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Query: UMLS:C0026936 (Mycoplasma)
 14,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A hybridization test for the diagnosis of Mycoplasma pneumoniae infection (Gen-Probe Rapid Diagnostic System) was evaluated using throat swabs and sputum samples from 160 army conscripts with acute infection of the lower respiratory tract. M. pneumoniae were cultivated from sputa, and Mycoplasma serology was done with paired sera by both complement fixation and enzyme immunoassay techniques. Comparison of the probe test results with the Mycoplasma culture and serologic results showed that the Gen-Probe test was sensitive and specific for the rapid diagnosis of acute M. pneumoniae infection of the lower respiratory tract when sputum was used: It had good sensitivity (0.95) and specificity (0.85) among patients whose serologic results were consistent with their culture results. In contrast, the probe test performed with throat swabs seemed to have only limited value.
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PMID:Rapid diagnosis of Mycoplasma pneumoniae infection: clinical evaluation of a commercial probe test. 211 79

This communication reports the physical map of mycoplasma virus L3 (MV-L3) DNA derived from restriction patterns obtained by digestion with seven different restriction endonucleases. The length of the restriction map is 36,200 bp in contrast to the contour length of native MV-L3 DNA molecules which is 39,400 bp as determined by electron microscopy. The difference in length of 3,200 bp (corresponding to 8.1% of the native viral DNA contour length) is explained by terminal redundancy. It was possible to clone all fragments from particular restriction patterns into Escherichia coli vector pAT153, an indication of circular permutation within a population of MV-L3 DNA. However clear evidence has been obtained from the molar ratios of fragments and from hybridization experiments. We suppose that viral DNA is packaged from a concatemeric precursor molecule starting at a specific site called pac.
J Gen Virol 1990 Sep
PMID:Terminal redundancy and circular permutation of mycoplasma virus L3 DNA. 221 95

The existence of a mycoplasmal arginine deiminase which catalyzes the conversion of L-arginine to L-citrulline has been postulated. Here we show the partial amino acid sequence of arginine deiminase of Mycoplasma arginini and the complete nucleotide sequence of the arginine deiminase gene of M. arginini. The open reading frame deduced from this sequence consists of 1,230 bp encoding 410 amino acids. The mature form of this enzyme contains 409 amino acids after the deletion of the first methionine. In this open reading frame, TGA nonsense codons are used as tryptophan codons; this usage was verified by determination of the amino acid sequence. The molecular weight of the enzyme calculated from the deduced amino acid sequence is 46,372. Recently, the nucleotide sequence of the arginine deiminase gene of M. arginini was reported by Kondo et al. (K. Kondo, H. Sone, H. Yoshida, T. Toida, K. Kanatani, Y.-M. Hong N. Nishino, and J. Tanaka, Mol. Gen. Genet. 221:81-86, 1990). However, their sequence differed from ours in several places and especially at the C terminus.
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PMID:Cloning and nucleotide sequence of the gene encoding arginine deiminase of Mycoplasma arginini. 222 48

Arginine deiminase from Mycoplasma arginini was purified. The purified enzyme has a molecular weight of 46,000 daltons as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Its specific activity (20 units/mg protein) and amino acid composition showed a strong similarity to that of the Mycoplasma arthritidis arginine deiminase. The amino acid sequences of the N-terminal region and three internal peptides generated by enzymatic cleavage of the purified protein were determined. Using a synthetic oligonucleotide mixture complementary to part of the determined N-terminal amino acid sequence, the gene coding for arginine deiminase was isolated from a phage library. A nucleotide sequence of 2189 bp encoding the gene was determined. An open reading frame (ORF) contained the amino acid sequences corresponding to the determined N-terminal region and the three internal peptides of arginine deiminase. Thus it was concluded that this ORF encoded the arginine deiminase, a 385 amino acid polypeptide (mol.wt. 43,900 daltons). The three tryptophan residues in the sequenced peptides align with UGA codons in the nucleotide sequence, indicating that the nonsense codon UGA is used as a tryptophan codon in M. arginini.
Mol Gen Genet 1990 Mar
PMID:Cloning and sequence analysis of the arginine deiminase gene from Mycoplasma arginini. 232 33

