Mycoplasma infections of man

Early Serologic Diagnosis of Mycoplasma pneumoniae Pneumonia: An Observational Study on Changes in Titers of Specific-IgM Antibodies and Cold Agglutinins

There have been some limitations on early diagnosis of Mycoplasma pneumoniae (MP) infection because of no immunoglobulin M (IgM) responses and variable detection rates of polymerase chain reaction in the early stage of the disease. We wanted to discuss regarding early diagnostic method using short-term paired titration of MP-specific IgM and cold agglutinins (CAs) in the early stage of MP pneumonia.The participants of this study were 418 children with MP pneumonia during 2 recent epidemics (2006-2007 and 2011), and they were diagnosed by an anti-MP IgM antibody test (Serodia Myco II) examined twice during hospitalization at presentation and around discharge (mean of 3.4 ± 1.3 days apart). CA titers were simultaneously examined twice during study period. Anti-MP IgM antibody titer ≥1:40 and CA titer ≥1:4 were considered positive, respectively. The relationships between 2 IgM antibodies in the early stage were evaluated.Regarding MP-specific antibody titers, 148 patients showed a seroconversion, 245 patients exhibited increased titers, and 25 patients had unchanged higher titers (≥1:640) during hospitalization. The median MP-specific antibody titers at each examination time were 1:80 and 1:640, respectively; those of CAs were 1:8 and 1:32, respectively. Illness duration prior to admission showed a trend of association with both titers, and patients with shorter illness duration had a higher rate of negative titers or lower titers at each examination time. CAs and MP-specific antibody titers were correlated in the total patients at presentation and at 2nd examination (P < 0.001, respectively), and the diagnostic corresponding rates of CAs to IgM antibody test were 81% to 96% in patient subgroups.Short-term paired MP specific-IgM determinations in the acute stage may be used as a definitive diagnostic method for MP pneumonia. Paired CA titers showed a correlation with MP-specific antibody titers, suggesting they can be used as an adjuvant diagnostic method.

Empiric treatment of ambulatory community-acquired pneumonia: always include treatment for atypical agents

There are no data from proper studies to answer whether it is necessary to include antibiotics that are active against atypical pneumonia agents as part of the empiric therapy of CAP. Until such data are available, clinical judgment and severity of the pneumonic illness are the best guides to empiric antimicrobial therapy.

Towards a two-dimensional proteome map of Mycoplasma pneumoniae

A Proteome map of the bacterium Mycoplasma pneumoniae was constructed using two-dimensional (2-D) gel electrophoresis in combination with mass spectrometry (MS). M. pneumoniae is a human pathogen with a known genome sequence of 816 kbp coding for only 688 open reading frames, and is therefore an ideal model system to explore the scope and limits of the current technology. The soluble protein content of this bacterium grown under standard laboratory conditions was separated by 1-D or 2-D gel electrophoresis applying various pH gradients, different acrylamide concentrations and buffer systems. Proteins were identified using liquid chromatography-electrospray ionization ion trap and matrix-assisted laser desorption/ionization-MS. Mass spectrometric protein identification was supported and controlled using N-terminal sequencing and immunological methods. So far, proteins from about 350 spots were characterized with MS by determining the molecular weights and partial sequences of their tryptic peptides. Comparing these experimental data with the DNA sequence-derived predictions it was possible to assign these 350 proteins to 224 genes. The importance of proteomics for genome analysis was shown by the identification of four proteins, not annotated in the original publication. Although the proteome map is still incomplete, it is already a useful reference for comparative analyses of M. pneumoniae cells grown under modified conditions.

Comparison of the Seradyn Color Vue passive agglutination test and complement fixation for detection of Mycoplasma pneumoniae antibodies

We compared traditional complement fixation (CF) with a new passive agglutination method, the Seradyn Color Vue (SCV) test (Seradyn, Indianapolis, Ind.), for detection of Mycoplasma pneumoniae antibodies in 170 stored serum samples. The SCV test was 90% sensitive in identifying as positive 27 of 30 CF high-titer (> or = 1:64) serum samples and 100% specific in identifying as negative 134 of 134 CF low-titer (< or = 1:32) or negative (< 1:8) serum samples. The SCV test was technically undemanding, and it required no expensive equipment.

