Molecular Detection of Medically Important Candida species from Droppings of Pigeons (Columbiformes) and Captive Birds (Passeriformes and Psittaciformes)

• Published in: Brazilian Archives of Biology and Technology 2021-01, Vol.64
• Main Authors: Queiroz-Aaltonen, Isabelle Regina de Oliveira, Melo Neto, Marcílio Ferreira de, Fonseca, Luísa Andrea Villanueva da, Silva, Denise Maria Wanderlei, Maranhão, Fernanda Cristina Albuquerque
• Format: Article
• Language: English
• Subjects: Avian excreta; Candida spp; captive birds; DNA extraction; PCR
• ISSN: 1516-8913; 1678-4324
• DOI: 10.1590/1678-4324-2021200763

Abstract Passeriformes and Psittaciformes birds and pigeons (Columba livia) are known to be reservoirs of microorganisms, and their stool allows fungi development. Since accumulated avian excreta can interfere with public health, this study aimed to perform a molecular screening of medically important Candida species in pigeon droppings in public places and birds raised in captivity. Excreta collected from captive birds (3 residences) and pigeons (4 districts) were inoculated on Sabouraud dextrose agar with chloramphenicol for Gram staining and subculture on Hicrome® Candida. Three DNA extraction methods were performed for comparison (commercial kit, in-house and by boiling) and PCR to screen 6 clinically important Candida species among the isolates. The correlation between phenotypic and molecular methods was calculated by kappa/K. Only 6 C. parapsilosis (20%) were identified from captive birds’ feces among 30 isolates (80% not identified), while pigeons’ feces harbored a greater diversity, with the 6 pathogenic species confirmed among 41 isolates: C. albicans (31.70%/13), C. krusei (14.63%/6), C. tropicalis (14.63%/6), C. parapsilosis (17.10%/7), C. glabrata (14.63%/6) and C. guilliermondii (7.31%/3); 100% correlation between tested methods (K = 1) for the first 3 species. Boiling DNA extraction method was fast and efficient to obtain viable DNA from Candida spp. for PCR. Our results indicate that pigeon droppings harbor more potentially pathogenic species than birds in residential captivity, which probably have non-albicans Candida less frequently isolated in infectious processes. The greater availability of nutrients may have contributed to a diversity of Candida spp. in feces from public environments.