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mycoplasma-like micro-organisms in malignant tumors and non-tumours dermatovenerological diseases. electron microscopic investigations (author's transl).in examination of the ultrastructure of excised tissue and other material from patients with various diseases, principally dermatovenerological affections and with malignant tumors, and in healthy control subjects, patterns suggesting mycoplasma were repeatedly found in certain diseases only. specific attempts to isolate mycoplasma from the material were made, in which previously patterns of a mycoplasma type had frequently been seen. it was possible to culture mycoplasma-like organisms in vitro ...19754729
ultrastructure of mycoplasma-like organisms purified from clover phyllody-affected plants. 1976175171
chlamydiae (with phages), mycoplasmas, and richettsiae in chesapeake bay bivalves.intracytoplasmic chlamydia-like organisms, some with phages, rickettsia-like organisms, and mycoplasma-like organisms have been found in clams and oysters from the chesapeake bay area by electron microscopy. none of these organisms have been previously detected in mollusks, nor have phages been previously observed in chlamydia sp.1977193184
[treatment of swine cell line with antibiotics: effect on growth kinetics and susceptibility to foot-and-mouth disease virus and to mycoplasma-like organisms].cell cultures treated with tylosin tartrate and kanamycin sulphate antibiotics were studied in relation to the cell growth rate, the susceptibility to the foot-and-mouth disease virus and to the microorganism eradication. these treatments did not affect the cell growth rate and the cell behavior to the viral infection. on the other hand, the decontamination of the intracytoplasmatic formas of mycoplasma-like organism was not observed.1979233199
banded filaments associated with the aster yellows mlo in vinca rosea l.the ultrastructure of an aster yellows mycoplasma-like organism was studied in the phloem of periwinkle (vinca rosea l.) plants. banded filaments were observed in association with mycoplasma-like organisms of characteristic morphology. the filaments were variable in length, from 50-100 nm in width, and displayed a regular periodic banding of alternating electron-dense and electron-lucent structures.1978570447
intracellular membrane structures of the mycoplasma-like organisms inducing carrot yellows.intracellular membrane structures from 16 to 22 nm wide were found in the mycoplasma-like organisms causing carrot yellows. these structures are composed of five layers, three electron-dense and two electron-transparent. the membrane structures are situated, as a rule, in the central nucleoid zone of the cells of the mycoplasma-like organisms and may be seen to be in direct contact with the dna fibrils. ribosomes may be seen around the membrane structures. in this work we show the morphological ...1978753398
the occurrence of bacteria and mycoplasma like organisms in a monogenean parasite diclidophora merlangi. 19751158551
identification and analysis of a genomic strain cluster of mycoplasmalike organisms associated with canadian peach (eastern) x disease, western x disease, and clover yellow edge.genetic interrelatedness among 13 strains of mycoplasmalike organisms (mlos) from various sources was evaluated by dot hybridization and restriction fragment length polymorphism analyses using cloned dna probes derived from canadian peach x (cx) and western x (wx) mlos. dot hybridization analysis indicated that cx, wx, and clover yellow edge mlos are closely related and form a distinct strain cluster that is only distantly related to the 10 other mlos. similarity coefficients derived from restri ...19921356968
sensitive detection and identification of mycoplasma-like organisms in plants by polymerase chain reactions.dna amplification by polymerase chain reactions (pcr) was employed to detect host plant infection by several mycoplasmalike organisms (mlos), including the aster yellows (ay), dwarf aster yellows (day), and periwinkle little leaf (0-1) mlos. for pcr, two pairs of oligonucleotide primers, designated ay18pm and ay19pm, respectively, were synthesized on the basis of partial sequences of cloned ay mlo dna fragments ay18 and ay19. reaction mixtures containing primer pair ay18pm yielded a dna product ...19921510676
evolutionary relationships of a plant-pathogenic mycoplasmalike organism and acholeplasma laidlawii deduced from two ribosomal protein gene sequences.the families within the class mollicutes are distinguished by their morphologies, nutritional requirements, and abilities to metabolize certain compounds. biosystematic classification of the plant-pathogenic mycoplasmalike organisms (mlos) has been difficult because these organisms have not been cultured in vitro, and hence their nutritional requirements have not been determined nor have physiological characterizations been possible. to investigate the evolutionary relationship of the mlos to ot ...19921556079
membrane properties of a plant-pathogenic mycoplasmalike organism.in terms of biosystematics, the plant-pathogenic mycoplasmalike organisms (mlos) have been tentatively placed into the class mollicutes. certain physiological tests have been used to distinguish families within this class: the sterol-nonrequiring acholeplasmataceae differ from the sterol-requiring mycoplasmataceae in that the former are more resistant to lysis by digitonin and more sensitive to lysis in hypotonic salt solutions. to test mlos for these membrane properties and thus assist in their ...19921732203
postinflammatory cataracts in the mouse: induction by human mycoplasma-like organisms.cataracts often occur in humans secondary to uveitis. uveitis may be caused by various infectious agents, but rarely is the agent detected in the cataract. mycoplasma-like organisms (mlo) were recently reported to cause human uveitis and retinitis. cataracts were often present in those inflamed eyes. mlo are intracellular cell wall deficient pathogenic bacteria. they are pleomorphic tubulospherical and filamentous organisms with a characteristic ultrastructural appearance. no mlo culture system ...19911751463
dna sequence of the ribosomal protein genes rp12 and rps19 from a plant-pathogenic mycoplasma-like organism.a segment of a ribosomal protein operon from a plant-pathogenic mycoplasma-like organism (mlo) was cloned and sequenced, to provide supplemental molecular data pertinent to the question of mlo phylogeny. comparisons of the deduced amino acid sequences indicate an ancient divergence of the mlos from the animal-pathogenic mycoplasmas. furthermore, although both the plant and animal pathogens have a-t rich genomes, a fundamental difference was apparent in their usage of the uga codon.19911769558
mycoplasma-like organisms. 19901973792
