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1.
V D Bokkenheuser J Winter P Dehazya W G Kelly 《Applied and environmental microbiology》1977,34(5):571-575
It has been known for a decade that human intestinal flora include organisms capable of 21-dehydroxylating corticoids. Yet the identity of the organisms synthesizing 21-dehydroxylase has remained unknown. Using diluted human feces, we determined the prevalence of colonies of 21-dehydroxylating organisms on a variety of media. Isolation from the medium of colonies with the highest prevalence yielded an obligate anaerobe capable of 21-dehydroxylating deoxycorticosterone and tetrahydrodeoxycorticosterone. This transformation could be carried out in a prereduced medium by the microbial culture alone or in an aerobic medium reduced by growth of Escherichia coli. The culture shares many characteristics with Eubacterium lentum, the neotype strain of which elaborated both 21-dehydroxylase and 3alpha-hydroxysteroid dehydrogenase. 相似文献
2.
Examination of Methods for Enumerating Hemicellulose-Utilizing Bacteria in the Rumen 总被引:3,自引:2,他引:1
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Penelope A. Henning 《Applied microbiology》1979,38(1):13-17
Counts of colonies that developed after 4 days on agar medium containing 0.3% xylan and preincubated rumen fluid were similar to counts of xylanolytic bacteria obtained when total culturable counts were multiplied by the percentage of isolates capable of producing acid from xylan. Shortening the incubation period reduced the chance of including satellite colonies of non-xylanolytic organisms in the count. Nearly all of the xylanolytic isolates irrespective of the medium from which they were isolated degraded and utilized xylan extensively. The use of a culture medium containing a high concentration (3%) of xylan is also described. The number of colonies capable of producing clearings in this medium was less than 10% of the total culturable counts. Isolates from such colonies were shown to produce diffusible (extracellular) xylanases. 相似文献
3.
V D Bokkenheuser J Winter S M Finegold V L Sutter A E Ritchie W E Moore L V Holdeman 《Applied microbiology》1979,37(5):1001-1006
Of 37 strains of Eubacterium lentum and phenotypically similar organisms, 26 (70%) synthesized a corticoid 21-dehydroxylase and/or a 3 alpha-hydroxysteroid dehydrogenase. It appeared that the corticoid 3 alpha-hydroxysteroid dehydrogenase was identical to the bile acid 3 alpha-hydroxysteroid dehydrogenase. Steroid-metabolizing enzymes were found both in E. lentum and in phenotypically similar organisms. E. lentum is characterized by nitrate reduction and enhanced growth in the presence of arginine. Many phenotypically similar organisms possess either one or the other of the two markers. In contrast, using the steroid-metabolizing enzymes as markers, a "steroid-active" and a "steroid-inactive" group were established with minimal overlapping of metabolic characteristics. Synthesis of the steroid enzymes was positively correlated with production of gas from H2O2 and formation of H2S. A simple method for the detection of corticoid 21-dehydroxylase and 3 alpha-hydroxysteroid dehydrogenase, one or both of which were present in 92% of the steroid-active group, is described. 相似文献
4.
Clostridium paraputrificum, an obligate anaerobe recovered from human feces, reduces the alpha,beta-unsaturated carbonyl of deoxycorticosterone, corticosterone, cortisone, and cortisol. The same steroids are 21-dehydroxylated by Culture 116, recently isolated from human feces, and by a closely related organism, Eubacterium lentum. The 21-dehydroxylase has no effect on hydroxyl groups at carbon atoms 11 and 17. 相似文献
5.
Clonal analysis of vertebrate myogenesis. II. Environmental influences upon human muscle differentiation 总被引:4,自引:0,他引:4
S D Hauschka 《Developmental biology》1974,37(2):329-344
In vitro procedures for obtaining the differentiation of human fetal muscle colonies were developed, and the sensitivity of clonal differentiation to environmental influences was examined. Human muscle colonies are capable of differentiating in the absence of an exogenous collagen substrate. The dependence of clonal diffeentiation upon the addition of chick embryo extract to the culture medium is determined by the serum type used in the medium and by the substrate upon which the colonies are grown. Clonal differentiation also depends upon conditioning of the medium by the colonies. The rate of medium conditioning is affected by clonal density and initial medium composition. The required medium modification is not species specific since medium conditioned by chick muscle cells also permits the early differentiation of human muscle clones. By manipulating the various environmental parameters described above it has been possible to define a number of in vitro conditions which permit a normal rate of cell proliferation but do not permit cell fusion. Results from these experiments are discussed in terms of their developmental implications. 相似文献
6.
