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PubMed1984

Flask-shaped mycoplasmas: properties and pathogenicity for man and animals.

In spite of the variations in cell form and cell size, some mycoplasmas show several consistent and peculiar structural features: a flask- or club-shaped cell form and a more or less defined terminal structure. Organisms with these features can be observed within the species Mycoplasma pneumoniae, M. genitalium, M. pulmonis, M. gallisepticum, M. alvi, M. sualvi and Mycoplasma sp. strain 163 K. Ultrastructural peculiarities of some flask-shaped mycoplasmas are a surface nap and a cytoskeleton. With the exception of M. alvi and M. sualvi, for which detailed investigations are lacking, the flask-shaped mycoplasmas differ from the other mycoplasmas by their gliding motility and adherence properties. All of the flask-shaped mycoplasmas ferment glucose, but there are differences in the other biochemical properties investigated and in the guanine + cytosine ratio. The question remains whether the flask shape, the adherence and the motility are associated with pathogenicity, since three mycoplasmas with these properties are established pathogens. No data are available at present on the pathogenicity of the remaining four species, but several criteria suggest that at least two of them may have an etiological role in disease.

Adhesiveness↗

PubMed1981

Mycoplasma-lymphocyte interactions: Ir gene control of mitogenesis and a paradoxical interaction with thy-1 bearing cells.

A novel interaction occurs between mycoplasmas and lymphocytes whereby the mycoplasmas behave as multivalent ligands and, following attachment to the lymphocyte plasma membrane, redistribute to one pole of the cell. This mycoplasma-capping event is accompanied by co-capping of certain specific lymphocyte surface antigens. Mycoplasma capping occurs on both lymphoblastoid cells and resting lymphocytes. There is a high degree of correlation between mycoplasma capping on resting (splenic) lymphocytes and blast transformation of these cells. This appears to be a general phenomenon, and many different mycoplasma species are mitogenic for lymphocytes from a number of animal species, including human. In the mouse, mycoplasma-induced triggering does not appear to be influenced by H-2 differences and the primary lymphocyte triggered is the B cell. In other animal species T cells or B and T cells are stimulated. The importance of these interactions with reference to mycoplasma pathogenesis will be discussed.

Animals↗

PubMed1980

[Mycoplasmas isolated from the genital tract of mares (author's transl)].

Mycoplasmas were isolated from 11 (=#6,8%) of 161 cervix swabs from infertile mares. A total of 17 strains was isolated and characterized by indirect immunofluorescent test and metabolic inhibition test as Mycoplasma equigenitalium (11 strains), Mycoplasma subdolum (2 strains), Acholeplasma laidlawii (3 strains) and Acholeplasma equifetale (1 strain). In addition cervix swabs of the mares were investigated for bacteria. There was no specific correlation between presence of mycoplasmas and bacteria (table 1). In clinical investigations 5 of the 11 mares which harboured mycoplasmas showed a pneumovagina (table 1). The isolated mycoplasmas were tested for senstivity to antibiotics (table 2). All of the isolates were sensitive to Chloramphenicol (10 microgram), Tetracyclin (10 microgram), Tylosin (30 microgram) and Gentamycin (10 microgram) and resistant to Penicillin (6 IU) and Polmyxin B (300 IU). Against Erythromycin (15 microgram) all of the Acholeplasma-isolates were sensitive and all of the Mycoplasma-isolates resistant. Against Streptomycin (10 microgram) the two M. subdolum strains showed resistance, whereas M. equigenitalium and the Acholeplasma-isolates were sensitive. It is not yet possible to elucidate the significance of acholeplasmas and mycoplasmas in the genital organs of mares.

Acholeplasma↗

PubMed1981

Mycoplasmal adherence with particular reference to the pathogenicity of Mycoplasma pulmonis.

