Diagnostic Mycology Laboratories Should Have a Central Role for the Management of Fungal Disease

The absence of awareness of fungal diseases as part of the differential diagnosis in at-risk populations has severe consequences. Here, we show how the active role of laboratories can improve patients’ survival. Recently, major advances have been made in non-culture-based assays for fungal diseases, improving accuracy and turnaround time. Furthermore, with the introduction of proficiency control systems, laboratories are an easily monitored environment with good analytical accuracy. Diagnostic packages for opportunistic infections can overcome many deficiencies caused by the absence of awareness. In Guatemala, to make diagnosis accessible, we set up a diagnostic laboratory hub (DLH) providing screening for cryptococcosis, histoplasmosis and tuberculosis to a network of 13 healthcare facilities attending people living with HIV (PLWHIV). In two years, we screened 2127 newly HIV-diagnosed patients. The frequency of opportunistic infections was 21%, rising to 30.3% in patients with advanced HIV disease (<200 CD4); 8.1% of these patients had more than one infection. With the implementation of this diagnostic package, mortality decreased by 7%, a key goal of many public health interventions. Screening for serious infection in high-risk populations can partially overcome training or experiential deficiencies among clinicians for life-threatening fungal diseases.The program implemented in Guatemala was supported by Global Action for Fungal Infections and JYLAG, a charity foundation based in Switzerland (E.A. received this funding under the proposal: “Minimizing HIV deaths through rapid fungal diagnosis and better care in Guatemala”).S

Efficacy of DNA amplification in tissue biopsy samples to improve the detection of invasive fungal disease

AbstractThe performance of a pan-fungal PCR-based technique was evaluated to assess the aetiology of invasive fungal diseases (IFDs). A total of 89 formalin-fixed paraffin-embedded biopsy samples from 84 patients with proven IFD were studied. Culture of tissue was performed in 68 (81%) patients. The sensitivities of the PCR-based technique and microbiological culture of tissues were 89% and 56%, respectively (p <0.01). According to PCR results, Aspergillus species accounted for 67%, Candida species for 13%, zygomycetes for 11%, and rare and emerging fungi for 9%. Aspergillus species were significantly associated with lung samples (79.6%, p <0.01), Mucorales were associated with skin/subcutaneous samples, and Candida species were associated with gastrointestinal samples. Regarding biopsy samples with Aspergillus species, Aspergillus fumigatus DNA was detected in 43 of 50 (86%), and Aspergillus flavus in six of 50 (12%). PCR was positive in 24 of 30 (80%) cases with negative culture. In nine of the 84 patients, the PCR technique failed to amplify the DNA. Six also had negative cultures, and in the remaining three cases culture was positive (Rhizopus microsporus, Rhizopus arrhizus, and Sakseneae vasiformis), suggesting that the PCR technique was not as effective in amplifying the DNA of some species of Zygomycetes. In five cases, there was no correlation between culture results and those obtained with DNA amplification, indicating the possibility of a mixed infection or the presence of colonizer/contaminant microorganisms. In summary, PCR-based techniques for DNA amplification should be implemented in histopathology and microbiology departments, as they appear to be complementary to conventional methods for IFD detection

Characterization of a possible nosocomial aspergillosis outbreak

ObjectiveTo study the epidemiologic aspects of a suspected outbreak of nosocomial invasive aspergillosis.MethodsSixteen Aspergillus fumigatus strains were isolated from bronchoalveolar washings or sputa of 10 patients during a 9-month period. Furthermore, two environmental samples, isolated in a microbiological screening of the hospital, were also available for analysis. Random amplified polymorphic DNA analysis (RAPD) was carried out.ResultsThe analysis performed by RAPD clearly demonstrated substantial genetic variation among the isolates. Both of the two different primers selected for RAPD analysis (R-108 and AP12h) were able to demonstrate that the strains isolated from all patients infected with the same fungal species and the environmental samples were genotypically distinct. The results by RAPD typing demonstrated that this technique could detect variability among isolates of Aspergillus fumigatus from different patients and even from the same patient.ConclusionsRAPD genotyping proved that the outbreak of invasive aspergillosis consisted of a series of events, non-related, and probably not coming from the same source within the hospital. This type of analysis is an easy, quick and highly discriminatory technique that may help in planning epidemiologic studies of aspergillosis

Statistical analyses of correlation between fluconazole MICs for Candida spp. assessed by standard methods set forth by the European Committee on Antimicrobial Susceptibility Testing (E.Dis. 7.1) and CLSI (M27-A2).

