;   detecting fluorescence emissions of at least the selected biomarker with an image detector of a handheld imaging device; and   determining the presence, location, and/or quantity of contamination on the illuminated target based on the detected fluorescence emissions of at least the selected biomarker,   wherein the target is selected from the group consisting of a food product, a food-preparation surface, a food-handling surface, a food packaging surface, an area in a food processing plant, an area in a food production facility, and a food-equipment surface.   
     
     
         10 . The method of  claim 9 , further comprising comparing fluorescence emission band(s) of the at least one biomarker to a predetermined look-up table of fluorescence emission spectra and/or fluorescence emission band(s) of biomarkers. 
     
     
         11 . The method of  claim 9 , wherein labelling the selected biomarker at the target comprises labelling the selected biomarker with a combination of two or more contrast agents, wherein the combination is specific to the selected biomarker. 
     
     
         12 . The method of  claim 9 , wherein labelling the selected biomarker at the target comprises labelling the selected biomarker with an exogenous, bacteria-specific contrast agent. 
     
     
         13 . The method of  claim 12 , wherein the exogenous, bacteria-specific contrast agent is configured to make visible one or more of  Listeria monocytogenes, Enterobacter sakazakii, Campylobacter coli, Campylobacter jejuni, Campylobacter lari,  coliform bacteria, all bacteria of the  E. coli  species,  Salmonella,  all bacteria of the  Staphylococcus aureus  species, all bacteria of the  Staphylococcus genus,  and  Pseudomonas aeruginosa.    
     
     
         14 . The method of  claim 9 , wherein determining the presence, location, and/or quantity of contamination on the illuminated target includes detecting the presence, location, and/or quantity of a bacterial strain based on the fluorescence emissions of at least the selected biomarker. 
     
     
         15 . The method of  claim 14 , wherein the bacterial strain is at least one selected from the group consisting of:  Staphylococcus  bacteria,  Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, Enterobacter sakazakii, Campylobacter  species of bacteria, coliform bacteria,  Escherichia coli  bacteria,  Propionibacterium acnes  and  Salmonella.    
     
     
         16 . The method of  claim 14 , wherein detecting the presence, location, and/or quantity of a bacterial strain based on the fluorescence emissions of at least the selected biomarker includes differentiating the presence, location and/or quantity of two or more different bacterial strains based on the fluorescence emissions of at least the selected biomarker. 
     
     
         17 . The method of  claim 16 , wherein the different bacterial strains include  Staphylococcus aureus  and  Pseudomonas aeruginosa,  and the different bacterial strains are differentiated based on their fluorescence emission signatures. 
     
     
         18 . The method of  claim 9 , wherein the selected biomarker is chosen from the group consisting of: bacteria, fungi, yeast, spores, virus, microbes, parasites, connective tissues, tissue components, exudates, pH, blood vessels, reduced nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FAD), microorganisms, vascular endothelial growth factor (VEGF), endothelial growth factor (EGF), epithelial growth factor, epithelial cell membrane antigen (ECMA), hypoxia inducible factor (HIF-1), carbonic anhydrase IX (CAIX), laminin, fibrin, fibronectin, fibroblast growth factor, transforming growth factors (TGF), fibroblast activation protein (FAP), tissue inhibitors of metalloproteinases (TIMPs), nitric oxide synthase (NOS), inducible and endothelial NOS, lysosomes in cells, macrophages, neutrophils, lymphocytes, hepatocyte growth factor (HGF), anti-neuropeptides, neutral endopeptidase (NEP), granulocyte-macrophage colony stimulating factor (GMCSF), neutrophil elastases, cathepsins, arginases, fibroblasts, endothelial cells and keratinocytes, keratinocyte growth factor (KGF), macrophage inflammatory protein-2 (MIP-2), macrophage inflammatory protein-2 (MIP-2), and macrophage chemoattractant protein-1 (MCP-1), polymorphonuclear neutrophils (PMN), macrophages, myofibroblasts, interleukin-1 (IL-1), tumour necrosis factor (TNF), nitric oxide (NO), c-myc, beta-catenin, endothelial progenitor cells (EPCs), matrix metalloproteinases (MMPs) and MMP inhibitors. 
     
     
         19 . The method of  claim 9 , wherein illuminating the target with a light source emitting excitation light having at least one wavelength or wavelength band causing at least the selected biomarker to fluoresce comprises illuminating the target with a light source emitting light having a wavelength between about 400 nm and about 450 nm. 
     
     
         20 . The method of  claim 9 , wherein detecting fluorescence emissions of at least the selected biomarker with the image detector of the handheld imaging device includes filtering emissions responsive to illumination of the target with one or more filters configured to permit optical signals having wavelengths corresponding to bacterial fluorescence to pass through the one or more filters to the image detector of the handheld device. 
     
     
         21 . The method of  claim 20 , wherein the wavelengths corresponding to bacterial fluorescence include wavelengths of about 490 nm to about 550 nm and/or wavelengths above about 600 nm. 
     
     
         22 . The method of  claim 9 , wherein determining the presence, location, and/or quantity of contamination on the illuminated target comprises displaying the detected fluorescence emissions on a display of the handheld imaging device or a display configured to receive transmissions from the handheld device. 
     
     
         23 . The method of  claim 9 , further comprising displaying an image of a location and/or biodistribution of bacteria, microorganisms, selected biomarker(s), and/or pathogens detected on the illuminated target on a display of the handheld device or a display configured to receive transmissions from the handheld device.