We evaluated the usefulness of a serum Aspergillus PCR assay for the diagnosis and prognosis of invasive aspergillosis in a study involving 941 patients for a total of 5146 serum samples. Fifty-one ...patients had proven/probable aspergillosis. We compared galactomannan (GM), PCR and mycologic analysis of pulmonary samples in both neutropenic and nonneutropenic patients. PCR performed in serum yielded 66.7% sensitivity, 98.7% specificity, 75.6% positive predictive value and 98.0% negative predictive value, while the GM index yielded 78.4% sensitivity, 87.5% specificity, 27% positive predictive value and 98.6% negative predictive value. The inclusion of PCR in the European Organization for Research and Treatment of Cancer (EORTC) and the Mycosis Study Group (MSG) mycologic criteria permitted the reclassification of nine other cases from possible to probable aspergillosis and increased the sensitivity to 71.7%. Combining the GM index with serum PCR increased the detection rate of invasive aspergillosis with 88.2% sensitivity. PCR was systematically negative in 16 patients with noninvasive forms of aspergillosis (namely aspergilloma and chronic aspergillosis). Remaining PCR positive after a period of 14 to 20 days of treatment was related to poor outcome at 30 and 90 days. Our results also indicate that, unlike the determination of the GM index, the initial fungus load as determined by PCR was highly predictive of 90-day mortality, with the rate of the latter being 15.8% for patients with <150 copies/mL vs. 73.2% for patients at or above that cutoff (p <0.0001). Therefore, PCR appears to be a powerful and interesting tool for the identification of patients with invasive aspergillosis who might benefit from more intense care.
There has been significant increase in the use of molecular tools for the diagnosis of invasive aspergillosis (IA) and mucormycosis. However, their range of detection may be too limited as species ...diversity and coinfections are increasing. Here, we aimed to evaluate a molecular workflow based on a new multiplex PCR assay detecting the whole Aspergillus genus and the Mucorales order followed by a species-specific PCR or a DNA-sequencing approach for IA and/or mucormycosis diagnosis and species identification on serum. Performances of the MycoGENIE Aspergillus spp./Mucorales spp. duplex PCR kit were analyzed on a broad range of fungal strains and on sera from high-risk patients prospectively over a 12-month period. The kit allowed the detection of nine Aspergillus species and 10 Mucorales (eight genera) strains assessed. No cross-reactions between the two targets were observed. Sera from 744 patients were prospectively analyzed, including 35 IA, 16 mucormycosis, and four coinfections. Sensitivity varies from 85.7% (18/21) in probable/proven IA to 28.6% (4/14) in COVID-19-associated pulmonary aspergillosis. PCR-positive samples corresponded to 21 A. fumigatus, one A. flavus, and one A. nidulans infections. All the disseminated mucormycosis were positive in serum (14/14), including the four Aspergillus coinfections, but sensitivity fell to 33.3% (2/6) in localized forms. DNA sequencing allowed Mucorales identification in serum in 15 patients. Remarkably, the most frequent species identified was
(eight cases), whereas it is barely found in fungal culture. This molecular workflow is a promising approach to improve IA and mucormycosis diagnosis and epidemiology.
, the third species responsible for invasive aspergillosis, has been considered as a homogeneous species until DNA-based identification uncovered many cryptic species. These species have been ...recently reclassified into the
section
However, little is yet known among the section
about the species distribution and the antifungal susceptibility pattern of each cryptic species. A total of 112 clinical isolates collected from 5 teaching hospitals in France and phenotypically identified as
were analyzed. Identification to the species level was carried out by nucleotide sequence analysis. The MICs of itraconazole, voriconazole, posaconazole, isavuconazole, and amphotericin B were determined by both the EUCAST and gradient concentration strip methods.
