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Ihara S, Nguyen BV, Miyamoto Y, Eckmann L. Mucosal vaccination in a murine gnotobiotic model of Giardia lamblia infection. Infect Immun 2024; 92:e0006524. [PMID: 38722167 DOI: 10.1128/iai.00065-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 04/10/2024] [Indexed: 06/12/2024] Open
Abstract
Giardia lamblia is an important protozoan cause of diarrheal disease worldwide, delayed development and cognitive impairment in children in low- and middle-income countries, and protracted post-infectious syndromes in developed regions. G. lamblia resides in the lumen and at the epithelial surface of the proximal small intestine but is not mucosa invasive. The protozoan parasite is genetically diverse with significant genome differences across strains and assemblages. Animal models, particularly murine models, have been instrumental in defining mechanisms of host defense against G. lamblia, but mice cannot be readily infected with most human pathogenic strains. Antibiotic pretreatment can increase susceptibility, suggesting that the normal microbiota plays a role in controlling G. lamblia infection in mice, but the broader implications on susceptibility to diverse strains are not known. Here, we have used gnotobiotic mice to demonstrate that robust intestinal infection can be achieved for a broad set of human-pathogenic strains of the genetic assemblages A and B. Furthermore, gnotobiotic mice were able to eradicate infection with a similar kinetics to conventional mice after trophozoite challenge. Germ-free mice could also be effectively immunized by the mucosal route with a protective antigen, α1-giardin, in a manner dependent on CD4 T cells. These results indicate that the gnotobiotic mouse model is powerful for investigating acquired host defenses in giardiasis, as the mice are broadly susceptible to diverse G. lamblia strains yet display no apparent defects in mucosal immunity needed for controlling and eradicating this lumen-dwelling pathogen.
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Affiliation(s)
- Sozaburo Ihara
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Brian V Nguyen
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Yukiko Miyamoto
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Lars Eckmann
- Department of Medicine, University of California San Diego, La Jolla, California, USA
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Dremova O, Mimmler M, Paeslack N, Khuu MP, Gao Z, Bosmann M, Garo LP, Schön N, Mechler A, Beneich Y, Rebling V, Mann A, Pontarollo G, Kiouptsi K, Reinhardt C. Sterility testing of germ-free mouse colonies. Front Immunol 2023; 14:1275109. [PMID: 38022683 PMCID: PMC10662041 DOI: 10.3389/fimmu.2023.1275109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 09/28/2023] [Indexed: 12/01/2023] Open
Abstract
In biomedical research, germ-free and gnotobiotic mouse models enable the mechanistic investigation of microbiota-host interactions and their role on (patho)physiology. Throughout any gnotobiotic experiment, standardized and periodic microbiological testing of defined gnotobiotic housing conditions is a key requirement. Here, we review basic principles of germ-free isolator technology, the suitability of various sterilization methods, and the use of sterility testing methods to monitor germ-free mouse colonies. We also discuss their effectiveness and limitations, and share the experience with protocols used in our facility. In addition, possible sources of isolator contamination are discussed and an overview of reported contaminants is provided.
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Affiliation(s)
- Olga Dremova
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Maximilian Mimmler
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Nadja Paeslack
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - My Phung Khuu
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Zhenling Gao
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Markus Bosmann
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Lucien P. Garo
- Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, MA, United States
| | - Nathalie Schön
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Alexa Mechler
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Yunes Beneich
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Vivian Rebling
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Amrit Mann
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Giulia Pontarollo
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Klytaimnistra Kiouptsi
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), University Medical Center of the Johannes Gutenberg-University Mainz, Partner Site Rhine-Main, Mainz, Germany
| | - Christoph Reinhardt
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), University Medical Center of the Johannes Gutenberg-University Mainz, Partner Site Rhine-Main, Mainz, Germany
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Krüger TIM, Herzog S, Mellmann A, Kuczius T. Impact of Chlorine Dioxide on Pathogenic Waterborne Microorganisms Occurring in Dental Chair Units. Microorganisms 2023; 11:1123. [PMID: 37317097 DOI: 10.3390/microorganisms11051123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/21/2023] [Accepted: 04/22/2023] [Indexed: 06/16/2023] Open
Abstract
Bacterial contamination is a problem in dental unit water lines with the consequence of implementing regular disinfection. In this study, the short-term impact of chlorine dioxide (ClO2) treatment was investigated on the microorganisms Legionella pneumophila and L. anisa, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The environmental background was proven as an important factor regarding the tolerance to 0.4 mg/L ClO2 as saline and phosphate-buffered saline resulted in a higher bacterial reduction than tap water. Gram-positive microorganisms demonstrated higher robustness to ClO2 than Gram-negative, and microorganisms adapted to tap water showed increased stability compared to cultured cells. At high densities, substantial numbers of bacteria were able to withstand disinfection, whereby the use of 4.6 mg/L ClO2 increased the inactivation rate. A massive cell decrease occurred within the first 5 minutes with subsequent plateau formation or slowed cell reduction upon further exposure. This biphasic kinetics cannot be explained by a ClO2 depletion effect alone, because the probability of bacterial subpopulations with increased tolerance should be taken into account, too. Our results prove high disinfection efficiency to microorganisms that were rather found in correlation to the level of bacterial contamination and background solutions than the chosen concentration for ClO2 treatment itself.