conjunctivitis associated with a mycoplasma-like organism in swine.a midwestern producer reported high incidence of conjunctivitis and keratoconjunctivitis in a herd of crossbred finishing swine. complete necropsy was performed on 3 pigs with bilateral mucopurulent conjunctivitis and chemosis; other gross lesions were not seen. mycoplasma sp was isolated from conjunctival swab specimens obtained from 1 pig; small numbers of streptococci and coagulase-negative staphylococci were isolated from conjunctival swab specimens from all 3 pigs. neither swine influenza v ...19912010341
primary biliary cirrhosis in the mouse: induction by human mycoplasma-like organisms.human intraocular and orbital chronic inflammatory disease with autoimmune features has been reported to be caused by mycoplasma-like organisms (mlo). mlo are intracellular cell-wall deficient pathogenic bacteria, closely related to rickettsia, with a characteristic ultrastrural pleomorphic tubulo-spherical and filamentous appearance. no culture system has been developed for mlo and diagnosis of mlo disease is made by detecting these bacteria within infected cells using a transmission electron m ...19902206991
identification and characterization of plasmids from the western aster yellows mycoplasmalike organism.supercoiled double-stranded dna molecules (plasmids) were isolated from plants infected with three laboratory strains of western aster yellows mycoplasma-like organism (ay-mlo) by using cesium chloride-ethidium bromide density gradients. southern blot analysis, using plasmids from the severe strain of ay-mlo (say-mlo) as the probe, identified at least four plasmids in celery, aster, and periwinkle plants and in macrosteles severini leafhopper vectors infected with either the dwarf ay-mlo, tulela ...19902307660
16s rrna sequence indicates that plant-pathogenic mycoplasmalike organisms are evolutionarily distinct from animal mycoplasmas.the plant-pathogenic mycoplasmalike organisms (mlos) are so named because they lack cell walls. many features that are essential to a definitive classification remain uncharacterized, because these organisms have resisted attempts at in vitro culturing. to establish the taxonomic position of the mlos, the dna region containing the 16s rrna gene from a representative of the mlos has been cloned and sequenced. sequence comparisons indicate that the mlos are related to mycoplasma capricolum and tha ...19892808301
crohn's disease uveitis. parasitization of vitreous leukocytes by mollicute-like organisms.crohn's disease (cd) is an idiopathic chronic inflammatory gut disease with frequent extragut inflammatory manifestations in the eyes, orbit, lungs, joints, and skin. a bacterial cause of cd is suspected, but cultivation of a specific pathogen has not been forthcoming. mollicute-like organisms (mlos) were recently reported to cause human chronic ocular inflammatory disease. inoculation of this mlo into mouse eyelids produced chronic progressive granulomatous ocular and orbital inflammatory disea ...19892923094
enzymatic activities in cell fractions of mycoplasmalike organisms purified from aster yellows-infected plants.mycoplasmalike organisms (mlos), purified from aster yellows-infected plants were osmotically lysed, and the membranes were separated from the cytoplasmic fraction through differential centrifugation. electron microscopic examinations of sections of the purified mlos and the isolated membranes showed pleomorphic bodies and unit membranous empty vesicles, respectively. cell fractions were tested for nadh oxidase, nadph oxidase, atpase, rnase, dnase, and p-nitrophenyl phosphatase activity. nadh ox ...19852997132
ultrastructural localization of glucoside residues on tissue sections by applying the enzyme-gold approach.the enzyme-gold approach was applied for ultrastructural localization of glucoside residues in animal and plant tissues. a beta-glucosidase-gold complex was prepared and used on thin tissue sections to reveal the corresponding substrate molecules by electron microscopy. conditions for preparation of the complex, as well as for its application, were determined. once applied on thin tissue sections, the glucosidase-gold complex yielded labeling over the rough endoplasmic reticulum, mainly on the r ...19873114363
ultrastructural evidence for the presence of bacteria, viral-like particles, and mycoplasma-like organisms associated with giardia spp.giardia trophozoites and cysts, isolated from mammalian and avian hosts, were examined by transmission electron microscopy (tem), scanning electron microscopy (sem), and by fluorescent light microscopy for the presence of microbial symbionts. mycoplasma-like organisms were observed on the surfaces of trophozoites isolated from the prairie vole, laboratory rat, and beaver. intracellular bacteria were observed by tem in the trophozoites and cysts of g. microti and by fluorescence microscopy in tro ...19883284999
further characterization of an unusual plant mollicutes species of uncertain taxonomic status.ppav is a type of mollicutes that was isolated in sp4 medium from seeds of apples affected by proliferation, a disease in which mycoplasma-like organisms (mlos) are involved. however, ppav is probably not the etiological mlo agent for at least two reasons: 1) optimal temperature growth is 43 c, and 2) in spite of numerous isolation attempts over several years, no second ppav culture could be obtained. ppav is surrounded by a single cytoplasmic membrane and forms typical fried egg-shaped colonies ...19873312108
dna probes for detection and identification of mycoplasmas (mollicutes).dna probes are expected to prove a specific, sensitive, rapid and inexpensive means for diagnosis of mycoplasma infections, replacing procedures that depend on cultivation of the fastidious organisms. probes made up of conserved genes, such as rrna genes, do offer the advantage of identifying and distinguishing multiple species with a single labeled reagent. the mycoplasmal rrna gene probe pmc5 was effective in detection and identification of mycoplasmas infecting cell cultures. however, use of ...19873312110
in vitro detection of plant mycoplasmas by immunofluorescent staining with monoclonal antibodies.hybridoma techniques have been applied to develop specific monoclonal antibodies (mcabs) against spiroplasmas and mycoplasma-like organisms (mlos). advantages of the mcabs have been clearly demonstrated in the detection of aster yellows (ay) mlo by indirect enzyme-linked immunosorbent assay (elisa) and immunofluorescent staining, compared with conventionally produced polyclonal antibodies. mcabs have also been applied in the in vitro detection and identification of spiroplasmas and ay mlos on me ...19873312112
bud-like structures of mycoplasma-like organisms (mlo) demonstrated by freeze-fracturing. 19873657991
multiplication of mycoplasma-like organisms brought in a culture medium by inactivated bovine serum. 19724591524
studies on burkitt's lymphoma. i. a preliminary report on the presence of mycoplasma-like organisms in specimens examined by electron microscopy. 19724632446
[electron microscopic demonstration of mycoplasma-like organisms in phloem of hydrangea macrophylla]. 19715172502
