Foodborne Pathogens and Food-Related Microorganisms
Devarajan Thangadurai, Leo M. L. Nollet, Saher Islam, Jeyabalan Sangeetha in Sequencing Technologies in Microbial Food Safety and Quality, 2021
Foodborne diseases are one of the most important public health troubles in many countries, and every year millions of cases of foodborne illness or associated complications are reported. Hence, identifying and studying the food associated pathogenic microorganisms and their mechanisms are crucial to preventing foodborne infections and implementing strategic methods to control disease outbreaks. Besides foodborne pathogens, diverse beneficial microorganisms are also associated with various food products. They enhance the nutritional status of associated foods and thereby improve the quality of foods. In this chapter, different foodborne pathogens and their mechanisms are discussed in detail. This also describes the beneficial microorganisms associated with various food products and their health benefits.
Introduction to Pathogenesis
Michael F. Cole in Unifying Microbial Mechanisms, 2019
This chapter examines common themes in microbial pathogenesis. Pathogenics is at the interface of microbiology and immunology because it considers the properties of a microorganism that harm the host and the innate and acquired host defence mechanisms that can neutralise them. Humans are the experimental subject with the greatest fidelity when the infectious agent is solely a human pathogen and the experiments meet ethical requirements. The chapter aims to identify the aetiological agent of a particular infectious disease and to determine what property or properties of the microorganism and the host allow it to cause disease. It discusses methods of neutralising and eradicating the agent by the use of antimicrobial agents and by harnessing the host immune system. The phenotype or property under investigation should be associated with the pathogenic members of a genus or pathogenic strains of a species. A nucleic acid sequence belonging to a putative pathogen should be present in most cases of an infectious disease.
Reaching Backwards
Scott O. Rogers, John D. Castello in Defrosting Ancient Microbes, 2019
While large multicellular organisms cannot be revived after they die, a surprising number of unicellular organisms, including a few small multicellular organisms, can survive long-term entrapment in environmental ice. This includes glaciers, ice domes, lake ice, permafrost, and others. Thus, ice is a repository of ancient life on Earth. This has both positive and negative consequences, because both beneficial and pathogenic organisms are frozen in the ice. Most of the ice is in Antarctica and Greenland, with smaller amounts around the world. Study of the ice provides information about past climate changes on Earth, as well as information about ancient organisms. It can affect people directly, through the release of pathogenic organisms.
Molecular basis of host specificity in human pathogenic bacteria
Published in Emerging Microbes & Infections, 2014
Xiaolei Pan, Yang Yang, Jing-Ren Zhang
Pathogenic bacteria display various levels of host specificity or tropism. While many bacteria can infect a wide range of hosts, certain bacteria have strict host selectivity for humans as obligate human pathogens. Understanding the genetic and molecular basis of host specificity in pathogenic bacteria is important for understanding pathogenic mechanisms, developing better animal models and designing new strategies and therapeutics for the control of microbial diseases. The molecular mechanisms of bacterial host specificity are much less understood than those of viral pathogens, in part due to the complexity of the molecular composition and cellular structure of bacterial cells. However, important progress has been made in identifying and characterizing molecular determinants of bacterial host specificity in the last two decades. It is now clear that the host specificity of bacterial pathogens is determined by multiple molecular interactions between the pathogens and their hosts. Furthermore, certain basic principles regarding the host specificity of bacterial pathogens have emerged from the existing literature. This review focuses on selected human pathogenic bacteria and our current understanding of their host specificity.
Enteric pathogens and gut function: Role of cytokines and STATs
Published in Gut Microbes, 2010
Terez Shea-Donohue, Alessio Fasano, Allen Smith, Aiping Zhao
The gut harbors the largest immune system in the body. The mucosa is considered to be the initial site of interaction with commensal and pathogenic organisms; therefore, it is the first line of defense against the pathogens. In response to the invasion of various pathogens, naïve CD4+ cells differentiate into subsets of T helper (Th) cells that are characterized by different cytokine profiles. Cytokines bind to cell surface receptors on both immune and non-immune cells leading to activation of JAK-STAT signaling pathway and influence gut function by up-regulating the expression of specific target genes. This review considers the roles of cytokines and receptor-mediated activation of STATs on pathogen-induced changes in gut function. The focus on STAT4 and STAT6 is because of their requirement for the full development of Th1 and Th2 cytokine profiles.
Regulatory T cells and immunity to pathogens
Published in Expert Opinion on Biological Therapy, 2007
Immune responses to pathogens are modulated by one or more types of cells that perform a regulatory function. Some cells with this function, such as CD4+Foxp3+ natural regulatory T cells (nTreg), pre-exist prior to infections whereas others may be induced as a consequence of infection (adaptive Treg). With pathogens that have a complex pathogenesis, multiple types of regulatory cells could influence the outcome. One major property of Treg is to help minimize collateral tissue damage that can occur during immune reactions to a chronic infection. The consequence is less damage to the host but in such situations the pathogen is likely to establish persistence. In some cases, a fine balance is established between Treg responses, effector components of immunity and the pathogen. Treg responses to pathogens may also act to hamper the efficacy of immune control. This review discusses these issues as well as the likely mechanisms by which various pathogens can signal the participation of Treg during infection.