(
= 51, 45.5%) and
(
= 50, 44.6%) were the most common species while
accounted for only 6.3% (
= 7). The MICs of azole drugs were higher for
than for
The MIC of amphotericin B was 2 mg/liter or less for all isolates. Importantly, MICs determined by EUCAST showed no correlation with those determined by the gradient concentration strip method, with the latter being lower than the former (Spearman's rank correlation tests ranging from 0.01 to 0.25 depending on the antifungal agent;
> 0.4). In conclusion,
should be considered as a minority species in the section
The differences in MICs between species for different azoles underline the importance of accurate identification. Significant divergences in the determination of MIC between EUCAST and the gradient concentration strip methods require further investigation.
Since their introduction in the 2000s, echinocandin drugs have become widely used for the treatment and prophylaxis of invasive fungal infections and, notably, invasive candidiasis. Although cases of ...breakthrough candidiasis in patients receiving echinocandins have been reported, clinical failure during echinocandin treatment due to the acquisition of resistance by a normally susceptible
Candida
spp. isolate is considered rare. To date, no publications have been published correlating the use of echinocandins and the emergence of echinocandin resistance among
Candida
species. So, our goal is to report an initial analysis of echinocandin use in relation to the emergence of resistant
Candida
isolates. We report here a single-centre experience of the emergence of eight resistant isolates belonging to normally susceptible
Candida
species in six patients receiving echinocandins. We describe the context and analyse the use of echinocandins over the previous decade. For seven of these isolates, we identified FKS gene mutations involved in decreased susceptibility. Seven isolates were obtained in 2011, on the heels of a ten-fold increase in caspofungin use over the preceding decade. In contrast, in 2012, the use of echinocandins decreased in our institution by 19.5 % and, in that year, only one
Candida
-resistant isolate was detected, despite the stable global epidemiology of invasive candidaemia. This work underlines the necessity of improving the prescription of antifungal drugs. Improvement in the monitoring of strain susceptibility should also be considered in order to better detect the emergence of resistant or non-susceptible yeast strains.
The clinical involvement and antifungal susceptibility of Aspergillus section
are poorly known. We analyzed 52 isolates, including 48 clinical isolates, belonging to 9 species inside the section
. ...The whole section exhibited, by the EUCAST reference method, a poor susceptibility to amphotericin B, but species/series-specific patterns were observed for azole drugs. This underlines the interest in getting an accurate identification inside the section
to guide the choice of antifungal treatment in clinical practice.
Cerebral aspergillosis is a rare but often fatal form of invasive aspergillosis that remains difficult to diagnose. The literature has shown the value of Aspergillus PCR in blood-derived samples for ...the diagnosis of invasive aspergillosis but provides far less information for cerebrospinal fluid (CSF) in cerebral aspergillosis. Here, we evaluated the usefulness of an Aspergillus PCR assay performed on CSF for the diagnosis of cerebral aspergillosis.
This retrospective study involved 72 patients with suspected cerebral aspergillosis for a total of 88 CSF samples in whom CSF Aspergillus PCR was performed.
Seventeen patients had proven/probable invasive aspergillosis according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria, including 12 cases of proven/probable cerebral aspergillosis. Aspergillus PCR in CSF was positive in nine of the twelve patients with cerebral aspergillosis, i.e. 75% sensitivity. In contrast, CSF culture was positive for Aspergillus in only two patients. In the non-cerebral aspergillosis group (60 patients), PCR was positive in one patient, i.e. 98.3% specificity. In this particular population of high-risk patients with suspicion of cerebral aspergillosis, the disease incidence was 16.7%. Therefore, the positive and negative predictive values of PCR were 90% and 95.2%, respectively.
The results of this study indicate that Aspergillus PCR in CSF is an interesting tool that may eliminate the need for cerebral biopsy in patients with suspected cerebral aspergillosis.