association, development, and growth cycle of mycoplasma-like organisms in plants affected with clover phyllody. 19695358829
bioassay techniques to assess plant pathogenicity of mycoplasma-like organisms (mlo).a bioassay for mycoplasma-like organisms ( mlo ) plant yellows is proposed. the relation p=e(-)nm enables calculation of the average number (m) of infectious units (iu) injected per insect as a function of the proportion p on non-diseased plants and of the number n of vectors per plant. the injected volume was determined by injecting a radioactive solution, and the results can thus be expressed in iu/ml. a diagram is proposed which directly gives the concentration in iu/ml of the tested extract ...19846372580
the aster yellows controversy: current status.evidence for and against the spiroplasmal etiology of aster yellows (ay) disease is examined. a spiroplasma, serologically identical to spiroplasma citri, was cultivated by some workers from lettuce (lactuca sativa l.) plants claimed to be naturally infected with ay. the isolated spiroplasma was shown to be infectious by injecting macrosteles fascifrons with the cultured organisms and then confining the injected leafhoppers on healthy plants. the reports claiming that a spiroplasma is the etiolo ...19836382826
in vitro studies of mycoplasma-like organisms.we determined whether the western x mycoplasma (wxm) isolated from colladonus montanus could be maintained in vitro by ultrathin sections or by assay of infectivity. large spherical or small electron-dense bodies like those found in intact infected cells were observed in some media. infectivity of wxm can be maintained for 28 days in cultured salivary glands in a newly developed medium, and for 281 days (seven passages) in modified actc, for 231 days (eight passages) in modified pc, 107 days (on ...19836382828
microscopical evidence of mycoplasma-like organisms in mycoplasma positive bovine semen.contamination with mycoplasma-like organisms was observed microscopically in a bull with impaired sperm quality and positive isolation of mycoplasma bovigenitalium and ureaplasma. the bull's spermiogram was characterized by decreased initial motility and post-freeze survival rate, primary defects in nucleoplasm, changes in tail conformation and regressive changes of the plasmalemma and acrosome. vesiculo-lamellar bodies in the periacrosomal region were an accompanying feature. the cytologic pict ...19846465546
mycoplasma-like organisms (mlo), pathogens of the plant yellows diseases, as a model of coevolution between prokaryotes, insects and plants.there is no satisfactory theory to explain how parasites whose effect is to kill or to weaken their hosts have been able to survive evolution. a good explanation may be found in the study of mycoplasma-like organisms (mlo). we show here the existence of natural cycles of mlo between symptomless wild plants and unaffected vectors. such natural cycles may be the basis of a coevolutionary process by which the prokaryotes and the whole cycle have persisted to our time. disease outbreaks occur with i ...19846511314
pathogenicity of mollicutes for insects: possible use in biological control.acholeplasmas, spiroplasmas and other non-helical sterol-requiring mycoplasmas of unknown phylogenetic affinity inhabit insects. of these, only spiroplasmas are known to be pathogenic. group i-2 spiroplasmas, or spiroplasma apis, especially in combination with other organisms, reduce honey-bee longevity. plant pathogenic mycoplasma-like organisms are often found intracellularly in insects. spiroplasmas are found predominantly in the gut lumen or haemolymph (or both) of their insect hosts. pathog ...19846712057
antibiotic treatment for control of tree diseases associated with mycoplasma-like organisms.tetracycline-induced remission of the development of symptoms has been used as an aid in the diagnosis of plant diseases associated with mycoplasma-like organisms and, in a few cases, for field control of some tree diseases. infusion and injection into the trunk are the most widely adopted methods for the treatment of trees with the antibiotic. initial translocation of tetracycline in trees appears to occur in the xylem, but transfer to the phloem is a prerequisite for disease control. the durat ...19827123053
mycoplasma infections of plants.plants can be infected by two types of wall-less procaryotes, spiroplasmas and mycoplasma-like organisms (mlo), both located intracellularly in the phloem tissues of affected plants. spiroplasmas have been cultured, characterized and shown to be true members of the class mollicutes. mlo have not yet been cultured or characterized; they are thought to be mycoplasma-like on the basis of their ultrastructure as seen in situ, their sensitivity to tetracycline and resistance to penicillin. mycoplasma ...19817287398
phylogenetic classification of phytopathogenic mollicutes by sequence analysis of 16s ribosomal dna.the phylogenetic relationships of 17 phytopathogenic mycoplasmalike organisms (mlos) representing seven major taxonomic groups established on the basis of mlo 16s ribosomal dna (rdna) restriction patterns were examined by performing a sequence analysis of the 16s rdna gene. the sequence data showed that the mlos which we examined are members of a relatively homogeneous group that evolved monophyletically from a common ancestor. in agreement with results obtained previously with other mlos, our r ...19947520735
a novel method for cloning dna of plant-pathogenic mycoplasmalike organisms.a novel method was developed for cloning the dna from a representative of plant-pathogenic mycoplasmalike organisms (mlos). this procedure utilized random amplified polymorphic dna (rapd) and basic recombinant dna techniques. it consisted of amplification of total dna from diseased plants using one oligonucleotide primer with arbitrary sequence and separation of rapd products in agarose gels. unique rapd band(s) of mlo origin was (were) then recovered from the gel and cloned into the specificall ...19957553457
isolation and characterization of full-length chromosomes from non-culturable plant-pathogenic mycoplasma-like organisms.we describe the isolation and characterization of full-length chromosomes from non-culturable plant-pathogenic, mycoplasma-like organisms (mlos). mlo chromosomes are circular and their sizes (640 to 1185 kbp) are heterogeneous. divergence in the range of chromosome sizes is apparent between mlos in the two major mlo disease groups, and chromosome size polymorphism occurs among some related agents. mlo chromosome sizes overlap those of culturable mycoplasmas; consequently, small genome size alone ...19937679771
dna probes and pcr in diagnosis of mycoplasma infections.laboratory diagnosis of mycoplasma infections is hampered by the difficulty or total failure to cultivate the organisms in vitro, and by the frequently weak and poorly specific serological response of the host. dna probes consisting of cloned ribosomal rna genes, cdna to mycoplasmal rrna, synthetic 16s rrna oligonucleotide sequences, or cloned mycoplasmal protein genes, have been developed and applied as diagnostic tools in a variety of human and animal mycoplasma infections. these included prim ...19947700272
