Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Mycoplasma fermentans”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Failure to detect Mycoplasma fermentans, Mycoplasma penetrans, or Mycoplasma pirum in the urethra of patients with acute nongonococcal urethritis.

Urethral swab specimens collected from 108 male Japanese patients with acute nongonococcal urethritis (NGU) and from 50 Japanese men without NGU were examined for the presence of Mycoplasma fermentans, Mycoplasma penetrans, and Mycoplasma pirum by means of polymerase chain reaction-based assays. These mycoplasmas were not detected in any of the specimens, which suggests that they are unlikely to have a pathogenic role in acute NGU.

Acute Disease↗

Morphology, ultrastructure, and mode of division of Mycoplasma fermentans, Mycoplasma hominis, Mycoplasma orale, and Mycoplasma salivarium.

The morphology of viable Mycoplasma fermentans, Mycoplasma hominis, Mycoplasma orale types 1 and 2, and Mycoplasma salivarium was studied in broth cultures by interference microscopy and in thin sections by electron microscopy. Only spherical cells were seen by interference microscopy. M. hominis had a capsule-like outer layer. Except for M. orale type 1, mycoplasmas in thin sections were 0.3-1 mum in diameter, with a bounding trilaminar membrane 7.5-10 nm thick. The mycoplasmas contained DNA fibrils and randomly distributed ribosomes. No polyribosomes were seen. Dividing mycoplasmas elongated slightly; the membrane invaginated, forming one bud. Sometimes M. hominis and M. salivarium produced one bud by elongation, and the bud was attached by a tube. This method of division is not considered as characteristic but rather as due to centrifugal force separating unfixed cells during preparation for electron microscopy. Cross-septa were never observed. In thin sections M. orale type 1 was elongated and without buds, an observation which suggested that preparation for electron microscopy distorted the mycoplasmas.

Cell Division↗

Identification of S-(2,3-dihydroxypropyl)cystein in a macrophage-activating lipopeptide from Mycoplasma fermentans.

Mycoplasmas are capable of stimulating monocytes and macrophages to release cytokines, prostaglandins, and nitric oxide. The aim of this study was to characterize the chemical nature of the previously isolated [Mühlradt, P. F., & Frisch, M. (1994) Infect. Immun. 62, 3801-3807] macrophage-stimulating material "MDHM" from Mycoplasma fermentans. Mycoplasmas were delipidated, and MDHM activity was extracted with octyl glucoside and further purified by reversed-phase HPLC. Macrophage-stimulating activity was monitored by nitric oxide release from peritoneal macrophages from C3H/HeJ endotoxin low responder mice. HPLC-purified MDHM was rechromatographed on an analytic scale RP 18 column before and after proteinase K treatment. Proteinase treatment did not diminish biological activity but shifted MDHM elution toward higher lipophilicity, suggesting that the macrophage-stimulating activity might reside in the lipopeptide moiety of a lipoprotein. Proteinase K-treated MDHM was hydrolyzed, amino groups were dansylated, and the dansylated material was isolated by HPLC. Dansylated S-(2,3-dihydroxypropyl)cystein (glycerylcystein thioether), typical for Braun's murein lipoprotein, and Dns-Gly and Dns-Thr were identified by tandem mass spectrometry. These amino acids were isolated from biologically active but not from the neighboring inactive HPLC fractions. IR spectra from proteinase K-treated, HPLC-purified MDHM and those from the synthetic lipopeptide [2,3-bis(palmitoyloxy)-(2-RS)-propyl]-N-palmitoyl-(R)-CysSerSer AsnAla were very similar. The data, taken together, indicate that lipoproteins of a nature previously detected in eubacteria are expressed in M. fermentans and that at least one of these lipoproteins and a lipopeptide derived from it constitute the macrophage-activating principle MDHM from these mycoplasmas.

Animals↗

The ftsZ gene as a tool for detection of Mycoplasma fermentans.

