Fluconazole-resistant Candida parapsilosis: fast detection of the Y132F ERG11p substitution, and a proposed microsatellite genotyping scheme.

OBJECTIVES: We propose fast and accurate molecular detection of the Y132F ERG11p substitution directly on pure-cultured C. parapsilosis isolates. We also assessed a discriminative genotyping scheme to track circulating genotypes. METHODS: A total of 223 C. parapsilosis isolates (one patient each) from 20 hospitals, located in Spain and Italy were selected. Isolates were fluconazole-resistant (n=94; harbouring the Y132F ERG11p substitution [n=85], the G458S substitution [n=6], the R398I substitution [n=2], or the wild-type ERG11 gene sequence) or fluconazole-susceptible (n=129). Two targeted-A395T-mutation PCR formats (conventional and real-time) were engineered and optimized on fluconazole-susceptible and fluconazole-resistant pure-cultured isolates, thus skipping DNA extraction. Two genotyping schemes were compared: Scheme 1 (CP1, CP4a, CP6, and B markers), and Scheme 2 (6A, 6B, 6C, CP1, CP4a, and CP6 markers). RESULTS: The screening performed using both PCR formats showed 100% specificity (fluconazole-susceptible isolates; n=129/129) and sensitivity (Y132F isolates; n=85/85) values, however, results were available in 3 and 1.5 hours with the conventional and real-time PCR formats, respectively. Overall, Scheme 1 showed higher genetic diversity than Scheme 2, as shown by the number of alleles detected (n=98; mean 23, range 13-38), the significantly higher observed and expected heterozygosity, and the probability of identity index (2.5x10-6). Scheme 2 markers did not provide further genotypic discrimination of Y132F fluconazole-resistant genotypes. CONCLUSION: Both proposed PCR formats allow to speed up the accurate detection of substitution Y132F ERG11p in C. parapsilosis isolates with 100% specificity and sensitivity. In addition, we recommend CP1, CP4a, CP6, and B microsatellite markers for genotyping fluconazole-resistant isolates.

Prognostic value of serial (1,3)-ß-D-glucan measurements in ICU patients with invasive candidiasis.

BACKGROUND: To determine whether a decrease in serum (1,3)-ß-D-glucan (BDG) was associated with reduced mortality and to investigate the performance of BDG downslope in predicting clinical outcome in invasive candidiasis. METHODS: Observational cohort study in ICU patients over a ten-year period (2012-2022) in Italy. Proven invasive candidiasis with at least 2 BDG determinations were considered. RESULTS: In the study population of 103 patients (age 47 [35-62] years, SAPS II score 67 [52-77]) 68 bloodstream and 35 intrabdominal infections were recorded. Serial measurements showed that in 54 patients BDG decreased over time (BDG downslope group) while in 49 did not (N-BDG downslope group). Candida albicans was the pathogen most frequently isolated (61%) followed by C. parapsilosis (17%) and C. glabrata (12%), in absence of any inter-group difference. Invasive candidiasis related mortality was lower in BDG downslope than in N-BDG downslope group (17% vs 53%, p < 0.01). The multivariate Cox regression analysis showed the association of septic shock at infection occurrence and chronic liver disease with invasive candidiasis mortality (HR [95% CI] 3.24 [1.25-8.44] p = 0.02 and 7.27 [2.33-22.66] p < 0.01, respectively) while a BDG downslope was the only predictor of survival (HR [95% CI] 0.19 [0.09-0.43] p < 0.01). The area under the receiver operator characteristic curve for the performance of BDG downslope as predictor of good clinical outcome was 0.74 (p = 0.02) and our model showed that a BDG downslope > 70% predicted survival with both specificity and positive predictive value of 100%. CONCLUSIONS: A decrease in serum BDG was associated with reduced mortality and a steep downslope predicted survival with high specificity in invasive candidiasis.

Donor-derived mold infections in lung transplant recipients: The importance of active surveillance.