On the basis of information from computer-assisted sequence comparison of the Mycoplasma pneumoniae 16S ribosomal RNA (rRNA) sequences with sequences from various other mycoplasmal and bacterial species, we constructed M. pneumoniae-specific oligonucleotide probes complementary to variable regions in the 16S rRNA molecule. Using a DNA/RNA dot blot hybridization procedure, it was possible to detect less than 1 X 10(3) mycoplasmas. This test is a most sensitive assay for species-specific detection of bacteria. It can easily be adapted for detection and identification of other bacterial species and may have wide medical and industrial application.
J Gen Microbiol 1987 Jul
PMID:Oligonucleotide probes complementary to variable regions of ribosomal RNA discriminate between Mycoplasma species. 244 70

Mycoplasma pneumoniae was isolated for first time in Panama and identified from a nine years old girl with pneumonia. SP4 medium was used to isolate the bacteria. Confirmatory serological results were obtained by indirect immunofluorescence and were also suggested by the presence of cryoagglutinins in the sera of this patient. DNA hybridization tests (Gen--Probe) were carried out.
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PMID:[The first isolation of Mycoplasma pneumoniae in Panama]. 250 60

We examined 10 monoclonal antibodies (mAbs) directed against Mycoplasma pneumoniae proteins of 200, 170, 67, 46 and 42 kDa, and one mAb directed against a glycolipid component. The membrane association of the antigens reacting with our mAbs was investigated, in particular by phase-fractionation involving use of the detergent Triton X-114. The 170 kDa protein was shown to be membrane-associated, and surface exposure of this antigen was demonstrated by its disappearance from SDS-PAGE patterns after treatment of intact mycoplasmas with proteolytic enzymes. Cross-reactions with protein antigens of Mycoplasma genitalium were also shown. A mAb directed against a component of a lipid extract, prepared by the method used for preparation of the antigen used in the complement fixation (CF) test for serological diagnosis of M. pneumoniae infection, reacted with one major and a few minor bands in thin-layer chromatography (TLC) of the crude extract. The glycolipid character of this major antigen was demonstrated by treatment of the extract with sodium periodate, and by development of the TLC with orcinol/ferric chloride. These reactive bands were the same as those detected by the use of polyclonal mouse antiserum and a human convalescent serum, a result showing that the CF antigen contains a glycolipid moiety reacting with our mAb. The surface exposure of this antigen was demonstrated by binding of mAbs to intact cells.
J Gen Microbiol 1989 Mar
PMID:Demonstration of membrane association and surface location of Mycoplasma pneumoniae antigens using monoclonal antibodies. 251 14

Human cytomegalovirus (HCMV) infection has previously been associated with the production of immunosuppression. The mechanism by which any such immunosuppressive effect might be mediated is unclear but previous work has implicated an effect of the virus on monocytes. We have attempted to characterize the immunosuppressive activity produced by in vitro infection of normal monocytes with HCMV strain AD169. We first examined the ability of HCMV AD169 and recent clinical isolates to infect normal peripheral blood mononuclear cells in vitro. We have found by immunofluorescence analysis that only a very limited number of peripheral blood mononuclear cells (0.2 to 0.5%) showed evidence of virus infection as demonstrated by expression of the major immediate early protein. We found that the inhibitory activity of supernatants of monocytes exposed to HCMV which suppressed mitogen-driven T cell responsiveness was associated with a protein of about 95K. Experiments to investigate the mechanism of action of this inhibitor suggested the possibility of mycoplasma contamination and we were subsequently able to isolate Mycoplasma hyorhinis from our AD169 virus stock. When a series of low passage clinical isolates of HCMV were examined for their ability to cause immunosuppression, there was a direct correlation between suppression and the presence of contaminating mycoplasmas. Using mycoplasma-free isolates of HCMV we could demonstrate no immunosuppressive effect on mitogen-mediated T cell proliferation of both unseparated human peripheral blood lymphocytes and nylon wool non-adherent T cells; these virus isolates also did not suppress accessory cell function or interleukin 1 production by monocytes infected in vitro. We conclude that the previously reported immunosuppressive effects of HCMV in vitro may be attributable to the presence of mycoplasmas and are unlikely to be due to expression of HCMV in monocytes. We suggest that mycoplasma contamination of isolates of HCMV may be a more extensive problem than is currently recognized.
J Gen Virol 1989 Mar
PMID:Human cytomegalovirus and monocytes: limited infection and negligible immunosuppression in normal mononuclear cells infected in vitro with mycoplasma-free virus strains. 254 53