Mycoplasma fermentans was reported as a common contaminant of cell cultures, and was shown to either induce or suppress several immunological functions. A strain of M. fermentans was recently isolated from a mouse T-lymphoma cell line, which differs from other M. fermentans strains by its growth characteristics and was designated (in the authors' records) as strain 609. Using the differential display technique (DD), a differentially expressed gene that was identified as the M. fermentans 609 ftsZ gene was isolated. Comparison of the nucleotide sequence of the M. fermentans 609 ftsZ gene to other ftsZ genes showed a 98% homology with Mycoplasma fermentans strain K7 and approximately 50% homology with Mycoplasma pulmonis and Mycoplasma genitalium. Comparison of the putative amino acid sequences of the FtsZ proteins showed similar homology. A polymerase chain reaction (PCR) assay to detect the presence of this ftsZ gene was established; it is a fast and convenient assay to detect infection of cells by the M. fermentans species. This work demonstrates that: (i) DD can be used as a useful technique to identify and isolate mycoplasmal genes from infected cells; and (ii) the ftsZ gene can be a useful marker to distinguish between different species of mycoplasma.

Amino Acid Sequence↗

Phosphocholine-containing glycoglycerolipids (GGPL-I and GGPL-III) are species-specific major immunodeterminants of Mycoplasma fermentans.

Mycoplasma fermentans has unique glycoglycerophospholipids (GGPLs: GGPL-I and GGPL-III). Previously, the structure of these lipids was determined as phosphocholine-6'-alpha-glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (GGPL-I) and 1"-phosphocholine-2"-aminodihydroxypropane-3"-phospho-6'-alph++ + a- glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (GGPL-III). Thin-layer chromatography (TLC) immunostaining showed that the GGPLs were main lipid-antigens of the M. fermentans species. Anti-M. fermentans serum stained mainly the GGPLs, but the other anti-mycoplasma sera (anti-M. arginini, anti-M. hyorhinis, anti-M. pneumonia, anti-M. primatum, and anti-Acholeplasma laidlawii, anti-M. hominis, anti-M. orale, and M. salivarium) stained neither GGPL-I nor GGPL-III. The TLC analysis of glycolipids and phospholipids of various human related mycoplasmas showed clearly that GGPLs are specifically expressed in M. fermentans species. GGPL-I and GGPL-III ranged from 1.6 to 28% and from an undetectable level to 35% of total phospholipids, respectively. Although there was heterogeneity among the amounts of GGPL-I or GGPL-III of M. fermentans strains, all of the M. fermentans strains had GGPL-I and/or GGPL-III. These observations showed that GGPL structures are species-specific immunodeterminants of M. fermentans. The fact that the GGPLs are main phospholipid components of the M. fermentans species means the M. fermentans has a unique choline metabolic pathway. This observation may raise phylogenetic interest.

Animals↗

The physico-chemical characteristics of the phosphocholine-containing glycoglycerolipid MfGL-II govern the permeability properties of Mycoplasma fermentans.

Mycoplasma fermentans seems to be involved in several pathogenic conditions in humans, and is among other things capable of fusing with T-cells and lymphocytes. The choline-containing phosphoglycolipid 6'-O-(3"-phosphocholine-2"-amino-1"-phospho-1",3"-propanediol)-alpha-D-glucopyranosyl-(1'-->3)-1,2-diacylglycerol (MfGL-II) in the membrane of M. fermentans has been suggested to enhance the fusion process, and the characteristics of MfGL-II were therefore investigated. When a cell culture ages the fraction of MfGL-II increases, and the fraction of the other major membrane lipid, phosphatidylglycerol (PtdGro), decreases concomitantly. Swelling experiments showed that the permeability and osmotic fragility are markedly reduced in aged cells. MfGL-II is selectively released into the surrounding medium when aged M. fermentans cells are incubated in buffer containing EDTA. The physico-chemical properties of MfGL-II were studied by NMR spectroscopy and differential scanning calorimetry, and they can explain the biochemical results. The temperature for the transition between gel and lamellar liquid crystalline (Lalpha) phases is 35-45 degrees C higher for MfGL-II than for PtdGro, which most probably gives rise to the reduced permeability in aged cells. At high water contents MfGL-II forms an Lalpha phase and isotropic aggregates which were interpreted to be vesicles with a radius of approximately 450 A. It is proposed that MfGL-II forms vesicles in the surrounding medium when it is released from the cell membrane. Neither EDTA nor Ca2+ ions have a significant influence on the aggregate structures formed by MfGL-II. Our results indicate that MfGL-II has no fusogenic properties. It is more probable that a recently identified lysolipid in the M. fermentans membrane acts as a fusogen.

