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Aghighi F, Salami M. What we need to know about the germ-free animal models. AIMS Microbiol 2024; 10:107-147. [PMID: 38525038 PMCID: PMC10955174 DOI: 10.3934/microbiol.2024007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 03/26/2024] Open
Abstract
The gut microbiota (GM), as a forgotten organ, refers to the microbial community that resides in the gastrointestinal tract and plays a critical role in a variety of physiological activities in different body organs. The GM affects its targets through neurological, metabolic, immune, and endocrine pathways. The GM is a dynamic system for which exogenous and endogenous factors have negative or positive effects on its density and composition. Since the mid-twentieth century, laboratory animals are known as the major tools for preclinical research; however, each model has its own limitations. So far, two main models have been used to explore the effects of the GM under normal and abnormal conditions: the isolated germ-free and antibiotic-treated models. Both methods have strengths and weaknesses. In many fields of host-microbe interactions, research on these animal models are known as appropriate experimental subjects that enable investigators to directly assess the role of the microbiota on all features of physiology. These animal models present biological model systems to either study outcomes of the absence of microbes, or to verify the effects of colonization with specific and known microbial species. This paper reviews these current approaches and gives advantages and disadvantages of both models.
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Affiliation(s)
| | - Mahmoud Salami
- Physiology Research Center, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, I. R. Iran
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2
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Panzer JJ, Romero R, Greenberg JM, Winters AD, Galaz J, Gomez-Lopez N, Theis KR. Is there a placental microbiota? A critical review and re-analysis of published placental microbiota datasets. BMC Microbiol 2023; 23:76. [PMID: 36934229 PMCID: PMC10024458 DOI: 10.1186/s12866-023-02764-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 01/10/2023] [Indexed: 03/20/2023] Open
Abstract
The existence of a placental microbiota is debated. The human placenta has historically been considered sterile and microbial colonization was associated with adverse pregnancy outcomes. Yet, recent DNA sequencing investigations reported a microbiota in typical human term placentas. However, this detected microbiota could represent background DNA or delivery-associated contamination. Using fifteen publicly available 16S rRNA gene datasets, existing data were uniformly re-analyzed with DADA2 to maximize comparability. While Amplicon Sequence Variants (ASVs) identified as Lactobacillus, a typical vaginal bacterium, were highly abundant and prevalent across studies, this prevalence disappeared after applying likely DNA contaminant removal to placentas from term cesarean deliveries. A six-study sub-analysis targeting the 16S rRNA gene V4 hypervariable region demonstrated that bacterial profiles of placental samples and technical controls share principal bacterial ASVs and that placental samples clustered primarily by study origin and mode of delivery. Contemporary DNA-based evidence does not support the existence of a placental microbiota.ImportanceEarly-gestational microbial influences on human development are unclear. By applying DNA sequencing technologies to placental tissue, bacterial DNA signals were observed, leading some to conclude that a live bacterial placental microbiome exists in typical term pregnancy. However, the low-biomass nature of the proposed microbiome and high sensitivity of current DNA sequencing technologies indicate that the signal may alternatively derive from environmental or delivery-associated bacterial DNA contamination. Here we address these alternatives with a re-analysis of 16S rRNA gene sequencing data from 15 publicly available placental datasets. After identical DADA2 pipeline processing of the raw data, subanalyses were performed to control for mode of delivery and environmental DNA contamination. Both environment and mode of delivery profoundly influenced the bacterial DNA signal from term-delivered placentas. Aside from these contamination-associated signals, consistency was lacking across studies. Thus, placentas delivered at term are unlikely to be the original source of observed bacterial DNA signals.
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Affiliation(s)
- Jonathan J Panzer
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, MI, USA
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Roberto Romero
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, MI, USA.
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan, USA.
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, Michigan, USA.
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, USA.
