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16S rRNA based polymerase chain reaction compared with culture and serological methods for diagnosis of Mycoplasma pneumoniae infection.

The use of a 16S rRNA based polymerase chain reaction (PCR) for the detection of Mycoplasma pneumoniae infection was investigated. Sputum samples from 34 patients with respiratory illness and evidence of pneumonia as judged by chest X-ray were analyzed by PCR and microbiological culture. Throat swabs from 14 healthy individuals were used as controls. For serology, an enzyme immunoassay for the detection of immunoglobulin M antibodies and a complement fixation assay were performed. Evidence of Mycoplasma pneumoniae infection was obtained in ten patients (29%), eight of whom were found positive by both PCR and serology. Two of the sputum samples from these eight patients were negative by culture. Of the remaining two patients positive for Mycoplasma pneumoniae, one was positive by PCR and culture but negative by serology, and one was found positive by serology but negative by PCR and culture. Thirteen of the 14 controls were negative by both PCR and serology. One control, however, was negative by serology but positive by PCR, which was probably due to asymptomatic carriage of Mycoplasma pneumoniae. The results of this study indicate the suitability of the PCR for the detection of Mycoplasma pneumoniae in clinical samples as well as its potential value as an additional tool for the diagnosis of infection.

Adolescent↗

Genital mycoplasmas in preterm infants: prevalence and clinical significance.

The genital mycoplasmas: Ureaplasma urealyticum and Mycoplasma hominis have recently assumed an increasing importance as neonatal pathogens. The aim of the present survey was to determine the prevalence of infections with these organisms in preterm infants in two neonatal intensive care units in Israel. Among 99 preterm infants, 24 (24%) harboured mycoplasmas in their throats shortly after birth. U. urealyticum was the most common organism. M. hominis was isolated only from 3 infants. Six out of 27 (22%) mechanically ventilated infants secreted U. urealyticum in their lower airways. The rate of colonization was inversely correlated with gestational age; 80% of infants younger than 28 weeks gestation were found to be colonized as opposed to 17.9% at 28-36 weeks of gestation. No mycoplasmas were isolated in blood cultures drawn from 146 infants and CSF cultures obtained from 47 preterm infants. Neonatal mortality, respiratory complications and intraventricular haemorrhage grade 3-4 were significantly increased in colonized infants. However, above gestational age of 27 weeks, colonization with mycoplasmas was not associated with a worse prognosis. We conclude that colonization with U. urealyticum is common in Israeli preterm infants, correlates inversely with gestational age and has no detrimental effect on neonatal morbidity and mortality of infants older than 27 wks of gestation.

Genitalia↗

Mycoplasma blood infection in chronic fatigue and fibromyalgia syndromes.

Chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS) are characterised by a lack of consistent laboratory and clinical abnormalities. Although they are distinguishable as separate syndromes based on established criteria, a great number of patients are diagnosed with both. In studies using polymerase chain reaction methods, mycoplasma blood infection has been detected in about 50% of patients with CFS and/or FMS, including patients with Gulf War illnesses and symptoms that overlap with one or both syndromes. Such infection is detected in only about 10% of healthy individuals, significantly less than in patients. Most patients with CFS/FMS who have mycoplasma infection appear to recover and reach their pre-illness state after long-term antibiotic therapy with doxycycline, and the infection can not be detected after recovery. By means of causation and therapy, mycoplasma blood infection may permit a further subclassification of CFS and FMS. It is not clear whether mycoplasmas are associated with CFS/FMS as causal agents, cofactors, or opportunistic infections in patients with immune disturbances. Whether mycoplasma infection can be detected in about 50% of all patient populations with CFS and/or FMS is yet to be determined.

Anti-Bacterial Agents↗

Emerging role of Mycoplasma pneumoniae in children with acute pharyngitis.

In order to define the role, the risk factors, and the clinical and laboratory characteristics of Mycoplasma pneumoniae infection in children with pharyngitis, 184 patients with acute non-streptococcal pharyngitis (102 males; median age, 5.33 years) were studied. Acute Mycoplasma pneumoniae infection was demonstrated in 44 (23.9%) patients. A history of recurrent episodes of pharyngitis (defined as at least 3 acute episodes of pharyngitis in the 6 months preceding enrollment) appeared to be the more useful parameter for differentiating Mycoplasma pneumoniae pharyngitis from non-streptococcal non- Mycoplasma pneumoniae pharyngitis ( P<0.05 in multivariate analysis). These data, which highlight the emerging role of Mycoplasma pneumoniae in acute pharyngitis, must be taken into account in the diagnosis and treatment of this clinical manifestation in children.

