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

BACKGROUND

Respiratory 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.

METHODS

We 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.

RESULTS

The detection limits using uniplex PCR for C. pneumoniae, L. pneumophila and M. pneumoniae were approximately 1pg, 2.4fg and 12pg 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.

CONCLUSIONS

The 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.