V D Bokkenheuser J Winter S M Finegold V L Sutter A E Ritchie W E Moore L V Holdeman 《Applied and environmental microbiology》1979,37(5):1001-1006
Of 37 strains of Eubacterium lentum and phenotypically similar organisms, 26 (70%) synthesized a corticoid 21-dehydroxylase and/or a 3 alpha-hydroxysteroid dehydrogenase. It appeared that the corticoid 3 alpha-hydroxysteroid dehydrogenase was identical to the bile acid 3 alpha-hydroxysteroid dehydrogenase. Steroid-metabolizing enzymes were found both in E. lentum and in phenotypically similar organisms. E. lentum is characterized by nitrate reduction and enhanced growth in the presence of arginine. Many phenotypically similar organisms possess either one or the other of the two markers. In contrast, using the steroid-metabolizing enzymes as markers, a "steroid-active" and a "steroid-inactive" group were established with minimal overlapping of metabolic characteristics. Synthesis of the steroid enzymes was positively correlated with production of gas from H2O2 and formation of H2S. A simple method for the detection of corticoid 21-dehydroxylase and 3 alpha-hydroxysteroid dehydrogenase, one or both of which were present in 92% of the steroid-active group, is described. 相似文献
7.
Casal Manuel Linares María José Solís Francisco Rodríguez Fernando C. 《Mycopathologia》1997,137(2):79-82
The microorganisms capable of producing opportunist infections include the yeast-like organisms of the genus Candida, and
the unicellular algae of the genus Prototheca, which share common features and can, therefore, lead to confusion. Their colonies
are almost identical and they grow in the same culture media used routinely in mycology.
CHROMagar Candida is a new chromogenic differential isolation medium that facilitates the presumptive differentiation of some
of the most clinically important yeast-like organisms. To our knowledge, the use of CHROMagar Candida with Prototheca spp.
has not been reported in the literature.
This report describes the growth of 151 strains of Prototheca on CHROMagar Candida compared to the growth of a total of 326
well-characterized yeast organisms of the genera Candida, Cryptococcus, Trichosporon, Geotrichum, and Saccharomyces.
It is clinically relevant to note that algae of the genus Prototheca (P. wickerhamii, P. zopfii, and P. stagnora) and of the
genus Candida parapsilosis produced similar cream-colored colonies on CHROMagar Candida medium.
Based on their growth on CHROMagar, a new species of Candida is described, C. zeylanoides, which has blue-green colonies.
The colonies of two species of Trichosporon are also differentiated: the blue-green colonies of T. beigelii and the pink colonies
of T. capitatum.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
Isolation and characterization of fecal bacteria capable of 16 alpha-dehydroxylating corticoids. 总被引:4,自引:4,他引:0
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For more than a decade it has been known that the fecal flora of humans and rats includes organisms capable of 16 alpha-dehydroxylating corticoids, but their identity has remained unknown. To isolate these organisms, Mueller-Hinton agar plates were seeded with fresh feces from Proteus-free rats and incubated anaerobically. On an average, 1 of every 35 colonies consisted of organisms synthesizing 16 alpha-dehydroxylase. Isolation of the individual colonies yielded two obligate anerobes, strains 144 and 146, which elaborated the enzyme. The steroid transformation could be attained by the microbial culture alone in prereduced media or in aerobic media in the presence of Escherichia coli. Although both strains were phenotypically similar to Eubacterium lentum, they differed between themselves in their enzymatic equipment. 相似文献
9.
