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M F Barile

Publications and source records attributed to M F Barile.

114 records · Page 7Linked to original sources
PubMedDate not supplied

Characterization of the mycoplasma genome.

Recent advances on the properties of the mycoplasma genome, including size, base composition, replication, extrachromosomal DNA, and transfer of genetic material are briefly reviewed, with emphasis on their phylogenetic implications. The use of cleavage patterns of the mycoplasma genome by restriction endonucleases as "finger-prints" indicating genetic relatedness among strains is discussed. The data support the notion that strains of mycoplasma species of strict host and tissue specificity exhibit marked genetic homogeneity, suggesting a clonal origin for some species. The regions of the mycoplasma genome carrying the ribosomal RNA (rRNA) genes have been studied using restriction endonucleases, cloning, and hybridization procedures. The mycoplasmal rRNA cistrons cross-hybridized among themselves, and with the seven rRNA cistrons of Escherichia coli, demonstrating the marked conservation of structure during evolution of this part of the procaryotic genome. In most of the mollicutes tested so far the number of rRNA cistrons is two, but a few species appear to carry only one rRNA cistron in their genome.

Acholeplasma↗
PubMedDate not supplied

Mycoplasma pneumoniae attachment to WiDr cell cultures: competitive inhibition assays.

Attachment of radiolabeled M. pneumoniae to human WiDr cell culture monolayers was dependent on the WiDr cell density and the concentration of M. pneumoniae. Saturation of confluent monolayers grown on 5 mm coverslips was attained with only 40 micrograms of M. pneumoniae protein. Preincubating the WiDr monolayers with unlabeled M. pneumoniae or with a protein-rich extract prepared from M. pneumoniae inhibited subsequent attachment of radiolabeled organisms. Attachment inhibition by the M. pneumoniae extract provided a quantitative assay for mycoplasmal binding components. Treatment of radiolabeled M. pneumoniae with orosomucoid, ceruloplasmin, and gangliosides inhibited attachment to WiDr cells. These sialoglycoconjugates may be structural analogues of the target cell receptor.

Adhesiveness↗
PubMedDate not supplied

Interspecies and intraspecies DNA homology among established species of Acholeplasma: a review.

Radiolabeled DNA probes prepared in vitro by the nick translation method were used to determine the nucleotide sequence homology among the eight established and one unclassified species of Acholeplasma. Very little DNA homology (2 to 21 percent) was found among these nine distinct species and the heteroduplexes showed at least 15 percent mismatching as determined by thermal elution endpoints. The data obtained by hybridization analyses paralleled the results obtained by the growth inhibition and epi-immunofluorescence serologic procedures. The small amount of nucleotide sequence homology among the nine distinct species indicate that the Acholeplasma species are quite distinct and unrelated to each other genomically, findings which should provide useful insight on the molecular biology and evolutionary pathways of these organisms. Labeled 3H-DNA probes to five strains of either A. laidlawii or A. axanthum hybridized to a varying degree to excess amounts of unlabeled DNAs from 12 strains of A. laidlawii and six strains of A. axanthum, respectively. Nucleic acid hybridization analyses showed a wide variation (48 to 100 percent) in DNA homologies among different strains of the two species. The results demonstrate that strains of A. laidlawii and/or A. axanthum isolated from diverse hosts and habitats (birds, rodents, cats, swine, sheep, cattle, horses, goats, primates, and plants) exhibit extensive genotypic variations. 3H-DNA-DNA hybridization procedures were found to be extremely useful in establishing or confirming the existence of distinct species within the genus Acholeplasma.

Acholeplasma↗
PubMedDate not supplied

On the distribution and characteristics of isozyme expression in Mycoplasma, Acholeplasma, and Ureaplasma species.

A summary of a survey of three genera of mycoplasmatales (Mycoplasma, Acholeplasma, and Ureaplasma) for isozyme expression is presented. Isozyme analysis of mycoplasmas has been employed in at least three distinct areas: (1) as genetic markers for identification, individualization, and taxonomic classification; (2) as markers for cell culture contamination; and (3) as a qualitative measure of the operative metabolic pathways in the diverse species. We have found five ubiquitous enzymes: purine nucleoside phosphorylase, adenylate kinase, inorganic pyrophosphatase, dipeptidase, and esterase. Three enzymes, glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, and superoxide dismutase, were restricted to Acholeplasma species and were not detected in Mycoplasma or Ureaplasma. Four glycolytic enzymes, glucose phosphate isomerase, triose phosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, and lactate dehydrogenase, were restricted to those species of Mycoplasma and Acholeplasma capable of glucose fermentation. Two of these glycolytic enzymes, glucose phosphate isomerase and lactate dehydrogenase, were detected in serovars I and II of U. urealyticum, which is inconsistent with the non-glycolytic activity in this genus.

Acholeplasma↗
PubMedDate not supplied

Survey of plasmids in various mycoplasmas.

Thirty-three strains representing 15 distinct Mycoplasma, Acholeplasma, and Spiroplasma species were examined for the presence of plasmid DNA by agarose gel electrophoresis. The electrophoretic patterns of the DNAs of three strains, Mycoplasma sp. strain 747, Spiroplasma mirum strain SMCA, and M. hominis strain 1257, suggested the presence of a plasmid with molecular weights of approximately 70, 10, and 9 megadaltons, respectively. The functions of these plasmids are currently unknown.

Acholeplasma laidlawii↗