Enzyme make-up of trichophyton rubrum and t. mentagrophytes

Summary Aldolase activity in the cell-free extracts of two dermatophytes,T. mentagrophytes andT. rubrum, was investigated. The kinetics of the enzyme and the effects of metal ions and metal-binders are also reported. The enzyme was more active inT. mentagrophytes than inT. rubrum. The optimum pH for the enzyme action was 7.2 and it was completely inactivated at 60° C. Cobalt and magnesium ions and cysteine activated the enzyme. Inhibition caused by EDTA and o-phenanthroline was partially reversed by cobalt ions. The dermatophyte aldolase resembles bacterial aldolase in its properties.     

The detection of contamination in Trichophyton rubrum and trichophyton mentagrophytes

This report concerns the usefulness of two media, brain heart infusion agar (BHIA) and BCP milk dextrose agar in the detection of contamination inT. rubrum andT. mentagrophytes and provides cultural information in the identification of these species.Department of Microbiology, Public Health Laboratory, Ontario Department of Health, Box 9000, Postal Terminal A, Toronto 1, Ontario, Canada.Head, Medical Mycology Section.Mycologist, Medical Mycology Section.     

In vitro characterization of Trichophyton rubrum and T. mentagrophytes biofilms

Dermatophytes are fungi responsible for a disease known as dermatophytosis. Biofilms are sessile microbial communities surrounded by extracellular polymeric substances (EPS) with increased resistance to antimicrobial agents and host defenses. This paper describes, for the first time, the characteristics of Trichophyton rubrum and T. mentagrophytes biofilms. Biofilm formation was analyzed by light microscopy, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) as well as by staining with crystal violet and safranin. Metabolic activity was determined using the XTT reduction assay. Both species were able to form mature biofilms in 72?h. T. rubrum biofilm produced more biomass and EPS and was denser than T. mentagrophytes biofilm. The SEM results demonstrated a coordinated network of hyphae in all directions, embedded within EPS in some areas. Research and characterization of biofilms formed by dermatophytes may contribute to the search of new drugs for the treatment of these mycoses and might inform future revisions with respect to the dose and duration of treatment of currently available antifungals.     

A highly efficient synthesis of an octasaccharide,the repeating unit of the cell-wall mannan of Trichophyton mentagrophytes and T. rubrum

A highly concise and effective synthesis of the mannose octasaccharide repeating unit of the cell-wall mannan of Trichophyton mentagrophytes and T. rubrum was achieved via 6-O-glycosylation of a tetrasaccharide acceptor with a tetrasaccharide donor, followed by deprotection. The key tetrasaccharide (11) was constructed by selective 6-O-glycosylation of allyl 3,4-di-O-benzoyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranoside with 6-O-acetyl-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate, then with 2,3,4,6-tetra-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate. The tetrasaccharide acceptor (13) was obtained by selective 6-O-deacetylation of 11, while the tetrasaccharide donor 12 was obtained by deallylation of 11, followed by trichloroacetimidation.     

Molecular Analysis of Chitin Synthase 1 (CHS1) Gene Sequences of Trichophyton mentagrophytes Complex and T. rubrum

Nucleotide sequences of chitin synthase 1 (CHS1) gene of dermatophytes, Arthroderma benhamiae, A. simii, A. vanbreuseghemii, Trichophyton mentagrophytes var. interdigitale (T. interdigitale), and T. rubrum were analyzed for their phylogenetic relationship. About 620-bp genomic DNA fragments of the CHS1 gene were amplified from these dermatophytes by polymerase chain reaction (PCR) and sequenced. The CHS1 nucleotide sequences of these five dermatophytes showed more than 90% similarity between the species. The phylogenetic analysis of their sequences revealed that A. benhamiae, A. simii, A. vanbreuseghemii, and T. rubrum were genetically distinct from one another, but T. interdigitale was genetically very close to A. vanbreuseghemii. On the other hand, a specific restriction endonuclease site of HinfI was present in the CHS1 gene fragment of T. rubrum but not in those of A. benhamiae, A. simii, A. vanbreuseghemii and T. interdigitale. The molecular analysis of CHS1 genes will provide useful information for the identification of these Trichophyton species and the understanding of their evolution. Received: 6 March 1998 / Accepted: 4 May 1998     

Preliminary studies on the use of biochemical and physiological tests for the characterization of Fusarium isolates

Twenty-two isolates of Fusarium were examined for their ability to grow on a range of carbon sources, resistance to inhibitory chemicals, and their API ZYM enzyme profiles. Growth on common carbon sources showed little discrimination between isolates, but they could be differentiated on the basis of their enzymic activity and tolerance to inhibitors, particularly copper sulphate and malachite green.     

Usefulness of ELISA and radial immunodiffusion tests for evaluation of the degree of purification of influenza diagnostic and vaccine preparations

It is necessary to use new diagnostic tests for careful and rapid evaluation of a degree of purification and immunogenicity of vaccine anti-influenza preparations. In this study in order to obtain this purpose a radial immunodiffusion++ test and immunoenzymatic test (ELISA) were used Recommended by WHO radial immunodiffusion++ test enable to determine a level of haemagglutinin of particular types and subtypes of influenza virus in polyvalent preparations. However, this test is time consuming therefore for hemagglutinin level determination ELISA test was adapted. This test is hundred times more sensitive and can be applied with success for determination of hemagglutinin level of influenza virus A or B. For evaluation of a degree of purification of vaccine preparations ELISA was elaborated, in which as an index of purification of preparation a level of ovalbumin is determined. This test is specific and extremely sensitive, and it is possible to determine ovalbumin level with accuracy of 1ng in 1 ml of preparation.     