Various eucaryotic cells adhere to colonies of some mycoplasmas (adsorption). The chemical nature of the receptors on the cells is not the same for all mycoplasma species, nor are the binding sites on different mycoplasmas the same. Some receptors comprise sialic acid, but in the case of Mycoplasma pulmonis, for example, attachment to cells is not mediated in this way. Nevertheless, adherence seems to be an important factor in the pathogenicity of this mycoplasma. Strain JB caused pneumonia in mice when inoculated intranasally, and colonies of this strain on agar absorbed erythrocytes (hemadsorption) strongly. After multiple passes in mycoplasma liquid medium, the strain lost its hemadsorbing capacity and also its mouse virulence, suggesting that the ability to attach to cells is virulence factor. Examination by electron microscopy of the virulent mycoplasma and its induced avirulent form after ruthenium-red staining showed that the stain was less thick on the surface of the avirulent form. In addition, the protein pattern of the avirulent mycoplasma, demonstrated by polyacrylamide gel electrophoresis, was deficient in three bands. These observations suggest that a glycosylated protein may form the binding site on M. pulmonis organisms that mediates their attachment to cells.

Adhesiveness↗

PubMed1997

Mycoplasmas and arthritides.

Rheumatoid arthritis and other autoimmune diseases might be triggered by infectious agents. We have reviewed the evidence suggesting that mycoplasmas may play a role in the genesis of arthritis. Mycoplasmas are a common cause of spontaneous arthritis in many animal species. Numerous experimental models of mycoplasma-induced arthritis have been developed, some with mycoplasmas known to cause disease in humans. Mycoplasmas entertain complex relationships with the immune system of their hosts and frequently induce autoimmune events such as rheumatoid factor production. However, the potential role of mycoplasmas in human joint disease remains unknown. Mycoplasmas can be responsible for septic arthritis in patients with immune deficiencies, especially hypogammaglobulinemia. Whether mycoplasmas can incite or perpetuate inflammatory joint diseases such as rheumatoid arthritis remains controversial. Advances in molecular biology techniques for detecting infectious agents can be expected to settle this issue in the near future.

Animals↗

PubMedDate not supplied

Erythema multiforme due to Mycoplasma pneumoniae infection in two children.

Mycoplasma pneumoniae is an important and highly relevant cause of bullous erythema multiforme, isolated mucositis, and Stevens-Johnson syndrome in children. In this article, we present two children with respiratory Mycoplasma pneumoniae infection and associated cutaneous findings within the spectrum of erythema multiforme. We review the literature associating these three entities with Mycoplasma pneumoniae infection and discuss controversies regarding the classification of erythema multiforme, as well as update reported infectious causes of the bullous form. Many understand the erythema multiforme spectrum to include bullous erythema multiforme, mucositis, and Stevens-Johnson syndrome in the order of increasing severity. We feel that this relationship should be reconsidered to help better understand the prognosis and outcomes. It is our opinion that bullous erythema multiforme is a separate, yet related condition that can occur in the context of Mycoplasma pneumoniae infection. With many similarities to mucositis and Stevens-Johnson syndrome, bullous erythema multiforme can be considered part of a spectrum of disease that includes Stevens-Johnson syndrome. Unlike mucositis and Stevens-Johnson syndrome, bullous erythema multiforme caused by Mycoplasma pneumoniae infection has low morbidity for the child. Mycoplasma pneumoniae-associated mucositis and Stevens-Johnson syndrome seem to occur along a spectrum with separate prognosis and potential pathogenesis compared with bullous erythema multiforme. Making the distinction between these conditions is valuable for predicting the child's prognosis. Patients who develop symptoms consistent with these conditions should be appropriately evaluated for Mycoplasma pneumoniae infection and closely monitored.

Adolescent↗

PubMed1994

Antibiotic susceptibilities of AIDS-associated mycoplasmas.

Because mycoplasmas may be a cofactor in the progression of human immunodeficiency virus infection to AIDS, their susceptibilities to antibiotics need to be known in the event that appropriate therapy is required. The mycoplasmas studied were a stock culture strain of Mycoplasma fermentans, two strains of M. fermentans isolated from patients with AIDS, M. fermentans var. incognitus, Mycoplasma penetrans, and Mycoplasma pirum. The antibiotics tested were doxycycline, tetracycline, clindamycin, ofloxacin, erythromycin, azithromycin, and clarithromycin at levels consistent with the attainable levels in serum. By the macrodilution metabolic inhibition method, all six mycoplasma strains were susceptible to doxycycline, tetracycline, clindamycin, ofloxacin, azithromycin, and clarithromycin. M. penetrans was susceptible to erythromycin. The M. fermentans strains and M. pirum were resistant to erythromycin. The macrodilution metabolic inhibition method results showed agreement with the Sensititre Gram Positive MIC Panel results for tetracycline, clindamycin, and erythromycin. MICs of clarithromycin for all six mycoplasma isolates tested were low, indicating susceptibility.

