Antifungal Susceptibility and Phylogeny of Opportunistic Members of the GenusFusariumCausing Human Keratomycosis in South India

Abstract

Fusarium species are reported frequently as the most common causative agents of fungal keratitis in tropical countries such as India. Sixty-five fusaria isolated from patients were subjected to multilocus DNA sequencing to characterize the spectrum of the species associated with keratitis infections in India. Susceptibilities of these fusaria to ten antifungals were determined in vitro by the broth microdilution method. An impressive phylogenetic diversity of fusaria was reflected in susceptibilities differing at species level. Typing results revealed that the isolates were distributed among species in the species complexes (SCs) of F. solani (FSSC; n = 54), F. oxysporum (FOSC; n = 1), F. fujikuroi (FFSC; n = 3), and F. dimerum (FDSC; n = 7). Amphotericin B, voriconazole, and clotrimazole proved to be the most effective drugs, followed by econazole.

In vitro Antifungal Susceptibility Testing of Clinical and Environmental Fusarium Isolates in Iran

“…Based on this standard, ITC was inactive against all clinical and the majority of environmental Fusarium isolates. The results obtained in this study are in agreement with results of other studies that reported low activity of ITC against Fusarium species (13,15,30,31). On the other hand, in the present study, almost all Fusarium species had high MICs above the published epidemiological cut -off values and were insensitive to ITC with MICs ≥ 16 µg/mL which can lead to treatment failure in patients infected with these resistant strains.…”

Global molecular epidemiology and genetic diversity of Fusarium , a significant emerging group of human opportunists from 1958 to 2015

“…Although human opportunists were highlighted in many studies focusing on specific regions of the world and specific types of infections, 10, 11, 12, 13, 27, 28, 29, 30, 31, 32, 33, 34 the 127 Fusarium strains from the current study were collected from 26 countries in six continents and included clinical and environmental strains and isolates from cold blooded animals. Of these, Australia, Brazil, India, Mexico and the USA were among the top 10 countries with the highest Fusarium infections based on clinical isolates in the CBS collection.…”

“…Of these species, F. falciforme ( n =14/127 cases; 11%) was the dominant species in our study and mainly isolated from keratitis cases in Brazil, India and Mexico. Recently, Hassan et al 13 showed that the majority of keratitis cases ( n =46/65 cases; 70.7%) were F. falciforme . This species is emerging as one of the most virulent Fusarium species associated with fusariosis and keratitis.…”

“…This species was also recently reported in Asia (India and Qatar). 13, 16 Given the large distances of identical strains occurring in many different countries, airborne distribution seems likely. However, the presence of F. incarnatum, F. equiseti and F. chlamydosporum in clinical samples from various infections in North America remains puzzling but can perhaps be explained by sampling effects.…”

“…Most published studies have focused on prevalence in single healthcare centers. 10, 11, 12, 13, 14, 15, 16 Nucci et al 17 reported 233 cases from different hospitals on a global scale. Mohammed et al 18 reported 26 cases from the United States and reviewed 97 cases from the literature, and Horn et al 12 described 65 cases from the North American Path Alliance Registry.…”