Detection of Mycoplasma pneumoniae by polymerase chain reaction in middle ear fluids from infants with acute otitis media

[Clinical implications of the genus Mycoplasma]

Dentro del género Mycoplasma, las especies que tradicionalmente se han relacionado con cuadros infecciosos han sido principalmente M. pneumoniae, M. genitalium, M. hominis o U. urealyticum. Sin embargo, existen otras muchas que están implicadas y, que muchas veces, son desconocidas para los profesionales sanitarios. El objetivo de esta revisión es identificar todas las especies del género Mycoplasma que se han aislado en el hombre y determinar su participación en la patología infecciosa humana.

The role of Mycoplasma in upper respiratory infections

Mycoplasma pneumoniae is a common cause of upper and lower respiratory tract infections. Pneumonia is the most clinically important manifestation, but tracheobronchitis and various nonspecific upper respiratory tract symptoms are more typically seen in clinical settings. M. pneumoniae can cause pharyngitis with or without concomitant lower respiratory tract involvement, but it is less commonly detected in other upper respiratory conditions such as otitis media, sinusitis, and the common cold. A variety of methods exist for laboratory diagnosis of M. pneumoniae infection, including culture, serology, and the polymerase chain reaction assay, but each has limitations. This article provides a summary of recent studies that have evaluated the role of M. pneumoniae in upper respiratory tract infections; a brief discussion of its cell biology, pathogenic mechanisms, and epidemiology; and recommendations for laboratory diagnosis and management.

Pathogenic bacteria and viruses in induced sputum or pharyngeal secretions of adults with stable asthma

BACKGROUND

Respiratory infections are well known triggers of asthma exacerbations, but their role in stable adult asthma remains unclear.

METHODS

103 asthmatics and 30 control subjects were enrolled in the study. Sputum was induced by inhalation of 3% NaCl solution. Oropharyngeal swab specimens were obtained from the posterior wall of the oropharynx. Respiratory specimens were analysed by RT-PCR for rhinovirus, enterovirus and respiratory syncytial virus and by PCR for adenovirus, Chlamydia pneumoniae, Mycoplasma pneumoniae and Bordetella pertussis.

RESULTS

Sputum samples from two of the 30 healthy controls (6.7%), five of 53 patients with mild asthma (9.4%), and eight of 50 with moderate asthma (16.0%) were positive for rhinovirus. Rhinovirus positive asthmatic subjects had more asthma symptoms and lower forced expiratory volume in 1 second (FEV(1)) (79% predicted) than rhinovirus negative cases (93.5% predicted; p = 0.020). Chlamydia pneumoniae PCR was positive in 11 healthy controls (36.6%), 11 mild asthmatics (20.8%), and 11 moderate asthmatics (22%), and PCR positive asthmatics had lower FEV(1)/FVC than negative cases (78.2% v 80.8%, p = 0.023). Bordetella pertussis PCR was positive in 30 cases: five healthy controls (16.7%), 15 mild asthmatics (28.3%), and 10 moderate asthmatics (20%). Bordetella pertussis positive individuals had lower FEV(1)/FVC (77.1% v 80.7%, p = 0.012) and more asthma symptoms than B pertussis negative cases.

CONCLUSIONS

Rhinovirus, C pneumoniae, and B pertussis are found in the sputum or pharyngeal swab specimens of asthmatic subjects without concurrent symptoms of infection or asthma exacerbation, as well as in some healthy controls. Positivity is associated with lower lung function and more frequent asthma symptoms.

No evidence of Mycoplasma pneumoniae in acute myringitis

Our aim was to discover Mycoplasma pneumoniae in bullous and hemorrhagic myringitis in children <2 years of age. Middle ear fluid samples (n = 37) and samples taken from the blisters of the tympanic membranes (n = 12) studied by polymerase chain reaction for M. pneumoniae were negative. This study does not support an important role for M. pneumoniae as an etiologic agent in acute myringitis.

Emerging role of Mycoplasma pneumoniae and Chlamydia pneumoniae in paediatric respiratory-tract infections

Increased use of specialised diagnostic techniques over the past 10 years has allowed considerable new information to be obtained concerning Mycoplasma pneumoniae and Chlamydia pneumoniae infections. In children, these pathogens seem to have a more important role in causing respiratory-tract infections than previously thought; they have been associated with wheezing, and they are also frequent in children aged under 5 years. Contrary to original belief, no clinical, laboratory, or radiological findings seem to be unique to M. pneumoniae or C. pneumoniae; furthermore, there is no rapid and cost-effective diagnostic test capable of identifying these pathogens. Appropriate antimicrobial treatment of the infections they cause is needed to reduce the recurrent episodes of wheezing and other respiratory symptoms, to decrease morbidity, and to avoid the spread of the pathogens. However, a number of therapeutic issues remain unsolved.