simple and rapid preparation of infected plant tissue extracts for pcr amplification of virus, viroid, and mlo nucleic acids.a rapid, simple method for preparing plant tissues infected with viruses, viroids, or mlos using a commercial product known as gene releaser is described. the gene releaser polymeric matrix method produced plant extracts suitable for pcr amplification without the use of organic solvents, ethanol precipitation, or additional nucleic acid purification techniques. modification of maceration methods and/or extraction buffers resulted in the pcr amplification of potato spindle tuber, apple scar skin, ...19947868647
murine chronic tubulointerstitial nephritis: induction by human uveitis mycoplasma-like organisms.mycoplasma-like organisms (mlo) are non-cultivated intracellular cell wall deficient pathogenic bacteria with a distinctive ultrastructural appearance. diagnosis of mlo disease rests on finding the organisms in parasitized cells using a transmission electron microscope. mlo are a well studied cause of transmissible chronic plant vascular disease responsive to antibiotics. mlo have recently been found to cause human chronic progressive ophthalmic disease including uveitis. in human uveitis mlo ar ...19947892050
differentiation of mycoplasmalike organisms (mlos) in european fruit trees by pcr using specific primers derived from the sequence of a chromosomal fragment of the apple proliferation mlo.a 1.8-kb chromosomal dna fragment of the mycoplasmalike organism (mlo) associated with apple proliferation was sequenced. three putative open reading frames were observed on this fragment. the protein encoded by open reading frame 2 shows significant homologies with bacterial nitroreductases. from the nucleotide sequence four primer pairs for pcr were chosen to specifically amplify dna from mlos associated with european diseases of fruit trees. primer pairs specific for (i) malus-affecting mlos, ...19947916180
identification and grouping of mycoplasmalike organisms associated with grapevine yellows and clover phyllody diseases based on immunological and molecular analyses.immunofluorescent staining, dot blot hybridization, pcr, random amplified polymorphic dna (rapd) markers, and restriction fragment length polymorphism wee used to study the genetic relatedness among mycoplasmalike organisms (mlos) associated with several geographically diverse grapevine yellows diseases (ca1, ch1, sa1, and sa2 from bologna, italy; gyu from udine, italy; gyr from rome, italy; and gyg from germany). the relationship between these and mlos associated with clover phyllody diseases i ...19948031086
phylogeny of mycoplasmalike organisms (phytoplasmas): a basis for their classification.a global phylogenetic analysis using parsimony of 16s rrna gene sequences from 46 mollicutes, 19 mycoplasmalike organisms (mlos) (new trivial name, phytoplasmas), and several related bacteria placed the mlos definitively among the members of the class mollicutes and revealed that mlos form a large discrete monophyletic clade, paraphyletic to the acholeplasma species, within the anaeroplasma clade. within the mlo clade resolved in the global mollicutes phylogeny and a comprehensive mlo phylogeny ...19948071198
phylogenetic relationships among members of the class mollicutes deduced from rps3 gene sequences.a gene for a ribosomal protein, rps3, was amplified by pcr and sequenced from representatives of the class mollicutes. alignments of the deduced amino acid sequences allowed the construction of a phylogeny that is consistent with the phylogenetic trees created from 5s and 16s rrna comparisons, including the position of the former acholeplasma florum on the mycoplasma branch, rather than with the classical acholeplasmataceae. additional confirmation of the phylogeny comes from the deduction that ...19948123554
mycoplasma-like organisms and ophthalmic disease. 19938140710
phylogenetic diversity of phytopathogenic mycoplasmalike organisms.by using specific primers, the 16s rrna genes of japanese mycoplasmalike organisms (mlos) were amplified by polymerase chain reactions from mlo-enriched fractions of plants infected with each of six different mlos. each of the polymerase chain reaction fragments (length, 1,370 nucleotides) was directly sequenced in both strands by using 17 oligonucleotide primers. a phylogenetic tree constructed by using the sequence data showed that these japanese mlos are phylogenetically diverse microorganism ...19938347505
mycoplasma-like organism induced murine cardiac microvasculopathy. a transmission electron microscopic study.mycoplasma-like organisms [mlo] are intracellular cell wall deficient bacteria that cause ocular chronic vasculitis in man and chronic vascular disease in plants. since mlo do not grow in culture, diagnosis of mlo-induced disease requires identification of the organisms by electron microscopy. ultrastructurally, mlo appear as pleomorphic tubulo-spherical and filamentous organisms. in human ocular disease mlo have been detected in parasitised leucocytes and retinal pigment epithelial cells. we ha ...19938351248
experimental murine chronic hepatitis: results following intrahepatic inoculation of human uveitis mycoplasma-like organisms.mycoplasma-like organisms (mlo) are non-cultivated intracellular cell-wall deficient pathogenic bacteria with a distinctive ultrastructural appearance. diagnosis of mlo disease depends on finding the organisms in parasitized cells using a transmission electron microscope. mlo are a well studied cause of transmissible chronic plant disease responsive to antibiotics. mlo have recently been found to cause human chronic uveitis, orbital, and retinal disease with autoimmune features. ophthalmic leuco ...19938398804
mycoplasmalike organisms (mlos) and distinguish them from other mlos.dna of 10 lines of rice yellow dwarf (ryd) mycoplasmalike organisms (mlos) from japan, the phillippines, and thailand hybridized with four probes containing chromosomal and six probes containing extrachromosomal dna of a tochigi (japan) line of ryd mlo. one chromosomal probe (ryd9) and all six extrachromosomal probes hybridized with various other mlos (sugarcane white leaf, onion yellows, cineraria witches'-broom, japanese hornwort witches'-broom, water dropwort wiches'-broom, gentian witches'-b ...19938489230
genomic diversity and differentiation among phytoplasma strains in 16s rrna groups i (aster yellows and related phytoplasmas) and iii (x-disease and related phytoplasmas).conserved gene sequences, including 16s rrna and ribosomal protein gene sequences, were used to evaluate genetic variations in phytoplasma strains belonging to 16s rrna groups i (aster yellows and related phytoplasmas) and iii (x-disease and related phytoplasmas). we used pcr to amplify the sequences of the 16s ribosomal dna and a segment of the ribosomal protein gene operon (encoding the 3' region of rps19, all of rp122, and rps3) from diverse phytoplasma group i and iii strains. additional chr ...19968573523
