Aims: Listeria monocytogenes is capable, under certain conditions, of producing chemiluminescence which is amplified by luminol. This property was used to detect and count microcolonies of Listeria spp. in a few hours, without the use of a microscope.
Methods And Results: After trapping Listeria cells on polyvinylidene fluoride membranes, a chemiluminescence mixture was sprayed onto the membrane. The chemiluminescent spots emitted were analysed by a charge-coupled device camera connected to a data-processing system, which restored the intensity of the signals into three dimensional images. The intensity of the luminescence of microcolonies was improved by addition of cellobiose, and by brief exposure to u.v. light.
Conclusion: Microcolonies of Listeria spp. can be imaged and counted by luminol-enhanced chemiluminescence with a photon-counting system.
Significance And Impact Of The Study: This method can be applied to the rapid detection and counting of Listeria spp. in raw milk.
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http://dx.doi.org/10.1046/j.1365-2672.2001.01332.x | DOI Listing |
Foodborne Pathog Dis
January 2025
Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil.
Foodborne pathogens have always been of public health concern and represent safety issues for food processors. These pathogens develop new ways to overcome antibiotics, survive in different environmental conditions, and the ability to reproduce in many hostile environments configure them as serious health hazards. Considering the huge number of microorganisms, three bacterial representatives were selected to provide a better knowledge about the question of which one is the worst enemy for humans, from the food industry point of view, taking into consideration their multiplication specificity, virulence, and resistance.
View Article and Find Full Text PDFItal J Food Saf
November 2024
Department of Veterinary Medicine, University of Sassari.
This study aimed to conduct a preliminary investigation in eight Sardinian fermented sausage (SFS) production plants to acquire knowledge about the differences in the applied technological process and their influence on the safety and sensory characteristics of the finished product. Two audits were conducted in each plant to evaluate structural characteristics and process technologies; 72 samples of SFS at the end of seasoning and 48 environmental samples were analyzed. , spp.
View Article and Find Full Text PDFJ Food Prot
December 2024
Department of Food Science, The Pennsylvania State University, University Park, PA 16802, USA; One Health Microbiome Center, The Pennsylvania State University, University Park, PA 16802, USA. Electronic address:
Cleaning and sanitizing are of vital importance to control Listeria monocytogenes in food processing facilities. Here, we evaluated the effect of four cleaning and sanitation standard operating procedures (SSOPs; T1, T2, T3, T4) on the reduction of total aerobic mesophilic microorganisms, the occurrence of L. monocytogenes, and the microbiota composition in three tree fruit packing facilities (F1, F2, and F3) over two packing seasons (Y1 and Y2).
View Article and Find Full Text PDFInt J Food Microbiol
December 2024
Center for Food Science and Nutrition, Natural and Computational Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Electronic address:
This study aimed to comprehensively examine the prevalence of L. monocytogenes and Listeria spp. in dairy products including raw milk, pasteurized milk, and cottage cheese, and identify potential risk factors for contamination throughout the dairy value chain in major milk sheds in Ethiopia.
View Article and Find Full Text PDFGMS Hyg Infect Control
November 2024
Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Background: Postbiotics comprise soluble compounds freed from the structure of destroyed bacteria or created by living bacteria. Such byproducts provide the host with enhanced biological function as well as specific physiological consequences. This research aims to examine the characteristics and possible health advantages of -derived postbiotics.
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