Calorimetry, Differential Scanning↗

Structure of a novel phosphocholine-containing aminoglycoglycerolipid of Mycoplasma fermentans.

Mycoplasma fermentans is thought to be a pathogen of rheumatoid arthritis or a cofactor of AIDS (acquired immunodeficiency syndrome). To elucidate the possible involvement of membrane constituents in the pathogenesis of these diseases, we studied its lipid components. Several alkali labile glycophospholipids were detected and named glycoglycerophospholipids (GGPLs). Previously, we purified and determined the structure of one of them as 6'-O-phosphocholine-alpha-glucopyranosyl-(1'-3)-1,2-diacyl-sn-glycerol (GGPL-I). The present paper describes the purification and structural characterization of GGPL-III, the major GGPL of M. fermentans using 1H-, 13C- and 31P-nuclear magnetic resonance spectroscopy, and mass-spectroscopy as 1"-phosphocholine,2"-amino dihydroxypropane-3"-phospho-6'-alpha-glucopyranosyl-(1'-3)-1,2-dia cyl-glycerol.

Glycolipids↗

High-frequency DNA rearrangements in the chromosomes of clinically isolated Mycoplasma fermentans.

Mycoplasma fermentans is currently being examined as an agent potentially associated with human disease. Several strains of M. fermentans were isolated from patients with respiratory tract disease and AIDS. Two of these clinical strains, M64 and SK6, were triple-filter-cloned and designated as the parental clones in this study. Genomic DNA of randomly picked subclones in four and five subsequent generations passed from the parental M64 and SK6 clones were analyzed by using a radiolabeled M. fermentans-specific insertion sequence (IS)-like element as the probe. The hybridization patterns of DNA restriction fragments revealed high frequencies of chromosomal changes accompanied with excision or new insertion of the IS-like element in M. fermentans chromosome. The findings indicate M. fermentans has an effective mechanism(s) to produce a rapid gene rearrangement that may be mediated by one or more copies of the IS-like element.

Blotting, Southern↗

Variability in the distribution and composition of insertion sequence-like elements in strains of Mycoplasma fermentans.

Mycoplasma fermentans has been reported to be pathogenic for man. All fourteen strains tested contain an insertion sequence-like element (ISLE) which may be present in multiple copies. To determine whether ISLE copies are similarly distributed in different strains of M. fermentans, restriction enzyme digest fragments of genomic DNA from 14 isolates, from a variety of sources, were separated by electrophoresis, blotted and hybridized to a biotin labelled polymerase chain reaction (PCR) amplified fragment of ISLE. A range of patterns was observed suggesting that the element has a tendency to undergo rearrangement within the genome. Analysis of ISLE sequences revealed inter- and intra-strain polymorphisms.

Base Sequence↗

Structure of a novel phosphocholine-containing glycoglycerolipid from Mycoplasma fermentans.

Mycoplasma fermentans is thought to be a pathogen of rheumatoid arthritis or cofactor of AIDS. A novel phosphocholine-containing glycoglycerophospholipid named GGPL-I was isolated from a M. fermentans-infected human helper T-cell culture. It was revealed that GGPL-I is a lipid component of the M. fermentans and a major immunological determinant. The GGPL-I was purified by DEAE-Sephadex column chromatography and repeated Iatrobeads column chromatography. The purified glycophospholipid was subjected to structural characterization by thin-layer chromatography, Fourier-transform infrared spectrometry, liquid secondary ion mass spectrometry, and nuclear magnetic resonance spectroscopy. Its structure was determined to be as follows: 6'-O-phosphocholine-alpha-glucopyranosyl-(1'-3)-1,2-diacyl-sn-glycerol. This glycoglycerophospholipid is unique in containing phosphocholine, which is attached to C-6 of glucose. The stereospecific numbering (sn) of naturally occurring GGPL-I was determined through comparison with chemically synthesized compounds.