characterization of the mycoplasmalike organism associated with witches'-broom disease of lime and proposition of a candidatus taxon for the organism, "candidatus phytoplasma aurantifolia".witches'-broom disease of small-fruited acid lime (wbdl) is a severe disease caused by a mycoplasmalike organism (mlo) in the sultanate of oman and the united arab emirates. the wbdl mlo was characterized by studying its genome size, the sequences of its 16s ribosomal dna and the 16s-23s ribosomal dna spacer region, and hybridization profiles obtained by using wbdl mlo-specific probes. the size of the wbdl mlo genome is 720 kbp. genomic similarities with the mlos of sunhemp, sesame, and alfalfa ...19958590671
characterisation of mycoplasmas isolated from genital tract infections of sheep in nigeria.four mycoplasma-like organisms isolated from ewes with mucopurulent vaginal discharge and swollen vulva were characterised. biochemical tests showed three of the isolates to be negative for glucose fermentation and arginine hydrolysis, while the remaining isolate was negative for glucose fermentation but hydrolysed arginine. serological identification using the growth inhibition, growth precipitation and indirect immunofluorescence tests indicated the three similar isolates as mycoplasma bovigen ...19958593416
mycoplasma-like organisms in hodgkin's disease. 19968622416
physical map of the western x-disease phytoplasma chromosome.a physical map of the chromosome of the western x-disease phytoplasma was constructed and represents the first physical map of a phytoplasma chromosome. the western x-disease phytoplasma is a nonculturable, plant-pathogenic member of the class mollicutes and is the causal agent of a severe disease of fruit trees in north america. the map was generated by performing restriction digests of the chromosome and resolving the restriction fragments by pulsed-field gel electrophoresis. southern blot ana ...19968682811
phytoplasma-specific pcr primers based on sequences of the 16s-23s rrna spacer region.in order to develop a diagnostic tool to identify phytoplasmas and classify them according to their phylogenetic group, we took advantage of the sequence diversity of the 16s-23s intergenic spacer regions (srs) of phytoplasmas. ten pcr primers were developed from the sr sequences and were shown to amplify in a group-specific fashion. for some groups of phytoplasmas, such as elm yellows, ash yellows, and pear decline, the sr primer was paired with a specific primer from within the 16s rrna gene. ...19968702291
sequence heterogeneity in the two 16s rrna genes of phormium yellow leaf phytoplasma.phormium yellow leaf (pyl) phytoplasma causes a lethal disease of the monocotyledon, new zealand flax (phormium tenax). the 16s rrna genes of pyl phytoplasma were amplified from infected flax by pcr and cloned, and the nucleotide sequences were determined. dna sequencing and southern hybridization analysis of genomic dna indicated the presence of two copies of the 16s rrna gene. the two 16s rrna genes exhibited sequence heterogeneity in 4 nucleotide positions and could be distinguished by the re ...19968795200
pulmonary sarcoidosis: could mycoplasma-like organisms be a cause?the etiology of sarcoidosis is unknown but an unusual bacterial agent is possible. mycoplasma-like organisms [mlo] are obligate intracellular cell wall deficient bacteria with a distinctive ultrastructural appearance. mlo are a common cause of various transmissible plant diseases. despite over 25 years of effort mlo remain uncultivated. molecular biologic studies indicate mlo are only distantly related to extracellular cultivable mycoplasma. diagnosis of mlo diseases is based chiefly on detectio ...19968865408
phytoplasma induced free-branching in commercial poinsettia cultivars.free-branching poinsettia cultivars that produce numerous axillary shoots are essential for propagating desirable multi-flowered poinsettias (euphorbia pulcherrima wild. klotz). for more than a decade, a biological agent has been suspected to cause free-branching in poinsettias. attempts to identify the branching agent have failed. isolation of the pathogen was accomplished using a living host and it was concluded that an unculturable phytoplasma is the cause of free-branching in poinsettias. th ...19979035146
identification of phytoplasmas in eggs, nymphs and adults of scaphoideus titanus ball reared on healthy plants.a survey for the presence of aster yellows-related phytoplasmas in the different life stages of scaphoideus titanus was carried out by means of pcr and nested-pcr assays. using a phytoplasma 16srl group-specific primer pair followed by rflp analysis of amplified products, we were able to detect and identify phytoplasmas from eggs, newly hatched nymphs, fourth and fifth instar nymphs and adults reared on ten phytoplasma-free vicia faba seedlings. two of these broad beans became infected, whereas ...19979099575
"candidatus phytoplasma australiense," a new phytoplasma taxon associated with australian grapevine yellows.a phytoplasma was detected in naturally diseased 'chardonnay' grapevines exhibiting symptoms of australian grapevine yellows disease. the use of pcr designed to amplify phytoplasma dna resulted in detection of phytoplasma dna in all of the diseased plants examined; no phytoplasma dna was detected in healthy seedling grapevines. the collective restriction fragment length polymorphism (rflp) patterns of amplified 16s ribosomal dna differed from the patterns described previously for other phytoplam ...19979103609
[what are the costs of pediatric cardiosurgery?].a cost analysis of patients discharged from the department of pediatric cardiology and heart surgery of "bambino gesu" children's hospital was performed. analysis focused on the costs and revenue from diagnosis-related group 108 ("other cardiovascular procedures") during a six-month period in 1994 (n. = 76). the sample of 30 charts reviewed (mlos 20.36 +/- 27.87 days) showed a mean cost of 30,381,000 italian lire (itl) vs a revenue of itl 23,545,800. the pearson correlation coefficient between l ...19979244755
non-cultivable phytopathogenic mycoplasmas: characterization, detection and perspectives for control.phytoplasmas (ex mlos) and spiroplasmas are important groups of plant pathogenic mollicutes, discovered in 1967 and 1970 respectively. spiroplasmas, like other mollicutes, can be cultured in artificial media and are thus well characterized. on the contrary, phytoplasmas have resisted in vitro cultivation and their study was difficult until the recent development of molecular techniques. from the sequence of their 16s rdna, phytoplasmas have been shown to be true mollicutes. fourteen phytoplasma ...19979286069
