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1.
Summary Eighty strains ofC. diphtheriae typemitis and 80C. belfanti strains were tested for the rate of rapidity of glucose fermentation according to the method ofParsons andFrobisher. 90% ofC. diphtheriae mitis strains, in contrast to only 13.7% ofC. belfanti strains, fermented glucose in 1 to 2 days. 76% ofC. belfanti strains fermented glucose in 3 to 4 days, whereas some strains needed 8 to 9 days to complete the fermentation. So the results of this test revealed next to that of nitrate reduction, a further difference between the strains ofC. diphtheriae typemitis found in diphtheria and ozaena.  相似文献   

2.
An atypical sucrose-fermenting Corynebacterium diphtheriae strain was isolated from three blood cultures of a 14-year-old girl presented to a university teaching hospital in Rio de Janeiro, Brazil. She had mitral endocarditis that proved to be fatal despite intensive antibiotic therapy. Blood cultures showed a fluorescent Gram-positive, aerobic, coryneform-like bacillus presenting pyrazinamidase and CAMP reaction negative. The isolate was identified as a toxigenic strain of C. diphtheriae var. mitis by both Elek and radial immunodiffusion (RID) tests. The invasive C. diphtheriae sucrose-fermenting biotype strain adhered to glass surfaces and expressed pronounced hemagglutinating activity (titer 8), a property common among the nonfermenting biotype strains. Laboratories should be alert to the possibility of the isolation of C. diphtheriae with a positive sucrose fermentation test, especially when nontoxigenic strains are isolated from uncommon anatomic sites. Received: 24 November 1997 / Accepted: 5 March 1998  相似文献   

3.
Summary Pathogenicity of 30 strains ofCorynebacterium belfanti by inoculation of chorioallantoic membrane of the developing chick embryo was investigated. The embryos usually died in 2 to 4 days and chorioallantoic membranes showed the presence of nodules and/or pseudomembranes sometimes accompanied by hemorrhages. Histologically the lesions consisted of oedema, cell infiltration and necrosis. In the second passage through eggs, enhanced virulence ofC. belfanti was noticed. During experiments withC. beljanti eight chickens were hatched, five of them showing digital malformations and contractures. All the results are presented in four tables and six figures.  相似文献   

4.
Abstract

Embriologycals researches in the thalictrum genus. — Embriology of Thalictrum angustifolium L. v. flavum L.

In this research has been studied the development of the female gametophyte of Thalictrum angustifolium L. v. flavum L.; it has been found a tetrasporic bipolarized type: the Pyretrum type, with sixteen nuclei.

The gametophyte is characterized by cellularization of every antipodal nucleus.

Besides this is a new type in the Thalictrum genus, supposing that in others species of this genus, has been recognized the Normal type.

The author supposes another type in this specie, probably a development of the tetrasporic tetrapolarized type, of which he will refer when the necessary elements emerge.

In this specie the microsporogenesis is simultaneous.  相似文献   

5.
In this study we report an aerobiological sampling of the atmosphere of Córdoba, in which airborne conidia belonging to the genusCladosporium were volumetrically counted for a period of 3 years. Two types ofCladosporium conidia were identified, differentiated by their morphological characteristics: the typecladosporioides and the typeherbarum. Correlation analyses with meteorological parameters have shown that daily mean temperature and relative humidity were the most influential factors governing the daily presence ofCladosporium in the atmosphere. Regression analyses were also done in order to establish predictive models of future airborne concentrations. The models that have shown the best adjustment to our data set have been obtained through the utilization of the weekly average temperature prior to the conidia forecast as an independent variable and the 5-day moving average conidia count as the dependent variable. Finally, our statistical analyses showed that variations of theherbarum type adjust more closely to the model of variations obtained than that of thecladosporioides type.  相似文献   

6.
For investigation of the genes of proteins associated in vivo with botulinum neurotoxin (BoNT), polymerase chain reaction (PCR) experiments were carried out with oligonucleotide primers designed to regions of the nontoxic-nonhemagglutinin (NTNH) gene ofClostridium botulinum type C. The primers were used to amplify a DNA fragment from genomic DNA ofC. botulinum types A, B, E, F, G and toxigenic strains ofClostridium barati andClostridium butyricum. The amplified product from all of these strains hybridized with an internal oligonucleotide probe, whereas all nontoxigenic clostridia tested gave no PCR product and showed no reaction with the probe. TheNTNH gene was shown to be located upstream of the gene encoding BoNT, thereby revealing a conserved structure for genes encoding the proteins of the M complex of the progenitor botulinum toxin in these organisms. The sequence of theNTNH gene of nonproteolyticC. botulinum type F was determined by PCR amplification and sequencing of overlapping cloned fragments. NTNH/F showed 71% and 61% identity with NTNH ofC. botulinum type E and type C respectively.  相似文献   

