The implementation of MALDI-TOF MS in medical microbiology laboratories has revolutionized practices and significantly reduced turnaround times of identification processes. However, although bacteriology quickly benefited from the contributions of this technique, adjustments were necessary to accommodate the specific characteristics of fungi. MALDI-TOF MS is now an indispensable tool in clinical mycology laboratories, both for the identification of yeasts and filamentous fungi, and other innovative uses are gradually emerging. Based on the practical experience of our medical mycology laboratory, this review will present the current uses of MALDI-TOF MS and the adaptations we implemented, to allow their practical execution in a daily routine. We will also introduce some less mainstream applications, like those for fungemia, or even still under development, as is the case for the determination of sensitivity to antifungal agents or typing methods.

MALDI-TOF mass spectrometry (MS) identification of pathogenic filamentous fungi is often impaired by difficulties in harvesting hyphae embedded in the medium and long extraction protocols. The ID Fungi Plate (IDFP) is a novel culture method developed to address such difficulties and improve the identification of filamentous fungi by MALDI-TOF MS. We cultured 64 strains and 11 clinical samples on IDFP, Sabouraud agar-chloramphenicol (SAB), and ChromID Candida agar (CAN2). We then compared the three media for growth, ease of harvest, amount of material picked, and MALDI-TOF identification scores after either rapid direct transfer (DT) or a long ethanol-acetonitrile (EA) extraction protocol. Antifungal susceptibility testing and microscopic morphology after subculture on SAB and IDFP were also compared for ten molds. Growth rates and morphological aspects were similar for the three media. With IDFP, harvesting of fungal material for the extraction procedure was rapid and easy in 92.4% of cases, whereas it was tedious on SAB or CAN2 in 65.2% and 80.3% of cases, respectively. The proportion of scores above 1.7 (defined as acceptable identification) were comparable for both extraction protocols using IDFP (P = 0.256). Moreover, rates of acceptable identification after DT performed on IDFP (93.9%) were significantly higher than those obtained after EA extraction with SAB (69.7%) or CAN2 (71.2%) (P = <0.001 and P = 0.001, respectively). Morphological aspects and antifungal susceptibility testing were similar between IDFP and SAB. IDFP is a culture plate that facilitates and improves the identification of filamentous fungi, allowing accurate routine identification of molds with MALDI-TOF-MS using a rapid-extraction protocol.

Toxoplasmosis is a globally distributed parasitic infection that can be particularly severe when opportunistic or congenital. Its diagnosis requires accurate and rapid techniques that rely mainly o...

T cells are critical to control Toxoplasma gondii (T. gondii) parasite infection. Yet, our understanding of T. gondii-specific CD8+ T cell responses in humans remains scarce. Here, we studied 56 HLA-A2+ healthy blood donors, including 40 latently infected subjects. In addition to routine T. gondii serodiagnosis, we quantified IgG specific for the bradyzoite-restricted Brain Cyst Load-associated Antigen (BCLA) and we enumerated blood-circulating parasite-specific CD8+ T cells by IFN-γ ELISPOT using a panel of 29 T. gondii peptides, previously reported to be HLA-A2 ligands. We identified a set of 16 epitopes that stimulates detectable CD8+ T cell responses in 50% routine T. gondii seropositive subjects, yet none was a universal immunodominant T. gondii epitope. Among individuals with either positive BCLA-specific serology and/or detectable T. gondii-specific T cell response, T. gondii-specific ELISPOT responses were inversely correlated with BCLA-specific IgG titers, suggesting that stronger CD8+ T cell responses may contribute to reduce chronic parasite burden or that certain long-standing infections may result in waning of antibody levels but persistence of CD8+ T cell memory. Furthermore, 2 out of 56 subjects displayed null T. gondii-specific humoral responses across 4 serological assays, but had measurable CD8+ T cell responses to 2 T. gondii peptides. This study sheds light on the complexity of T. gondii-specific immune responses in humans and rationalizes the cellular and serological toolkits for immune monitoring of latent T. gondii infection in humans.

Schistosomiasis is a neglected tropical disease classically responsible for intestinal or urogenital forms. We report the incidental diagnosis of ectopic mammary schistosomiasis involving Schistosoma haematobium following a breast cancer screening mammogram in a European patient with a distant history of travel.