AIDS-Related Opportunistic Infections↗

PubMed2000

Mycoplasmas isolated from the respiratory tract of cattle and goats in Tanzania.

A microbiological study of the mycoplasma flora in the respiratory tracts of cattle and goats in selected regions of Tanzania is described. In the examination of cattle, mycoplasmas were isolated from 60 (17.8%) of the 338 examined lung samples, 8 (47.1%) of the 17 lymph nodes, 4 (13.3%) of the 30 pleural fluid samples and 4 (3.9%) of the 103 nasal swabs examined. All the isolates were identified as Mycoplasma mycoides subsp. mycoides, Small Colony type except for one isolate from pleural fluid which was identified as Mycoplasma arginini. M. mycoides subsp. mycoides, Small Colony type was isolated from samples originating from Dodoma, Iringa, Mbeya, Morogoro and Shinyanga regions where outbreaks of contagious bovine pleuropneumonia had been reported. In the examination of goats, mycoplasmas were isolated from 54 (34.0%) of the 159 examined lung samples, 41 (18.1%) of the 226 nasal swabs and 4 (40.0%) of the 10 pleural fluid samples. The species demonstrated were Mycoplasma capricolum subsp. capripneumoniae, M. mycoides subsp. mycoides, Small Colony type Mycoplasma ovipneumoniae and M. Capricolum subsp. arginini. The isolation of M. capripneumoniae in the Coast and Morogoro regions confirmed the presence of contagious caprine pleuropneumonia in the regions.

Animals↗

PubMedDate not supplied

[Detection of mycoplasma antigens and immune complexes in sera of the children with bronchial asthma].

The study was targeted at revealing Mycoplasma pneumoniae (M.p.) and Mycoplasma hominis (M.h.) antigens in blood samples of children with bronchial asthma (BA),both in a free state and those included in circulating immune complexes (CIC). The mycoplasma antigens of one or both species have been detected in one third out of 62 patients with BA. In this group of patients the frequency of detection of specific antibodies twice exceeded that of mycoplasma antigens. Testing paired blood samples of children with BA (n=26) showed, that at receipt in a hospital and a month after primary examination the mycoplasma antigens were detected in 16 and 12 patients, respectively, the association of M.p. and M.h. antigens being more frequent. Data on distribution of antibodies according to immunoglobulin classes testify that basically two (M, G), or four (M, G, A, E) classes were registered in children, the M class antibodies in high percentage of cases (from 36.6 up to 50.0%)being detected in every term of examination. These data indirectly testify that the antigens can be partly included in the CIC structure. The level of the total CIC content in BA children's blood sera one month after hospitalization twice exceeded the value detected at primary examination. Three months later later this parameter decreased not reaching the control value. The differential analysis of the precipitated CIC within the whole period of examination showed that mycoplasma antigens were present in the CIC structure in 87.4 - 65.0% of cases. The data obtained precondition future studies on the role of mycoplasma and M.p. and M.h. antigens included in the CIC in the pathogenesis of BA.

Adolescent↗

PubMed1997

Comparative genomics of mycoplasmas.

The mycoplasmas are the smallest and simplest self-replicating organisms. The goal of defining in molecular terms the entire machinery of a living cell by using mycoplasmas as models was put forward by Harold Morowitz in 1984. The recent complete sequencing of the genomes of the human pathogens Mycoplasma genitalium and Mycoplasma pneumoniae brings us much closer to achieving this goal. The M. genitalium genome contains only 479 predicted protein coding sequences (genes) and that of M. pneumoniae 677, as compared with 1703 in Haemophilus influenzae and about 4000 in E. coli. Thus, M. genitalium is apparently the simplest organism capable of independent life with a minimal set of genes. The drastic economization in genetic information must have been associated with the parasitic mode of life of the mycoplasmas. During their reductive evolution from Gram-positive bacteria the mycoplasmas have lost the cell wall and many biosynthetic systems involved in synthesis of macromolecule building blocks provided by their host. Thus, the M. genitalium and M. pneumoniae genomes do not carry any gene involved in amino acid biosynthesis, and very few genes for vitamin, nucleic acid precursor and fatty acid biosynthesis. The mycoplasma genomes carry a minimal set of energy metabolism genes, being content with a restricted supply of ATP needed for their parasitic mode of life. Nevertheless, these minimal organisms carry the essential genes for DNA replication, transcription and translation, but even here gene saving is expressed by a minimal number of rRNA and tRNA genes. A genomic price had been paid to maintain parasitism, so that a significant number of mycoplasmal genes is devoted to adhesins, attachment organelles and variable membrane surface antigens directed towards evasion of the host immune system.

