Comparison between HRM and Culture to Detect Most Common Pathogenic Fungi in Patients with Respiratory Diseases
Authors: Rasheid Hadeel Jamal , Al-Attraqchi Dr. Azhar A.F. , Al_rubaye Dr. Dalal Saleh 
Published: April 2022

Back Ground: The respiratory fungal infection has increased globally, becoming an important cause of morbidity and mortality, especially in immunocompromised patients, such as patients with Diabetic Mellitus (DM), cancer patients. The most common fungal related result from species that belong genera include: Candida spp., Aspergillus spp., Cryptococcus spp., and Mucor spp. Clinically respiratory fungal infection was nonspecific and indistinguishable from other infection, making early diagnosis and correct treatment essential and urgent. Laboratory diagnosis involves traditional diagnostic methods, such as direct and culture, which are still considered the gold standards but have low sensitivity, time consuming and is sometimes only confirmed in late stages. Molecular method as High Resolution Melting (HRM PCR) for Broncho alveolar lavage (BAL) to detect and identify of most clinically important fungal pathogens with high sensitivity and specificity are showing the potential assay to replace traditional diagnostic assay. Material and method: One hundred seventeen (BAL) lavage sample from patients with respiratory disease were submitted to conventional methods (culture) and molecular method (HRM PCR) for detection of most common infection of fungal respiratory tract. Results: Out of the 117 BAL samples collected in the study, in the age group (61–70) years recorded the highest pulmonary diseases, 34 (29.0%), whereas the age group (31–40) recorded the lowest prevalence of pulmonary diseases was 3 (2.5%). There was significant association between age and prevalence of pulmonary diseases (P = 0.055). Males had relatively higher prevalence of fungal isolates, 18 (60%) than females' counterpart, 12(40%) it was no significant association was seen between sex and the prevalence of fungal pathogens (P = 0.55). Based on the risk factors considered in the study, participants with smoking, cancer and diabetic mellitus had a significantly higher risk of pulmonary fungal pathogens. By culture method, the following Fungi were identified: Candida spp. Twenty (66.6%), five (16.6%) samples were Aspergillus spp., Cryptococcus spp. 4 (13.3%), and only one (3.3%) sample as Mucor spp. while by molecular method (Multiplex HRM PCR) the result of 29 (24.7%) samples which were culture and conventional PCR positive detected, 15 (51.7%) were positive including: 8 (53.3%) Candida spp., 4(26.6%) Aspergillus spp., 2(13.3%) Cryptococcus neoformans, and only one (4.3%) Mucor spp. Conclusion: Referring to fungal species which was detected by culture method and HRM using specificspecies primers include: Candida pp. Aspergillus spp., Cryptococcus spp. and Mucor spp. It was seen that, Candida spp. and Apergillus spp. Had the highest positive percentages among other species. Multiplex HRM PCR is a faster analysis with high sensitive 100% to detect the most common fungal pathogens. Despite a cost-effective, make it an ideal tool for fast screening in patients at risk of fungal respiratory infection.