Cryptococcus neoformans/gattii and Histoplasma capsulatum var. capsulatum may present atypical histopathological features inducing diagnostic errors. We aimed to estimate the frequency of these atypical features in formalin-fixed tissue (FT) samples and to assess the relevance of an integrated histomolecular diagnosis using specific H. capsulatum PCR and panfungal PCR followed by Sanger sequencing and/or targeted massive parallel sequencing (MPS). A total of 27 FT from 23 patients with a histopathological diagnosis of cryptococcosis (n = 16 FT from 13 patients) or histoplasmosis (n = 11 FT from 10 patients) were retrospectively included. All FT were consultation cases. Mycological identifications on equivalent fresh tissue were available for 11/23 (47.8%) patients. The expert pathologist review modified the diagnosis suggested by the initial pathologist in 7/27 (25.9%) FT. Fungal morphology and tissue inflammation were compared between both mycoses. The most discriminant atypical criterion was the presence of dented-looking yeasts, observed in 68.75% (11/16) of C. neoformans/gattii and none (0/11) of H. capsulatum var. capsulatum (P = .002). For the 12/23 (52.2%) patients without mycological identification on fresh tissue, an integrated histomolecular diagnosis on FT using specific PCR or panfungal PCR followed by Sanger sequencing and/or MPS led to fungal identification in 9/12 (75%) cases; for cryptococcosis, the targeted MPS sensitivity was higher than that of Sanger sequencing (P = .041). Thus, because atypical histopathological features may be tricky, integrated histomolecular diagnosis is essential for optimal patient care. Pathological features of Cryptococcus neoformans showed more atypical dented-looking yeasts than Histoplasma capsulatum. An integrated histomolecular diagnosis improved fungal identification in 75% of the cases, with a higher sensitivity of targeted massive parallel compared to Sanger sequencing for cryptococcosis.

The epidemiology of Toxoplasma infection is known to vary geographically, but is also likely to vary over time, under the influence of many contributing factors. Monitoring is particularly useful in the context of preventing congenital toxoplasmosis. We took advantage of the French prenatal prevention programme to retrospectively assess changes between 2017 and 2023 in seroprevalence and incidence rates of Toxoplasma infection in pregnant women and the incidence of congenital infections. We conducted a longitudinal retrospective study including all pregnancies with known Toxoplasma status followed up at Lyon’s public maternity hospitals between 2017 and 2023 (71,922 pregnancies). We used a multivariable logistic regression model to identify factors (age-group, WHO region of origin, population density of the area of residence and parity) associated with seropositivity. The seroprevalence of toxoplasmosis decreased consistently from 26.4% in 2017 to 22.1% in 2023 (p = 0.003), while maternal infection incidence remained stable at 1.3/1,000 pregnancies at risk. Notably, the seroprevalence showed a linear increase with age from 18.9% in women aged 25–29 years to 38.0% in women aged ≥40 years (p < 0.001). The seroprevalence was lower in pregnant women living in rural areas [adjusted seroprevalence ratio (aPR) = 0.87, 95% CI: 0.82–0.92] and higher in multiparous women (aPR = 1.08, 95% CI: 1.04–1.12). This study confirms the ongoing decline in toxoplasmosis seroprevalence while seroconversions remained stable, indicating a need for more tests in seronegative women in the future. These findings highlight the need for ongoing monitoring and refinement of congenital toxoplasmosis prevention strategies in high-income countries.

Conventional diagnosis of fungal infections of the skin, nail, and hair requires both expertise in mycology and prolonged cultures. We evaluated a new molecular tool based on an innovative technology, the DendrisKIT^®DP, combining a pan-fungal PCR, a DNA chip and a decision algorithm using machine learning, for the diagnosis of superficial fungal infections directly from clinical samples. It enables the simultaneous detection of Candida albicans and twelve dermatophytes, providing faster results than conventional techniques. Among 85 clinical samples (50 skin scrapings, 29 nail specimens, and 6 hair specimens) routinely tested by microscopic examination and cultures that were retrospectively tested by the DendrisKIT^®DP, we found a sensitivity of 83.9% and a specificity of 88.9%. This performance appeared satisfactory compared to microscopy and culture, and results were achieved much faster than with cultures, saving time for patient management. Moreover, thanks to the continuous improvement in the identification algorithm due to enriching the database, its performance is likely to be further enhanced.

