The damage response framework of microbial pathogenesis is based on three tenets 1,2. What is infectiveness and how is it involved in infection and. Clinicians deal with disease and disease management. The damageresponse framework of microbial pathogenesis and infectious diseases. The strong similarity in bacterial and ciliate community composition of these diseases suggests that they are actually the same syndrome. In fact, the question of whether pathogenicity is a microbial trait and the question of whether hosts distinguish socalled pathogens from nonpathogens have the same answer. The damageresponse framework of microbial pathogenesis is based on three tenets 1,2.
The extension of the curve below the xaxis represents the beneficial effect that interactions with class 1 microorganisms can produce in normal hosts, whereby the host response prevents significant damage and commensalism confers a benefit to the host. Mar 26, 2015 according to definitions put forth in the damage response framework, the states of commensalism, colonization, disease, and latency differ from one another by the amount of damage in the host. Thus, the purpose of this work is to unify criteria and basic concepts related to the hostmicroorganism interactions, allowing a common dialogue in both, the public and animal health. The host damage response framework states that microbial pathogenesis is a product of microbial virulence factors and collateral damage from host immune responses. Liiseanne pirofski, infectious disease specialist in.
Clearly more research needs to be done to clarify the molecular mechanisms of hendra virus pathogenesis. Start studying lecture 4 damage response framework. In designating host damage as the readout of hostmicrobe interaction, the damageresponse framework differs from theories of microbial pathogenesis that attribute virulence to either host or microbial factors. The damageresponse framework drf is an integrated theory that views microbial pathogenesis as an outcome of hostmicrobe interaction. I first heard of it when i heard arturo casadevall give a talk. The damageresponse framework of microbial pathogenesis was developed to provide a flexible construct that encompasses microbes with and without diseaseassociated determinantseg, classical virulence factors. Causes exserohilum can also cause more invasive forms of infection in the sinuses, lungs, lining of the heart, and bone, which are thought to be more likely to occur in people with weak. Microbes are defined by their state in a host, not by their traits. The relevant measure of hostmicrobe interaction is host damage due to host or microbial factors, or both.
The damage response framework of microbial pathogenesis 3 suggests that both ends of the scale would lead to the development of the disease, where a weak response would benefit the dissemination. The impact of the host on fungal infections sciencedirect. A reappraisal of humoral immunity based on mechanisms of antibody. Damageresponse framework as a tool for the physicianscientist. Remarkably, despite the increasing recognition that host immunity plays a role in microbial pathogenesis, there has. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Bacterial cell death, antibiotics, and antibodies may cause the release of endotoxins. Disease as a function of microbial burden as viewed from the damage response framework of microbial pathogenesis 5. Frontiers mechanisms of cryptococcus neoformansmediated. A reappraisal of humoral immunity based on mechanisms of. The drf was formulated over a decade ago and put forth in a series of essays to provide an alternative to the aforementioned microbecentric view that virulence is a microbedictated progress which had prevailed from the late 1890s to the late 1990s 7, 10. The damageresponse framework plots damage as a function of the immune response and uses the qualifiers strong and weak to denote quantitative and. Ab the late twentieth century witnessed the emergence of numerous infectious diseases that are caused by microorganisms that rarely cause disease in.
The damageresponseframework of microbial pathogenesis is based on three tenets1,2 box 1. His lab continues to work on fungal and bacterial pathogenesis. The damageresponse framework of microbial pathogenesis posits that disease occurs when host damage is sufficient to affect hemostasis, which in turn produces clinical symptoms. The damage response framework, a theory of microbial pathogenesis, is discussed in detail in the following articles 26. During the 201920 coronavirus pandemic pirofski looked to understand the impact of sarscov2 on patients as well as identifying a new treatment strategy. Incorporating the microbiota into the damageresponse framework. Accidental virulence, cryptic pathogenesis, martians, lost. The drf is based on the core principle that there are no exclusive pathogens, commensals, or opportunists, but that microbial pathogenesis. Together with liiseanne pirofski, he proposed the damageresponse framework of microbial pathogenesis, a new synthesis that shifted the emphasis away from focusing on microbes as pathogens, commensals, opportunists to the outcome of hostpathogen interactions. What are the costs and benefits for microbes of having the capacity for virulence. The graph shown here illustrates how the damage response framework can be applied to a yersinia pseudotuberculosis infection. Key words damageresponse framework, microbe, pathogen, pathogenicity, virulence. The host damageresponse framework states that microbial pathogenesis is a product of microbial virulence factors and collateral damage from host immune responses. Liiseanne pirofski is an infectious disease specialist in bronx, new york and is affiliated with one hospital.
Pathogenesis thoughts from the front line, page 1 of 2. What is infectiveness and how is it involved in infection. The damageresponse framework of microbial pathogenesis ncbi. The drf was formulated over a decade ago and put forth in a series of essays to provide an alternative to the aforementioned microbecentric view that virulence is a microbedictated progress which had prevailed from the late 1890s to the late 1990s 7 10. Mediated protection against intracellular pathogens arturo casade vall and liise.
Endotoxins cause fever by inducing the release of interleukin1 and shock because of a tnfinduced decrease in blood pressure. At the initial moment of infection, generally via a fecaloral transmission route, there is neither a positive nor a negative affect on the host. The damage response framework of microbial pathogenesis is an idea, put forward by liise anne pirofksi and arturo casadevall in 1999. The damageresponse framework of microbial pathogenesis and. The damageresponse framework of microbial pathogensis. Formulated in 1999, the drf first served as an educational tool for the inaugural microbial pathogenesis course at albert einstein college of medicine, for which we were course leaders. The damageresponse framework of microbial pathogenesis 2003 by cupton may 4, 2015. Casadevall a and pirofski l 2003 the damageresponse framework of microbial pathogenesis. The premise of the drf is that damage to the host can be mediated by either the pathogen or the host, and therefore microbial virulence is a measure of the outcome of an interaction between a microbe and a susceptible host.
