401
|
Greenblum S, Chiu HC, Levy R, Carr R, Borenstein E. Towards a predictive systems-level model of the human microbiome: progress, challenges, and opportunities. Curr Opin Biotechnol 2013; 24:810-20. [PMID: 23623295 PMCID: PMC3732493 DOI: 10.1016/j.copbio.2013.04.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/28/2013] [Accepted: 04/01/2013] [Indexed: 01/15/2023]
Abstract
The human microbiome represents a vastly complex ecosystem that is tightly linked to our development, physiology, and health. Our increased capacity to generate multiple channels of omic data from this system, brought about by recent advances in high throughput molecular technologies, calls for the development of systems-level methods and models that take into account not only the composition of genes and species in a microbiome but also the interactions between these components. Such models should aim to study the microbiome as a community of species whose metabolisms are tightly intertwined with each other and with that of the host, and should be developed with a view towards an integrated, comprehensive, and predictive modeling framework. Here, we review recent work specifically in metabolic modeling of the human microbiome, highlighting both novel methodologies and pressing challenges. We discuss various modeling approaches that lay the foundation for a full-scale predictive model, focusing on models of interactions between microbial species, metagenome-scale models of community-level metabolism, and models of the interaction between the microbiome and the host. Continued development of such models and of their integration into a multi-scale model of the microbiome will lead to a deeper mechanistic understanding of how variation in the microbiome impacts the host, and will promote the discovery of clinically relevant and ecologically relevant insights from the rich trove of data now available.
Collapse
Affiliation(s)
- Sharon Greenblum
- Department of Genome Sciences, University of Washington, Seattle WA 98102, USA
| | - Hsuan-Chao Chiu
- Department of Genome Sciences, University of Washington, Seattle WA 98102, USA
| | - Roie Levy
- Department of Genome Sciences, University of Washington, Seattle WA 98102, USA
| | - Rogan Carr
- Department of Genome Sciences, University of Washington, Seattle WA 98102, USA
| | - Elhanan Borenstein
- Department of Genome Sciences, University of Washington, Seattle WA 98102, USA
- Department of Computer Science and Engineering, University of Washington, Seattle WA 98102, USA
- Santa Fe Institute, Santa Fe NM 87501, USA
| |
Collapse
|
402
|
Abstract
Clostridium difficile infection, the most frequent cause of nosocomial diarrhea, disproportionately affects older adults. The two most important risk factors for developing C. difficile infection are antimicrobial exposure and age >65 years old. Risk factors specific to older adults are frequent interactions with healthcare systems and age-related changes in physiology, including immune senescence and changes to the gut microbiome. Metronidazole and oral vancomcyin are the mainstays of conventional treatment for C. difficile infection. Alternative therapies include fidaxomicin, a narrow-spectrum macrocyclic antibiotic, and fectal bacteriotherapy, which offers an excellent therapeutic outcome. Strategies to prevent C. difficile infections include enhanced infection control measures and reducing inappropriate antimicrobial use through stewardship.
Collapse
Affiliation(s)
- Robin LP Jump
- Geriatric Research Education & Clinical Center & Infectious Diseases Section, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Blvd, Cleveland, OH 44106, USA
- Division of Infectious Diseases & HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| |
Collapse
|
403
|
Adamu BO, Lawley TD. Bacteriotherapy for the treatment of intestinal dysbiosis caused by Clostridium difficile infection. Curr Opin Microbiol 2013; 16:596-601. [PMID: 23866975 PMCID: PMC3840269 DOI: 10.1016/j.mib.2013.06.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 06/25/2013] [Indexed: 12/21/2022]
Abstract
Antibiotics damage the intestinal microbiota and disrupt colonization resistance predisposing us to recurrent C. difficile infection (CDI). Faecal microbiota transplantation (FMT) is a promising treatment for recurrent C. difficile infection. Mixtures of beneficial bacteria known as bacteriotherapy should be developed for treatment of CDI and other diseases linked to dysbiosis in the intestinal microbiota.
