مطالعه ميزان كارايي PCR و فلورسنت آنتي بادي در تشخيص كلاتيديا پنمونيه

A STUDY OF THE EFFICIENCY OF POLYMERASE CHAIN REACTION (PCR) AND FLUORESCENT ANTIBODY TEST IN DIAGNOSIS OF CHLAMYDIA PNEUMONIAE

Background and Objectives: Chlamydia species have been always considered as one of the most important causative agents of human diseases. With introduction of C. pneumoniae and C. pecorum as two new species to the group of bacteria, it has drawn more attention towards health concern. Routine laboratory methods are not able to identify these organisms because of them being obligate intracellular. Classic diagnostic procedure is their isolation in cell culture. However, low sensitivity, time-consumption and being expensive makes the method less accepted. Serological methods can be applied but they are less sensitive and are not been able to identify the causative agent of the disease in early stage of infection. Therefore, antigen detection methods and molecular techniques have gained more interest. In this study, fluorescent antibody test ( FAT) and PCR were used to detect C. pneumoniae in clinical specimens and the results were compared. Materials and Methods: Fluorescent antibody test was carried out by the use of C.pneumoniae specific monoclonal antibody ʹA3ʹ and fluorescein-isothiocyanate-labeled anti-mouse immuno-globulin. PCR was applied to amplify 545 base pair of MOMP gene by CpnA and CpnB2 primers. These two methods were first optimized by pure DNA extracted from proliferated known C. pneumoniae strains: 10L-207, N16, VR1310; One hundred six throat swabs obtained from 30 HIV positive patients were tested to evaluate the sensitivity of these two methods. Results: Results with pure DNA showed detection limit was 10 chromosomal DNA and 10 ifu for the PCR and FAT respectively. Analysis of collected throat swabs indicated that 39 and 42 specimens were positive by PCR and FAT respectively. Conclusion: Examined specimens confirmed nearly same sensitivity for both methods, but PCR is more suitable for clinical laboratory with a lot of specimens, while application of FAT needs accurate observation in suitable time.