Gonococci from subcutaneously implanted chambers in guinea pigs produced, on agar, more than 95% small colonies showing a "double highlight" (DH) effect in oblique reflected light combined with transmitted light. Laboratory strains of gonococci produced some DH colonies, but other showed a single highlight (SH) or no highlight (NH). Selection of DH colonies and comparison of their organisms with gonococci grown in vivo and with those from SH colonies, showed that the DH character was associated with high infectivity for guinea-pig chambers, resistance to killing by human phagocytes and heavy pilation. Furthermore, DH colonies were found in the first culture of three fresh samples of urethral pus. Thus, the DH colony characteristic may be a more reliable criterion of pathogenicity of gonococcal isolates than systems used previously. There were, however, some differences between the gonococci grown in vivo and the DH colony types. The gonococci grown in vivo and cultured once on solid medium possessed one or two antigens which differed from those of DH (or SH) colonies. They also formed smooth suspensions (which separated slowly) in saline, compared with the rough suspensions (which separated quickly) formed by gonococci from DH (or SH) colonies. Finally, the organisms grown in vivo were resistant to killing by human serum whereas the DH (and SH) colony types were susceptible; the resistance of the organisms grown in vivo was lost during one subculture on agar suggesting that the property is a phenotypic characteristic. Hence, in addition to selecting DH colony types the conditions in vivo produce organisms which differ, probably phenotypically, from cultured organisms. 相似文献
10.
An anaerobic, gram-positive diplobacillus that reduces cholesterol to coprostanol was isolated from human feces and rat cecal contents. The isolates closely resemble a cholesterol-reducing organism isolated by Eyssen et al. (H. Eyssen et al., Eur. J. Biochem. 36:412-421, 1973) from a rat's cecum. These organisms would not form colonies and were isolated and cultivated in an anaerobic medium containing homogenized pork brains (naturally high in cholesterol). These organisms require free or esterified cholesterol for growth. They were isolated by serially diluting feces or cecal contents and inoculating brain medium. Colony-forming organisms, which did not reduce cholesterol, were eliminated by addition of inhibitory agents to the brain medium cultures. This serial dilution procedure was performed until a pure culture of a cholesterol-reducing organism was obtained. 相似文献
11.
An anaerobic, gram-positive diplobacillus that reduces cholesterol to coprostanol was isolated from human feces and rat cecal contents. The isolates closely resemble a cholesterol-reducing organism isolated by Eyssen et al. (H. Eyssen et al., Eur. J. Biochem. 36:412-421, 1973) from a rat's cecum. These organisms would not form colonies and were isolated and cultivated in an anaerobic medium containing homogenized pork brains (naturally high in cholesterol). These organisms require free or esterified cholesterol for growth. They were isolated by serially diluting feces or cecal contents and inoculating brain medium. Colony-forming organisms, which did not reduce cholesterol, were eliminated by addition of inhibitory agents to the brain medium cultures. This serial dilution procedure was performed until a pure culture of a cholesterol-reducing organism was obtained. 相似文献
12.
On reinforced clostridial agar with blood and 0.03% China blue, organisms of the bacteroides group grow with blue translucent colonies, whereas bifidobacteria grow with opaque brown colonies. This permits the differential counting of the predominant anaerobic organisms in human feces on one medium. 相似文献
13.
S D Feighner V D Bokkenheuser J Winter P B Hylemon 《Biochimica et biophysica acta》1979,574(1):154-163
A strain of the obligate anaerobe, Eubacterium lentum, isolated from human feces, catalyzes the 21-dehydroxylation of 11-deoxycorticosterone to progesterone. A quantitative radiochromatographic assay was developed to measure 21-dehydroxylase activity in cell extracts. Maximum enzyme activity in cell extracts required both a reduced pyridine nucleotide and an oxidized flavin coenzyme. However, photochemically reduced flavin (FMNH2) could replace the requirement for NAD(P)H plus oxidized flavin. NAD(P)H : flavin (either FMN or FAD) oxidoreductase activity was detected spectrophotometrically in cell extracts assayed under anaerobic conditions. 21-Dehydroxylase was active from pH 5.4 to 8.5 with an apparent optimum between 6.4 and 6.8 using mixtures of NADH plus FMN as coenzymes. The substrate concentration at half-maximal reaction velocity was 8.0 microM and a specific acitivity of 5.8 nmol [3H]progesterone formed . h-1 . mg-1 protein was determined using [3th]deoxycorticosterone as substrate. Atabrine, rotenone, acriflavin, and 2,4-dinitrophenol (all at 1 mM) inhibited 21-dehydroxylase activity in cell extracts by 25, 24, 35 and 84%, respectively. These results suggest that 21-dehydrogenase may be coupled to a NAD(P)H : flavin oxidoreductase system in E. lentum. 相似文献
14.