Animals↗

PubMed1981

Mycoplasma-virus contacts, budding and scars remaining in the membranes of Acholeplasma laidlawii and its virus.

Various stages of virus and mycoplasma budding indicated that both virus and, most probably some mycoplasma progeny developed by budding. Besides this alternative, binary fission was the mode of mycoplasma reproduction. Mycoplasma-virus and mycoplasma-mycoplasma connections by stems were observed. Circular scars, 40-80 nm in diameter, often in groups, were left in the membrane of mycoplasmas by the budding bodies. cytoplasmic structures seen in cross-fraction are presented. a relatively small number of globular virus-like bodies, not identical with MV-Lg-L 172, were observed budding from mycoplasma cells in the non-infected host culture.

Acholeplasma laidlawii↗

PubMed1999

Beta-chemokines are produced in lungs of mice with mycoplasma respiratory disease.

The recruitment of mononuclear cells in lungs is a key event in the pathogenesis of mycoplasma respiratory disease, but the cascade of events responsible is unknown. Studies were conducted to determine whether beta-chemokines, which are chemotactic for lymphocytes and macrophages, are produced in murine mycoplasma respiratory disease. Our results show that mRNA expression of the macrophage chemoattractant factor (MCP-1) and macrophage inflammatory peptides (MIP-1alpha and MIP-1beta), but not RANTES, increases in Mycoplasma pulmonis-infected mice. Also, MCP-1 concentrations were much higher in lung extracts from mycoplasma-infected mice than in uninfected mice. As beta-chemokines are chemotactic for lymphocytes and macrophages, these results suggest that MCP-1, MIP-1alpha, and/or MIP-1beta, but not RANTES, contribute to mononuclear cell infiltration associated with murine mycoplasma respiratory disease. Thus, the activation of cells to produce beta-chemokines is associated with mycoplasma infection, and the beta-chemokines, along with other factors and cytokines, are most likely involved in the cascade of events leading to mycoplasma inflammatory disease.

Animals↗

PubMed2003

Detection of several Mycoplasma species at various anatomical sites of homosexual men.

In order to determine the colonisation patterns of several Mycoplasma species in homosexual men, urethral, oral and rectal specimens from 10 homosexual men with acute non-gonococcal urethritis (NGU) and 18 without NGU were examined using sensitive methods. Mycoplasma hominis and Ureaplasma urealyticum existed in both groups, which is in keeping with previous studies of heterosexual men. Mycoplasma genitalium was detected in the rectum of both NGU-positive and NGU-negative men and in the urethra of one man with chlamydia-negative NGU, but not in those without urethritis. Mycoplasma fermentans was found in the throat and rectum only and Mycoplasma penetrans in all three anatomical sites. In contrast, Mycoplasma pirum was found in the rectum only, that is, in 5 of the 28 men studied. Infrequent examination of this site is a possible explanation for previous failures to detect Mycoplasma pirum at a mucosal surface.

Adult↗

PubMed1984

Effect of mycoplasma infection on pyruvate dehydrogenase complex activity of normal and pyruvate dehydrogenase complex-deficient fibroblasts.

The fermentative mycoplasmas A. laidlawii JS, M. hyorhinis DBS-50, M. hyorhinis GDL and M. pneumoniae FH have very high apparent activities of pyruvate dehydrogenase (PDH) (EC 1.2.4.1) and pyruvate dehydrogenase complex (PDHC). Infection of normal and PDHC-deficient fibroblasts with these mycoplasma species resulted in a marked increase of the specific activity of these two enzymes, and under certain conditions could conceal the enzymatic defect. The non-fermentative mycoplasmas M. salivarium VV and M. arthritidis PG-6 have very low apparent activities of these two enzymes. Normal fibroblasts infected with non-fermentative mycoplasmas could appear as deficient in these two enzymes. The degree of interference depends on the number of mycoplasmas associated with the harvested cells. Besides the mycoplasma species, this depends (1) on the duration of infection which determines mycoplasmal titers and also can have a killing effect on both host cells and/or mycoplasmas; (2) harvest of the cells by scraping or trypsinization; (3) centrifugal force used in the collection of the cells; (4) washing and the inherent mechanical treatment; and (5) other possibilities.

