Germfree Life Research Articles

The human microbiome: 340 years of history, 140 years of interrogations, technological innovations and emergence of "microbial medicine"

For 350 years, we have known that the human body hosts microbes, then called "animalcules". For over a century, following the demonstration of the role of some of these microbes in diseases, questions have arisen about the role of the largely predominant ones colonizing human skin and mucous surfaces, particularly the rich microbial ecosystem of the intestine, the gut microbiota. From the invention of germ-free life - axenism - which experimentally validated the human-microbe symbiosis, resulting from a long coevolution, to the development of anaerobic culture methods, then to the invention of molecular diagnosis, deep sequencing opening up metagenomic and omics approaches in general, a remarkable race has taken place between technological innovations and conceptual advances. This race, beyond the exhaustive description of the microbiota in its intra- and inter-human diversity, and the essential symbiotic functions of the microbiome, has paved the way for a new field of medicine: microbial medicine.

Plant gnotobiology: Epiphytic microbes and sustainable agriculture

ABSTRACTIn 1963, a monograph by Thomas D. Luckey entitled Germfree Life and Gnotobiology was published, with a focus on animals treated with microbes and reference to the work of Louis Pasteur (1822–1895). Here, we review the history and current status of plant gnotobiology, which can be traced back to the experiments of Jean-Baptiste Boussingault (1801–1887) published in 1838. Since the outer surfaces of typical land plants are much larger than their internal areas, embryophytes “wear their guts on the outside.” We describe the principles of gnotobiological analyses, with reference to epiphytic metylobacteria, and sunflower (Helianthus annuus) as well as Arabidopsis as model dicots. Finally, a Californian field experiment aiming to improve crop yield in strawberries (Fragaria ananassa) is described to document the practical value of this novel research agenda.

"Standardization through mechanization". Germ-free life and the engineering of the ideal laboratory animal.

This article examines efforts to establish germ-free animals as ideal laboratory animals, tracing the development of germ-free technology by James Reyniers (1908–67) and Philip Trexler (1911–) at the University of Notre Dame. Despite capturing the scientific imagination between 1942 and the late 1950s, germ-free animals never became the generic tools that Reyniers hoped. This article shows how Reyniers failed to establish germ-free animals because the tension between standardization and the need for novelty was not successfully managed. However, Trexler adapted techniques of producing germ-free life to produce more successful Specific Pathogen Free (SPF) animals. Now so ubiquitous as to be invisible, SPF animals succeeded where germ-free animals failed because they embodied a standard that could be reconfigured to suit local research agendas, while also remaining highly defined and capable of representing natural forms of life. SPF animals became the ideal laboratory animal, used around the world.

Five Microflora Associated Characteristics in Conventional Rats

Five microflora associated characteristics (MACs) were studied in faecal samples from two groups of inbred rats, either obtained from three consecutive days or up to 13 times during a one month period. The results show minor inter- and intra-individual variations. Baselines for each MAC have to be established with regard both to species and diet, before studying host-microbiota related co-functions. Keywords: rats, microbiota, biochemical functions, germfree life.

Life Span, Morphology, and Pathology of Diet-Restricted Germ-Free and Conventional Lobund-Wistar Rats

The effect of germ-free life and dietary restriction (DR) on life span and pathology was investigated in isolator housed germ-free (GF) and conventional (CV) Lobund-Wistar rats fed either ad libitum or restricted to 12 grams per day (70% of adult ad libitum intake) of a natural ingredient diet from weaning. The median length of life of ad libitum CV and GF rats was 31.0 and 33.6 months respectively, while DR increased the median length of life of CV and GF rats to 38.6 and 37.8 months respectively. DR reduced the frequency or postponed the occurrence of diseases which eventually lead to death in the Lobund-Wistar rat. This was especially true of prostate adenocarcinoma, prostatitis, and mammary fibroma. The reduced early food intake and smaller body weight of adult GF rats may be the reason ad libitum fed GF rats live slightly longer than their CV counterparts, but GF life was without additional effect on life span when food intake was restricted.

Faecal tryptic activity in humans: influence of antibiotics on microbial intestinal degradation

Soluble faecal tryptic activity (FTA) was determined in healthy adults using a spectrophotometric method. Mean FTA was 100 mg/kg faeces (range 0-980), inter-individual variations were more pronounced than the intra-individual ones. Ten different antimicrobial drugs given orally for six days caused alterations in some individual FTA levels. Keywords: Tryptic activity; germfree life; intestinal flora; antibiotics.

Overview of gastrointestinal microecology.

In germ-free life many characteristics are not the consequence of living bacteria's metabolic activities but of bacteria acting as antigens. On the other hand, merely some bacteria species are able to activate the immune system. Noteworthy experimental results relate to inhibitory effects of dietary lactobacilli on intestinal carcinomas. Besides bacteria other components play a role within the very complex man-microbe ecosystem. Thus, protozoa, fungi, and viruses may be generally concerned with diseases in monogastric animals.

Pneumonic disease in germ-free animals.

Although the germfree animal, as defined, is free from the aforementioned microorganisms, its status with respect to viruses, especially, and to rickettsia and pleuropneumonia-like organisms is largely unknown. It is believed by some investigators of germfree life, however, that viruses may sometimes be present. This is based upon the following premises. Transplacental transmission of viruses occurs in human and lower animal life (Biegeleisen and Scott, 1958). Hence, it is reasonable to assume their presence, sometimes, in mature fetuses delivered by Caesarean section into a

Lobund Reports. Germfree Life Studies, No. 3

Lobund Reports. Germfree Life Studies, No. 3

TUMORIGENISIS AND THE GERMFREE CHICKEN: A PRELIMINARY REPORT*

Annals of the New York Academy of SciencesVolume 78, Issue 1 p. 328-353 TUMORIGENISIS AND THE GERMFREE CHICKEN: A PRELIMINARY REPORT* James A. Reyniers, James A. Reyniers Lobund Institute, University of Notre Dame, Notre Dame, Ind. Germfree Life Research Center, Tampa, Fla.Search for more papers by this authorMiriam R. Sacksteder, Miriam R. Sacksteder Lobund Institute, University of Notre Dame, Notre Dame, Ind.Search for more papers by this author James A. Reyniers, James A. Reyniers Lobund Institute, University of Notre Dame, Notre Dame, Ind. Germfree Life Research Center, Tampa, Fla.Search for more papers by this authorMiriam R. Sacksteder, Miriam R. Sacksteder Lobund Institute, University of Notre Dame, Notre Dame, Ind.Search for more papers by this author First published: May 1959 https://doi.org/10.1111/j.1749-6632.1959.tb53118.xCitations: 7 ‡ The work reported in this paper was supported in part by Research Grant No. 48 from The Damon Runyon Memorial Fund for Cancer Research, Inc., New York, N. Y. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume78, Issue1Germfree Vertebrates: Present SatusMay 1959Pages 328-353 RelatedInformation

Morphological and physiological characterization of germfree life.

Morphological and physiological characterization of germfree life.

Germ-Free Life Studies. James A. Reyniers

Previous articleNext article No AccessNew Biological BooksGerm-Free Life Studies. James A. Reyniers Walter C. TobieWalter C. Tobie Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 23, Number 2Jun., 1948 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/396355 PDF download Crossref reports no articles citing this article.