Acute Disease↗

Identification of ruminant mycoplasmas by dot immunobinding on membrane filtration (MF dot).

A simple method of species identification of ruminant mycoplasmas by dot immunobinding (MF dot) is described. Mycoplasmas from broth cultures were directly trapped onto the surface of low protein-binding affinity membranes by vacuum filtration. Specific polyclonal anti-mycoplasma sera were then applied. Mycoplasma-antibody complexes were then revealed by an enzyme conjugated anti-immunoglobulin. A positive reaction was indicated by the development of a color reaction when substrate was added. The method was tested on 22 type-strains representative of species, subspecies, types or yet unnamed serogroups of mycoplasmas isolated from ruminants. MF dot presented a specificity close to that which could be expected from the reference serological tests. The advantages of the MF dot over the other tests are utility, rapidity, ready standardization and it allows many samples to be treated simultaneously.

Animals↗

Optimising the conditions for isolation of Mycoplasma gallisepticum collected on applicator swabs.

An experiment to compare the recovery of Mycoplasma gallisepticum (Mg) on dry swabs and swabs wet with mycoplasma broth (MB) was carried out by swabbing choanal clefts of Mg infected turkey poults at days 3, 6, 9, 12 post-infection. Wet swabs yielded significantly greater numbers of mycoplasmas than dry swabs on three out of four sampling days. When low numbers of mycoplasmas were collected on wet or dry swabs (in vitro) and then stored at room temperature (RT) or 4 degrees C for various intervals, those on dry swabs at RT had lost viability by 8 to 24 h. They survived at least 24 h on wet swabs kept at 4 degrees C. When Mg was collected and stored on dry and wet swabs from experimentally infected poults survival was again best on wet swabs stored at 4 degrees C. Swabs pre-wet with MB and stored before sampling could be used without any ill effects on mycoplasma recovery as long as they were stored at 4 degrees C and for no more than 48 h. After storage at RT for 48 h such swabs appeared to be detrimental to the organism. Mg collected on wet charcoal swabs was viable for 48 to 72 h when kept at 4 degrees C whereas it was viable for only 24 h when stored at RT. Mg was recovered from wet charcoal swabs sent through the mail but not from dry or wet plain swabs.

Animals↗

[Prospective study of neonatal genital mycoplasma colonization and infection].

Genital mycoplasmas have been implicated in different neonatal diseases as pneumonia, sepsis and meningitis. This prospective study was conducted to specify their role in these diseases. POPULATION AND METHODS--A pharyngeal or tracheal swab specimen for mycoplasmas culture was obtained from 100 infants admitted consecutively to the Neonatal Care Unit (NCU) during the first 24 hours of life. Mycoplasma culture of blood and cerebrospinal fluid was also performed. Pharyngeal and/or tracheal specimens were collected again on days 5, 15 and 28 if the child was still in the NCU. Mycoplasma hominis (Mh) and Ureaplasma urealyticum (Uu) were identified by culture in a modified Hayflick's medium. RESULTS--Three-hundred and ten pharyngeal or tracheal swabs were obtained (100 on day 0, 89 on day 5, 72 on day 15 and 49 on day 28). Twenty-one infants had one or more positive swabs in the first five days of life (20 on day 0 and one on day 5); those forming the "Myco+" group and the others forming the "Myco-" group. Uu was isolated alone from 20 infants, associated with Mh from one. Both groups were similar for gestational age, birth weight, maternal fever during labor, prolonged rupture of the fetal membranes or chorioamnionitis and for the incidence of acute respiratory distress. There was a statistically significant difference for the route of delivery (chi 2 < 0.02). One blood culture (from 92 performed) was positive for Uu and another positive for Uu and Mh. Both children were cured without any specific mycoplasmacidal therapy. Three children had probable Uu infection and were also cured without specific therapy. CONCLUSIONS--A pharyngeal colonization with genital mycoplasmas is common in the first days of life (21%) but our data do not allow us to conclude that they are accountable for newborn infections.

Bacteremia↗

A specific PCR for the detection of Mycoplasma putrefaciens, one of the agents of the contagious agalactia syndrome of goats.

