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 damage response framework of microbial pathogenesis. Clinicians deal with disease and disease management. 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. 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. 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. Future studies may interpret sex differences in infectious disease pathogenesis in the context of the damageresponse framework, recognizing that the underlying causes of microbial pathogenesis may be mediated by the host immune response, the pathogen, or both. At the initial moment of infection, generally via a fecaloral transmission route, there is neither a positive nor a negative affect on the host. Damageresponse framework as a tool for the physicianscientist.
Frontiers mechanisms of cryptococcus neoformansmediated. The damageresponse framework of microbial pathogenesis is based on three tenets1,2 box 1. 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. Liiseanne pirofski, infectious disease specialist in. 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 damage response framework of microbial pathogenesis and infectious diseases. Benefits and costs of animal virulence for microbes mbio. 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. If you ever get to see him speak, do so, its well worth it. Cryptococcus neoformans interactions with amoebae suggest an explanation for its virulence and intracellular pathogenic strategy in macrophages. Pathogenesis thoughts from the front line, page 1 of 2. The damageresponse framework of microbial pathogenesis and. These models show that the pathogen dynamics exhibit an allee effect and that increasing dilution and diffusion of the toxin increases the infective dose. It covers microbiology, hostpathogen interaction and immunology related to infectious agents, including bacteria, fungi, viruses and protozoa.
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. 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. Ab the late twentieth century witnessed the emergence of numerous infectious diseases that are caused by microorganisms that rarely cause disease in. The damage response framework of microbial pathogenesis is based on three tenets 1,2. The damageresponse framework of microbial pathogenesis ncbi. In 2003, casadevall and pirofski9 proposed the damageresponse framework of microbial pathogenesis. The emerging damageresponse framework of microbial pathogenesis casadevall and pirofski, 2003 suggests that diseases in general arise from complex host pathogen interactions. The drf is based on the core principle that there are no exclusive pathogens, commensals, or opportunists, but that microbial pathogenesis. Available concepts of microbial pathogenesis and virulence simply could not explain how such.
Model of bacterial toxindependent pathogenesis explains. Request pdf the damageresponse framework of microbial. The host damageresponse framework states that microbial pathogenesis is a product of microbial virulence factors and collateral damage from host immune responses. Remarkably, despite the increasing recognition that host immunity plays a role in microbial pathogenesis, there has. The damageresponse framework of microbial pathogenesis posits that disease occurs when host damage is sufficient to affect hemostasis, which in turn produces clinical symptoms. Liiseanne pirofski is a professor of infectious diseases at the albert einstein college of medicine. Ciliate and bacterial communities associated with white. Microbes are defined by their state in a host, not by their traits.
Jan 31, 2012 the immune system does not distinguish between pathogens and commensals. The damageresponse framework as a tool for the physician. One approach to understanding the current epidemic is to consider it based on the tenets of the damageresponse framework drf of microbial pathogenesis. The strong similarity in bacterial and ciliate community composition of these diseases suggests that they are actually the same syndrome. A reappraisal of humoral immunity based on mechanisms of antibody. Microbial pathogenesis needs a microbe and a host 2.
A for hostmicrobe interactions resulting in the commensal state, there is a relatively constant microbial population over time that is maintained in its. Candida albicans biology, molecular characterization. Fungal virulence, vertebrate endothermy, and dinosaur. 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. 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. Original research papers should report complete findings and include only. This has led to the revolutionary concept of the damage response framework drf that defines microbial virulence as a function of host immunity. Disease as a function of microbial burden as viewed from the damage response framework of microbial pathogenesis 5. Applying the hostmicrobe damage response framework to. The host damage response framework states that microbial pathogenesis is a product of microbial virulence factors and collateral damage from host immune responses. Endotoxins cause fever by inducing the release of interleukin1 and shock because of a tnfinduced decrease in blood pressure.
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. 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. Exserohilum rostratum australia pdf ppt case reports. I first heard of it when i heard arturo casadevall give a talk. The relevant measure of hostmicrobe interaction is host damage due to host or microbial factors, or both. First, we start with a simple analytical model and extend it into a spatial diffusion model. To address this impediment to studies of hostmicroorganism interactions, we propose a new theoretical approach to understanding microbial pathogenesis, known as the damageresponse framework.
