First Confirmed Description of <i>Acremonium egyptiacum</i> from Greece and Molecular Identification of <i>Acremonium</i> and <i>Acremonium</i>-like Clinical Isolates

Abstract

Acremonium and the recently separated acremonium-like genera, such as Sarocladium, are emerging causes of opportunistic disease in humans, mainly post-traumatic infections in immunocompetent hosts, but also invasive infections in immunocompromised patients, such as those undergoing transplantation. Acremonium egyptiacum has emerged as the major pathogenic Acremonium species in humans, implicated mainly in nail but also in disseminated and organ specific infections. In this first study of acremonium-like clinical isolates in Greece, 34 isolates were identified and typed by sequencing the internal transcribed spacer, and their antifungal susceptibility was determined by a modified CLSI standard M38 3rd Edition method for filamentous fungi. A. egyptiacum was the primary species (18 isolates) followed by Sarocladium kiliense (8), Acremonium charticola, Gliomastix polychroma, Proxiovicillium blochii, Sarocladium terricola, Sarocladium zeae, and Stanjemonium dichromosporum (all with one isolate). Two isolates, each with a novel ITS sequence, possibly represent undescribed species with an affinity to Emericellopsis. All three A. egyptiacum ITS barcode types described to date were identified, with 3 being the major type. Flutrimazole, lanoconazole, and luliconazole presented the lower minimum inhibitory concentration (MIC) values against A. egyptiacum, with a geometric mean (GM) MIC of 2.50, 1.92, and 1.57 μg/mL, respectively. Amphotericin B, itraconazole, posaconazole, voriconazole, terbinafine, amorolfine, and griseofulvin MICs were overall high (GM 12.79–29.49 μg/mL). An analysis of variance performed on absolute values showed that flutrimazole, lanoconazole, and luliconazole were equivalent and notably lower than those of all the other drugs tested against A. egyptiacum. Antifungal susceptibility of the three different A. egyptiacum genotypes was homogeneous. Overall, the high MICs recorded for all systemically administered drugs, and for some topical antifungals against the tested A. egyptiacum and other acremonium-like clinical isolates, justify the routine susceptibility testing of clinical isolates.

Keywords

• acremonium-like fungi
• <i>Acremonium egyptiacum</i>
• Greece
• ITS
• antifungal susceptibility
• CLSI M38 Ed3