diseases of plants transmissible between plants and man (phytonoses) exist.since zoonoses (singular zoonosis) are infections or infectious diseases of animals transmissible to man, or occasionally from man to other animal species, it is logical that should any diseases of plants be found that are transmissible between plants and man they should be termed phytonoses (singular phytonosis). the genome of human uveitis mycoplasma-like organisms (mlo) has been reported to be showing a very high homology to plant mlo. for this reason, and because there are several other know ...19979352506
molecular identification and relatedness of potato witches'-broom phytoplasma isolates from four potato cultivars.four isolates of potato witches'-broom phytoplasma, designated as pw1, pw2, pw3 and pw4, were established on four potato cultivars. the identity of each isolate was confirmed by pcr using two universal primer pairs and one specific primer set derived from phytoplasma of 16s rdna sequences. the four isolate samples formed similar rflp patterns after digestion of 1.2 kb pcr products with restriction endonucleases alui, hhai, rsai and sau3a. the direct dna sequencing with the specific primer pair s ...19979352664
sequence and rflp analysis of the elongation factor tu gene used in differentiation and classification of phytoplasmas.primers designed from sequences of the gene encoding the elongation factor tu (tuf gene) of several culturable mollicutes amplified most of the tuf gene from phytoplasmas of the aster yellows, stolbur and x-disease groups. about 85% of the tuf gene from two aster yellows strains and a tomato stolbur phytoplasma was sequenced. the nucleotide sequence similarity between these related phytoplasmas was between 87.8 and 97.0%, whereas the homology with other mollicutes was 66.3-72.7%. the similarity ...19979353940
classification of new phytoplasmas associated with diseases of strawberry in florida, based on analysis of 16s rrna and ribosomal protein gene operon sequences.strawberry plants exhibiting symptoms of stunting and abnormally small leaves were observed in production fields in central florida, usa. since the symptoms were suggestive of phytoplasma infection, plants were assayed for presence of phytoplasma by pcr amplification of 16s rdna and ribosomal protein (rp) gene sequences. amplification of phytoplasma-specific dna sequences by pcr indicated infection of the diseased strawberry plants by phytoplasmas. rflp analyses of amplified 16s rdna revealed th ...19989542097
an antigenic protein gene of a phytoplasma associated with sweet potato witches' broom.a gene encoding the major antigenic protein of phytoplasma associated with sweet potato witches' broom (spwb) was cloned and analysed by screening the genomic library of spwb phytoplasma with monoclonal antibodies for spwb phytoplasma. the entire predicted structural gene encoded an antigenic protein composed of 172 amino acids with a computed molecular mass of 19.15 kda and a pl value of 9.78. the -10 region of the promoter and the terminator region of the gene were identified and found to be s ...19989611800
a small-scale procedure for extracting nucleic acids from woody plants infected with various phytopathogens for pcr assay.the complexity of most nucleic acid extraction procedures limits the number of samples that can be easily processed for analysis by polymerase chain reaction (pcr). a simple, small-scale procedure was developed which can be carried out entirely in 1.5-ml microfuge tubes whereby the container and contents are frozen with liquid nitrogen, tissue is pulverized, and targeted nucleic acids are extracted. dna of bacterial and phytoplasmal plant pathogens was extracted in hot ctab buffer followed by ch ...19989628220
phylogenetic positions of phytoplasmas associated with dieback, yellow crinkle and mosaic diseases of papaya, and their proposed inclusion in 'candidatus phytoplasma australiense' and a new taxon, 'candidatus phytoplasma australasia'.dna extracted from three papaya (carica papaya l.) plants, individually affected by dieback, yellow crinkle or mosaic diseases, was subjected to pcr using phytoplasma-specific primers to amplify the 16s rrna gene plus 16s-23s rrna intergenic spacer region. near-complete dna sequences obtained for the three pcr amplimers were subjected to phylogenetic analyses and direct sequence comparison with other phytoplasma 16s rdna and 16s-23s spacer region dna sequences. the papaya yellow crinkle (ppyc) a ...19989734050
engineering of a single-chain variable-fragment (scfv) antibody specific for the stolbur phytoplasma (mollicute) and its expression in escherichia coli and tobacco plantsfrom a hybridoma cell line (2a10) producing an immunoglobulin g1 directed against the major membrane protein of the stolbur phytoplasma, we have engineered scfv (single-chain variable-fragment) antibodies from the variable heavy (vh) and light (vl) domains of the immunoglobulin. the scfv gene was cloned and expressed in escherichia coli. the expressed protein of 30 kda could be recovered from the periplasmic fraction of the bacterial cells and was shown to be fully functional toward its phytopla ...19989797323
a plasmid isolated from phytopathogenic onion yellows phytoplasma and its heterogeneity in the pathogenic phytoplasma mutant.a 3.6-kbp dna fragment was cloned from the extrachromosomal dna of a pathogenic plant mollicute, onion yellows phytoplasma (oy-w). sequence analysis of the fragment revealed an open reading frame (orf) encoding the replication (rep) protein of rolling-circle replication (rcr)-type plasmids. this result suggests the existence of a plasmid (poyw1) in oy-w that uses the rcr mechanism. this assumption was confirmed by detecting the single-stranded dna (ssdna) of a replication intermediate that is sp ...19989805390
chromosomal organization and nucleotide sequence of the genes coding for the elongation factors g and tu of the apple proliferation phytoplasma.genes coding for elongation factors g (fus) and tu (tuf) of the non-culturable apple proliferation (ap) phytoplasma were cloned and sequenced. arrangement of these genes and identification of the ribosomal protein gene rps7 upstream of the fus gene suggest a transcriptional organization similar to that of the streptomycin operon of escherichia coli and other bacteria. the fus and tuf genes from other tested phytoplasmas were found to be similarly linked as in the ap agent. thus, it is likely tha ...19999889337
oligodeoxynucleotides as probes for in situ hybridization with transmission electron microscopy to specifically localize phytoplasma in plant cells.phytoplasmas are plant-pathogenic mollicutes restricted to phloem. they belong to several groups in a unique phylogenetic clade. non-related phytoplasmas may infect the same plant species, often with similar symptoms. hence methods are needed to specifically localize phytoplasmas and to study their multiplication and movement in their hosts. conditions for post-embedding in situ hybridization (ish) with transmission electron microscopy using oligodeoxynucleotides as probes for labelling of phyto ...199910024432
