Dancing with the Stars: How Choreographed Bacterial Interactions Dictate Nososymbiocity and Give Rise to Keystone Pathogens, Accessory Pathogens, and Pathobionts. Issue 6 (June 2016)

• Record Type: Journal Article
• Authors: Hajishengallis, George; Lamont, Richard J.
• Is Part Of: Trends in microbiology. Volume 24:Issue 6(2016)
• Page Start: 477
• Page End: 489
• Publication Date: 2016-06
• Subjects: polymicrobial synergy -- keystone pathogen -- accessory pathogen -- pathobiont -- nososymbiocity; Microbiology -- Periodicals; Infection -- Periodicals; Virulence (Microbiology) -- Periodicals; Infection -- Periodicals; Microbiology -- Periodicals; Virulence -- Periodicals; Microbiologie -- Périodiques; Infection -- Périodiques; Virulence (Microbiologie) -- Périodiques; Infection; Microbiology; Virulence (Microbiology); 579
• DOI: 10.1016/j.tim.2016.02.010
• Languages: English
• ISSNs: 0966-842X

Abstract

Abstract : Many diseases that originate on mucosal membranes ensue from the action of polymicrobial communities of indigenous organisms working in concert to disrupt homeostatic mechanisms. Multilevel physical and chemical communication systems among constituent organisms underlie polymicrobial synergy and dictate the community's pathogenic potential or nososymbiocity, that is, disease arising from living together with a susceptible host. Functional specialization of community participants, often originating from metabolic codependence, has given rise to several newly appreciated designations within the commensal-to-pathogen spectrum. Accessory pathogens, while inherently commensal in a particular microenvironment, nonetheless enhance the colonization or metabolic activity of pathogens. Keystone pathogens (bacterial drivers or alpha-bugs) exert their influence at low abundance by modulating both the composition and levels of community participants and by manipulating host responses. Pathobionts (or bacterial passengers) exploit disrupted host homeostasis to flourish and promote inflammatory disease. In this review we discuss how commensal or pathogenic properties of organisms are not intrinsic features, and have to be considered within the context of both the microbial community in which they reside and the host immune status. Trends: The emerging appreciation that certain inflammatory diseases are initiated by multispecies communities, wherein constituent organisms contribute to disease collectively rather than individually, challenges the notion that bacteria can be divided into two categories: commensals and pathogens. A more nuanced understanding of microbial pathogenic potential views the health- or disease- associated properties of a given microbe as a spectrum that ranges from commensalism to pathogenicity, dependent upon the nature of its interactions with other community members and the host's condition. Within this spectrum, newly recognized categories include 'accessory pathogens', 'keystone pathogens', and pathobionts. When referring to the potential of an indigenous community to cause disease, 'nososymbiocity' may be a more context-dependent and accurate term than 'pathogenicity'.