Membrane Filter Technique for Enumeration of Enterococci in Marine Waters 总被引:16,自引:13,他引:3
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A membrane filter procedure is described for the enumeration of enterococci in marine waters. The procedure utilizes a highly selective and somewhat differential primary isolation medium followed by an in situ substrate test for identifying colonies of those organisms capable of hydrolyzing esculin. The procedure (mE) was evaluated with known streptococci strains and field samples with regard to its accuracy, sensitivity, selectivity, specificity, precision, and comparability to existing methods. Essentially quantitative recovery was obtained with seawater-stressed cells of Streptococcus faecalis and S. faccium. Neither S. bovis, S. equinus, S. mitis, nor S. salivarius grew on the medium. The selectivity of the medium was such that a 10,000-fold reduction in background organisms was obtained relative to a medium which contained no inhibitors and was incubated at 35 C. About 90% of those typical colonies designated as enterococci confirmed as such and about 12% of the colonies not so designated were, in fact, identified as enterococci. Plate to plate variability across samples approximated that expected by chance alone. Verified recoveries of enterococci from natural samples by the mE procedure, on the average, exceeded those by the KF method by one order of magnitude. 相似文献
15.
CG-1 human nasopharyngeal carcinoma cells in monolayer culture formed both cohesive, epithelial-like colonies and scattered, fibroblastic-like colonies in mixed proportions. In the presence of exogenously added bFGF (4 ng/ml), about 85% of the colonies formed were fibroblastic-like. CG-1 cells were capable of synthesizing and releasing bFGF, and, when compared by the immunological method, cells in fibroblastic-like colonies were found to contain higher levels of endogenous bFGF than cells in the epithelial-like colonies. Furthermore, cells in the peripheral region of the epithelial-like colonies, which were fibroblastic-like in morphology, also appeared to contain higher levels of endogenous bFGF. In addition, in the presence of suramin, neutralizing antibody to bFGF, or neutralizing antibodies to bFGF and EGF, the number of cohesive colonies formed was greatly increased. Moreover, addition of the 2 M NaCl-eluted heparin-Sepharose fraction of the CG-1 cell-coditioned medium promoted the formation of dispersed colony in a dose-dependent manner. The results suggest that bFGF can regulate CG-1 cell phenotype in an autocrine manner. © 1994 Wiley-Liss, Inc. 相似文献
16.
Yoo SY Kim PS Hwang HK Lim SH Kim KW Choe SJ Min BM Kook JK 《Journal of microbiology (Seoul, Korea)》2005,43(2):204-208
The objective of this study was to both isolate and identify non-mutans streptococci organisms (non-MSO) from dental plaques recovered on mitis-salivarius sucrose bacitracin agar (MSB) plates. The dental plaque samples, which had been collected from 63 human subjects, were diluted and plated on MSB. The bacteria growing on the MSB plates were then identified with biochemical tests, as well as with 16S rDNA cloning and sequencing techniques. Our data indicated that bacteria from 30 subjects had been recovered on the MSB plates. Among the 21 typical colonies selected from the 30 subjects, 12 colonies, derived from 10 subjects, were identified as non-MSO. These 12 colonies were determined to be Streptococcus anginosus (8 colonies), S. sanguinis (1 colony), and Pantoea agglomerans (3 colonies). These results strongly suggest that a new selective medium will be required for the reliable isolation of mutans streptococci. 相似文献
17.