Unexpected donor-derived fungal infections represent a rare but potentially fatal complication in lung transplant (Tx) recipients. Timely communication of the results of donor cultures and prompt treatment of recipients are crucial to mitigate the consequences of donor-derived transmissions. In this prospective cohort study, all consecutive patients who underwent lung transplantation from 2015 to 2022 were included. In December 2015, a Local Active Surveillance System has been implemented to provide biovigilance of donor culture results and optimize recipients' management. The aim of this study is to investigate the incidence of unexpected, mold-positive cultures among lung donors and the rate of transmission to recipients. Furthermore, management strategies and outcome of recipients with mold transmission are described. In case of isolation of the same mold in donor and recipient cultures, when possible, transmission was confirmed by dendrogram analysis. During the study period, 82 lung Tx were performed from 80 donors. The prevalence of donors with "unexpected" mold isolation from the respiratory tract was 3.75% (3/80). Isolated molds were Aspergillus niger, Rhizopus oryzae, and Aspergillus flavus. Transmissions occurred in all the three cases (100%) with a mean time of 5 days from lung Tx but none of the recipients developed invasive mold disease. Our Local Active Surveillance System allowed prompt recognition of lung donors unexpected mold colonization. Even though transmission occurred, introduction of early targeted antifungal therapy prevented potential catastrophic consequence of mold donor-derived infection in the immediate post-Tx period.

Fluconazole-resistant Candida parapsilosis genotypes from hospitals located in five Spanish cities and one in Italy: Description of azole-resistance profiles associated with the Y132F ERG11p substitution.

BACKGROUND: Fluconazole-resistant Candida parapsilosis is a matter of concern. OBJECTIVES: To describe fluconazole-resistant C. parapsilosis genotypes circulating across hospitals in Spain and Rome and to study their azole-resistance profile associated with ERG11p substitutions. PATIENTS/METHODS: We selected fluconazole-resistant C. parapsilosis isolates (n = 528 from 2019 to 2023; MIC ≥8 mg/L according to EUCAST) from patients admitted to 13 hospitals located in five Spanish cities and Rome. Additionally, we tested voriconazole, posaconazole, isavuconazole, amphotericin B, micafungin, anidulafungin and ibrexafungerp susceptibility. RESULTS: Of the 53 genotypes found, 49 harboured the Y132F substitution, five of which were dominating city-specific genotypes involving almost half the isolates. Another genotype involved isolates harbouring the G458S substitution. Finally, we found two genotypes with the wild-type ERG11 gene sequence and one with the R398I substitution. All isolates were fully susceptible/wild-type to amphotericin B, anidulafungin, micafungin and ibrexafungerp. The azole-resistance patterns found were: voriconazole-resistant (74.1%) or voriconazole-intermediate (25.2%), posaconazole-resistant (10%) and isavuconazole non-wild-type (47.5%). Fluconazole-resistant and voriconazole non-wild-type isolates were likely to harbour substitution Y132F if posaconazole was wild type; however, if posaconazole was non-wild type, substitution G458S was indicated if isavuconazole MIC was >0.125 mg/L or substitution Y132F if isavuconazole MIC was ≤0.125 mg/L. CONCLUSIONS: We detected a recent clonal spread of fluconazole-resistant C. parapsilosis across some cities in Spain, mostly driven by dominating city-specific genotypes, which involved a large number of isolates harbouring the Y132F ERG11p substitution. Isolates harbouring substitution Y132F can be suspected because they are non-susceptible to voriconazole and rarely posaconazole-resistant.

Evaluation of Autof MS2600 and MBT Smart MALDI-TOF MS Systems for Routine Identification of Clinical Bacteria and Yeasts.

The identification of microorganisms at the species level has always constituted a diagnostic challenge for clinical microbiology laboratories. The aim of the present study has been the evaluation in a real-time assay of the performance of Autobio in comparison with the Bruker mass spectrometry system for the identification of bacteria and yeasts. A total of 535 bacteria and yeast were tested in parallel with the two systems by direct smear or fast formic acid extraction for bacteria and yeasts, respectively. Discordant results were verified by 16S, ITS rRNA or specific gene sequencing. Beyond giving comparable results for bacteria with respect to the MBT smart system, Autof MS2600 mass spectrometer provided excellent accuracy for the identification of yeast species of clinical interest.

The Fourier-transform infrared spectroscopy-based method as a new typing tool for Candida parapsilosis clinical isolates.