- Detroit Medical Center, Detroit, Michigan, USA.
| | - Jonathan M Greenberg
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Andrew D Winters
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, MI, USA
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Jose Galaz
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, MI, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
- Division of Obstetrics and Gynecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Nardhy Gomez-Lopez
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, MI, USA
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Kevin R Theis
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Detroit, MI, USA.
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA.
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, USA.
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Gars A, Ronczkowski NM, Chassaing B, Castillo-Ruiz A, Forger NG. First Encounters: Effects of the Microbiota on Neonatal Brain Development. Front Cell Neurosci 2021; 15:682505. [PMID: 34168540 PMCID: PMC8217657 DOI: 10.3389/fncel.2021.682505] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/11/2021] [Indexed: 12/20/2022] Open
Abstract
The microbiota plays important roles in host metabolism and immunity, and its disruption affects adult brain physiology and behavior. Although such findings have been attributed to altered neurodevelopment, few studies have actually examined microbiota effects on the developing brain. This review focuses on developmental effects of the earliest exposure to microbes. At birth, the mammalian fetus enters a world teeming with microbes which colonize all body sites in contact with the environment. Bacteria reach the gut within a few hours of birth and cause a measurable response in the intestinal epithelium. In adults, the gut microbiota signals to the brain via the vagus nerve, bacterial metabolites, hormones, and immune signaling, and work in perinatal rodents is beginning to elucidate which of these signaling pathways herald the very first encounter with gut microbes in the neonate. Neural effects of the microbiota during the first few days of life include changes in neuronal cell death, microglia, and brain cytokine levels. In addition to these effects of direct exposure of the newborn to microbes, accumulating evidence points to a role for the maternal microbiota in affecting brain development via bacterial molecules and metabolites while the offspring is still in utero. Hence, perturbations to microbial exposure perinatally, such as through C-section delivery or antibiotic treatment, alter microbiota colonization and may have long-term neural consequences. The perinatal period is critical for brain development and a close look at microbiota effects during this time promises to reveal the earliest, most primary effects of the microbiota on neurodevelopment.
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Affiliation(s)
- Aviva Gars
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | | | - Benoit Chassaing
- INSERM U1016, Team "Mucosal Microbiota in Chronic Inflammatory Diseases", CNRS UMR 8104, Université de Paris, Paris, France
| | | | - Nancy G Forger
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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No evidence for a placental microbiome in human pregnancies at term. Am J Obstet Gynecol 2021; 224:296.e1-296.e23. [PMID: 32871131 DOI: 10.1016/j.ajog.2020.08.103] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 08/19/2020] [Accepted: 08/26/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND The placenta plays an important role in the modulation of pregnancy immunity; however, there is no consensus regarding the existence of a placental microbiome in healthy full-term pregnancies. OBJECTIVE This study aimed to investigate the existence and origin of a placental microbiome. STUDY DESIGN A cross-sectional study comparing samples (3 layers of placental tissue, amniotic fluid, vernix caseosa, and saliva, vaginal, and rectal samples) from 2 groups of full-term births: 50 women not in labor with elective cesarean deliveries and 26 with vaginal deliveries. The comparisons were performed using polymerase chain reaction amplification and DNA sequencing techniques and bacterial culture experiments. RESULTS There were no significant differences regarding background characteristics between women who delivered by elective cesarean and those who delivered vaginally. Quantitative measurements of bacterial content in all 3 placental layers (quantitative polymerase chain reaction of the 16S ribosomal RNA gene) did not show any significant difference among any of the sample types and the negative controls. Here, 16S ribosomal RNA gene sequencing of the maternal side of the placenta could not differentiate between bacteria in the placental tissue and contamination of the laboratory reagents with bacterial DNA. Probe-specific quantitative polymerase chain reaction for bacterial taxa suspected to be present in the placenta could not detect any statistically significant difference between the 2 groups. In bacterial cultures, substantially more bacteria were observed in the placenta layers from vaginal deliveries than those from cesarean deliveries. In addition, 16S ribosomal RNA gene sequencing of bacterial colonies revealed that most of the bacteria that grew on the plates were genera typically found in human skin; moreover, it revealed that placentas delivered vaginally contained a high prevalence of common vaginal bacteria. Bacterial growth inhibition experiments indicated that placental tissue may facilitate the inhibition of bacterial growth. CONCLUSION We found no evidence to support the existence of a placental microbiome in our study of 76 term pregnancies, which used polymerase chain reaction amplification and sequencing techniques and bacterial culture experiments. Incidental findings of bacterial species could be due to contamination or to low-grade bacterial presence in some locations; such bacteria do not represent a placental microbiome per se.