Faecal microbiota transplantation (FMT) has been used for more than five decades to treat a variety of intestinal diseases associated with pathological imbalances within the resident microbiota, termed dysbiosis. FMT has been particularly effective for treating patients with recurrent Clostridium difficile infection who are left with few clinical options other than continued antibiotic therapy. Our increasing knowledge of the structure and function of the human intestinal microbiota and C. difficile pathogenesis has led to the understanding that FMT promotes intestinal ecological restoration and highlights the microbiota as a viable therapeutic target. However, the use of undefined faecal samples creates a barrier for widespread clinical use because of safety and aesthetic issues. An emerging concept of bacteriotherapy, the therapeutic use of a defined mixture of harmless, health-associated bacteria, holds promise for the treatment of patients with severe C. difficile infection, and possibly represents a paradigm shift for the treatment of diseases linked to intestinal dysbiosis.
Collapse
|
404
|
Atarashi K, Tanoue T, Oshima K, Suda W, Nagano Y, Nishikawa H, Fukuda S, Saito T, Narushima S, Hase K, Kim S, Fritz JV, Wilmes P, Ueha S, Matsushima K, Ohno H, Olle B, Sakaguchi S, Taniguchi T, Morita H, Hattori M, Honda K. Treg induction by a rationally selected mixture of Clostridia strains from the human microbiota. Nature 2013; 500:232-6. [PMID: 23842501 DOI: 10.1038/nature12331] [Citation(s) in RCA: 2024] [Impact Index Per Article: 184.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 05/22/2013] [Indexed: 02/07/2023]
Abstract
Manipulation of the gut microbiota holds great promise for the treatment of inflammatory and allergic diseases. Although numerous probiotic microorganisms have been identified, there remains a compelling need to discover organisms that elicit more robust therapeutic responses, are compatible with the host, and can affect a specific arm of the host immune system in a well-controlled, physiological manner. Here we use a rational approach to isolate CD4(+)FOXP3(+) regulatory T (Treg)-cell-inducing bacterial strains from the human indigenous microbiota. Starting with a healthy human faecal sample, a sequence of selection steps was applied to obtain mice colonized with human microbiota enriched in Treg-cell-inducing species. From these mice, we isolated and selected 17 strains of bacteria on the basis of their high potency in enhancing Treg cell abundance and inducing important anti-inflammatory molecules--including interleukin-10 (IL-) and inducible T-cell co-stimulator (ICOS)--in Treg cells upon inoculation into germ-free mice. Genome sequencing revealed that the 17 strains fall within clusters IV, XIVa and XVIII of Clostridia, which lack prominent toxins and virulence factors. The 17 strains act as a community to provide bacterial antigens and a TGF-β-rich environment to help expansion and differentiation of Treg cells. Oral administration of the combination of 17 strains to adult mice attenuated disease in models of colitis and allergic diarrhoea. Use of the isolated strains may allow for tailored therapeutic manipulation of human immune disorders.
Collapse
Affiliation(s)
- Koji Atarashi
- RIKEN Center for Integrative Medical Sciences (IMS-RCAI), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
405
|
Ursell LK, Van Treuren W, Metcalf JL, Pirrung M, Gewirtz A, Knight R. Replenishing our defensive microbes. Bioessays 2013; 35:810-7. [PMID: 23836415 DOI: 10.1002/bies.201300018] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Large-scale characterization of the human microbiota has largely focused on Western adults, yet these populations may be uncharacteristic because of their diets and lifestyles. In particular, the rise of "Western diseases" may in part stem from reduced exposure to, or even loss of, microbes with which humans have coevolved. Here, we review beneficial microbes associated with pathogen resistance, highlighting the emerging role of complex microbial communities in protecting against disease. We discuss ways in which modern lifestyles and practices may deplete physiologically important microbiota, and explore prospects for reintroducing or encouraging the growth of beneficial microbes to promote the restoration of healthy microbial ecosystems.
Collapse
Affiliation(s)
- Luke K Ursell
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO, USA
| | | | | | | | | | | |
Collapse
|
406
|
de Vos WM. Fame and future of faecal transplantations--developing next-generation therapies with synthetic microbiomes. Microb Biotechnol 2013; 6:316-25. [PMID: 23574632 PMCID: PMC3917466 DOI: 10.1111/1751-7915.12047] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 02/20/2013] [Indexed: 12/13/2022] Open
Abstract
While practised for over thousand years, there is presently a renaissance in the interest of using of faecal transplantations to modify the intestinal microbiota of patients. This clinical practice consists of delivering large amounts of bowel microbes in various forms into the intestinal tract of the recipient that usually has been cleared previously. The major reason for the popularity of faecal transplantations is their effectiveness in treating a variety of diseases. Hence, there is a need to develop this procedure to the next level. While there are various developments to select, standardize and store the donor microbiota, it is more challenging to understand the intestinal microbial communities and develop ways to deliver these via robust biotechnological processes. The various approaches that have been followed to do so are discussed in this contribution that is also addressing the concept of the minimal microbiome as well as the production of the synthetic communities that can be instrumental in new therapeutic avenues to modify the intestinal microbiota.