Mycoplasma putrefaciens is listed as one of the etiologic agents of the contagious agalactia syndrome by the world organisation for animal health. This species has been characterized only recently, 1974, and the number of outbreaks caused by this microorganism so far is very scarce. It induces mastitis in infected goats although other symptoms such as arthritis in adults and septicaemia in kids are also frequently described. Up to now, the identification of M. putrefaciens relied on classical isolation and identification techniques which present a number of limitations. Specific primers for PCR have been designed based on sequence comparisons of the ArcB gene among the 'Mycoplasma mycoides cluster' and related species such as Mycoplasma cottewii and Mycoplasma yeatsii. Sequence alignments confirmed the taxonomic position of M. putrefaciens, which is related to the 'M. mycoides cluster' but also very close to M. yeatsii. The polymorphism observed amongst the different ArcB sequences allowed the determination of a primer pair yielding a specific amplification of a 316 bp-long DNA fragment by PCR. This PCR was validated in two different laboratories with a variety of mycoplasma strains isolated from goats. This new PCR technique will be very useful for a quicker determination of M. putrefaciens strains as well as a better understanding of the prevalence of M. putrefaciens infections.

Animals↗

Phase and size variable surface-exposed proteins in equine genital mycoplasmas.

Mycoplasma equigenitalium and Mycoplasma subdolum have been associated with infertility, endometritis, vulvitis and abortions in mares, and with reduced fertility and balanoposthitis in stallions. Despite their role in equine genital disorder, determinants of virulence and pathogenesis as well as factors provoking specific host immune responses have not been identified, so far. To establish the major immunogenic components of Mycoplasma (M.) equigenitalium and M. subdolum, antigen profiles of their type strains as well as 30 clinical isolates were compared by SDS-PAGE and immunoblot analysis using hyperimmune rabbit sera and equine sera from clinical cases. To define the major protein antigens of both mycoplasma species, detergent-phase fractionation with Triton X-114 was performed. Western blot analysis of 30 clinical isolates revealed a high similarity of their overall antigen profile with only slight differences. In contrast, monospecific polyclonal antibodies raised against detergent-phase proteins of the two mycoplasma species identified three prominent proteins (pST17, pST42, and pET45) undergoing variation in expression and size among clinical and clonal isolates.

Animals↗

Genital mycoplasmas in women attending a family planning clinic in Guiné-Bissau and their susceptibility to antimicrobial agents.

A study on the prevalence of genital mycoplasmas and their susceptibility to the most common antimicrobial agents used for treating the infection was conducted on 94 women attending a family planning clinic in Guiné-Bissau. Fifty-four women (57.4%) were positive for Mycoplasma hominis and/or Ureaplasma urealyticum. M. hominis and U. urealyticum separately isolated from infected women yielded frequencies of 31.5 and 27.8%, respectively, the remainder were infected with both species. No strain was found to be resistant to all three commonly employed antibiotics for the management of these infections (erythromycin, tetracycline and ofloxacin), although multiple resistance to two antibiotics was frequent, especially when both genital mycoplasmas were present. Some 90.7 and 24.1% of all isolates were resistant to erythromycin and tetracycline, respectively. No resistance was observed to ofloxacin, although 50% of the strains had intermediate resistance. The high prevalence of genital mycoplasmas in women attending a family planning clinic in Guiné-Bissau, as demonstrated in this study, appears to be associated with trichomonosis and bacterial vaginosis. These infections were also found to be highly resistant to erythromycin and tetracycline and to have intermediate resistance to ofloxacin. However, further studies are necessary to establish the burden of infection due to antibiotic resistant genital mycoplasmas.

Adult↗

Detection of Mycoplasma mycoides subspecies mycoides by growth-inhibition using monoclonal antibodies.

A pool of three monoclonal antibodies, 3H12, 6D11 and 2A3, inhibited the in vitro growth of 12 Mycoplasma mycoides subspecies mycoides small colony (MmmSC) strains and seven Mycoplasma mycoides subspecies mycoides large colony (MmmLC) strains. This test did not cross-react with other 16 Mycoplasma mycoides cluster and nine non-Mycoplasma mycoides cluster strains representing 13 different species. Although MmmSC was not differentiated from MmmLC, the monoclonal antibodies distinguished both M mycoides subspecies mycoides biotypes from the other Mycoplasma species tested in contrast to results with polyclonal antisera.

Animals↗

A reverse transcription-PCR assay to detect viable Mycoplasma synoviae in poultry environmental samples.