Carbohydrate Conformation↗

Differential protein expression and surface presentation generate high-frequency antigenic variation in Mycoplasma fermentans.

Mycoplasma fermentans, a wall-less prokaryote, is currently under investigation as a potential human pathogen. Recently, several surface lipoproteins have been shown to vary in expression between M. fermentans strains. Using specific antibodies to these lipoproteins, we investigated the extent and nature of antigenic variation within this species. Immunoscreening of type strain PG18 agar-grown colonies revealed marked heterogeneity in expression of distinct surface lipoproteins. Subsequent isolation and propagation of clonal isolates established isogenic lineages which displayed high-frequency (10(-2) to 10(-5) per generation) antigenic phase variation. [35S]cysteine-labeled protein profiles and Western immunoblots of phase-variant clones showed that several distinct integral membrane proteins undergo noncoordinate variation in expression. In addition to differential expression of epitope-bearing lipoproteins, differential accessibility of epitopes to antibodies was also documented as a mechanism generating surface phenotypic variation. Examination of one strain-variant antigen showed high-frequency phase variation to underlie previously observed antigenic differences between strains of this species. Thus, M. fermentans has a complex system capable of creating rapid changes in surface mosaics. This may profoundly affect mycoplasma-host interactions and may limit the methods by which populations of M. fermentans may be studied in vivo.

Antibodies, Monoclonal↗

The reducing antioxidant capacity of Mycoplasma fermentans.

Mycoplasma fermentans is an extracellular microorganism capable of adhering to the surface of host cells. It has been recently shown that plasminogen binding to M. fermentans in the presence of the urokinase-type plasminogen activator promotes the invasion of host cells by this organism. In this report, we show that viable mycoplasmas persist within the infected HeLa cells for prolonged periods of time despite the expectation that within host cells the organism may be exposed to oxidative stress. Using cyclic voltammetry and luminol-enhanced chemiluminescence assays, we detected a potent reducing antioxidant activity in M. fermentans. The reducing antioxidant activity was heat stable, not affected by proteolysis and was almost totally lost upon dialysis suggesting that the activity is due to a nonproteinaceus low molecular weight antioxidant. This antioxidant was partially purified by Bio-Gel column chromatography followed by high-pressure liquid chromatographic analysis. We suggest that the high reducing antioxidant capacity in M. fermentans is a principal defense mechanism playing a major role in the battle of the organism against oxidative stress within the host cells.

Antioxidants↗

Experimental infection of the upper genital tract of female grivet monkeys with Mycoplasma fermentans.

Mycoplasma fermentans inoculated directly into the uterine tubes of female grivet monkeys produced a self-limiting acute salpingitis and parametritis. The inflammation was accompanied by a significant rise in titre of specific indirect haemagglutinating antibodies. Inoculation of M. fermentans into the uterine cavity through the cervical canal without dilatation of the cervix produced practically no signs of inflammation and no antibody response. However, when the intrauterine inoculation of mycoplasmas was followed by currettage of the endometrium, in animals whose uterine tubes had been closed by ligatures, pronounced upper genital-tract inflammation developed, together with a significant antibody response.

Animals↗

Extracellular ATP regulates cell death of lymphocytes and monocytes induced by membrane-bound lipoproteins of Mycoplasma fermentans and Mycoplasma salivarium.

The cytotoxicities of lipoproteins of Mycoplasma fermentans and Mycoplasma salivarium to a lymphocytic cell line, MOLT-4, and a monocytic cell line, HL-60, was upregulated by ATP added extracellularly in a dose-dependent manner. These lipoproteins induced ATP release and plasma membrane permeability increase in these cell lines. In addition, periodate-oxidized ATP, an antagonist for P2X purinergic receptors, suppressed the cytotoxicity of the lipoproteins, suggesting the possibility that P2X receptors for ATP play crucial roles in the cytotoxicity. Activation of caspase-3 induced by the lipoproteins, which was assessed by the cleavage of the synthetic substrate DEVD-pNA and the endogenous substrate poly(ADP-ribose) polymerase, was also upregulated and downregulated by extracellular ATP and periodate-oxidized ATP, respectively. On the basis of these results, this study suggests that mycoplasmal lipoproteins induce the permeability increase in lymphocytes and monocytes, by which ATP is released, and the ATP regulates the cytotoxicities of the lipoproteins to the cells, possibly by interaction with ATP receptors such as P2X purinergic receptors.

