Molecular detection of Mycoplasma pneumoniae in Community acquired pneumonia

Abstract

Community acquired pneumonia (CAP) remains a common and serious illness despite availability of potent anti-microbials and effective vaccine. Two types of CAP are commonly recognised - typical and atypical. Typical pneumonia is usually caused by bacteria such as Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catharralis, whereas, atypical pneumonia can be caused by Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneuomophila. Mycoplasma pneumoniae is found to be the most common cause of CAP among atypical pathogens and is called “Walking pneumonia”. It is a common atypical respiratory pathogen that produces diseases of varied severity ranging from mild upper respiratory tract infection to severe atypical pneumonia and is also responsible for producing a wide spectrum of non-pulmonary manifestations like neurological, hepatic, cardiac diseases, hemolytic anemia, polyarthritis and erythema multiforme which occur in as many as 25% of infected persons. As it lacks cell wall they are resistant to β lactam antibiotics, hence accurate and rapid diagnosis of M. pneumoniae infections is critical to initiate appropriate antibiotic treatment. Identification of M pneumoniae allows narrowing of initial empirical regimen which decreases antibiotic selection pressure and may lessen the risk of resistance. In view of this present study will be conducted in a tertiary care hospital for identification of M pneumoniae in cases of CAP by Polymerase chain reaction (PCR). 1. To detect proportion of Mycoplasma Pneumoniae among cases of CAP. 2. Detection of 16SrRNA Mycoplasma pneumoniae by PCR.Clinico-radiologically diagnosed 92 CAP patients were included in the study. Out of which 15 cases were caused by typical CAP pathogens like Streptococcus species, K.pneumoniae & M.tuberculosis. Samples (Sputum Bronchoalveolar lavages) from 77 suspected cases of atypical pneumonia are inoculated on PPLO broth (Difco) followed by identification of genus specific 16S rRNA Mycoplasma pneumoniae using PCR. PCR was found to be positive in 9 (11.68%) out of 77 CAP patients. PCR was found to be positive in 9 (11.68%) out of 77 CAP patients. Detection of M.pneumoniae is essential for prompt diagnosis and start of empirical therapy, thereby reducing antibiotic selection pressure.