geminivirus-related extrachromosomal dnas of the x-clade phytoplasmas share high sequence similarity.southern blot hybridization analysis revealed that the extrachromosomal dnas (ec-dnas) associated with vaccinium witches' broom (vac) and walnut witches' broom phytoplasmas and various strains of the italian clover phyllody phytoplasma (icph) were highly homologous among themselves but distinct from ec-dnas of aster yellows related phytoplasmas occurring in the same insect and plant hosts and collected at the same site as the icph strains. the ec-dnas of various strains of the icph differed sign ...199910411272
'candidatus phytoplasma japonicum', a new phytoplasma taxon associated with japanese hydrangea phyllody.a phytoplasma was discovered in diseased specimens of field-grown hortensia (hydrangea spp.) exhibiting typical phyllody symptoms. pcr amplification of dna using phytoplasma specific primers detected phytoplasma dna in all of the diseased plants examined. no phytoplasma dna was found in healthy hortensia seedlings. rflp patterns of amplified 16s rdna differed from the patterns previously described for other phytoplasmas including six isolates of foreign hortensia phytoplasmas. based on the rflp, ...199910425791
isolation of the gene encoding an immunodominant membrane protein of the apple proliferation phytoplasma, and expression and characterization of the gene product.an immunodominant membrane protein (imp) of the apple proliferation (ap) phytoplasma was detected in preparations from ap-diseased periwinkle plants using monoclonal and polyclonal antibodies to the ap agent. following isolation from western blots and partial sequencing, degenerate oligonucleotides derived from the imp sequence were used as probes to identify a dna fragment containing the orf encoding the imp. complete sequencing and subsequent analysis of the cloned dna fragment revealed the pr ...199910463160
the phytoplasma associated with ash yellows and lilac witches'-broom: 'candidatus phytoplasma fraxini'.phytoplasmas associated with the plant diseases ash yellows (ashy, occurring in fraxinus) and lilac witches'-broom (lwb, occurring in syringa) represent a putative species-level taxon. phytoplasmal dna from 19 ash or lilac sources across the known geographic range of ashy (71-113 degrees w) was examined to determine if ashy and lwb phytoplasmas are a coherent group, if variability exists in both conserved and anonymous dna, and if variability in 16s rdna is related to host or geographic origin. ...199910555342
physical map of the chromosome of the apple proliferation phytoplasma.a physical map of the apple proliferation phytoplasma strain at chromosome was constructed from genomic dna extracted from diseased tobacco plants. the map was generated with single and double digestions of the chromosome with bsshii, smai, mlui, and apai restriction endonucleases and resolving the fragments by pulsed-field gel electrophoresis. partial digestion and southern blot analysis were used to assist in the arrangement of the 14 contiguous restriction fragments obtained. from the restric ...200010671466
genetic variability of apple proliferation phytoplasmas as determined by pcr-rflp and sequencing of a non-ribosomal fragment.apple proliferation phytoplasmas are considered as quarantine organisms in europe and north america, but reliable polymerase chain reaction (pcr) primers for their identification in routine diagnosis were missing, because they show genetic variability. therefore, 100 apple proliferation phytoplasma isolates, derived from most of the european countries where apple proliferation disease has been detected, were analysed for their genetic variability. a detailed restriction fragment length polymorph ...200010722788
chromosome mapping of the sweet potato little leaf phytoplasma reveals genome heterogeneity within the phytoplasmas.to further understand the genomic diversity and genetic architecture of phytoplasmas, a physical and genetic map of the sweet potato little leaf (spll) strain v4 phytoplasma chromosome was determined. pfge was used to determine the size of the spll-v4 genome, which was estimated to be 622 kb. a physical map was prepared by two-dimensional reciprocal digestions using the restriction endonucleases bsshii, smal, eagl and i-ceul. sixteen cleavage sites were located on the map. southern hybridization ...200010784048
diseases of plants transmissible between plants and man (phytonoses) exist--follow-up paper.the purpose of this paper is to revise the original paper by qualifying a statement made therein and making two sections more inclusive. the qualification is the insertion of the word 'adult' before the word 'volunteers' in one sentence. the scope of the first section is increased by: (i) drawing attention to the possibility that besides other organisms (i.e. non-mycoplasma-like organisms (non-mlos)) and viruses that could be inadvertently transmitted between members of the plant and animal king ...200010790767
molecular and microscopical detection of aster yellows phytoplasma associated with infected parsnip.typical phytoplasma yellows symptoms were observed in parsnip (pastinaca sativa l.) plants grown around edmonton, alberta, canada. examination of ultrathin sections of leaf midribs by electron microscopy revealed numerous phytoplasma bodies localized in the phloem cells. dna extracted from the infected leaves was amplified with a 16s rdna universal primer pair p1/p6 giving the expected pcr product of 1.5 kb. the phytoplasma was confirmed as a member of the aster yellows (ay) group by amplificati ...200010830901
heteroduplex mobility assay detects dna mutations for differentiation of closely related phytoplasma strains.we present the first use of dna heteroduplex mobility assay (hma) to detect the point mutations including substitutions and deletions/insertions in 16s rdna of aster yellows phytoplasma (ay27) and to differentiate phytoplasmas collected from field samples of clover proliferation (cp) and alfalfa witches'-broom (awb). the phytoplasmal 16s rdna fragment was amplified from ay27 by polymerase chain reaction (pcr) and cloned into a plasmid vector. the cloned dna fragment was subjected to in vitro mut ...200010856778
pcr-rflp and sequence analysis of a non-ribosomal fragment for genetic characterization of european stone fruit yellows phytoplasmas infecting various prunus species.a 927 bp non-ribosomal fragment was used to assess the genetic variability of the european stone fruit yellows (esfy) phytoplasma infecting 14 different prunus species. for this, 175 isolates originating from four different mediterranean countries were tested by pcr-rflp analysis with seven restriction enzymes. no polymorphism among the esfy phytoplasma could be observed but 12 out of 18 restriction sites differed between the homologous fragments of esfy and apple proliferation (ap) phytoplasmas ...200010860715