In order to study horizontal transmission of Mycoplasma synoviae an avian pathogen, a reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to detect viable Mycoplasma in environment. The test was based on the RT-PCR of the 16S ribosomal RNA (rRNA) of Mycoplasma genus. Results showed that Mycoplasma 16S rRNA was stable up to 23 h after cell death. Therefore, the test allowed detection of viable or very recently (less than 23 h) dead mycoplasmas. M. synoviae survival in artificially contaminated water, food and soil and in the environment of M. synoviae experimentally infected turkeys was estimated by culture and RT-PCR. The RT-PCR method was then applied in a naturally infected laying hen farm showing problems of recurrent mycoplasmosis in the hens. Results confirmed the usefulness of RT-PCR in checking the efficiency of biosecurity measures and in improving cleaning and disinfection protocols.

Air Microbiology↗

Immunomodulatory properties of Mycoplasma pulmonis. I. Characterization of the immunomodulatory activity.

For many years, it has been recognized that Mycoplasma infection affects the host's immune system in different ways. In this work, experiments were performed to characterize the influence of Mycoplasma pulmonis infection on various immunological parameters and to follow the kinetics of their variations. A Balb/c mouse model was used to assess hematological evaluations, changes in spleen weight, antibody responses against sheep erythrocytes, neutrophil phagocytosis, colloidal carbon clearance, and anti-Mycoplasma antibody responses. At the hematological level, infected animals were found to have significantly increased total lymphocyte and polymorphonuclear leukocyte counts and an augmentation in spleen weight. Seven days after Mycoplasma infection, antibody responses against sheep erythrocytes were considerably diminished, and at days 7 and 14 after infection, phagocytic activity was also reduced. After 1 week of infection, the colloidal carbon clearance pattern was decreased, and during the whole infectious process, anti-Mycoplasma antibody titers were found to be low. Results from this part of research show a persistent infection that does not resolve in a short period, which is associated with a general dysfunction in the immune system and poor immune responses against several different antigens.

Adjuvants, Immunologic↗

Respiratory disease in a colony of rats. II. Isolation of Mycoplasma pulmonis from the natural disease, and the experimental disease induced with a cloned culture of this organism.

Mycoplasma pulmonis was isolated from the pneumonic lung of a rat. Two groups of mycoplasma-free rats were inoculated, one with a culture of the M. pulmonis strain which had been cloned four times (group A) and the other with a lung homogenate of the rat from which the strain had been isolated (group B). A third group (C) consisted of uninoculated control animals. Each group was kept in strict isolation and allowed to breed so that the progeny was naturally exposed to any pathogens present in the inoculated animals. After different periods of exposure, rats were autopsied, respiratory tracts and inner ears were cultured for mycoplasmas and bacteria, and sera were tested for complement-fixing antibodies to murine mycoplasmas.In group-A rats, M. pulmonis was consistently isolated from the inner ears or lungs from 50 to 715 days after exposure. Complement-fixing antibody to M. pulmonis was detected 20 days after inoculation, but in the naturally exposed progeny antibody took longer than 50 days to develop. Antibodies to the other known mycoplasmas of murine origin, M. arthritidis and M. neurolyticum, were never found. Purulent otitis interna was consistently found from day 55 onwards, while lung lesions were first observed at 85 days and persisted to 715 days. Pulmonary lesions developed more slowly in inoculated parents than in exposed progeny. Similar results were found in group-B rats, which were examined up to 441 days after inoculation. Uninoculated group-C rats were examined up to 768 days of age, but M. pulmonis was not recovered; of the 54 animals whose serum was tested all were negative to the three species of mycoplasmas, except one which had a titre of 16 with M. pulmonis. Pneumonia, bronchiectasis or lymphoreticular hyperplasia were not seen in any of these control rats. Bacterial respiratory pathogens were not isolated from rats in any of the groups, nor was antibody to Sendai virus detected.The results suggest that M. pulmonis alone can cause pneumonia and bronchiectasis in rats since mechanical carry-over of another pathogen with the initial cloned inoculum is very unlikely and there was no evidence for the participation of any other rat pathogen. The respiratory disease induced by the cloned culture was comparable with that induced by the lung homogenate, and with the well-known syndrome of chronic respiratory disease and bronchiectasis in the rat.

Animals↗

Use of an alkaline phosphatase-labelled probe for the detection of Mycoplasma synoviae in chickens.