Treatment of female BALB/c mice with oestradiol rendered them susceptible to vaginal colonization by three of four different strains of Mycoplasma hominis. Overall, the organisms were recovered persistently from the vagina of 68 (87%) of 78 of these mice. Strain TO mice given one of the strains were at least susceptible, all of ten becoming colonized and larger numbers of organisms being recovered. The hormone arrested the reproductive cycle in the oestrous phase, characterized by non-nucleated, cornified vaginal epithelial cells. In contrast, M. hominis organisms were isolated transiently from only seven (10.5%) of 66 BALB/c mice not treated with oestradiol, after intravaginal inoculation; treatment with progesterone, which induced the dioestrous phase of the cycle, did not render any of 10 BALB/c mice susceptible to vaginal colonization. The minimum number of organisms (2.5 x 10(5)) of one strain of M. hominis and the minimum dose of oestradiol (0.05 mg) required to induce persistent colonization were established. Vaginal colonization persisted for more than 200 d in some mice, the numbers of organisms recovered ranging between 10(1) and 10(8). At autopsy there was evidence of spread to the uterine horns and ovaries, and also to the oropharynx, of some animals but not to other organs. Infection was not associated with a polymorphonuclear leucocyte response in the vagina or elsewhere, but a fourfold serum antibody response to M. hominis, measured by the metabolism-inhibition technique, was detected in almost half of the mice tested.
J Gen Microbiol 1989 Oct
PMID:Oestradiol-induced infection of the genital tract of female mice by Mycoplasma hominis. 263 70

Twenty-five strains classified as Mycoplasma mycoides subsp. mycoides LC or subsp. capri have been compared by one-dimensional SDS-PAGE of their cellular proteins. A computerized numerical analysis revealed that the protein patterns of all but two aberrant strains formed one large phenon that separated clearly from representatives of the four other members of the 'M. mycoides cluster' at a similarity level (S) of 66% and which remained undivided at up to 78% S. At higher similarity levels, these strains fell heterogeneously into mixed sub-phenons containing strains of both subspecies. Serological comparisons by immunofluorescence largely confirmed the subspecies designations of the test strains, but also showed that some were serologically intermediate between subsp. mycoides and subsp. capri, being cross-reactive with both. These results confirm and enlarge upon those of our earlier studies indicating the protein-pattern inseparability of subsp. capri and subsp. mycoides LC strains and their distinctiveness from the classical M. mycoides subsp. mycoides SC strains and other members of the 'M. mycoides cluster'. As also recognized by other workers, subsp. mycoides LC and subsp. capri strains appear to comprise one large group, wherein those most readily identifiable as either type lie at either end of a serological spectrum that also contains serologically cross-reactive strains. Our observations therefore suggest the lines along which the three groups classified at present within the species M. mycoides (SC and LC strains of subsp. mycoides; subsp. capri) might eventually be reclassified, subject to direct genomic comparisons.
J Gen Microbiol 1989 Nov
PMID:Relationship between Mycoplasma mycoides subsp. mycoides ('large-colony' strains) and M. mycoides subsp. capri, as indicated by numerical analysis of one-dimensional SDS-PAGE protein patterns. 269 91


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