histopathology and polyphenol content in plants infected by phytoplasmas.the alterations of cell walls and the localization of several compounds such as polyphenols, suberin, lignin, in plum and apple plants infected with plum leptonecrosis (pln) and apple proliferation (ap) phytoplasmas respectively, were investigated. catharanthus roseus plants, infected with ap or pln were also studied. the 4,6-diamidino-2-phenylindole (dapi) test and transmission electron microscopy showed the presence of phytoplasmas in all infected plants. specific histological stainings for cu ...200010969878
phytoplasma: phytopathogenic mollicutes.during the past decade, research has yielded new knowledge about the plant and insect host ranges, geographical distribution, and phylogenetic relationships of phytoplasmas, and a taxonomic system has emerged in which distinct phytoplasmas are named as separate "candidatus phytoplasma species." in large part, this progress has resulted from the development and use of molecular methods to detect, identify, and classify phytoplasmas. while these advances continue, research has recently begun on th ...200011018129
classification of aster yellows-group phytoplasmas based on combined analyses of rrna and tuf gene sequences.seventy phytoplasma isolates, including 10 previously characterized reference strains, of the aster yellows group were examined by rflp analysis of pcr-amplified rdna and rflp and sequence analysis of the tuf gene. on the basis of rdna restriction profiles, seven previously proposed 16s rdna subgroups (16sri-a, -b, -c, -d, -e, -f and -k) were recognized in the material examined. in addition, three new subgroups that differ in the rflp profiles were identified and designated 16sri-l, 16sri-m and ...200011034478
diversity of phytoplasmas isolated from insects, determined by a dna heteroduplex mobility assay and a length polymorphism of the 16s-23s rdna spacer region analysis.two techniques were developed for the analysis of non-cultivable mollicutes in insects. the first was aimed at detecting organisms belonging to undiscovered groups within the phytoplasma clade. after prescreening by polymerase chain reaction with phytoplasma-specific primers, nucleic acids from 54 positive samples were amplified using phytoplasma-specific fluorescein-labelled primers flanking the 16s-23s rdna spacer region, which is variable in length among the phytoplasmas. the sizes of all the ...200011119147
in planta expression of a protein encoded by the extrachromosomal dna of a phytoplasma and related to geminivirus replication proteins.a new extrachromosomal dna, ecoyw1, was cloned from the onion yellows phytoplasma (oy-w). southern blot and pcr analysis showed that ecoyw1 is not present in the oy-m, a mild symptom line derived from oy-w. we determined the complete nucleotide sequence of ecoyw1; it is a circular dsdna of 7.0 kbp in length, which contains seven orfs. orf1 encoded a homologue of the geminivirus rep protein. western immunoblot analysis revealed that this rep homologue is expressed in oy-w infected plants, suggest ...200111158368
catharanthus roseus genes regulated differentially by mollicute infections.a differential display of mrnas was used to isolate periwinkle cdnas differentially expressed following infection with one of three mollicutes: spiroplasma citri, candidatus phytoplasma aurantifolia, and stolbur phytoplasma. twenty-four differentially expressed cdnas were characterized by northern blots and sequence analysis. eight of them had homologies with genes in databanks coding for proteins involved in photosynthesis, sugar transport, response to stress, or pathways of phytosterol synthes ...200111204786
an immunodominant membrane protein gene from the western x-disease phytoplasma is distinct from those of other phytoplasmas.membrane proteins mediate several important processes, including attachment, in several mollicute species. phytoplasmas are non-culturable plant pathogenic mollicutes that are transmitted in a specific manner by certain phloem-feeding insect vectors. because it is likely that phytoplasma membrane proteins are involved with some aspect of the transmission process, their identification, isolation and characterization are important first steps in understanding phytoplasma transmission. a 32 kda imm ...200111238964
organization of ribosomal rna genes from a loofah witches' broom phytoplasma.using the technique of integrative mapping with three vectors carrying chromosomal rdna sequences, one of two rrna operons of loofah witches' broom (lfwb) phytoplasma was constructed. this is the first complete rrna operon of a phytoplasma to be reported. the operon has a context of 5'-16s-23s-5s-3' with a trna(ile) gene in the its and trna(val) and trna(asn) genes downstream from the 5s rrna gene. although the other operon has not been cloned, the dna sequence of a pcr-amplified product shows t ...200111244569
a chromosome map of the european stone fruit yellows phytoplasma.a physical map of the european stone fruit yellows phytoplasma strain gsfy1 chromosome was constructed using pfge-purified genomic dna from diseased tobacco and tomato plants. the map was generated with single and double digestions of the chromosome with smai, bsshii, apai, bamhi and xhoi restriction endonucleases and the fragments were resolved by pfge. reciprocal double digestions were used to locate 26 restriction sites on the chromosome. southern blot analysis was also used to assist in the ...200111320124
expression of chloramphenicol acetyltransferase in bacillus subtilis under the control of a phytoplasma promoter.a cloned putative promoter region upstream of the 16s rrna gene of the western x-disease phytoplasma was inserted behind the promoterless chloramphenicol acetyltransferase gene of plasmid ppl603. the dna construct was used to transform bacillus subtilis cells. the transformants were assayed for chloramphenicol acetyltransferase activity, showing that the phytoplasma promoter is efficiently expressed in a b. subtilis background.200111377863
the first phytoplasma rnase p rna provides new insights into the sequence requirements of this ribozyme.a high variability of rnase p rna structures is seen among members of the mycoplasma group. to gain further insight into the structure-function relations of this ribozyme, we have searched for the rnase p rna gene from more distant relatives, the phytoplasmas. these mycoplasma-like organisms are the aetiological agents of many severe plant diseases. we report the sequence and catalytic properties of rnase p rna from the phytoplasma causing apple proliferation disease. the primary and postulated ...200111410676
'candidatus phytoplasma brasiliense', a new phytoplasma taxon associated with hibiscus witches' broom disease.hibiscus rosa-sinensis is a valuable ornamental species widely planted in brazil. many plants are affected by witches' broom disease, which is characterized by excessive axillary branching, abnormally small leaves, and deformed flowers, symptoms that are characteristic of diseases attributed to phytoplasmas. a phytoplasma was detected in diseased hibiscus by amplification of rrna operon sequences by pcrs, and was characterized by rflp and nucleotide sequence analyses of 16s rdna. the collective ...200111411679
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