Disease relevance of Germ-Free Life

• Bacteroides vulgatus protects against Escherichia coli-induced colitis in gnotobiotic interleukin-2-deficient mice [1].
• We have used a gnotobiotic mouse model to show that Bacteroides thetaiotaomicron, a component of the intestinal microflora of mice and humans, uses a repressor, FucR, as a molecular sensor of L-fucose availability [2].
• Effect of 2-nitrofluorene, 1,2-dimethylhydrazine, and azoxymethane on Salmonella typhimurium mutants in the gastrointestinal tract of gnotobiotic rats [3].
• Conventional (complex-intestinal flora) IL-10 KO mice developed IBD within 10 to 15 weeks of age and showed more pathology in the cecum (typhlitis) than we observed with E. faecalis-induced IBD in gnotobiotic IL-10 KO mice [4].
• Accordingly, the lactose tolerance of gnotobiotic newborn lambs, infected with lamb rotavirus, has been investigated by clinical studies and tissue enzyme assays [5].

High impact information on Germ-Free Life

• In these rats nearly all cecal, colonic, and fecal bile salt sulfate esters were hydrolyzed, resulting in a decrease of total fecal bile salt excretion of greater than 25% compared with gnotobiotic rats without a bile salt desulfating flora [6].
• The gacA mutants of strain CHA0 have a drastically reduced ability to suppress black root rot under gnotobiotic conditions, supporting the previous observations that the antibiotic Phl and HCN individually contribute to the suppression of black root rot [7].
• Several lines of evidence, including further enhancement of Mx1 expression during organ culture and gnotobiotic mice analyses, indicated that this apparent constitutive epithelial Mx1 expression was a locally induced response to stimuli present in the respective lumina [8].
• The infectivity of sera from the viremic virulent HRV-inoculated pigs was confirmed by inoculating gnotobiotic pigs orally with pooled HRV-positive serum [9].
• Better colonization of the phenylpropanoid-utilizing strain in a gnotobiotic system on the roots of flavonoid-producing plants leads to almost 90% removal of PCBs in a 28-d period [10].

Chemical compound and disease context of Germ-Free Life

• Monoassociation with Bifidobacterium longum in gnotobiotic mice as a method to assess safety with respect to infection, and translocation and immune responses as a result of the monoassociation are also described [11].
• One-tenth percent sucrose significantly promotes dental caries induced by Streptococcus mutans in young gnotobiotic rats [12].
• Colonization of streptomycin-resistant mutants derived from Streptococcus mutans strain LB1, a human isolate, and strain FA-1, a rodent isolate, was studied in gnotobiotic and conventional rats [13].
• The calici-like virus (Newbury agent SRV-1) caused anorexia, diarrhea, and xylose malabsorption in gnotobiotic calves aged 17 to 60 days, whereas the bovine astrovirus was nonpathogenic in similar calves [14].
• Active immunization of germfree nu/nu mice with Formalin-killed C. jejuni also did not protect the gnotobiotic mice from Campylobacter infection and diarrhea [15].

Biological context of Germ-Free Life

• To investigate the underlying basis of autoimmunity, the particular role of commensal gut flora in the initiation of colitis, and the role of IL-2 in the development of intestinal intraepithelial lymphocytes (iIEL), we evaluated IL-2(-/-) mice reared and maintained under gnotobiotic (germfree) conditions [16].
• Involvement of nitrate reductase and pyoverdine in the competitiveness of the biocontrol strain Pseudomonas fluorescens C7R12 was determined, under gnotobiotic conditions, in two soil compartments (bulk and rhizosphere soil), with the soil being kept at two different values of matric potential (-1 and -10 kPa) [17].
• Antibody responses to human rotavirus (HRV) in gnotobiotic pigs following a new prime/boost vaccine strategy using oral attenuated HRV priming and intranasal VP2/6 rotavirus-like particle (VLP) boosting with ISCOM [18].
• Although some formation of N-nitrosoproline from proline and nitrate occurred in germ-free and gnotobiotic rats, nitrosation proceeded more readily in conventional rats [19].
• The laboratory strain of calf virus retained its virulence after being passaged seven times in gnotobiotic calves, which included sucrose density gradient purification on two occasions [20].