The Fourier-transform infrared spectroscopy-based IR Biotyper is a straightforward typing tool for bacterial species, but its use with Candida species is limited. We applied IR Biotyper to Candida parapsilosis, a common cause of nosocomial bloodstream infection (BSI), which is aggravated by the intra-hospital spread of fluconazole-resistant isolates. Of 59 C. parapsilosis isolates studied, n = 56 (48 fluconazole-resistant and 8 fluconazole-susceptible) and n = 3 (2 fluconazole-resistant and 1 fluconazole-susceptible) isolates, respectively, had been recovered from BSI episodes in 2 spatially distant Italian hospitals. The latter isolates served as an outgroup. Of fluconazole-resistant isolates, n = 40 (including one outgroup) harbored the Y132F mutation alone and n = 10 (including one outgroup) harbored both Y132F and R398I mutations in the ERG11-encoded azole-target enzyme. Using a microsatellite typing method, which relies on the amplification of genomic short tandem repeats (STR), two major clusters were obtained based on the mutation(s) (Y132F or Y132F/R398I) present in the isolates. Regarding IR Biotyper, each isolate was analyzed in quintuplicate using an automatic (i.e., proposed by the manufacturer's software) or tentative (i.e., proposed by us) cutoff value. In the first case, four clusters were identified, with clusters I and II formed by Y132F or Y132F/R398I isolates, respectively. In the second case, six subclusters (derived by the split of clusters I and II) were identified. This allowed to separate the outgroup isolates from other isolates and to increase the IR Biotyper typeability. The agreement of IR Biotyper with STR ranged from 47% to 74%, depending on type of cutoff value used in the analysis. IMPORTANCE Establishing relatedness between clinical isolates of Candida parapsilosis is important for implementing rapid measures to control and prevent nosocomial transmission of this Candida species. We evaluated the FTIR-based IR Biotyper, a new typing method in the Candida field, using a collection of fluconazole-resistant C. parapsilosis isolates supposed to be genetically related due to the presence of the Y132F mutation. We showed that IR Biotyper was discriminatory but not as much as the STR method, which is still considered the method of choice. Further studies on larger series of C. parapsilosis isolates or closely related Candida species will be necessary to confirm and/or extend the results from this study.

"CORE" a new assay for rapid identification of Klebsiella pneumoniae COlistin REsistant strains by MALDI-TOF MS in positive-ion mode.

Due to the global spread of pan resistant organisms, colistin is actually considered as one of the last resort antibiotics against MDR and XDR bacterial infections. The emergence of colistin resistant strains has been observed worldwide in Gram-negative bacteria, such as Enterobacteriaceae and especially in K. pneumoniae, in association with increased morbidity and mortality. This landscape implies the exploration of novel assays able to target colistin resistant strains rapidly. In this study, we developed and evaluated a new MALDI-TOF MS assay in positive-ion mode that allows quantitative or qualitative discrimination between colistin susceptible (18) or resistant (32) K. pneumoniae strains in 3 h by using the "Autof MS 1000" mass spectrometer. The proposed assay, if integrated in the diagnostic workflow, may be of help for the antimicrobial stewardship and the control of the spread of K. pneumoniae colistin resistant isolates in hospital settings.

Phaeohyphomycosis in Solid Organ Transplant Recipients: A Case Series and Narrative Review of the Literature.

Phaeohyphomycosis comprises a variety of infections caused by pigmented fungi. Solid organ transplant (SOT) recipients are particularly at risk of invasive infections due to their prolonged immunosuppression. Here, we describe three cases of phaeohyphomycosis in SOT recipients who were successfully treated with surgical excision and/or antifungal therapy. We additionally carried out a narrative review of the literature on phaeohyphomycosis in 94 SOT recipients from 66 published studies describing 40 different species of fungi. The most reported fungus was Alternaria (21%). The median time from transplant to diagnosis was 18 months (IQR 8.25-48), and kidney transplants were the most reported. Antifungal regimens were not homogeneous, though there was a prevalence of itraconazole- and voriconazole-based treatments. Clinical outcomes included recovery in 81% and death in 5% of infected SOT recipients. Susceptibility testing was done in 26.6% of the cases, with heterogeneous results due to the variety of species isolated. While the wide diversity of dematiaceous fungi and their host range make it difficult to offer a uniform approach for phaeohyphomycosis, an early diagnosis and therapy are critical in preventing the dissemination of disease in the immunocompromised host.