The European Committee on Antimicrobial Susceptibility Testing (EUCAST) Subcommittee on Antifungal Susceptibility Testing recently published a standard for determining the susceptibility of fermentative yeasts to antifungals. From the beginning, the EUCAST and its North American counterpart, the CLSI, decided to work together in order to establish common standards. As part of this exercise, the susceptibility of a set of 475 yeast isolates was tested by both standards. The intraclass correlation coefficient and the equations defining the linear regression between both methods were estimated. Both methods produced very similar results, with an intraclass correlation coefficient of 0.954 (0.945 to 0.962), although linear regression analysis shows that the EUCAST standard resulted in slightly lower MICs. There were only eight isolates showing at least four twofold dilution MIC differences between both standards. After 24 h of incubation, the MICs obtained by the CLSI method were equivalent to those obtained by the EUCAST standard. In summary, both methods produce very similar MICs, indicating that methodology does not pose any obstacle to obtaining uniform standards for antifungal susceptibility testing of yeast

Echinocandin susceptibility testing of Candida spp. using the EUCAST EDef 7.1 and CLSI M27-A3 standard procedures: Analysis of the influence of Bovine Serum Albumin Supplementation, Storage Time and Drug Lots

The MICs of echinocandins against Candida isolates with fks mutations are higher than those for wild-type (WT) isolates. However, the MIC ranges for susceptible and mutant populations overlap or are poorly separated. It was recently reported that a greater separation could be achieved in the presence of serum. To more fully explore this possibility, we compared the performances of the reference microdilution methods by using standard and bovine serum albumin (BSA)-supplemented growth medium. Anidulafungin, caspofungin, and micafungin MICs were determined according to EUCAST and CLSI methods and with 50% BSA in the medium for 93 clinical isolates, including Candida albicans (20/10 [number of isolates/number of mutants]), C. glabrata (19/10), C. dubliniensis (2/1), C. krusei (16/3), C. parapsilosis (19), and C. tropicalis (19/4) isolates. Stability of the plates was tested after storage at -80°C for 2 and 6 months, and the performance of two different lots of caspofungin was investigated. The addition of BSA to the medium resulted in higher MICs (1 to 9 2-fold dilution steps) for all isolates and compounds. The increases were greatest for anidulafungin and micafungin and, among WT isolates, for C. parapsilosis. The number of very major errors (VMEs) was reduced (24% [20/84 isolates] versus ≤ 7% [6/84 isolates]) using BSA-supplemented EUCAST medium but not using BSA-supplemented CLSI medium (6% versus 9%). MIC results were unchanged after 6 months of storage of test plates. The two lots of caspofungin yielded identical results. Addition of BSA to the EUCAST medium increases the ability to differentiate between WT isolates and isolates harboring resistance mutations.Fil: Arendrup, Maiken Cavling. Statens Serum Institut. Unit of Mycology and Parasitology; DinamarcaFil: Rodriguez Tudela, Juan Luis. Instituto de Salud Carlos III. Centro Nacional de Microbiología. Servicio de Micología; EspañaFil: Park, Steven. UMDNJ-New Jersey Medical School. Public Health Research Institute; Estados UnidosFil: Garcia, Guillermo Manuel. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. UMDNJ-New Jersey Medical School. Public Health Research Institute; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe; ArgentinaFil: Delmas, Guillaume. UMDNJ-New Jersey Medical School. Public Health Research Institute; Estados UnidosFil: Cuenca Estrella, Manuel. Instituto de Salud Carlos III. Centro Nacional de Microbiología. Servicio de Micología; EspañaFil: Gómez López, Alicia. Instituto de Salud Carlos III. Centro Nacional de Microbiología. Servicio de Micología; EspañaFil: Perlin, David Scott. UMDNJ-New Jersey Medical School. Public Health Research Institute; Estados Unido

Digital Platform for Automatic Qualitative and Quantitative Reading of a Cryptococcal Antigen Point-of-Care Assay Leveraging Smartphones and Artificial Intelligence

This work was presented in part at 31st European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), which will take place online from 9 – 12 July 2021. Abstract number 03467.Cryptococcosis is a fungal infection that causes serious illness, particularly in immunocompromised individuals such as people living with HIV. Point of care tests (POCT) can help identify and diagnose patients with several advantages including rapid results and ease of use. The cryptococcal antigen (CrAg) lateral flow assay (LFA) has demonstrated excellent performance in diagnosing cryptococcosis, and it is particularly useful in resource-limited settings where laboratory-based tests may not be readily available. The use of artificial intelligence (AI) for the interpretation of rapid diagnostic tests can improve the accuracy and speed of test results, as well as reduce the cost and workload of healthcare professionals, reducing subjectivity associated with its interpretation. In this work, we analyze a smartphone-based digital system assisted by AI to automatically interpret CrAg LFA as well as to estimate the antigen concentration in the strip. The system showed excellent performance for predicting LFA qualitative interpretation with an area under the receiver operating characteristic curve of 0.997. On the other hand, its potential to predict antigen concentration based solely on a photograph of the LFA has also been demonstrated, finding a strong correlation between band intensity and antigen concentration, with a Pearson correlation coefficient of 0.953. The system, which is connected to a cloud web platform, allows for case identification, quality control, and real-time monitoring.CrAg LFA tests were provided by IMMY at no cost. This research was funded by Global Action For Fungal Infections (www.GAFFI.org), JYLAG, a charity Foundation based in Geneva, Switzerland, and Fondo de Investigación Sanitaria from Instituto de Salud Carlos III (PI20CIII/00043). D.B.-P. was supported by grant PTQ2020-011340/AEI/10.13039/501100011033 funded by the Spanish State Investigation Agency. J.C.S.-D. was supported by a fellowship from the Fondo de Investigación Sanitaria (grant FI17CIII/00027).S