Start studying lecture 4 damage response framework. The drf is based on three tenets that are considered obvious and. The impact of the host on fungal infections sciencedirect. Clearly more research needs to be done to clarify the molecular mechanisms of hendra virus pathogenesis. The damage response framework of microbial pathogenesis is an idea, put forward by liise anne pirofksi and arturo casadevall in 1999. First, that microbial pathogenesis is the outcome of an interaction between a host and a microorganism. The field of bacterial pathogenesis has advanced dramatically in the last decade. Casadevall a and pirofski l 2003 the damageresponse framework of microbial pathogenesis. 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. The damageresponse framework of microbial pathogenesis and infectious diseases. Mediated protection against intracellular pathogens arturo casade vall and liise. 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 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.
His lab continues to work on fungal and bacterial pathogenesis. 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. Key words damageresponse framework, microbe, pathogen, pathogenicity, virulence. The meaning of microbial exposure, infection, colonisation. The damageresponse framework plots damage as a function of the immune response and uses the qualifiers strong and weak to denote quantitative and. What are the costs and benefits for microbes of having the capacity for virulence. 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. 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. First, that microbial pathogenesis is the outcome of an. The damageresponse framework drf is an integrated theory that views microbial pathogenesis as an outcome of hostmicrobe interaction. During the 201920 coronavirus pandemic pirofski looked to understand the impact of sarscov2 on patients as well as identifying a new treatment strategy.
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. The graph shown here illustrates how the damage response framework can be applied to a yersinia pseudotuberculosis infection. What is infectiveness and how is it involved in infection. The journal covers infectious agents of bacterial, fungal, viral, and protozoal origin. What is infectiveness and how is it involved in infection and. A reappraisal of humoral immunity based on mechanisms of. Disease is a complex outcome that can occur as a result of pathogenmediated damage, hostmediated damage or both. All other curves are derived from this basic curve. High throughput molecular technologies have empowered scientists as never before. The damage response framework, a theory of microbial pathogenesis, is discussed in detail in the following articles 26. The damageresponse framework of microbial pathogensis. Asmscience pathogenesis thoughts from the front line. Bacterial cell death, antibiotics, and antibodies may cause the release of endotoxins. This essay is written from the vantage point of the microbial world.
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. Learn vocabulary, terms, and more with flashcards, games, and other study tools. 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 drf outlines six scenarios classes of host damage or beneficial outcomes, depending on the microbe and the strength of the immune. Introduction the emerging damageresponse framework of microbial. Virulence factors and their mechanisms of action albert einstein. 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 damage response framework of microbial pathogenesis provides a foundation for understanding irs, and is discussed before focusing on irs itself.
Examples of pathogens classified by the six damageresponse curves are listed in table 2. Lesser and colleagues 2007 argued that coral diseases in particular may result more commonly from environmentally induced changes in. This cited by count includes citations to the following articles in scholar. The arrow indicates that the position of the curve is variable, and depends on the particular hostmicroorganism interaction. The damageresponse framework of microbial pathogenesis 2003 by cupton may 4, 2015. Sep 15, 2018 the damageresponse framework drf is an integrated theory that views microbial pathogenesis as an outcome of hostmicrobe interaction. The damageresponseframework of microbial pathogenesis is based on three tenets1,2 box 1. A for hostmicrobe interactions resulting in the commensal state, there is a relatively constant microbial population over time that is maintained in its ecological niche by competition with other microbes and host defense left panel. Accidental virulence, cryptic pathogenesis, martians, lost. Theory of the damageresponse framework of microbial pathogenesis. Disease as a function of microbial burden as viewed from the damage response framework of microbial pathogenesis.
The damageresponse framework of microbial patho genesis is based on three tenets1,2 box 1. The damage response framework the ways and means of the. The damageresponse framework of microbial pathogenesis is based on three tenets 1,2. Incorporating the microbiota into the damageresponse framework, abstract since proof of the germ theory of disease in the late 19th century, a major focus of the fields of microbiology and infectious diseases has been to seek differences between pathogenic and nonpathogenic microbes and the role that the host plays in microbial pathogenesis.
The damageresponse framework of microbial pathogenesis disease is only one outcome of an interaction between a microbe and a susceptible host. Liiseanne pirofski is an infectious disease specialist in bronx, new york and is affiliated with one hospital. The damageresponse framework of microbial pathogenesis was developed to provide a flexible construct that encompasses microbes with and without diseaseassociated determinantseg, classical virulence factors. Incorporating the microbiota into the damageresponse framework.