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Affiliation(s)
| | - Susann Herzog
- Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany
| | - Alexander Mellmann
- Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany
| | - Thorsten Kuczius
- Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany
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Immune Response of an Oral Enterococcus faecalis Phage Cocktail in a Mouse Model of Ethanol-Induced Liver Disease. Viruses 2022; 14:v14030490. [PMID: 35336897 PMCID: PMC8955932 DOI: 10.3390/v14030490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 12/10/2022] Open
Abstract
Cytolysin-positive Enterococcus faecalis (E. faecalis) cause more severe alcohol-associated hepatitis, and phages might be used to specifically target these bacteria in a clinical trial. Using a humanized mouse model of ethanol-induced liver disease, the effect of cytolytic E. faecalis phage treatment on the intestinal and liver immune response was evaluated. The observed immune response was predominantly anti-inflammatory and tissue-restoring. Besides, live phages could be readily recovered from the serum, spleen, and liver following oral gavage in ethanol-fed mice. We also isolated 20 new phages from the sewage water; six of them exhibited a relatively broad host range. Taken together, the oral administration of cytolytic E. faecalis phages leads to the translocation of phages to the systemic circulation and appears to be safe, following chronic-binge ethanol administration. A cocktail of three phages covers the majority of tested cytolysin-positive E. faecalis strains and could be tested in a clinical trial.
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Hartmann P, Duan Y, Miyamoto Y, Demir M, Lang S, Hasa E, Stern P, Yamashita D, Conrad M, Eckmann L, Schnabl B. Colesevelam ameliorates non-alcoholic steatohepatitis and obesity in mice. Hepatol Int 2022; 16:359-370. [PMID: 35075592 PMCID: PMC9013343 DOI: 10.1007/s12072-022-10296-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 12/20/2021] [Indexed: 12/12/2022]
Abstract
Background Obesity, non-alcoholic fatty liver disease (NAFLD) and its more advanced form non-alcoholic steatohepatitis (NASH) are important causes of morbidity and mortality worldwide. Bile acid dysregulation is a pivotal part in their pathogenesis. The aim of this study was to evaluate the bile acid sequestrant colesevelam in a microbiome-humanized mouse model of diet-induced obesity and steatohepatitis. Methods Germ-free C57BL/6 mice were associated with stool from patients with NASH and subjected to 20 weeks of Western diet feeding with and without colesevelam. Results Colesevelam reduced Western diet-induced body and liver weight gain in microbiome-humanized mice compared with controls. It ameliorated Western diet-induced hepatic inflammation, steatosis, fibrosis and insulin resistance. Colesevelam increased de novo bile acid synthesis and decreased hepatic cholesterol content in microbiome-humanized mice fed a Western diet. It further induced the gene expression of the antimicrobials Reg3g and Reg3b in the distal small intestine and decreased plasma levels of LPS. Conclusions Colesevelam ameliorates Western diet-induced steatohepatitis and obesity in microbiome-humanized mice.
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Affiliation(s)
- Phillipp Hartmann
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Yi Duan
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Yukiko Miyamoto
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Münevver Demir
- Department of Hepatology and Gastroenterology, Campus Virchow Clinic and Campus Charité Mitte, Charité University Medicine, Berlin, Germany
| | - Sonja Lang
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA, 92093, USA
- Faculty of Medicine, and University Hospital Cologne, Department of Gastroenterology and Hepatology, University of Cologne, Cologne, Germany
| | - Elda Hasa
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | | | | | | | - Lars Eckmann
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Bernd Schnabl
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
- Department of Medicine, VA San Diego Healthcare System, San Diego, CA, USA.