Antimycoplasmal activity of ofloxacin (DL-8280)

Ofloxacin (DL-8280; (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1- pipera-zinyl)-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid) showed a broader spectrum and a greater potency of antimycoplasmal activity than did pipemidic acid, norfloxacin, tetracyclines, and lincomycin, but was inferior to erythromycin. Its mycoplasmacidal potency against clinical isolates of Mycoplasma pneumoniae was also greater than that of other quinolones and tetracyclines.

Exfoliation of respiratory epithelium in hamster tracheal organ cultures infected with Mycoplasma pneumoniae

Hamster tracheal organ cultures were infected with M. pneumoniae and examined sequentially by transmission and scanning electron microscopy to correlate surface with intracellular alterations. Infection was established by culture and the demonstration of morphologically compatible organisms on the mucosal surface. Ciliated epithelial cells developed vacuolization of the apical and subnuclear cytoplasm and eventually fragmented along planes formed by coalescing vacuoles. Non-ciliated cells showed apical swelling and loss of microvilli during the course of infection. After degeneration and sloughing of both ciliated and non-ciliated cells, a flattened layer of intact basal cells covered the submucosa. It is likely that progressive vacuolization of epithelial cells leads to exfoliation of both cells and cell fragments in M. pneumoniae infection. Since organisms frequently are associated with these exfoliated cells, their potential presence in sputum and lavage specimens could prove to be of diagnostic importance.

Central nervous system complications of Mycoplasma pneumoniae

Three cases of central nervous system complications of Mycoplasma pneumoniae infections are reported. There were several atypical findings: the first patient presented with an acute disseminated encephalitis with normal cerebrospinal fluid and hypogammaglobulinaemia. The second patient presented with a left sixth nerve palsy followed six weeks later by choreoathetoid movements and an acute psychosis. The third patient presented with an acute encephalitis associated with acute renal failure secondary to rhabdomyolysis and was the only patient who did not completely recover; he was discharged akinetic and mute, but with normal renal function. The diagnosis of complications of Mycoplasma pneumoniae may be difficult. In two of the three cases a raised red blood cell volume secondary to a high titre of cold agglutinins rapidly led to the correct diagnosis.

Immunoprophylaxis of experimental Mycoplasma pneumoniae disease: effect of route of administration on the immunogenicity and protective effect of inactivated M. pneumoniae vaccine

Formalin-inactivated Mycoplasma pneumoniae vaccine was administered subcutaneously or intranasally to hamsters to examine the effect of route of administration on immunogenicity and protective effect. Parenterally administered vaccine in the doses employed induced serum complement-fixing antibody formation, but did not significantly decrease the frequency of pneumonia following challenge with virulent M. pneumoniae. Intranasally instilled vaccine was ineffective in stimulating serum antibody, but did diminish the frequency of experimentally induced pneumonia due to M. pneumoniae. However, a greater degree of resistance was induced by intranasal infection with either wild-type organisms or the ts 640 attenuated mutant of M. pneumoniae.

Comparison of josamycin and erythromycin in the therapy of Mycoplasma pneumoniae pneumonia

A controlled, double-blind study was performed to compare the efficacy of two macrolide antibiotics, erythromycin and josamycin, in the therapy of Mycoplasma pneumoniae pneumonia. Marine Corps recruit volunteers received one of the two antibiotics in a dosage of 2 g daily for 7 days. Twelve of 21 men treated with josamycin and 9 of 25 men treated with erythromycin had confirmed M. pneumoniae pneumonia. The josamycin-treated group remained hospitalized for 5.4 +/- 1.2 days compared to 5.1 +/- 2.0 days for the erythromycin-treated group (0.60 > P > 0.50). Fever days were similar for the josamycin-treated (1.4 +/- 0.4) and erythromycin-treated (1.2 +/- 0.3) groups (P = 0.95). There was no difference in resolution of signs and symptoms of illness in the two study populations. Thus, josamycin is as efficacious as erythromycin in the therapy of M. pneumoniae pneumonia.

