Chapters authored
Risk Factors for Brucella spp. in Domestic and Wild Animals
Brucella spp. is the aetiological agent of brucellosis, a serious contagious disease that results in reproductive failure and that has profound public health significance because of its zoonotic characteristics. This disease also is responsible for a high economic impact associated with the application of prevention, surveillance and test-and-slaughter programmes in animals by national authorities. Brucella spp. infects a large variety of animals and their prevalence is variable worldwide, mainly associated with the presence or absence of control programmes and also with the vaccination of animals against brucellosis. To achieve the control and eradication of brucellosis, the identification of the risk factors of brucellosis that maintain the infection in animals and/or the environment is fundamental. Although several risks have been identified, the most important have been associated with the biology of the bacteria, animal management (age, sex, species or breed), herd management (herd/flock size, number of species, contact with wild animals or type of animal production), farm management (facilities, cleaning and disinfection or veterinary support) and farmers’ knowledge about the disease. Thus, to benefit from proper risk identification of brucellosis, it is essential to put a cost-effective and efficient brucellosis control programme into place.
Part of the book: Updates on Brucellosis
Modeling the Behavior of Listeria monocytogenes in Meat
This work was conducted to present some studies that show the behavior of Listeria monocytogenes in meat, according to intrinsic and extrinsic factors. The understanding of factors that affect the survival and growth of L. monocytogenes in meat, such as temperature, pH, acid, salt, water activity or modified atmosphere packaging, is crucial to develop strategies for food operators to reduce and prevent Listeria contamination and growth. The knowledge of L. monocytogenes behavior according to its physiological and ecological characteristics, under all probable conditions, will support risk assessors to find strategies to control this ubiquitous bacteria in food industry and food service. The Regulation (EC) No 2073/2005, reviewed by the Regulation (EC) No 1441/2007, does not establish the limits for L. monocytogenes in fresh meat. However, it is generally accepted a level of 100 cells on fresh meat, except for some risk groups. Food business operators and authorities can use predictive microbiology models as important tools to model bacterial growth in quantitative microbial risk assessments.
Part of the book: Listeria Monocytogenes