Collapse
Affiliation(s)
- Willem M de Vos
- Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands.
| |
Collapse
|
407
|
Intestinal dysbiosis and depletion of butyrogenic bacteria in Clostridium difficile infection and nosocomial diarrhea. J Clin Microbiol 2013; 51:2884-92. [PMID: 23804381 DOI: 10.1128/jcm.00845-13] [Citation(s) in RCA: 349] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Clostridium difficile infection (CDI) causes nearly half a million cases of diarrhea and colitis in the United States each year. Although the importance of the gut microbiota in C. difficile pathogenesis is well recognized, components of the human gut flora critical for colonization resistance are not known. Culture-independent high-density Roche 454 pyrosequencing was used to survey the distal gut microbiota for 39 individuals with CDI, 36 subjects with C. difficile-negative nosocomial diarrhea (CDN), and 40 healthy control subjects. A total of 526,071 partial 16S rRNA sequence reads of the V1 to V3 regions were aligned with 16S databases, identifying 3,531 bacterial phylotypes from 115 fecal samples. Genomic analysis revealed significant alterations of organism lineages in both the CDI and CDN groups, which were accompanied by marked decreases in microbial diversity and species richness driven primarily by a paucity of phylotypes within the Firmicutes phylum. Normally abundant gut commensal organisms, including the Ruminococcaceae and Lachnospiraceae families and butyrate-producing C2 to C4 anaerobic fermenters, were significantly depleted in the CDI and CDN groups. These data demonstrate associations between the depletion of Ruminococcaceae, Lachnospiraceae, and butyrogenic bacteria in the gut microbiota and nosocomial diarrhea, including C. difficile infection. Mechanistic studies focusing on the functional roles of these organisms in diarrheal diseases and resistance against C. difficile colonization are warranted.
Collapse
|
408
|
Stecher B, Berry D, Loy A. Colonization resistance and microbial ecophysiology: using gnotobiotic mouse models and single-cell technology to explore the intestinal jungle. FEMS Microbiol Rev 2013; 37:793-829. [PMID: 23662775 DOI: 10.1111/1574-6976.12024] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/11/2013] [Accepted: 04/18/2013] [Indexed: 12/14/2022] Open
Abstract
The highly diverse intestinal microbiota forms a structured community engaged in constant communication with itself and its host and is characterized by extensive ecological interactions. A key benefit that the microbiota affords its host is its ability to protect against infections in a process termed colonization resistance (CR), which remains insufficiently understood. In this review, we connect basic concepts of CR with new insights from recent years and highlight key technological advances in the field of microbial ecology. We present a selection of statistical and bioinformatics tools used to generate hypotheses about synergistic and antagonistic interactions in microbial ecosystems from metagenomic datasets. We emphasize the importance of experimentally testing these hypotheses and discuss the value of gnotobiotic mouse models for investigating specific aspects related to microbiota-host-pathogen interactions in a well-defined experimental system. We further introduce new developments in the area of single-cell analysis using fluorescence in situ hybridization in combination with metabolic stable isotope labeling technologies for studying the in vivo activities of complex community members. These approaches promise to yield novel insights into the mechanisms of CR and intestinal ecophysiology in general, and give researchers the means to experimentally test hypotheses in vivo at varying levels of biological and ecological complexity.
Collapse
Affiliation(s)
- Bärbel Stecher
- Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Ludwig-Maximilians-University of Munich, Munich, Germany.