Acholeplasma laidlawii↗

PubMed2004

Canine mycoplasmas.

This review aims to summarise our current understanding of the role of mycoplasmas in domestic dogs. Canine mycoplasmology is a small field, with less than 50 publications in the past 40 years. In this time we have gained knowledge about the number of species and have made associations with infections in dogs. However much evidence is still lacking. The importance of all canine mycoplasmas remains unknown, yet certain species are associated with canine anaemia (Mycoplasma haemocanis), respiratory disease (Mycoplasma cynos) and urogenital tract infections (Mycoplasma canis). Mycoplasmas can be isolated in pure culture from canine clinical specimens and it is hoped that this review will stimulate veterinarians to consider mycoplasmas as a potential cause of disease in dogs, especially when antibiotic therapy is failing.

Anemia↗

PubMed2000

Isolation of Mycoplasma meleagridis from free-ranging birds of prey in Germany.

In this study tracheal swabs and air sac biopsies of 68 raptors of different species that were found injured or debilitated in Germany were investigated for the occurrence of mycoplasmas. Mycoplasma meleagridis, Mycoplasma falconis, Mycoplasma buteonis, Mycoplasma gypis and five mycoplasma isolates not identified so far could be isolated from 32 (47%) birds. Mycoplasma meleagridis could be detected in five birds. These birds did not show clinical signs or histopathological alterations in air sac biopsies related to the infection.

Air Sacs↗

PubMed2006

Neutrophil histamine contributes to inflammation in mycoplasma pneumonia.

Mycoplasmas cause chronic inflammation and are implicated in asthma. Mast cells defend against mycoplasma infection and worsen allergic inflammation, which is mediated partly by histamine. To address the hypothesis that mycoplasma provokes histamine release, we exposed mice to Mycoplasma pulmonis, comparing responses in wild-type and mast cell-deficient KitW-sh/KitW-sh (W-sh) mice. Low histamine levels in uninfected W-sh mice confirmed the conventional wisdom that mast cells are principal sources of airway and serum histamine. Although mycoplasma did not release histamine acutely in wild-type airways, levels rose up to 50-fold above baseline 1 week after infection in mice heavily burdened with neutrophils. Surprisingly, histamine levels also rose profoundly in infected W-sh lungs, increasing in parallel with neutrophils and declining with neutrophil depletion. Furthermore, neutrophils from infected airway were highly enriched in histamine compared with naive neutrophils. In vitro, mycoplasma directly stimulated histamine production by naive neutrophils and strongly upregulated mRNA encoding histidine decarboxylase, the rate-limiting enzyme in histamine synthesis. In vivo, treatment with antihistamines pyrilamine or cimetidine decreased lung weight and severity of pneumonia and tracheobronchitis in infected W-sh mice. These findings suggest that neutrophils, provoked by mycoplasma, greatly expand their capacity to synthesize histamine, thereby contributing to lung and airway inflammation.

Animals↗

PubMed1998

Isolation of Mycoplasma species from a patient with seal finger.

The etiologic agent of seal finger (speck finger) is unknown. Seal finger occurs after a seal bite, and the symptoms include acute pain, swelling, discharge, and, in some cases, there is joint involvement. The discovery of Mycoplasma species in epidemics of seal disease prompted attempts to link seal finger to mycoplasma. Mycoplasma species were isolated in cultures of a specimen from the finger of an aquarium trainer who was bitten by a seal and of a specimen from the front teeth of the biting seal. The two Mycoplasma isolates were identical biochemically; they were serum-dependent and hydrolyzed arginine. The isolates were susceptible to tetracycline but resistant to erythromycin. By growth inhibition and immunofluorescent antibody tests, both strains were identified as Mycoplasma phocacerebrale, a mycoplasma isolated in an epidemic of seal disease occurring in the Baltic Sea. The patient's infection was treated successfully with tetracycline. To our knowledge, this is the first case in which a mycoplasma has been associated with seal finger.

Animals↗