Amoebiasis is a cosmopolitan parasitic disease caused by Entamoeba histolytica . The most lethal form is extra-intestinal amoebiasis, mainly manifesting as liver abscesses. Diagnosis is based on clinical, radiological, and biological tests. However, there are currently few serology reagents still available on the European market for in vitro diagnosis, and comparative studies of existing reagents are required. We evaluated the performances of the four currently available reagents, either as standalone tests or in combination. Two enzyme-linked immunosorbent assays (ELISAs) for the detection of E. histolytica IgG were assessed: one manufactured by Bordier and the other by NovaTec. Additionally, an indirect hemagglutination technique, ELI.H.A Amoeba , and a latex particle agglutination technique, ELITex Bicolor Amoeba , both produced by ELITech Microbio, were evaluated. A total of 442 serum samples were selected from a shared centralized biobank of seven university hospitals in France. The samples included 79 from patients with amoebic abscess, 13 with amoebic colitis, and 350 from healthy donors and patients with parasitic and non-parasitic diseases, especially liver disease and immune dysfunction. The sensitivity of the four kits ranged from 87.3% to 97.5%, while their specificity ranged from 78.3% to 98.6%. Bordier ELISA demonstrated the highest sensitivity, while ELITex Bicolor Amoeba latex reagent exhibited the highest specificity. The combination of Bordier ELISA and/or ELI.H.A Amoeba for screening, combined with ELITex Bicolor Amoeba for confirmation of positive screening results, yielded the most optimal performance. This study highlights the benefits of large comparative studies of commercial assays to guide clinical microbiologists in their choices. IMPORTANCE: Amoebiasis caused by Entamoeba histolytica is common in countries with low socio-economic levels. The most lethal form is extraintestinal amoebiasis, mainly liver abscesses, which require rapid and accurate diagnosis. Diagnosis is based on clinical, radiological, and, most importantly, serological tests. Implementing a diagnostic strategy requires both knowledge of how diagnostic tests compare with each other and thorough cross-validation. To help the clinical microbiologist choose a serological reagent, we evaluated the performance of four serological reagents currently available on the European market using a large biobank of sera from seven French university hospitals. In addition to patients with amoebic abscess and healthy donors, our study included many samples from patients with other parasitic and non-parasitic pathologies (liver diseases, immune dysfunctions) in order to study particularly non-specific reactivities.

The diagnosis of the life-threatening invasive Candida infections is mainly established using culture of specimens that might be collected on different devices including ethylene diamine tetraacetic acid (EDTA)-coated tubes. Despite the knowledge that EDTA inhibits bacterial cultures, and its use to treat oral fungal infections, its impact on Candida cultures has not been completely assessed. This study aimed at assessing it on azole-resistant and azole-susceptible strains. Clinical and American Type Culture Collection (ATCC) strains for Candida albicans (CA), C. glabrata (CGS), C. krusei (CK), azole-susceptible and azole-resistant strains of C. glabrata (CGS and CGR), C. lipolytica (CL), and C. inconspicua (CI) were characterized using MALDI-TOF MS and susceptibility testing and then incubated (1) with serial dilutions of tripotassic EDTA (0%–500% of the concentration in a sample tube) for 2 hours before plating onto ChromID Can2 agar; (2) for 0, 2, 4, 6, 7, or 8 hours at EDTA concentrations at 20% and 33% before seeding; and (3) with sodium citrate or lithium heparinate instead of EDTA for 2 hours before plating. After 48 hours at 35°C, colony-forming units were automatically quantified. An inhibitory effect of EDTA was observed, at different concentrations, for CA (20%), CGS (100%), and CGR (500%) (P < .05), but none was observed for CL, CI, and CK. The effect increased with incubation duration, at a faster rate for azole-susceptible strains. K3-EDTA inhibits Candida growth and EDTA-coated tubes should not be used for mycological culture-based analyses. The correlation between EDTA inhibition and Candida azole-resistance offers perspectives for the development of selective agar and new antifungal strategies.

This report presents an extremely rare case of fungal mycotic aneurysm due to Magnusiomyces capitatus in a 51-year-old immunocompromised woman. The diagnosis was based on multiple CT-scans and various samples positive for the pathogen identified by sequencing of the Internal Transcribed Spacer region. Long-term treatment using caspofungin for previous candidemia would have promoted the dissemination of this intrinsically echinocandin-resistant fungus, from colonization sites in the lung and rectal areas. Long-term suppressive antifungal treatment using voriconazole followed by posaconazole, combined with numerous surgical procedures, led to an improvement in the patient's disease. This case highlights the need to consider the overall microbiological history of a patient and to reassess antimicrobial therapy in case of non-improvement or relapse.