Invasive infections caused by filamentous fungi are a major threat for immunocompromised patients. Innate/acquired resistance to antifungal drugs might necessitate combination therapies. We assessed ...the potential combination of voriconazole with miltefosine, an original drug with antifungal activity against 33 clinically relevant mold isolates, including both azole-susceptible and -resistant Aspergillus. Using complete inhibition as an endpoint, interactions were indifferent for 32/33 isolates. An alternative 50% inhibition endpoint showed synergistic interactions for 14/33 isolates. Antagonism was absent.
We report a severe case of kerion Celsi of the scalp in a previously healthy 13-year-old girl due to Trichophyton quinckeanum, an emerging dermatophyte species in Europe. The species was definitely ...identified by DNA sequencing and the patient was successfully treated by oral terbinafine for 6 weeks. Kerion Celsi is a severe inflammatory form of tinea capitis, which is characterised by a purulent discharge and alopecia 1. It typically occurs in children infected with zoophilic dermatophytes, such as Trichophyton mentagrophytes, and an increasing number of cases caused by other Trichophyton species has recently been reported 2. Herein we report a severe case of kerion Celsi of the scalp caused by the emerging species Trichophyton quinckeanum, which was successfully treated by oral antifungal.
Abstract
New mold species are increasingly reported in invasive fungal infections. However, these fungi are often misdiagnosed or undiagnosed due to the use of inappropriate laboratory diagnostic ...tools. Tropical countries, such as French Guiana, harbor a vast diversity of environmental fungi representing a potential source of emerging pathogens. To assess the impact of this diversity on the accuracy of mold-infection diagnoses, we identified mold clinical isolates in French Guiana during a five-month follow-up using both microscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. In total, 38.8% of the 98 obtained molds isolates could not be identified and required a DNA-based identification. Fungal diversity was high, including 46 species, 26 genera, and 13 orders. Fungal ecology was unusual, as Aspergillus species accounted for only 27% of all isolates, and the Nigri section was the most abundant out of the six detected Aspergillus sections. Macromycetes (orders Agaricales, Polyporales, and Russulales) and endophytic fungi accounted for respectively 11% and 14% of all isolates. Thus, in tropical areas with high fungal diversity, such as French Guiana, routine mold identification tools are inadequate. Molecular identifications, as well as morphological descriptions, are necessary for the construction of region-specific mass spectrum databases. These advances will improve the diagnosis and clinical management of new fungal infections.
Lay Summary
In French Guiana, environmental fungal diversity may be a source of emerging pathogens. We evaluated microscopy and mass spectrometry to identify mold clinical isolates. With 39% of unidentified isolates, a region-specific mass spectrum database would improve the diagnosis of new fungal infections.
section
is a species complex currently comprised of 14 cryptic species whose prevalence in clinical samples as well as antifungal susceptibility are poorly known. The aims of this study were to ...investigate
clinical isolates at the species level and to perform antifungal susceptibility analyses by reference and commercial methods. Eighty-two clinical
isolates were collected from 8 French university hospitals. Molecular identification was performed by sequencing parts of beta-tubulin and calmodulin genes. MICs or minimum effective concentrations (MECs) were determined for 8 antifungal drugs using both EUCAST broth microdilution (BMD) methods and concentration gradient strips (CGS). Among the 79
isolates,
(
= 61),
(
= 13),
(
= 3), and
(
= 2) were identified. All strains had MICs of ≥1 mg/liter for amphotericin B, except for two isolates (both
) that had MICs of 0.25 mg/liter. Four
isolates were resistant to at least one azole drug, including one with pan-azole resistance, yet no mutation in the
gene was found. All strains had low MECs for the three echinocandins. The essential agreements (EAs) between BMD and CGS were >90%, except for those of amphotericin B (79.7%) and itraconazole (73.4%). Isolates belonging to the
section
identified in clinical samples show wider species diversity beyond the known
Azole resistance inside the section
is uncommon and is not related to CYP51A mutations here. Finally, CGS is an interesting alternative for routine antifungal susceptibility testing.
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