UnusualAspergillusspecies in patients with cystic fibrosis

Abstract

Poorly sporulating Aspergillus isolates from patients with cystic fibrosis (CF) are generally identified in routine procedures as Aspergillus spp. In this study, we identified and characterized 11 isolates belonging to two unusual Aspergillus species of the section Fumigati (A. lentulus and Neosartorya pseudofischeri) recovered from four different patients. Aspergillus lentulus was found occasionally during a 10-year follow-up study of one CF patient colonized by A. fumigatus. Neosartorya pseudofischeri was isolated from three patients followed in different European hospitals. This species was recovered from two sputum samples of one patient, and from four successive samples of the two other patients, suggesting that it may be responsible for chronic colonization. Both species were isolated together with A. fumigatus. Isolates from both species did not grow at 50°C, and DNA sequence analysis, together with further morphological observations permitted identification at the species level. Growth at different temperatures and antifungal susceptibility were also investigated. All the isolates of N. pseudofischeri exhibited a very low susceptibility to voriconazole (VRZ) whereas a very low susceptibility to VRZ and amphotericin B was seen with the A. lentulus isolates.

An alternative host model of a mixed fungal infection by azole susceptible and resistantAspergillusspp strains

“…However, it has been increasingly reported in severely immunocompromised patients such as hematological and cystic fibrosis patients, those suffering from chronic obstructive pulmonary disease (COPD) or other populations receiving high doses of corticosteroids. [7][8][9][10] Invasive aspergillosis caused by A. lentulus is associated with high mortality and clinical isolates of this species show high MICs to azoles, echinocandins and amphotericin B. [6][7][8][9]11 Resistance to voriconazol (VRC) is especially worrisome considering that this antifungal is the primary drug used to treat invasive aspergillosis.…”

Misidentification of Neosartorya pseudofischeri as Aspergillus fumigatus in a Lung Transplant Patient

“…Two separate groups have also identified N. pseudofischeri from the sputum of cystic fibrosis patients (2,6). Colonization in these hosts may occur for extended periods of time, although the significance in terms of attributable disease is unclear.…”

“…No additional structures were seen on either CZA or IMA media, although culture for 7 days on malt extract agar (MEA) revealed that some strains of N. pseudofischeri produce ascogonia and ascomata (4). Ascogonia are precursors to ascoma and appear as hyphal coils, while hyaline ascomata contain 8 ascospores with spiny valves (2,6). These structures are unreliably produced and cannot always be used for identification, although lower temperatures may increase production (5).…”

“…Other techniques such as thermotolerance studies and multiplex PCR of the ␤-tubulin (␤-tub) and Rodlet A (rodA) genes can also been used, since they can separate A. fumigatus from less-common species such as A. lentulus, A. novofumigatus, A. unilateralis, N. hiratsukae, N. pseudofischeri, and N. udagawae species by amplicon size (6,9). To ensure that the organism was accurately identified, ␤-tub was also PCR amplified and then sequenced using previously published Bt2a and Bt2b primers (7,10).…”

A Case Report on Aspergillus lentulus Pneumonia

“…Isolations of A. lentulus defined in 2005 as a kind of new Aspergillus species were reported in America, Japan, South Korea, Australia, and Spain (9,12). The characteristics of some cases with colonisation or infection caused by A. lentulus in the literature are shown in Table 1 (3,8,9,13,14). However, an isolation of or infection caused by A. lentulus was not reported in Turkey until today.…”