Construction of an internal control for the detection of Chlamydia pneumoniae by PCR

For the detection of Chlamydia pneumoniae by polymerase chain reaction (PCR) in respiratory samples, an internal control was constructed to monitor the efficiency of amplification in each reaction. The internal control was designed in a way that the same primer pair can be used to amplify the internal control and target DNA. Nasopharyngeal aspirates of children suffering from asthma (> 2 years of age; 24 patients) or bronchiolitis (< 2 years of age; 47 patients) were analysed for the presence of C. pneumoniae, using the internal control in each amplification reaction. Two specimens from asthma patients, both children of 8 years old, were positive for C. pneumoniae. The number of cases studied is too small to draw conclusions regarding the incidence of C. pneumoniae in different age categories in children.