Application of three uniplex polymerase chain reaction assays for the detection of atypical bacteria in asthmatic patients in Kuwait

BackgroundRespiratory infections are known to exacerbate wheezing in many asthmatic patients. We aimed to use molecular methods for the fast detection of Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila in respiratory specimens from asthmatic patients in Kuwait.MethodsWe used uniplex PCR assays to detect the three atypical bacteria in clinical specimens from 235 asthmatic and non-asthmatic patients in Kuwait. A regression analysis was used to identify the risk factors related to the bacterial type. Group comparisons for similarity were conducted and correlation coefficients were calculated using SPSS statistical software.ResultsThe detection limits using uniplex PCR for C. pneumoniae, L. pneumophila and M. pneumoniae were approximately 1 pg, 2.4 fg and 12 pg of DNA, respectively. M. pneumoniae PCR positivity was more common in asthmatic patients (15%) than in non-asthmatic subjects (9%) (P < 0.05). A marked difference was observed between patients with acute asthma exacerbation (11%) and patients with chronic (stable) asthma (7%) among Kuwaiti patients; these percentages were 16% for non-Kuwaiti acute asthma patients and 14% for non-Kuwaiti chronic asthma patients (P < 0.201). There was a weak positive correlation between asthma severity and PCR positivity for M. pneumoniae. The PCR results for C. pneumoniae and L. pneumoniae were found to be statistically insignificant.ConclusionsThe results of this study suggest that infection with M. pneumoniae may be related to the exacerbation of asthma symptoms and could possibly be a factor that induces wheezing.

► We looked into the role of infection by atypical bacteria in asthma.
► A fast and sensitive molecular method (PCR) was used for the detection of three bacteria in asthmatic patients in Kuwait.
► A high detection rate of Mycoplasma pneumonia in the airway of adult with chronic asthma was found.
► No significant detection was found with Chlamydia pneumonia or Legionella pneumophila.
► The possibility of M. pneumonia infection should be considered in cases of acute and sever exacerbation and in difficult to treat asthmatics.