7.
Influence of resistance-factors on the phage types ofSalmonella Panama   总被引:2,自引:0,他引:2  
The resistance to antibiotics which has been increasingly observed in naturally occurringSalmonella panama, is due to an R-factor. A relationship was found between phage pattern and the presence of this R-factor. All strains belonging to phage types A, C and E are sensitive to all antibiotics and are indicated in phage-typing by wild-type phage 47 or host-range mutants of phage 47. All strains belonging to phage types B, D and F possess an R-factor and are indicated by host-modified variants of phage 47. Phage type G, indicated by a host-range mutant, and group Z contain strains with, as well as without an R-factor. Spontaneous drug-sensitive segregants of type B, D and F strains have the phage pattern A, C and E respectively. Conversely, the phage pattern of A, C and E type strains change into B, D and F respectively after infection with the R-factor ofS. panama. The theory can be advanced that type B type A+R-factor, D — C+R-factor and F = E+R-factor. This change in phage type can be considered to be due to the fact that the R-factor exerts restriction and modification of the phage which indicates theS. panama strain without the R-factor.Many of the antibiotic-resistantEscherichia coli strains found in nature possess an R-factor which can be transferred toS. panama in vitro. Relatively few of these R-factors were found to possess also the restriction marker. Thus up to the present the number ofE. coli strains possessing an R-factor which is able to create a dependable combination of phage type and drug resistance inS. panama is relatively small.  相似文献   

8.
An inducible cell-surface-bound starch-degrading enzyme produced byCorynebacterium diphtheriae typegravis in tryptose-sodium chloride-maltose broth was partially purified by diethylaminoethylcellulose (DEAE) column chromatography. The partially purified enzyme had approximately six times the specific activity of the crude enzyme. Forty-five percent of the enzyme was recovered in the partially purified form after DEAE chromatography. A molecular weight for the enzyme of approximately 61 200 was obtained by glycerol density gradient centrifugation. The enzyme was inhibited by mercuric ions,p-chloromercuribenzoate, and iodoacetic acid. It was inhibited slightly by EDTA and 1,10-phenanthroline. The enzyme was not inhibited by mercaptoethanol, dithiothreitol, fluoride, bromide, or chloride ions. Activity was lost after precipitation with ethanol, and after concentration with Lyphogel, Sephadex G-15, or lyophilization, but no activity was lost after precipitation with ammonium sulfate. Calcium ions did not activate the enzyme. Maltose was the best inducer of the enzyme. All the saccharides tested induced the enzyme slightly. No phosphorylase was found associated with the organism. However, a phosphatase and possibly an α-glucosidase were produced by the organism. The properties of the starch-degrading enzyme(s) ofCorynebacterium diphtheriae typegravis resemble those of either an amylase, an α-glucosidase, or both. This investigation was supported by Public Health Service grant A102924-10 from the National Institute of Allergies and Infectious Diseases.  相似文献   

9.
Aims: To examine the value of the DNase test as an alternative procedure for differentiating Corynebacterium diphtheriae from Corynebacterium‐like colonies. Methods and Results: DNase test medium was inoculated by spotting a loopful of bacterial growth and incubated aerobically at 37°C. The DNase production was detectable following both 24 and 48 h incubation periods. The DNase activity was detected in all 91 C. diphtheriae (37 toxigenic and 54 nontoxigenic) strains examined, previously identified by both conventional biochemical methods and API Coryne System. Conversely, DNase test results were negative in 93·9% of the 564 nondiphtherial Gram‐positive rod clinical strains. Conclusions: The DNase test emerged as an easily interpretable and cost‐effective alternative screening procedure for C. diphtheriae laboratory identification. Significance and Impact of the Study: The method should facilitate routine laboratory diagnosis of toxigenic and nontoxigenic C. diphtheriae.  相似文献   

10.
Candida transglucosyl-amylase (Sawai, 1958, 1960; Sawai and Hehre, 1962) was found to be produced intracellularly by three of 28 species within theCandida genus, i.e. by 29 of 35C. tropicalis strains, all of 15C. albicans strains and oneC. claussenii. The novel capacity of this enzyme to catalyze transglucosylation from starch was substantiated by the observation that preparations from all the positive strains were highly effective in causing such transfer to glycerol, and by the fact that isomaltose was synthesized from dextrin by the action of all preparations checked for this capacity (21 strains). Two strains ofC. pelliculosa produced an amylase of a different kind, while representatives of the remaining 24Candida species tested (one or two strains of each species) gave no evidence of amylase production. In view of the narrow and apparently specific distribution of transglucosyl-amylase within the genus, it seems possible that production of this enzyme might be useful as an aid in the taxonomic differentiation ofCandida yeasts.A preliminary account of this work was presented at the 60th National Meeting of the Society of American Bacteriologists, held at Philadelphia, Pa., U.S.A. (Sawai and Hehre, 1960).  相似文献   

