Secondary Aspergillus in Bronchoalveolar Lavages (BALs) of Pulmonary Tuberculosis Patients from North-India

To find out the prevalence of Aspergillus spp. in Bronchoalveolar Lavages (BALs) of pulmonary tuberculosis patients, to study the anti-Aspergillus antibodies in patient's sera and to study the anti-fungal susceptibility of the isolated Aspergillus strains. BALs obtained from sixty-five patients of pulmonary tuberculosis and 10 healthy volunteers were studied. Direct microscopy was performed by 10% KOH and Lacto- Phenol Cotton Blue (LPCB) mounts and fungal cultures were performed on two sets of Czapek Dox agar (CDA) after adding chloramphenicol (0.05 mg/ml). Minimum Inhibitory Concentrations (MICs) were determined for fluconazole, itraconazole and amphotericin B by broth micro-dilution method. Finally, fungal serology was performed by Double Immunodiffuion (DID), Enzyme Linked Immunosorbent Assay (ELISA) and Dot Blot Assay (DBA) to evaluate the efficacies of these tests for detection of anti-aspergillus antibodies. Aspergillus species were isolated from 13.8% (9/65) patients. A. fumigatus was isolated in 5 (55.5%) patients while A. flavus and A. niger were isolated from 3 (33.3%) and 1 (11.1%) patients respectively. None from the control group showed growth of any Aspergillus species. All the Aspergillus species were consistently resistant to fluconazole (MIC >16 µg/ml). MICs for itraconazole and amphotericin B ranged between 0.12- >16 µg/ml and 0.12- 0.5 µg/ml, respectively. Anti-aspergillus antibodies were detected in 14 (21.5%) patients by DID as well as by ELISA; whereas, 12 (18.4%) patients showed presence of anti-aspergillus antibodies by DBA. The prevalence of Aspergillus in BAL of pulmonary tuberculosis patients was 13.8%. Aspergillus fumigatus was the predominant species, however the isolation of A. flavus (33.3%) was also significant. We suggest that the diagnostic tests for Aspergillosis, including culture and serology, should be incorporated in routine clinical laboratories so that we may not miss the secondary Aspergillosis in tuberculosis patients.