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Bushman FD. De-Discovery of the Placenta Microbiome. Am J Obstet Gynecol 2019; 220:213-214. [PMID: 30832983 DOI: 10.1016/j.ajog.2018.11.1093] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
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Leiby JS, McCormick K, Sherrill-Mix S, Clarke EL, Kessler LR, Taylor LJ, Hofstaedter CE, Roche AM, Mattei LM, Bittinger K, Elovitz MA, Leite R, Parry S, Bushman FD. Lack of detection of a human placenta microbiome in samples from preterm and term deliveries. MICROBIOME 2018; 6:196. [PMID: 30376898 PMCID: PMC6208038 DOI: 10.1186/s40168-018-0575-4] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 10/10/2018] [Indexed: 05/22/2023]
Abstract
BACKGROUND Historically, the human womb has been thought to be sterile in healthy pregnancies, but this idea has been challenged by recent studies using DNA sequence-based methods, which have suggested that the womb is colonized with bacteria. For example, analysis of DNA from placenta samples yielded small proportions of microbial sequences which were proposed to represent normal bacterial colonization. However, an analysis by our group showed no distinction between background negative controls and placenta samples. Also supporting the idea that the womb is sterile is the observation that germ-free mammals can be generated by sterile delivery of neonates into a sterile isolator, after which neonates remain germ-free, which would seem to provide strong data in support of sterility of the womb. RESULTS To probe this further and to investigate possible placental colonization associated with spontaneous preterm birth, we carried out another study comparing microbiota in placenta samples from 20 term and 20 spontaneous preterm deliveries. Both 16S rRNA marker gene sequencing and shotgun metagenomic sequencing were used to characterize placenta and control samples. We first quantified absolute amounts of bacterial 16S rRNA gene sequences using 16S rRNA gene quantitative PCR (qPCR). As in our previous study, levels were found to be low in the placenta samples and indistinguishable from negative controls. Analysis by DNA sequencing did not yield a placenta microbiome distinct from negative controls, either using marker gene sequencing as in our previous work, or with shotgun metagenomic sequencing. Several types of artifacts, including erroneous read classifications and barcode misattribution, needed to be identified and removed from the data to clarify this point. CONCLUSIONS Our findings do not support the existence of a consistent placental microbiome, in either placenta from term deliveries or spontaneous preterm births.
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Affiliation(s)
- Jacob S Leiby
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA
| | - Kevin McCormick
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA
| | - Scott Sherrill-Mix
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA
| | - Erik L Clarke
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA
| | - Lyanna R Kessler
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA
| | - Louis J Taylor
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA
| | - Casey E Hofstaedter
- Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Aoife M Roche
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA
| | - Lisa M Mattei
- Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Kyle Bittinger
- Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Michal A Elovitz
- Maternal and Child Health Research Center, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - Rita Leite
- Maternal and Child Health Research Center, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - Samuel Parry
- Maternal and Child Health Research Center, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA, 19104, USA.
| | - Frederic D Bushman
- Department of Microbiology, University of Pennsylvania School of Medicine, 3610 Hamilton Walk, Philadelphia, PA, 19104-6076, USA.