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Zhou D, Xue J, Miyamoto Y, Poulsen O, Eckmann L, Haddad GG. Microbiota Modulates Cardiac Transcriptional Responses to Intermittent Hypoxia and Hypercapnia. Front Physiol 2021; 12:680275. [PMID: 34248668 PMCID: PMC8267877 DOI: 10.3389/fphys.2021.680275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/20/2021] [Indexed: 12/22/2022] Open
Abstract
The microbiota plays a critical role in regulating organismal health and response to environmental stresses. Intermittent hypoxia and hypercapnia, a condition that represents the main hallmark of obstructive sleep apnea in humans, is known to induce significant alterations in the gut microbiome and metabolism, and promotes the progression of atherosclerosis in mouse models. To further understand the role of the microbiome in the cardiovascular response to intermittent hypoxia and hypercapnia, we developed a new rodent cage system that allows exposure of mice to controlled levels of O2 and CO2 under gnotobiotic conditions. Using this experimental setup, we determined the impact of the microbiome on the transcriptional response to intermittent hypoxia and hypercapnia in the left ventricle of the mouse heart. We identified significant changes in gene expression in both conventionally reared and germ-free mice. Following intermittent hypoxia and hypercapnia exposure, we detected 192 significant changes in conventionally reared mice (96 upregulated and 96 downregulated) and 161 significant changes (70 upregulated and 91 downregulated) in germ-free mice. Only 19 of these differentially expressed transcripts (∼10%) were common to conventionally reared and germ-free mice. Such distinct transcriptional responses imply that the host microbiota plays an important role in regulating the host transcriptional response to intermittent hypoxia and hypercapnia in the mouse heart.
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Affiliation(s)
- Dan Zhou
- Division of Respiratory Medicine, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Jin Xue
- Division of Respiratory Medicine, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Yukiko Miyamoto
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Orit Poulsen
- Division of Respiratory Medicine, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Lars Eckmann
- Department of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Gabriel G Haddad
- Division of Respiratory Medicine, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States.,Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States.,Rady Children's Hospital-San Diego, San Diego, CA, United States
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Lebeuf M, Turgeon N, Faubert C, Robillard J, Paradis É, Duchaine C. Managing the bacterial contamination risk in an axenic mice animal facility. Can J Microbiol 2021; 67:657-666. [PMID: 33844954 DOI: 10.1139/cjm-2020-0519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A gap exists between good laboratory practices with axenic animals and the procedures applied. This work examined the efficacy of sodium dichloroisocyanurate (MB-10) and potassium peroxymonosulfate (Virkon™) disinfectants, as well as the appropriate soaking time for materials used with the ISOcage Biosafety Station™. We also compared the microbial load in cage systems hosting mice over 2 weeks in axenic rooms (ARs) and in typical specific-pathogen-free (SPF) non-axenic rooms (NARs) to identify resistant microorganisms, targeted for longer soaking disinfection, and evaluated the necessary procedures for reducing the microbial load in AR. Staphylococcus was the most frequently isolated genus (in both ARs and NARs). An average of three spore-forming microorganisms per cage were counted from AR. The disinfection time to reach 1 log reduction for Bacillus atrophaeus spores varied from 138 s (100 ppm MB-10) to 290 (Virkon™) to <20 s for S. epidermidis (100 ppm MB-10). AR management protocols lead to a microbial load that is 1000 times lower than that found in NARs. Data comparing the microbial load in SPF and axenic facilities can be used to improve the effectiveness of their microbial control procedures.
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Affiliation(s)
- Maria Lebeuf
- Département de biochimie, microbiologie et bioinformatique, Université Laval, Quebec city, Quebec, Canada
| | - Nathalie Turgeon
- Research center, Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, Quebec, Canada
| | - Cynthia Faubert
- Research animal facility, Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, Quebec, Canada
| | - Justin Robillard
- Research animal facility, Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, Quebec, Canada
| | - Éric Paradis
- Research center, Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, Quebec, Canada
| | - Caroline Duchaine
- Département de biochimie, microbiologie et bioinformatique, Université Laval, Quebec city, Quebec, Canada; Tier-1, Canada Research Chair on Bioaerosols, Institutuniversitaire de cardiologie et de pneumologie de Québec, Quebec City, Quebec, Canada
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