ThPOK在T细胞分化发育中的作用

ThPOK（T-helper-inducing POZ/Krueppel-like factor）又被称为Zbtb7b、Zfp67、cKrox,隶属于一个很大的转录因子家族——POK家族。ThPOK最初是被认为与Ⅰ型胶原蛋白基因的转录抑制有关,但近年来的研究发现,ThPOK在T细胞分化过程中至关重要,特别是对CD4^＋T细胞的分化发育起着命运决定的核心作用。该文综述了ThPOK在CD4^＋T细胞分化过程中的作用特点及其与另外两种重要转录因子GATA3和Runx3的相互作用关系,并在此基础上阐述了ThPOK在其他T细胞,如iNKT细胞、γδT细胞及效应CD8^＋T细胞中的作用功能。     

Genetic and physiological characterization of the Rhodospirillum rubrum carbon monoxide dehydrogenase system.

A 3.7-kb DNA region encoding part of the Rhodospirillum rubrum CO oxidation (coo) system was identified by using oligonucleotide probes. Sequence analysis of the cloned region indicated four complete or partial open reading frames (ORFs) with acceptable codon usage. The complete ORFs, the 573-bp cooF and the 1,920-bp cooS, encode an Fe/S protein and the Ni-containing carbon monoxide dehydrogenase (CODH), respectively. The four 4-cysteine motifs encoded by cooF are typical of a class of proteins associated with other oxidoreductases, including formate dehydrogenase, nitrate reductase, dimethyl sulfoxide reductase, and hydrogenase activities. The R. rubrum CODH is 67% similar to the beta subunit of the Clostridium thermoaceticum CODH and 47% similar to the alpha subunit of the Methanothrix soehngenii CODH; an alignment of these three peptides shows relatively limited overall conservation. Kanamycin cassette insertions into cooF and cooS resulted in R. rubrum strains devoid of CO-dependent H2 production with little (cooF::kan) or no (cooS::kan) methyl viologen-linked CODH activity in vitro, but did not dramatically alter their photoheterotrophic growth on malate in the presence of CO. Upstream of cooF is a 567-bp partial ORF, designated cooH, that we ascribe to the CO-induced hydrogenase, based on sequence similarity with other hydrogenases and the elimination of CO-dependent H2 production upon introduction of a cassette into this region. From mutant characterizations, we posit that cooH and cooFS are not cotranscribed. The second partial ORF starts 67 bp downstream of cooS and would be capable of encoding 35 amino acids with an ATP-binding site motif.     

Taxonomy of the Trichophyton mentagrophytes/T. interdigitale Species Complex Harboring the Highly Virulent,Multiresistant Genotype T. indotineae

Mycopathologia - A severe outbreak of highly virulent and multi-resistant dermatophytosis by species in the Trichophyton mentagrophytes/T. interdigitale complex is ongoing in India. The correct...     

Valine, malic, and pyruvic dehydrogenase tests in the differentiation of Bacteroides.

Fifteen isolates of Bacteroides were tested for their ability to dehydrogenate a variety of amino acids and organic acids. A simple and rapid method was developed for detecting dehydrogenase activity using 2,3,5-triphenyl tetrazolium chloride as a hydrogen acceptor and indicator. The results indicate that the tests for valine, malic, and pyruvic acid dehydrogenases have value in differentiating organisms in this genus.     

Cytochemistry of leukocytes in children. IV. The use of cytochemical tests in the differentiation and prognostic evaluation of acute leukemias]

From 63 children with acute leukaemia the bone-marrow smears were cytochemically examined before the beginning of therapy. The activity of peroxydase was examined according to Sato and Sekya, that of acid phosphatase according to L?ffler and Berghoff, that of alpha-naphthyl-acetate-esterase according to Gomori; the evidence of glycogen was examined by means of the PAS-diastase response according to McManus. Among the 63 cases of leukaemia we found 6 cases of paramyeloblastic leukaemia, 2 cases of parapromyelocytic leukaemia, and 3 cases of myelomonocytic leukaemia. 52 cases of leukaemia could not be further differentiated in morphological respect. They represented an immature paraleukoblastic leukaemia. A division according to leading cytochemical criteria was made for them. The therapeutic possibility of influencing the various groups was checked by means of prolonged observations. Children affected with paraleukoblastic leukaemia of the phosphatase type had a significantly low rate of remission similar to the myeloid leukaemia. Paraleukoblastic leukaemia of the PAS type, esterase type and the undifferentiated type revealed no essential differences. The rate of remission, however, was highest in leukaemia of the PAS type amounting to 100%. In one part of patients the prolonged cytochemical observations in 8 children with recidives showed that the cytochemical type under chemotherapy was changed.     

施氮和增温对降香黄檀幼苗生长发育和生理特征的影响

采用添加氮素模拟氮沉降和人工气候箱模拟增温的方法,设置了对照、施氮、增温以及增温×施氮交互作用4个处理,分析不同处理对降香黄檀(Dalbergia odorifera T. Chen)幼苗生长形态变化、生物量的积累、叶片和根系生理方面的影响。结果显示:与对照相比,增温、施氮以及增温×施氮交互作用均促进了降香黄檀幼苗的生长形态发育、增加了生物量的积累、光合参数、最大光化学量子产量、叶片硝酸还原酶及根系活力,但降低了叶片相对电导率和丙二醛含量;增温×施氮交互作用下降香黄檀幼苗的生物量积累、光合参数、最大光化学量子产量、叶片硝酸还原酶及根系活力的增幅最大,而叶片相对电导率和丙二醛含量降幅最显著;隶属函数分析结果表明,增温×施氮交互作用对降香黄檀幼苗生长发育的促进效果最好,其次为单独增温,最后为施氮处理。