Short nucleotides directly labelled to alkaline phosphatase (SNAP probes) are an interesting alternative to digoxigenin-labelled probes (DIG probes), because they reduce the number of steps necessary in dot blots for the detection of DNA or amplificate. This study examined the questions whether a SNAP probe might not only save time, but also increase the sensitivity of another PCR-based DNA probe test using a digoxigenin probe. Amplificates obtained by multispecies polymerase chain reaction (PCR), with either purified genomic DNA or DNA extracted from tracheal swabs taken in chicken flocks, were detected by both methods. The results for the clinical specimens were compared to culture. Under stringent conditions, the specificity and sensitivity obtained with the SNAP probe were comparable to the results obtained with the DIG probe. The quantities 10 fg (SNAP probe) and 100 fg (DIG probe) of purified Mycoplasma synoviae DNA were detected after amplification, but more positive clinical specimens were detected with the DIG probe. Under non-stringent conditions sensitivity with purified DNA did no change, but the coloration of the dots improved markedly, and more positive specimens could be detected with the SNAP probe than with the DIG probe, truly positives as confirmed by culture. Because cross-reaction with Mycoplasma gallisepticum and Mycoplasma imitans, two species with DNA that was also recognized by the multispecies primers, occurred under non-stringent conditions, it was concluded that, to take the full advantage of SNAP probes, their use in combination with species-specific primer pairs is recommended. PCR as a method for mycoplasma detection is however, always accompanied with serological and cultural methods. When a M. synoviae mono-infection is likely by serological results, non-stringent dot blot conditions and use of the SNAP probe will ease and improve the detection of mycoplasma.

Alkaline Phosphatase↗

Chorioamnionitis and colonization of the newborn infant with genital mycoplasmas.

To study the role of Mycoplasma hominis and T-mycoplasmas (Ureaplasma urealyticum) in chorioamnionitis, we obtained culture from 249 puerperal women and their babies. The placentas were examined histologically. Infants whose placentas showed inflammation (chorioamnionitis) had cultures positive for T-mycoplasmas more frequently (37.5 per cent) than those with normal placentas (19.0 per cent) (P = 0.021). Colonization with M. hominis was found in 16.0 per cent of the babies and was not significantly associated with chorioamnionitis. Material colonization with mycoplasmas was more frequent (73.4 per cent) and was not correlated with placental inflammation. We conclude that a substantial proportion of cases of chorioamnionitis may be caused by prenatal infection with T-mycoplasmas. The fact that these organisms are not highly virulent could explain the frequent finding of inflammed placentas from otherwise normal pregnacies. No adverse clinical effects of the placental lesions or of mycoplasmal colonization could be detected in this small study.

Amnion↗

Isolation and identification of avian mycoplasmas in Singapore.

Two hundred and forty batches of chickens with chronic respiratory syndrome were tested for mycoplasmas. One hundred and five batches (43.8%) were found to have mycoplasmosis. A total of 110 isolates of mycoplasma was cultured, of which nine isolates were identified as Mycoplasma gallisepticum, 48 avian sero-group D, 45 M. gallinarum, one M. iners and seven unclassified. 2. Identification of the mycoplasmas isolated was carried out by biochemical and serological tests (disc growth inhibition and agar gel diffusion tests). A modified agar gel diffusion test using solubilised antigens with sodium deoxycholate-glucose solution was developed for serotying of mycoplasmas.

Animals↗

Polymerase chain reaction for detection of Mycoplasma gallisepticum in environmental samples.

The polymerase chain reaction (PCR) was used to detect Mycoplasma gallisepticum in samples collected from the environment of experimentally or naturally infected poultry. Culture was also used in the experimental infections. Of 160 samples of food, drinking water, feathers, droppings or dust collected during experimental infection, 103 were positive using a M. gallisepticum-specific PCR (MG-PCR) and 68 were positive using a PCR (mycoplasma-PCR) that detects all species of the genera Mycoplasma, Spiroplasma, Acholeplasma and Ureaplasma. Six of these samples were also positive by culture. In environmental samples collected on a depopulated M. gallisepticum-positive turkey farm, three and two out of a total of 12 were positive by mycoplasma-PCR and MG-PCR, respectively. These results indicate the disseminating capacity of this mycoplasma and the possible use of PCR methods for epidemiological analyses and control of farm decontamination before the introduction of new birds.

Animals↗