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Perez-Muñoz ME, Arrieta MC, Ramer-Tait AE, Walter J. A critical assessment of the "sterile womb" and "in utero colonization" hypotheses: implications for research on the pioneer infant microbiome. MICROBIOME 2017; 5:48. [PMID: 28454555 PMCID: PMC5410102 DOI: 10.1186/s40168-017-0268-4] [Citation(s) in RCA: 605] [Impact Index Per Article: 86.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 04/21/2017] [Indexed: 05/10/2023]
Abstract
After more than a century of active research, the notion that the human fetal environment is sterile and that the neonate's microbiome is acquired during and after birth was an accepted dogma. However, recent studies using molecular techniques suggest bacterial communities in the placenta, amniotic fluid, and meconium from healthy pregnancies. These findings have led many scientists to challenge the "sterile womb paradigm" and propose that microbiome acquisition instead begins in utero, an idea that would fundamentally change our understanding of gut microbiota acquisition and its role in human development. In this review, we provide a critical assessment of the evidence supporting these two opposing hypotheses, specifically as it relates to (i) anatomical, immunological, and physiological characteristics of the placenta and fetus; (ii) the research methods currently used to study microbial populations in the intrauterine environment; (iii) the fecal microbiome during the first days of life; and (iv) the generation of axenic animals and humans. Based on this analysis, we argue that the evidence in support of the "in utero colonization hypothesis" is extremely weak as it is founded almost entirely on studies that (i) used molecular approaches with an insufficient detection limit to study "low-biomass" microbial populations, (ii) lacked appropriate controls for contamination, and (iii) failed to provide evidence of bacterial viability. Most importantly, the ability to reliably derive axenic animals via cesarean sections strongly supports sterility of the fetal environment in mammals. We conclude that current scientific evidence does not support the existence of microbiomes within the healthy fetal milieu, which has implications for the development of clinical practices that prevent microbiome perturbations after birth and the establishment of future research priorities.
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Affiliation(s)
- Maria Elisa Perez-Muñoz
- Department of Agriculture, Food and Nutritional Sciences, 4-126 Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, Alberta T6G 2E1 Canada
| | - Marie-Claire Arrieta
- Department of Physiology and Pharmacology, University of Calgary, Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1 Canada
- Department of Pediatrics, University of Calgary, Cumming School of Medicine, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1 Canada
| | - Amanda E. Ramer-Tait
- Department of Food Science and Technology, 260 Food Innovation Center, University of Nebraska-Lincoln, 1901 N 21st Street, Lincoln, Nebraska 68588-6205 USA
| | - Jens Walter
- Department of Agriculture, Food and Nutritional Sciences, 4-126 Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, Alberta T6G 2E1 Canada
- Department of Biological Sciences, 7-142 Katz Group Centre, University of Alberta, Edmonton, Alberta T6G 2E1 Canada
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Luczynski P, McVey Neufeld KA, Oriach CS, Clarke G, Dinan TG, Cryan JF. Growing up in a Bubble: Using Germ-Free Animals to Assess the Influence of the Gut Microbiota on Brain and Behavior. Int J Neuropsychopharmacol 2016; 19:pyw020. [PMID: 26912607 PMCID: PMC5006193 DOI: 10.1093/ijnp/pyw020] [Citation(s) in RCA: 361] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/18/2016] [Indexed: 12/13/2022] Open
Abstract
There is a growing recognition of the importance of the commensal intestinal microbiota in the development and later function of the central nervous system. Research using germ-free mice (mice raised without any exposure to microorganisms) has provided some of the most persuasive evidence for a role of these bacteria in gut-brain signalling. Key findings show that the microbiota is necessary for normal stress responsivity, anxiety-like behaviors, sociability, and cognition. Furthermore, the microbiota maintains central nervous system homeostasis by regulating immune function and blood brain barrier integrity. Studies have also found that the gut microbiota influences neurotransmitter, synaptic, and neurotrophic signalling systems and neurogenesis. The principle advantage of the germ-free mouse model is in proof-of-principle studies and that a complete microbiota or defined consortiums of bacteria can be introduced at various developmental time points. However, a germ-free upbringing can induce permanent neurodevelopmental deficits that may deem the model unsuitable for specific scientific queries that do not involve early-life microbial deficiency. As such, alternatives and complementary strategies to the germ-free model are warranted and include antibiotic treatment to create microbiota-deficient animals at distinct time points across the lifespan. Increasing our understanding of the impact of the gut microbiota on brain and behavior has the potential to inform novel management strategies for stress-related gastrointestinal and neuropsychiatric disorders.
