Antifungal drug resistance in filamentous fungi, particularly Aspergillus species, is increasing worldwide. Therefore, new antifungal drugs or combinations of drugs are urgently required to overcome this public health situation. In the present study, we examined the antifungal activity of vancomycin-functionalized AuNPs. These functionalized AuNPs were characterized, and their antifungal activity and associated killing mechanism were investigated using conventional methodologies against the conidia of A. fumigatus and A. flavus. The differential antifungal activity of vancomycin-functionalized Au-NPs against the conidia of Aspergillus species is dependent on structural differences in the conidial cell wall. The results demonstrated potent fungicidal activity against A. fumigatus, with a MIC value of 4.68 µg/mL, 93% germination inhibition, and 38.4% killing rate within 8 h of exposure. However, the activity against A. flavus was fungistatic; a MIC value of 18.7 µg/mL and 35% conidial germination inhibition, followed by 28.4% killing rate, were noted under similar conditions. Furthermore, endogenous reactive oxygen species (ROS) accumulation was 37.4 and 23.1% in conidial populations of A. fumigatus and A. flavus, respectively. Raman spectroscopy analysis confirmed the possible (but not confirmed) binding of functionalized AuNPs with the chitin and galactomannan components of the cell wall. A potential strategy that involves the exploration of antibacterial drugs using AuNPs as efficient drug carriers may also be appropriate for countering emerging drug resistance in filamentous fungi.

Candidiasis is the most incessant fungal disease affecting human population worldwide. In this research work, we explored the characteristics contributing

Respiratory aspergillosis refers to a range of infections, from allergic to chronic and invasive, which can be life‐threatening and are primarily caused by Aspergillus fumigatus and Aspergillus flavus . Other species, including Aspergillus terreus, Aspergillus nidulans , and Aspergillus versicolor , have also been implicated in respiratory infections. Treatment for chronic to invasive pulmonary aspergillosis typically involves azole antifungal drugs, although studies have shown varying minimum inhibitory concentrations (MIC) for these medications, with a growing concern over voriconazole resistance. During the period from August 2022 to May 2024, characteristic hyphae were detected in 7.2% of lower respiratory samples, with culture positivity in 12.8%, including early morning sputum and bronchoalveolar lavage fluid samples. A. flavus ( n = 282) was the most frequently isolated species, followed by A. fumigatus ( n = 86). Additionally, a seasonal trend was observed for Aspergillus infections, with peaks in April and September. The MIC of itraconazole, voriconazole, posaconazole, amphotericin B, ravuconazole, and caspofungin were assessed for the isolated Aspergillus species. A higher MIC of amphotericin B was observed against A. flavus and A. terreus , whereas azoles exhibited a relatively lower MIC. Caspofungin and posaconazole exhibited the lowest MIC against the isolated Aspergillus species. Therefore, it is crucial to identify the causative fungi and determine the antifungal MIC for Aspergillus species responsible for lower respiratory tract infections. This study emphasizes the significance of respiratory aspergillosis in TB‐endemic regions of Eastern India.

Aspergillus nidulans is a fungal pathogen that causes respiratory issues in individuals with compromised immune systems. It is identified through culture characteristics and microscopic features such as Cleistothecia and Hülle Cells. However, similar traits are found in cryptic Aspergillus species, such as stellatus, cristatus , and oryzae . In a case series from a hospital in North India, A. nidulans strains isolated from patients with pulmonary aspergillosis were phenotypically identified and then underwent molecular characterization through sequencing of the amplified ITS1‐5.8S rDNA‐ITS2 region and antifungal susceptibility testing (AST) according to the CLSI M38A3 guidelines. The molecular characteristics and antifungal profiles of the nine phenotypic A. nidulans were as follows: A. stellatus ( n = 5), A. nidulans ( n = 2), A. cristatus ( n = 1), and A. oryzae ( n = 1). Phylogenetic analysis revealed a close relationship between A. stellatus, A. nidulans , and A. cristatus , while A. oryzae showed significant divergence. Furthermore, the minimum inhibitory concentration (MIC) of antifungals was the lowest for caspofungin, followed by voriconazole. However, a higher amphotericin B MIC (2 µg/mL) was observed for A. stellatus . Thus, sequencing the ITS1‐5.8S rDNA‐ITS2 region can accurately identify cryptic species with superior taxonomic resolution. Additionally, the MIC of amphotericin B against A. stellatus underscores the importance of precise molecular identification and antifungal MIC profiling in each case of pulmonary aspergillosis.