Detection and Identification of Fungal Pathogens by Multiplex PCR in Pulmonary Tuberculosis Patients in Kancheepuram

Abstract

Tuberculosis is a common infection in developing countries. Pulmonary tuberculosis is the most commonly associated disease in cases of secondary aspergilloma. Fungus infection is gradually becoming commoner and has been difficult to evaluate since diagnoses were seldom confirmed. Multiplex PCR method provides a rapid, simple, and reliable alternative to conventional methods to identify common clinical fungal isolates. Hence, this study was taken up to find the fungal co-infections among TB patients and also to confirm the isolates by multiplex PCR. Sputum samples were collected from 80 patients who were TB-positive and were on ATT from MMCH&RI between Feb 2012 and Dec 2012. Samples were processed and identified as per standard protocol. Growth was confirmed by repeated isolation for at least 3 times. Out of 80 pulmonary tuberculosis-positive patients, 26 cultures grew fungus, 12 were found to be Aspergillus sp. three Candida albicans, four Mucor, four Fusarium, one Cladosporium spp. and one Paecelomyces spp. was obtained from the culture. Off all the 26 isolates obtained, 12 strains of Aspergillus sp. were taken for molecular identification by multiplex PCR. Opportunistic mycoses are often grave, the early, rapid, and accurate identification of the pathogenic fungus is critical for timely and appropriate management. From this study, the authors have found correlation between fungal isolation, duration of ATT, and extent of lesion and in relation to the cavity form. It is necessary to screen all TB patients irrespective of ATT in order to start antifungal therapy.

Keywords: Aspergillus, Tuberculosis, multiplex PCR, rapid