Anatomical context of Germ-Free Life

• Enhanced immune responses, especially of the IgA isotype, in both serum and saliva were induced in gnotobiotic rats given MDP and either S. mutans 6715 WC or purified cell walls (CW) by gastric intubation [21].
• The present study demonstrates that RSV-specific, major histocompatibility complex-restricted cytotoxic T cells appear in the peripheral blood of gnotobiotic calves 7-10 days after infection with bovine RSV and were also detected in the lungs 10 days after infection [22].
• 120 min after stomach intubation of gnotobiotic rats, only 31% of the ingested maltitol is found in the ileum [23].
• 1. Conventional or gnotobiotic chicks, when injected from 1 d to 3 weeks of age with adrenocorticotrophic hormone (120IU/kg, three times weekly), showed a depressed growth rate, adrenal hypertrophy and depletion of cholesterol form the adrenal glands [24].

Associations of Germ-Free Life with chemical compounds

• In gnotobiotic mice which were diassociated with C. difficile and C. butyricum and given drinking water with a lactose concentration of 20%, the cecal contents included about the same amount of butyric acid as did those of the monoassociated mice, although the population of C. difficile remained the same [25].
• Gnotobiotic rats infected with S. mutans 6715 and fed a purified diet containing no sucrose (300) until day 25 and subsequently fed diet 305 for 10 days developed lesions similar to rats fed diet 305 for 16 days [26].
• The effect of continuous administration of small doses of ampicillin, chlortetracycline, or streptomycin in the drinking water was studied in gnotobiotic mice inoculated with a human fecal flora [27].
• Control pigs, eight conventional and two gnotobiotic, dosed with diluent, uninfected cell material or left undosed failed to develop lesions also [28].
• Conversion of amoscanate to a mutagenic metabolite in gnotobiotic mice implanted with Streptococcus equinus [29].

Gene context of Germ-Free Life

• HS/R increased ileal mucosal IL-6 and COX-2 mRNA expression in conventional but not gnotobiotic mice [30].
• Escherichia coli O157:H7 strains that express Shiga toxin (Stx) 2 alone are more neurotropic for gnotobiotic piglets than are isotypes producing only Stx1 or both Stx1 and Stx2 [31].
• Colonization with a pure culture of C. albicans was not lethal for adult or neonatal IFN-gamma(-/-) gnotobiotic mice over the 15-week study [32].
• Both counts of EHEC O157:H7 and the amounts of shiga-like toxins (Stx1 and Stx2) in fecal contents of gnotobiotic mice di-associated with EHEC O157:H7 and C. butyricum were less than those of gnotobiotic mice mono-associated with EHEC O157:H7 [33].
• In the gnotobiotic rat model, the gbpA mutant strain was hypercariogenic though the colonization levels were not significantly different from those of the wild type [34].

Analytical, diagnostic and therapeutic context of Germ-Free Life

• Effects of roxithromycin on fecal bacteria in human volunteers and resistance to colonization in gnotobiotic mice [35].
• The establishment of germ-free, gnotobiotic, and SPF animal colonies is a major component of any effort to develop suitable animal models for aging research [36].
• Effect of amoxicillin-clavulanic acid on human fecal flora in a gnotobiotic mouse model assessed with fluorescence hybridization using group-specific 16S rRNA probes in combination with flow cytometry [37].
• Lactic acid-mediated suppression of Helicobacter pylori by the oral administration of Lactobacillus salivarius as a probiotic in a gnotobiotic murine model [38].
• Gas-liquid chromatography (G.L.C.) and the method of [4(-14C)] cholesterol isotopic equilibrium (C.I.E.) were used to determine the fecal bile acid excretion in gnotobiotic rats [39].

References