11.
Several kinds of chemicals were tested to determine their effects on the wings of avestigial mutant inDrosophila melanogaster. Two isogenic strains were used, viz.vg-ms andB; vg-ms, both co-isogenic with the Oregon-isogenic strain. Ammonium lactate was found to have a conspicuous effect in enlarging thevestigial wings. At an appropriate concentration of this agent the wings of thevg-ms- andB;vg-ms-co-isogenic strains were restored almost to wild-type wing at 27°C. This fact indicates that the wings of thevg-ms mutant can be restored to wild type not only by temperature but also by certain chemicals. Ammonium lactate was effective conspicuously on bothBar andvestigial-ms mutants. However, there was found an interaction betweenBar andvestigial-ms when these genes were combined. The manifestation ofB is enhanced byvg-ms, especially under the the condition of feeding in medium containing the chemical, and the manifestation ofvg-ms is reduced byB.This work forms part of a thesis for the doctorate of Kyoto University.  相似文献   

12.
The karyotypes ofCercopithecus alcogularis andC. mitis, both with 72 chromosomes, are similar but differ in a numer of rearrangements.C. nicitans (2n=70) andC. mitis karyotypes, even though differing in diploid number, appear to be closely related to each other because of several banding features and especially because they may be linked by a derived complex inversion polymorphism. The results show that chromosomal inversion variants can survive speciation. These results do not support recent chromosomal phylogenetic interpretations which were based on the finding of a diploid number of 2n=70 forC. mitis. The results described here emphasize the use of chromosomal characters in the study of the phylogeny and taxonomy ofCercopithecus.  相似文献   

13.
A total of 50Clostridium butyricum strains from clinical and nonclinical sources and 14C. beijerinckii strains originating from dairy products were analyzed for their plasmid content, antibiotic resistance, and bacteriocinogenic activity. The incidence of antibiotic resistance and presence of plasmidic DNA was more widespred among theC. butyricum strains from clinical source than among theC. beijerinckii strains, all of the originating from dairy products. In many of theC. butyricum strains, a small plasmid of 4.5 megadaltons was encountered. No relation was found between the plasmid pattern, the antibiotic resistance, the geographic localization of the isolates, or the clinical condition of the patients.  相似文献   

14.
Ten strains from a collection of mutants ofSynechocystis 6803 defective in Photosystem II (PS II) function were transformed with chromosomal DNA of wild-type and mutant cells. Cross hybridization data allowed to identify four groups of PS II-mutants. Highly efficient transformation was observed between different mutant groups, but not within the groups. Restoration of photosynthetic activity of the mutant cells was also achieved by transformation with different parts of a 5.6 kbBam HI fragment of wild typeSynechocystis DNA containing thepsbB gene. Each group of mutants was transformed to photoautotrophic growth by specific subfragments of thepsbB gene. DNA fragments of four selected mutant strains hybridizing with thepsbB gene were isolated and sequenced. The mutations were identified as a single nucleotide insertion or substitution leading to stop codon formation in two of the mutants, as a deletion of 12 nucleotides, or as a nucleotide substitution resulting in an amino acid substitution in the other two mutants. Deletion of 12 nucleotides in mutant strain PMB1 and stop codon formation in strain NF16 affect membrane-spanning regions of the gene product, the CP 47 protein.  相似文献   

15.
Nakashima-Tanaka  Eiji 《Genetica》1967,38(1):447-458
The eightvestigial strains,vg, vg-co-iso,vg;se-co-iso,vg-ms-1-co-iso,vg-ms-1; 3-co-iso,vg-ms-co-iso,vg-ms;se andvg-ms;se-co-iso showed various temperature responses. The five strains of thevg-ms group showed a greater response to temperature than did the three strains of thevg group. This tendency became more pronounced the higher the temperature was. The difference in temperature response between thevg-ms-1; 3-co-iso andvg-ms-co-iso strains indicates that the phenotypic expression ofvestigial is influenced by a modifier or modifiers located on the second chromosome of the Oregon(iso) strain. It was found that the X chromosome of the Oregon(iso) strain showed a slight modifier action in females but not in males of thevg-ms mutant.These gene in thevg-ms;se strain seemed to enhance the sensitivity to heat, and to inhibit the emergence of adult flies from pupal cases at 30°C when combined with thevg-ms gene, but no interaction was seen between these gene and thevg gene. From the results of this experiment, it is assumed that thevg-ms mutant either has a new recessive allele of thevg gene, or a modifier gene(s) closely linked tovg.This work forms part of a thesis for the doctorate of Kyoto University.  相似文献   