Adenosine Triphosphate↗

Susceptibilities of Mycoplasma fermentans and Mycoplasma hyorhinis to membrane-active peptides and enrofloxacin in human tissue cell cultures.

Mycoplasmas, which are bacteria that are devoid of a cell wall and which belong to the class Mollicutes, are pathogenic for humans and animals and are frequent contaminants of tissue cell cultures. Although contamination of cultures with mycoplasma can easily be monitored with fluorescent dyes that stain DNA and/or with molecular probes, protection and decontamination of cultures remain serious challenges. In the present work, we investigated the susceptibilities of Mycoplasma fermentans and Mycoplasma hyorhinis to the membrane-active peptides alamethicin, dermaseptin B2, gramicidin S, and surfactin by growth inhibition and lethality assays. In the absence of serum, the four peptides killed mycoplasmas at minimal bactericidal concentrations that ranged from 12.5 to 100 microM, but in all cases the activities were decreased by the presence of serum. As a result, under standard culture conditions (10% serum) only alamethicin and gramicidin S were able to inhibit mycoplasma growth (MICs, 50 microM), while dermaseptin B2 and surfactin were ineffective. Furthermore, 8 days of treatment of HeLa cell cultures experimentally contaminated with either mycoplasma species with 70 microM enrofloxacin cured the cultures of infection, whereas treatment with alamethicin and gramicidin S alone was not reliable because the concentrations and treatment times required were toxic to the cells. However, combination of alamethicin or gramicidin S with 70 microM enrofloxacin allowed mycoplasma eradication after 30 min or 24 h of treatment, depending on the mycoplasma and peptide considered. HeLa cell cultures experimentally infected with mycoplasmas should prove to be a useful model for study of the antimycoplasma activities of antibiotics and membrane-active peptides under conditions close to those found in vivo.

Anti-Bacterial Agents↗

Use of the polymerase chain reaction for detection of Mycoplasma fermentans and Mycoplasma genitalium in the urogenital tract and amniotic fluid.

In an attempt to further define the natural history of Mycoplasma genitalium and Mycoplasma fermentans infections in humans, we used cultures and the polymerase chain reaction (PCR) to determine whether these organisms were present in the urethra and cervix of sexually active adults and in the amniotic fluid of women whose membranes were intact and collected at the time of cesarean delivery (to preclude cervical contamination). M. genitalium was detected by PCR but not by culture in 11% of patients with urethritis or cervicitis. It was not detected by either PCR or culture in the 232 amniotic fluid samples analyzed. In contrast, M. fermentans was not detected by either method in patients with urethritis or cervicitis but was detected by PCR in 4 of 232 amniotic fluid samples tested. These results indicate that in these four cases M. fermentans was transferred transplacentally. Histological evidence of chorioamnionitis was present in two of the four patients, a finding suggesting that M. fermentans may be a cause of chorioamnionitis. These results must be confirmed by other investigators, and further studies should be undertaken to determine the potential clinical significance of M. fermentans infection.

Adolescent↗

[Comparative characteristics of joint changes in rats infected with Mycoplasma fermentans and Mycoplasma arthritidis].

Experiments on Wistar rats have shown that a single injection of M. fermentans or M. arthritidis causes various forms of polyarthritis differing in their course and morphological characteristics. M. arthritidis causes acute purulent arthritis. M. fermentans causes polyarthritis characterized mainly by a subacute course and early involvement of the articular cartilage. Plasma cells producing a factor similar to the rheumatoid factor of humans have been detected in the synovial membrane.

Animals↗