Lesser and colleagues 2007 argued that coral diseases in particular may result more commonly from environmentally induced changes in. If you ever get to see him speak, do so, its well worth it. It covers microbiology, hostpathogen interaction and immunology related to infectious agents, including bacteria, fungi, viruses and protozoa. Asmscience pathogenesis thoughts from the front line. Disease as a function of microbial burden as viewed from the damage response framework of microbial pathogenesis. The damageresponse framework as a tool for the physician. First, that microbial pathogenesis is the outcome of an.
Virulence factors and their mechanisms of action albert einstein. The damage response framework is an integrated theory of microbial pathogenesis that puts forth the view that microbial pathogenesis reflects the outcome of an interaction between a host and a. Model of bacterial toxindependent pathogenesis explains. The field of bacterial pathogenesis has advanced dramatically in the last decade. Sep 15, 2018 the damageresponse framework drf is an integrated theory that views microbial pathogenesis as an outcome of hostmicrobe interaction. Request pdf the damageresponse framework of microbial. High throughput molecular technologies have empowered scientists as never before. The emerging damageresponse framework of microbial pathogenesis casadevall and pirofski, 2003 suggests that diseases in general arise from complex host pathogen interactions. The damageresponse framework of microbial pathogenesis disease is only one outcome of an interaction between a microbe and a susceptible host.
The damage response framework of microbial pathogenesis provides a foundation for understanding irs, and is discussed before focusing on irs itself. The damageresponse framework of microbial pathogenesis 3 suggests that both ends of the scale would lead to the development of the disease, where a weak response would benefit the dissemination. First, that microbial pathogenesis is the outcome of an interaction between a host and a microorganism,and is attributable to neither the microorganism nor the host. Cryptococcus neoformans interactions with amoebae suggest an explanation for its virulence and intracellular pathogenic strategy in macrophages. The damageresponse framework is an integrated theory of microbial pathogenesis that puts forth the view that microbial pathogenesis reflects the outcome of an interaction between a host and a. The damageresponse framework is an integrated theory of microbial pathogenesis that puts forth the view that microbial pathogenesis reflects the outcome of an interaction between a host and a microbe, with each entiry contributing to the nature of the outcome, which in turn depends on the amount of host damage that results from the host. This cited by count includes citations to the following articles in scholar. The damageresponse framework of microbial pathogenesis.
All other curves are derived from this basic curve. Available concepts of microbial pathogenesis and virulence simply could not explain how such. Jan 31, 2012 the immune system does not distinguish between pathogens and commensals. This has led to the revolutionary concept of the damage response framework drf that defines microbial virulence as a function of host immunity. The meaning of microbial exposure, infection, colonisation. The damageresponse framework of microbial pathogenesis is based on three tenets1,2 box 1. The arrow indicates that the position of the curve is variable, and depends on the particular hostmicroorganism interaction. First, that microbial pathogenesis is the outcome of an interaction between a host and a microorganism,and is attributable to neither the microorganism nor the host alone. One approach to understanding the current epidemic is to consider it based on the tenets of the damageresponse framework drf of microbial pathogenesis. Microbial pathogenesis needs a microbe and a host 2. The drf is based on three tenets that are considered obvious and. This essay is written from the vantage point of the microbial world. These models show that the pathogen dynamics exhibit an allee effect and that increasing dilution and diffusion of the toxin increases the infective dose.
First, that microbial pathogenesis is the outcome of an interaction between a host and a microorganism. The damageresponse framework is an integrated theory of microbial pathogenesis that puts forth the view that microbial pathogenesis reflects the outcome of an interaction between a host and a microbe, with each entity contributing to the nature of the outcome, which in turn depends on the amount of host damage that results from the host. The damage response framework of microbial pathogenesis. To address this impediment to studies of hostmicroorganism interactions, we propose a new theoretical approach to understanding microbial pathogenesis, known as the damageresponse framework. First, we start with a simple analytical model and extend it into a spatial diffusion model. Candida albicans biology, molecular characterization. The damageresponse framework of microbial patho genesis is based on three tenets1,2 box 1. Ciliate and bacterial communities associated with white. Fungal virulence, vertebrate endothermy, and dinosaur. In 2003, casadevall and pirofski9 proposed the damageresponse framework of microbial pathogenesis. The drf outlines six scenarios classes of host damage or beneficial outcomes, depending on the microbe and the strength of the immune.
Despite this uncertainty, it is clear that an infection is characterized by a strong inflammatory response, the breakdown of endothelial cells around the body, and systematic infection by the hendra virus. While the focus of much thought in the microbial pathogenesis and infectious diseases fields has been on the impact of hostmicrobe interaction on the host, here we ask questions about what happens to the microbe. A for hostmicrobe interactions resulting in the commensal state, there is a relatively constant microbial population over time that is maintained in its. The damage response framework is an integrated theory of microbial pathogenesis that puts forth the view that microbial pathogenesis reflects the outcome of an interaction between a host and a microbe, with each entity contributing to the nature of the outcome, which in turn depends on the amount of host damage that results from the host. Liiseanne pirofski is a professor of infectious diseases at the albert einstein college of medicine. The damage response framework the ways and means of the. Theory of the damageresponse framework of microbial pathogenesis. Disease is a complex outcome that can occur as a result of pathogenmediated damage, hostmediated damage or both. Exserohilum rostratum australia pdf ppt case reports. Immunemediated host damage is particularly important within the sizerestricted central nervous system cns, where immune responses may exacerbate cerebral edema and neurological damage, leading to coma and death.