Hospital treatment and diagnosis of Mycoplasma pneumoniae pneumonia

A study was started in 1972 in order to determine the true etiology of patients who presented with obscure pulmonary infiltrates. Patients who were included in this study had sera drawn on two occasions. Complete testing was performed for the various viruses and also for Mycoplasma pneumoniae antibodies. The study continued through 1975 and a total of 159 patients were included. Of these 159 patients, 28 had positive complement fixation tests for M. pneumoniae antibodies. The clinical profile and treatment course is outlined and discussed.

Myocarditis and severe bilateral bronchopneumonia caused by Mycoplasma pneumoniae

A man with severe bilateral bronchopneumonia and a right lobar consolidation caused by Mycoplasma pneumoniae, had a concurrent myocarditis. The possible aetiology of the patchy pulmonary opacities is discussed. A literature review of cases of myocarditis associated with M.pneumoniae is presented.

Asymptomatic infection of adult volunteers with a temperature sensitive mutant of Mycoplasma pneumoniae

Temperature sensitive mutants of Mycoplasma pneumoniae were developed with the expectation that their temperature sensitive defects would restrict replication in vivo at the temperature of the lower respiratory tract, whereas such defects would not seriously impair replication in the cooler environment of the upper respiratory passages. One such ts mutant, ts-H43, which does not replicate at a temperature of 37 degrees or above, although noninfectious for hamsters, infected each of 16 seronegative adult volunteers when given by the intranasal route. The mutant remained genetically stable throughout the course of infection and stimulated a moderate systemic and local antibody response. The mutant was entirely avirulent for the volunteers but appeared to stimulate resistance to subsequent challenge with partially attenuated wild-type (ts(+)) Mycoplasma pneumoniae.

Adsorption of Mycoplasma pneumoniae to neuraminic acid receptors of various cells and possible role in virulence

Monkey, rat, and chicken tracheal epithelial cells, as well as monkey, rat, guinea pig, and chicken erythrocytes, adsorbed firmly to colonies of Mycoplasma pneumoniae and M. gallisepticum. Colonies of M. pulmonis also adsorbed erythrocytes but with less avidity than M. pneumoniae or M. gallisepticum; unlike the latter organisms, M. pulmonis did not adsorb tracheal epithelial cells. Colonies of M. orale type 1 and M. orale type 3 adsorbed only chicken red cells. Other mycoplasma species tested, including four of human origin and one of animal origin, did not adsorb red cells or epithelial cells. M. pneumoniae and M. gallisepticum appeared to attach to erythrocytes or tracheal epithelial cells by neuraminic acid receptors on these cells, whereas M. orale types 1 and 3 and M. pulmonis seemed to utilize another type or other types of receptors. Pretreatment of red cells or tracheal epithelial cells with receptor-destroying enzyme, neuraminidase, or influenza B virus removed the adsorption receptors for M. pneumoniae. Similarly, pretreatment of M. pneumoniae colonies with neuraminic acid-containing materials prevented adsorption of erythrocytes or respiratory tract cells. The adsorption sites on M. pneumoniae were specifically blocked by homologous but not heterologous antisera. This property made it possible to study the nature of the mycoplasma adsorption sites by testing the capacity of different fractions of the organism to block the action of adsorption-inhibiting antibodies. Such studies suggested that the mycoplasma binding sites were probably lipid or lipoprotein in nature. The glycerophospholipid hapten was implicated as one such site, since this serologically active hapten blocked the action of hemadsorption-inhibiting antibodies in M. pneumoniae rabbit antiserum. The affinity of M. pneumoniae for respiratory tract epithelium, unique among the mycoplasmas that infect man, may play a role in virulence, since this type of attachment provides an unusual opportunity for peroxide, secreted by the organism, to attack the tissue cell membrane without being rapidly destroyed by catalase or peroxidase present in extracellular body fluids.