Molecular identification of Fusarium species complex isolated from clinical samples and its antifungal susceptibility patterns

Abstract

Background and Purpose: More than 300 Fusarium species are grouped into approximately 23 species complexes out of which around 70 are involved in human infections. The nomenclature of these species has undergone considerable changes in recent years. These species cause localized infections in individuals while inducing systemic infections mainly in immunocompromised patients. The present study was conducted to identify Fusarium species in clinical isolates by molecular methods and determine their in vitro minimum inhibitory concentration (MIC) patterns to address the lack of data in this domain in Northern India.Materials and Methods: For the purpose of the study, Fusarium isolates obtained from various clinical samples were sent to the Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands, for molecular identification. The MIC testing was performed using the microbroth dilution method as per the Clinical and Laboratory Standards Institute reference method (M38-A2).Results: Fusarium was isolated from 33 patients (i.e., 1, 1, 2, 14, and 15 cases with endophthalmitis, sinusitis, pulmonary involvement, onychomycosis, and keratitis, respectively). These 33 isolates belonged to three species complexes, namely F. solani species complex (FSSC; n=13), F. fujikuroi species complex (FFSC; n=13), and F. incarnatum equiseti species complex (FIESC; n=7). The species identified within FSSC, FFSC, and FIESC included F. keratoplasticum (n=6)/F. falciforme (n=6)/F. solani (n=1), F. proliferatum (n=7)/F. sacchari (n=5)/F. anthophilum (n=1), and F. incarnatum SC species (n=6)/F. equiseti SC species (n=1), respectively. The MIC results showed that all isolates had a lower MIC against amphotericin B than against the other antifungal agents.Conclusion: Timely diagnosis and appropriate treatment will facilitate the improvement of patient outcomes.

In Vitro Antifungal Susceptibility Profile of Miltefosine against a Collection of Azole and Echinocandins Resistant Fusarium Strains

“…In the present study, the in vitro activity of amphotericin B against all the isolates was more potent than other agents tested. This is consistent with the findings of most studies in which amphotericin B was found to have lower MICs in vitro compared to other antifungals [ 4 , 13 , 35 , 36 , 37 ]. As previously reported [ 10 , 31 , 38 ], the susceptibility of Fusarium to amphotericin B varied, depending on the species.…”

“…Miltefosine in combination with voriconazole demonstrated synergy against three mucormycetes and one isolate of Scedosporium prolificans [25]. In our study, miltefosine showed good inhibitory activity against all Fusarium isolates with MIC values ranging from 0.25 to 4 µg/mL, making it more potent than voriconazole (0.125-16), itraconazole (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) and caspofungin (0.125-8). The MIC values for miltefosine reported here are consistent with the 2 µg/mL value reported for Cryptococcus neoformans and Cryptococcus gatti, C. glabrata, C. krusei, C. albicans, A. fumigatus, and Trichophyton mentagrophytes with this drug [40][41][42][43].…”

“…Fusarium species are saprobic molds that are found all over the world in the environment and various organic substrates [ 1 , 2 , 3 ]. Fusarium contains more than 300 species grouped in 22 species complexes with exceptional genetic diversity [ 1 , 4 ]. Most species of Fusarium are the primary causes of plant pathogens and are responsible for significant economic losses on crops [ 5 , 6 ].…”

“…This presents a significant challenge in the best treatment for patients with severe fusariosis infections. Furthermore, resistance mechanisms in Fusarium species have not been thoroughly studied and no clinical breakpoints for Fusarium infections have been defined [ 4 , 19 ]. Resistance of the Fusarium genus to the majority of antifungal drugs available in clinical settings is a significant threat for immunocompromised patients and therefore studies of alternative targets and therapeutic approaches that may improve the outcome of these severe opportunistic infections are critical [ 20 ].…”

Rapid identification of four Fusariumspp. complex by high-resolution melting curve analysis and their antifungal susceptibility profiles

“…However, approximately 70 Fusarium spp. are related to infections that cause fusariosis in humans [11,12]. The rate of human fungal infections increases with the upward trend of immunocompromised population, leading to an increase in the morbidity and mortality rates due to fusariosis [13][14][15][16][17].…”