C Péchoux L Frappart 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1992,315(10):365-372
A serum-free primary culture system has been developed which allows for three-dimensional growth and differentiation of normal human fetal mammary epithelial cells within an extracellular matrix preparation. Human fetal mammary epithelial cells were isolated from the mammary glands of human female fetuses, 17 to 39 weeks-old. The "organoids" were embedded within a reconstituted basement membrane matrix prepared from the Engelbreth-Holm-Swarm (EHS) sarcoma according to the method of Hahm and Ip. "Organoids" were grown in either serum-free medium or in medium with fetal calf serum (FCS). The "organoid" proliferated over a 2 to 3 weeks culture period and remained viable for 1 or 2 months within the basement membrane matrix in serum free medium. Several types of colonies were observed; including alveolar-like budding clusters obtained from cultures of mammary gland from fetuses of over 20 weeks age, units with ductule-like projections and stellate-type colonies. Cell proliferation was dependent on the culture medium (with FCS no proliferation was obtained) and on the substratum (without matrix, significantly less growth and development occurred). These types of colonies are obtained when a glandular differentiation of cells budding from the malpighian epithelium is observed. Light microscopic and transmission electron microscopic studies were undertaken at the time of culture. This unique system using normal fetal mammary epithelial cells thus provides a model in which the regulation of human mammary development can be investigated. 相似文献
18.
Seventy-five sputa and 10 faeces of human origin were examined for organisms capable of growing in carbon monoxide (CO). Specimens were plated onto a buffered agar medium containing trace vitamins, and incubated (2–4 weeks) in 60% v/v CO as the sole source of carbon and energy. All specimens yielded growth except for three sputa; many individual colonies were shown to comprise at least two different organisms. While no recognized carboxydotrophs were found, presumptive identification revealed that streptococci, staphyloccoci, coliform bacilli, yeasts and moulds were all represented. Using a specific enzyme test, evidence for CO dehydrogenase activity was found in a significant proportion of mixed and purified cultures. These studies indicate that CO-tolerant organisms which may be using CO as a source of carbon and energy are associated with man. 相似文献
19.
G.D.W. Curtis R.G. Mitchell Andrea F. King Emma J. Griffin 《Letters in applied microbiology》1989,8(3):95-98
A new medium has been developed for the isolation of Listeria monocytogenes from clinical specimens with a mixed flora. Almost complete inhibition of unwanted organisms was achieved and recognition of colonies of Listeria spp. was usually possible after 24 h using the aesculin-ferric ammonium citrate indicator system. Compared to McBride agar the new medium was more inhibitory to representative contaminating species in pure culture and more successful in isolating small numbers of L. monocytogenes from artificially seeded clinical specimens. 相似文献
20.
Tetsuro Okabe Hitoshi Nomura Noriharu Sato Nakaaki Ohsawa 《Journal of cellular physiology》1982,110(1):43-49
In order to obtain human granulocytic colony-stimulating factor (G-CSF) in large quantities, a large-scale culture system of human G-CSF-producing cells has been established. The cell used for this system was T3M-1, which grew in a monolayered sheet in F-10 synthetic medium supplemented with 10% fetal bovine serum. T3M-1 cells grew in rolling bottles at the velocity of 0.5 r.p.m. with about 22 hr. of population doubling time. When the culture reached confluency, it was incubated in a serum-free medium supplemented with 1% bovine serum albumin. The conditioned medium was harvested every week, concentrated by Amicon PM-10 membrane, and loaded on a Sephadex G-75 column. The molecular weight of G-CSF was estimated at about 30,000. This G-CSF was stable over a pH range of 1.0 to 11.0 at 4°C for 21 hr. The CSF activity was destroyed by either trypsin or chymotrypsin, but resisted to RNase and DNase. A slight decrease in the activity was produced by treatment with neuramidase. G-CSF stimulated granulocytic colony formation of human and mouse marrow cells. By using the roller bottle culture system, we could obtain more than 100 liters of cultured medium in a month, which was able to form about 150,000,000 colonies of human bone marrow cells. The recovery of the human G-CSF activity from gel-filtration column was very high (91.7%), and a large increase of specific activity was obtainable (13.3-fold). This culture system is therefore expected to aid in the large-scale preparation of human G-CSF, thereby facilitating further studies on this granulopoietic factor. 相似文献