. Diversity of Aspergillus species from respiratory secretions of patients with severe COVID-19 pneumonia from Argentina and their in vitro sensitivity to antifungals

DE ABREU MS; HERMIDA ALAVA KS; POLA SJ; TOSCANINI MA; MALDONADO I; LOPEZ MORAL L; VALDEZ RM; CHACÓN, YONE A.; POSSE GB; CAPECE P; GARCÍA-EFFRÓN, GUILLERMO; CUESTAS ML

Congreso; 19TH INFOCUS.; 2021

Objectives: Among the causes of morbidity and mortality of patients with COVID-19, invasive pulmonary aspergillosis (IPA) emerged as a bad prognosis complication, especially in critically ill patients such as those with acute respiratory distress syndrome (ARDS) at intensive care units (ICU). In this regard, it was reported that patients with ARDS triggered by SARS-CoV-2, are prone to IPA even in absence of prior immunodeficiency. Reports showed that 19-35% of those critically ill patients with COVID-19 have signs of Aspergillus co-infections, which is alarmingly high. This novel entity, also called CAPA (COVID-19 associated pulmonary aspergillosis), makes Aspergillus an agent capable of further compromising the prognosis of these patients. The aims of the present study were to give an overview of the diversity of Aspergillus species from critically ill patients with COVID-19 from Argentina and to analyze their susceptibility patterns to antifungal drugs.Methods: Fifty Aspergillus isolates were recovered from respiratory specimens (bronchoalveolar lavage specimens, tracheal aspirates, and sputum samples) of 46 COVID-19 patients with probable pulmonar aspergillosis that were admitted to the ICU of different medical centers of Buenos Aires, Salta and Santa Fe provinces, Argentina. Isolates were recovered during August 2020 and August 2021 and were studied looking for species prevalence and azole resistance incidence. Isolates were identified by morphological criteria based on standard macroscopic and microscopic characteristics, including colonial form, growth rate, surface appearance and color, and microscopic assessment of hyphae (size, branching and presence of septa), conidia and conidia-bearing structures. Antifungal susceptibility testing was performed by microdilution following the CLSI M38 3rd ed. Document. Amphotericin B (AMB), itraconazole (ITC), voriconazole (VRC) and posaconazole (POS) were evaluated. Results: Among the 50 Aspergillus isolates analyzed, 4 species complexes were found: 60 % belonged to section Fumigati, 30% to section Nigri, 8% to section Flavi and 2% to section Terrei. The MIC values for AMB ranged 0.125-1.0 µg/ml for A. fumigatus, 0.06-4.0 µg/ml for A. niger, 1.0-8.0 µg/ml for A. flavus and 4.0 µg/ml for A. terreus. The MIC values for ITC ranged 0.125-1.0 µg/ml for A. fumigatus, 0.06-4.0 µg/ml for A. niger, 0.06-0.5 µg/ml for A. flavus and 0.5 µg/ml for A. terreus. The MIC values for VRC ranged 0.25-1.0 µg/ml for A. fumigatus, 0.125-1.0 µg/ml for A. niger, 0.25-1.0 µg/ml for A. flavus and 2.0 µg/ml for A. terreus. The MIC values for POS ranged 0.015-0.5 µg/ml for A. fumigatus, A. niger and A. flavus and 0.125 µg/ml for A. terreus.Conclusion: This study shows that A. fumigatus and A. niger have a high frequency in COVID-19 patients with probable CAPA from Argentina. Continuous clinical surveillance is required to detect azole resistant isolates.