| | | | | |
Collapse
|
409
|
Walk ST, Micic D, Galecki AT, Rogers MAM, Washer L, Newton DW, Malani PN, Young VB, Aronoff DM. Reply to Walker et al. Clin Infect Dis 2013; 56:1846-7. [PMID: 23420819 PMCID: PMC3888128 DOI: 10.1093/cid/cit099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2024] Open
Affiliation(s)
- Seth T. Walk
- Department of Internal Medicine
- Division of Infectious Diseases
| | | | - Andrzej T. Galecki
- Department of Internal Medicine
- Division of Geriatric Medicine
- Department of Biostatistics
| | | | - Laraine Washer
- Department of Internal Medicine
- Department of Infection Control and Epidemiology
| | | | - Preeti N. Malani
- Department of Internal Medicine
- Division of Infectious Diseases
- Veterans Affairs Ann Arbor Healthcare System, Geriatric Research Education and Clinical Center, Ann Arbor, Michigan
| | - Vincent B. Young
- Department of Internal Medicine
- Division of Infectious Diseases
- Department of Microbiology, University of Michigan Health System
| | - David M. Aronoff
- Department of Internal Medicine
- Division of Infectious Diseases
- Department of Microbiology, University of Michigan Health System
| |
Collapse
|
410
|
Structure, function, and biology of the Enterococcus faecalis cytolysin. Toxins (Basel) 2013; 5:895-911. [PMID: 23628786 PMCID: PMC3709268 DOI: 10.3390/toxins5050895] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 04/22/2013] [Accepted: 04/23/2013] [Indexed: 11/17/2022] Open
Abstract
Enterococcus faecalis is a Gram-positive commensal member of the gut microbiota of a wide range of organisms. With the advent of antibiotic therapy, it has emerged as a multidrug resistant, hospital-acquired pathogen. Highly virulent strains of E. faecalis express a pore-forming exotoxin, called cytolysin, which lyses both bacterial and eukaryotic cells in response to quorum signals. Originally described in the 1930s, the cytolysin is a member of a large class of lanthionine-containing bacteriocins produced by Gram-positive bacteria. While the cytolysin shares some core features with other lantibiotics, it possesses unique characteristics as well. The current understanding of cytolysin biosynthesis, structure/function relationships, and contribution to the biology of E. faecalis are reviewed, and opportunities for using emerging technologies to advance this understanding are discussed.
Collapse
|
411
|
de Vos WM. Fame and future of faecal transplantations--developing next-generation therapies with synthetic microbiomes. Microb Biotechnol 2013. [PMID: 23574632 DOI: 10.1111/1751-7915] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
While practised for over thousand years, there is presently a renaissance in the interest of using of faecal transplantations to modify the intestinal microbiota of patients. This clinical practice consists of delivering large amounts of bowel microbes in various forms into the intestinal tract of the recipient that usually has been cleared previously. The major reason for the popularity of faecal transplantations is their effectiveness in treating a variety of diseases. Hence, there is a need to develop this procedure to the next level. While there are various developments to select, standardize and store the donor microbiota, it is more challenging to understand the intestinal microbial communities and develop ways to deliver these via robust biotechnological processes. The various approaches that have been followed to do so are discussed in this contribution that is also addressing the concept of the minimal microbiome as well as the production of the synthetic communities that can be instrumental in new therapeutic avenues to modify the intestinal microbiota.
Collapse
Affiliation(s)
- Willem M de Vos
- Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands.
| |
Collapse
|
412
|
Suwantarat N, Bobak DA. Fecal Bacteriotherapy for Recurrent Clostridium difficile Infection: What's Old Is New Again? Curr Infect Dis Rep 2013; 15:101-3. [PMID: 23549617 DOI: 10.1007/s11908-013-0314-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In recent years, effective management of recurrent Clostridium difficile infection (CDI) has emerged as an important issue for those clinicians who treat patients with CDI. In addition to antibiotic-based therapies, including alternating use, chaser, and tapering protocols, interest has increased in the potential utility of a variety of nonantibiotic forms of adjunctive therapy. Among these alternative forms of treatment, the concept of transferring extracts of a stool from donors to patients with CDI has been met with great interest among researchers, clinicians, and patients alike. Fecal bacteriotherapy, or so-called fecal microbiota transplantation, for therapy of CDI is a procedure that dates back to the 1950s. Recently, however, a variety of studies have garnered attention in the lay press, in addition to the standard scientific-reporting community. Although no well-controlled trials have been published as yet and the details of the procedures used have varied widely between institutions, the available evidence suggests that for selected patients, fecal bacteriotherapy appears to be generally safe and effective. Concerns about true efficacy and the theoretical potential for infectious complications have prevented widespread adoption of this concept as standard therapy, but its use in academic and community practices is on the rise.