16.
The systematics of theLactobacillus population of the intestines of 88 different rats was studied; 80 rats had been fed on fermented oat-meal soup (Molin et al. 1992). One-hundred-twenty-twoLactobacillus strains from the intestinal mucosa were phenotypically classified together with twenty-eight reference strains ofLactobacillus andLeuconostoc, using 49 unit characters. Data were examined using Jaccard coefficient, and unweighted pair group algorithm with arithmetic averages. Two major and eleven minor clusters were defined at the 76% SJ-similarity level: Cluster 1 included thirty isolates which could not be identified further, but had resemblance to the type strains ofL. jensenii, L. gasseri, L. crispatus, and to some extent toL. acidophilus. Cluster 12 including fifty-four intestinal isolates was identified asL. reuteri; and so was cluster 13 (five isolates). Isolates of the major clusters were found in all parts of the intestines. The genomic homogeneity of theL. reuteri isolates was scrutinized by endonuclease restriction analysis of the chromosomal DNA, and the isolates could be divided into six genomic strains.  相似文献   

17.
Sterigmatocystin (ST) is a secondary metabolite and a principal mycotoxin known to be produced by over 30 species of filamentous fungi. It is also one of the late intermediates in aflatoxin biosynthesis. We have tested the ability of 7 species ofAspergillus, including 4 strains ofA. versicolor, one species ofBipolaris, and two species ofChaetomium, to produce ST on a sucrose-salts-phenylalanine defined medium as well as on three complex substrates. Highest ST production in our survey was by a strain ofA. versicolor grown on wheat, whereas, the highest ST production on defined medium was byC. cellulolyticum. To our knowledge, this is the first report of ST production byC. cellulolyticum on any substrate. In precursor feeding studies, resting cultures of wild typeA. nidulans andA. versicolor were unable to biotransform O-methylsterigmatocystin (OMST), the last known intermediate in aflatoxin biosynthesis. These results suggest that ST is the end product of polyketide metabolism in the strains tested.  相似文献   

18.
A comparative biochemical study was performed on some strains ofCandida rhagii and on strains belonging to different subgroups ofCandida parapsilosis. Measurements of alcohol dehydrogenase activity, resistance to drugs and occurrence of an alternative pathway enabled us to confirm the classification between several subgroups within theC. parapsilosis species.  相似文献   

19.
Summary The isolations of three new strains ofFrankia were made from root nodules ofCasuarina cunninghamiana growing aeroponically. Two strains, HFPCCI1 and HFPCcI2 isolated by Lopez are typicalFrankia strains, producing sporangia among filamentous mats in culture and, in the absence of combined nitrogen, forming vesicles and showing acetylene reduction. They are red-pigmented and, although failing to nodulateCasuarina hosts, effectively nodulatedElaeagnus andHippophae. A third strain HFPCcI3 isolated by Zhang from the same source, also a typicalFrankia, can form sporangia and vesicles in culture and reduce acetylene, is unpigmented, fails to nodulateElaeagnus but effectively nodulatesC. cunninghamiana andC. equisetifolia. Comparisons are made among all of theCasuarina isolates in our collection from around the world (twelve in all) with regard to their cultural characteristics and capacity to infect host plant species. Questions are raised about the specificity of the various isolates and their possible affinities. Opportunities are suggested for inoculation of seedlings for forestry and field application using the infective, effective strains now available.  相似文献   

20.
The insensitivity ofCitrobacter freundii to the E colicins is based on tolerance to colicin E1 and resistance to colicins E2 and E3. Spontaneous colicin A resistant mutants ofC. freundii also lost their colicin E1 receptor function. Sensitivity to colicin E1 can be induced by F′gal + tol + plasmids, thetol A+ gene product of which is responsible for this effect. Receptor function for colicins E2 and E3 is induced by theE. coli F′14bfe + plasmid, which is also able to enhance notably the receptor capacity for colicin E1. Thebfe + gene product ofE. coli, which is responsible for these phenomena, also restores the receptor function for colicin A and E1 in colicin A resistant mutants ofC. freundii. All results show that there is a remarkable difference between theE. coli bfe + gene product and thebfe + gene product ofC. freundii and also between thetol A+ gene products of these strains. The sensitivity to phage BF23 parallels the sensitivity to colicins E2 and E3 and is also induced by the F′14bfe + plasmid.  相似文献   

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