Necrotizing Microascus tracheobronchitis in a bilateral lung transplant recipient

Abstract

Invasive fungal infections are a major cause of mortality among solid organ transplant recipients. Scopulariopsis species and their teleomorph Microascus are molds found in soil and decaying organic matter. We report here the case of a woman who underwent bilateral lung transplantation for severe emphysema. On day 25 after transplantation, endobronchial green-black lesions were detected during routine endoscopy. Endobronchial swabs, biopsies, and bronchoalveolar lavage samples were positive for Microascus cirrosus. This fungal infection developed despite voriconazole given for previous persistent invasive aspergillosis. Treatment consisted of a combination of antifungal medication (voriconazole, terbinafine, amphotericin B, and caspofungin) and endoscopic resection of necrosed bronchial mucosa. A favorable clinical outcome was achieved after 7 weeks of treatment. Seven cases of Scopulariopsis/Microascus infection have been previously described in solid organ transplant recipients. Only two survived after treatment with an antifungal combination therapy including echinocandins, posaconazole, and terbinafine. In immunocompromised patients, infection by Microascus species is a rare but life-threatening event because of innate resistance to most common antifungal drugs. Our patient was successfully cured by combined therapy including intravenous voriconazole and caspofungin, oral terbinafine, and inhaled voriconazole and amphotericin B administered for 7 weeks in association with iterative endoscopic debridement to reduce fungal inoculum.

Pulmonary Microascus cirrosus infection in an immunocompetent patient with bronchiectasis: A case report

“…Although Microascus is commonly found in different habitats and decaying organic matter, except for one case which was later reclassified as M. gracilis , only five publications concerning M. cirrosus infections have been reported to date [ 3 , 5 , 6 ]. In addition, respiratory infection was involved in just three immunosuppressed patients, with two received BMT for acute myelogenous leukemia and one underwent bilateral lung transplant for severe emphysema [ [7] , [8] , [9] ].…”

“…Multi-drug combination therapy, added with surgical resection of localized lesion and reconstitution of the immune system if necessary, may be a promising choice for Microascus infection [ 2 ]. In the latest report, a bilateral lung transplant recipient who developed invasive lung infection caused by M. cirrosus was successfully cured by a combined treatment consisting of four antifungal agents (voriconazole, terbinafine, amphotericin B, and caspofungin) and endoscopic resection of necrosed bronchial mucosa [ 9 ]. The patient in our study was given an antifungal combination therapy of voriconazole and amphotericin B.…”

First reported case of disseminated Microascus gracilis infection in a lung transplant patient

“…Opportunistic infections of Microascus spp have been reported mostly in immunocompromised patients, with most severe infections occurring in solid organ transplant patients, particularly lung transplant patients. A summary of previously reported infections by Microascus spp in solid organ transplant patients [ 3 , [10] , [11] , [12] , [13] , [14] , [15] ] is shown in Table 1 . Of the total eight cases, six occurred in lung transplant patients.…”

“…The in vitro synergy study by Cuenca-Estrella et al on ten Scopulariopsis brevicaulis isolates demonstrates that the combination of posaconazole plus terbinafine achieves the highest rate of synergistic effect, followed by amphotericin B plus caspofungin, posaconazole plus caspofungin, and voriconazole plus caspofungin [ 18 ]. In fact, as shown in Table 1 for Microascus spp, the combination of posaconazole plus terbinafine (with amphotericin B and/or micafungin) cured two of the three infections, while the combination of voriconazole, terbinafine, amphotericin B, and caspofungin was effective in the third case [ 10 , 11 , 15 ]. Therefore, for multidrug resistant molds like Microascus spp, in addition to in vitro susceptibility testing, knowledge of in vitro synergy studies would provide more data for clinical decision making.…”

A human subcutaneous infection by Microascus ennothomasiorum sp. nov

“…However, recent phylogenetic studies demonstrated that both Microascus and Scopulariopsis were distinct genera and the species nomenclature was adapted accordingly . Dermatologists are well acquainted with Scopulariopsis brevicaulis, which is a common cause of onychomycosis worldwide, but there are several Microascus species, less known to clinicians, that are able to cause both superficial and deep human infections especially in immunocompromised patients, including necrotising tracheobronchitis . It is also of note that currently some Microascus species, such as Microascus appendiculatus, M. brunneosporus , M. chinensis , M. onychoides , Microascus pseudolongirostris , Microascus restrictus and Microascus verrucosus , are exclusively known from human clinical specimens, although their clinical significance remains unknown.…”