Collapse
Affiliation(s)
- Nuntra Suwantarat
- Division of Infectious Diseases and HIV Medicine, Case School of Medicine, University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, OH, 44106, USA,
| | | |
Collapse
|
413
|
Duncan SH, Flint HJ. Probiotics and prebiotics and health in ageing populations. Maturitas 2013; 75:44-50. [PMID: 23489554 DOI: 10.1016/j.maturitas.2013.02.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 02/15/2013] [Indexed: 02/08/2023]
Abstract
In healthy adults microbial communities that colonise different regions of the human colon contribute nutrients and energy to the host via the fermentation of non-digestible dietary components in the large intestine. A delicate balance of microbial species is required to maintain healthy metabolism and immune function. Disturbance in this microbial balance can have negative consequences for health resulting in elevated inflammation and infection, that are contributory factors in diabetes and cancer. There is a growing awareness that the microbial balance in the colon may become increasingly perturbed with aging and therefore hasten the onset of certain diseases. Societal and dietary factors influence microbial community composition both in the short and long term in the elderly (>65 years old) whilst immunosenescence may also be linked to a perturbed distal gut microbiota and frailty in the elderly. Significant progress has been made in defining some of the dominant members of the microbial community in the healthy large intestine and in identifying their roles in metabolism. There is therefore an urgent need for better awareness of the impact of diet, prebiotic and probiotic strategies in driving human colonic microbial composition in order to understand the possibilities for maintaining healthy gut function and well-being in an increasingly elderly population. Here we review gut microbial changes associated with aging and how diet, prebiotics and probiotics may modulate the gut microbiota to maintain health in the elderly.
Collapse
Affiliation(s)
- Sylvia H Duncan
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, Greenburn Road, Bucksburn, Aberdeen, Scotland, UK.
| | | |
Collapse
|
414
|
Zucca M, Scutera S, Savoia D. Novel avenues forClostridium difficileinfection drug discovery. Expert Opin Drug Discov 2013; 8:459-77. [DOI: 10.1517/17460441.2013.770466] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Mario Zucca
- University of Torino, at S. Luigi Gonzaga Hospital, Department of Clinical and Biological Sciences, Regione Gonzole 10, Orbassano (To) 10043, Italy ;
| | - Sara Scutera
- University of Torino, Department of Public Health and Paediatric Sciences, V. Santena 9, Torino 10126, Italy
| | - Dianella Savoia
- University of Torino, at S. Luigi Gonzaga Hospital, Department of Clinical and Biological Sciences, Regione Gonzole 10, Orbassano (To) 10043, Italy ;
| |
Collapse
|
415
|
Armstrong GD, Pillai DR, Louie TJ, MacDonald JA, Beck PL. A Potential New Tool for Managing Clostridium difficile Infection. J Infect Dis 2013; 207:1484-6. [DOI: 10.1093/infdis/jit069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
|
416
|
A mixture of functionally oligoclonal humanized monoclonal antibodies that neutralize Clostridium difficile TcdA and TcdB with high levels of in vitro potency shows in vivo protection in a hamster infection model. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:377-90. [PMID: 23324518 DOI: 10.1128/cvi.00625-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Clostridium difficile infections are a major cause of antibiotic-associated diarrhea in hospital and care facility patients. In spite of the availability of effective antibiotic treatments, C. difficile infection (CDI) is still a major cause of patient suffering, death, and substantial health care costs. Clostridium difficile exerts its major pathological effects through the actions of two protein exotoxins, TcdA and TcdB, which bind to and disrupt gut tissue. Antibiotics target the infecting bacteria but not the exotoxins. Administering neutralizing antibodies against TcdA and TcdB to patients receiving antibiotic treatment might modulate the effects of the exotoxins directly. We have developed a mixture of three humanized IgG1 monoclonal antibodies (MAbs) which neutralize TcdA and TcdB to address three clinical needs: reduction of the severity and duration of diarrhea, reduction of death rates, and reduction of the rate of recurrence. The UCB MAb mixture showed higher potency in a variety of in vitro binding and neutralization assays (∼10-fold improvements), higher levels of protection in a hamster model of CDI (82% versus 18% at 28 days), and higher valencies of toxin binding (12 versus 2 for TcdA and 3 versus 2 for TcdB) than other agents in clinical development. Comparisons of the MAb properties also offered some insight into the potential relative importance of TcdA and TcdB in the disease process.
Collapse
|
417
|
Relman DA. Restoration of the gut microbial habitat as a disease therapy. Nat Biotechnol 2013; 31:35-7. [DOI: 10.1038/nbt.2475] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
418
|
|
419
|
Bacteria beaten by bacteria. Nature 2012. [DOI: 10.1038/491010c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|