Molecular detection of bacterial pathogens in intensification of chronic obstructive pulmonary disease by polymerase chain reaction methods

Abstract

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is one of the major causes of mortality all around the world, and research indicates that it will become more prevalent in future. Patients with COPD may sometimes also catch bacterial infections, including infections with Streptococcus Pneumonia, Mycoplasma Pneumonia, and Legionella Pneumophila. The purpose of this study is to use PCR as more sensitive, supplementary method for detection of these infections. METHODS: The study is of the cross-sectional-descriptive type. 109 specimens were collected under supervision of pulmonologists from the respiratory secretions of patients with COPD and suspicion of bacterial infections. The specimens entered the DNA extraction process. Then, molecular experiments were performed, and their results were finally analyzed with statistical tests. RESULTS: There was no significant difference in terms of gender (P value>0.05). The patients’ average age was 62.4±12.2. In the case of Legionella Pneumophila, 4 of the 109 patients were identified as positive using the kit, and 2 of them were reported as positive with the second PCR method using the designed primers. As for Streptococcus Pneumonia, 8 of the 109 patients were identified as positive with the standard kit me thod, and 5 of them were reported as positive with the second PCR method. Relative frequency was calculated for Legionella Pneumophila and Streptococcus Pneumonia as 4% and 7%, respectively. CONCLUSIONS: In general, the methods employed in this study have good sensitivity and accuracy as compared to the conventional and common methods and to those in similar studies. Of course, it is suggested that the experiments be performed on more samples and with other genes. KEY WORDS: Polymerase chain reaction; Pulmonary disease, chronic obstructive; Legionella pneumophila; Streptococcus pneumoniae