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Affiliation(s)
- Pauline Luczynski
- APC Microbiome Institute (Ms Luczynski, Dr McVey Neufeld, Ms Oriach, Dr Clarke, Dr Dinan, and Dr Cryan), Department of Psychiatry and Neurobehavioral Science (Ms Oriach, Dr Clarke, and Dr Dinan), and Department of Anatomy and Neuroscience (Dr Cryan), University College Cork, Cork, Ireland
| | - Karen-Anne McVey Neufeld
- APC Microbiome Institute (Ms Luczynski, Dr McVey Neufeld, Ms Oriach, Dr Clarke, Dr Dinan, and Dr Cryan), Department of Psychiatry and Neurobehavioral Science (Ms Oriach, Dr Clarke, and Dr Dinan), and Department of Anatomy and Neuroscience (Dr Cryan), University College Cork, Cork, Ireland
| | - Clara Seira Oriach
- APC Microbiome Institute (Ms Luczynski, Dr McVey Neufeld, Ms Oriach, Dr Clarke, Dr Dinan, and Dr Cryan), Department of Psychiatry and Neurobehavioral Science (Ms Oriach, Dr Clarke, and Dr Dinan), and Department of Anatomy and Neuroscience (Dr Cryan), University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Institute (Ms Luczynski, Dr McVey Neufeld, Ms Oriach, Dr Clarke, Dr Dinan, and Dr Cryan), Department of Psychiatry and Neurobehavioral Science (Ms Oriach, Dr Clarke, and Dr Dinan), and Department of Anatomy and Neuroscience (Dr Cryan), University College Cork, Cork, Ireland
| | - Timothy G Dinan
- APC Microbiome Institute (Ms Luczynski, Dr McVey Neufeld, Ms Oriach, Dr Clarke, Dr Dinan, and Dr Cryan), Department of Psychiatry and Neurobehavioral Science (Ms Oriach, Dr Clarke, and Dr Dinan), and Department of Anatomy and Neuroscience (Dr Cryan), University College Cork, Cork, Ireland
| | - John F Cryan
- APC Microbiome Institute (Ms Luczynski, Dr McVey Neufeld, Ms Oriach, Dr Clarke, Dr Dinan, and Dr Cryan), Department of Psychiatry and Neurobehavioral Science (Ms Oriach, Dr Clarke, and Dr Dinan), and Department of Anatomy and Neuroscience (Dr Cryan), University College Cork, Cork, Ireland.
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Kirk RG. "Life in a germ-free world": isolating life from the laboratory animal to the bubble boy. BULLETIN OF THE HISTORY OF MEDICINE 2012; 86:237-75. [PMID: 23000838 PMCID: PMC3477854 DOI: 10.1353/bhm.2012.0028] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This article examines a specific technology, the germ-free "isolator," tracing its development across three sites: (1) the laboratory for the production of standard laboratory animals, (2) agriculture for the efficient production of farm animals, and (3) the hospital for the control and prevention of cross-infection and the protection of individuals from infection. Germ-free technology traveled across the laboratory sciences, clinical and veterinary medicine, and industry, yet failed to become institutionalized outside the laboratory. That germ-free technology worked was not at issue. Working, however, was not enough. Examining the history of a technology that failed to find widespread application reveals the labor involved in aligning cultural, societal, and material factors necessary for successful medical innovation.
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