Chip-Based Molecular Evaluation of a DNA Extraction Protocol for Candida Species from Positive Blood Cultures.

The diagnosis of Candida bloodstream infection (BSI) may rely on a PCR-based analysis of a positive blood culture (PBC) obtained from the patient at the time of BSI. In this study, a yeast DNA extraction protocol for use on PBCs was developed and evaluated with the molecular mouse (MM) yeast blood (YBL) chip-based PCR assay, which allowed us to detect nine medically relevant Candida species. We studied 125 simulated or clinical PBCs for Candida species. A positive correlation between the DNA concentration and colony-forming unit count was found for simulated (Spearman's ρ = 0.58; p < 0.0001) and clinical (Spearman's ρ = 0.23, p = 0.09) PBCs. The extracted DNA yielded positive results with the MM YBL chip assay that agreed with the Candida species-level identification results for 63 (100%) of 63 isolates from simulated PBCs and 66 (99.5%) of 67 isolates from clinical PBCs. The false-negative result was for one C. tropicalis isolate that grew together with C. albicans in PBC. None of the 30 (Candida)-negative clinical BCs included as negative controls yielded a positive result with the MM YBL chip assay. Our DNA extraction protocol for the Candida species couples efficiency and simplicity together. Nevertheless, further studies are needed before it can be adopted for use with the MM YBL chip assay.

Old and New Insights into Sporothrix schenckii Complex Biology and Identification.

Sporothrix schenckii is a worldwide-distributed thermally dimorphic fungus, which usually causes a subacute to chronic infection through traumatic implantation or inoculation of its infectious propagules. The fungus encompasses a group of phylogenetically closely related species, thus named the S. schenckii complex, of which S. schenckiisensu stricto and S. brasiliensis are main causative species of sporotrichosis. Owing to a multifaceted molecular dynamic, the S. schenckii complex can switch between the mycelium and the yeast form. This characteristic along with a varying cell wall composition account for significant species-specific differences in the host range, virulence, and susceptibility to antifungal drugs. While culture remains the gold standard to diagnose sporotrichosis, polymerase chain reaction (PCR) or matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry-based methods have become an essential for accurate species identification in many clinical laboratories. If directly applied on tissue samples, molecular methods are helpful to improve both sensitivity of and time to the etiological diagnosis of sporotrichosis. This mini-review aims to put together the old and new knowledge on the S. schenckii complex biology and identification, with particular emphasis on the laboratory diagnosis-related aspects of disease.

A New PCR-Based Assay for Testing Bronchoalveolar Lavage Fluid Samples from Patients with Suspected Pneumocystis jirovecii Pneumonia.

To support the clinical laboratory diagnosis of Pneumocystis jirovecii (PJ) pneumonia (PCP), an invasive fungal infection mainly occurring in HIV-negative patients, in-house or commercial PJ-specific real-time quantitative PCR (qPCR) assays are todays' reliable options. The performance of these assays depends on the type of PJ gene (multi-copy mitochondrial versus single-copy nuclear) targeted by the assay. We described the development of a PJ-PCR assay targeting the dihydrofolate reductase (DHFR)-encoding gene. After delineating its analytical performance, the PJ-PCR assay was used to test bronchoalveolar lavage (BAL) fluid samples from 200 patients (only seven were HIV positive) with suspected PCP. Of 211 BAL fluid samples, 18 (8.5%) were positive and 193 (91.5%) were negative by PJ-PCR. Of 18 PJ-PCR-positive samples, 11 (61.1%) tested positive and seven (38.9%) tested negative with the immunofluorescence assay (IFA). All (100%) of the 193 PJ-PCR-negative samples were IFA negative. Based on IFA/PCR results, patients were, respectively, classified as having (n = 18) and not having (n = 182) proven (PJ-PCR+/IFA+) or probable (PJ-PCR+/IFA-) PCP. For 182 patients without PCP, alternative infectious or non-infectious etiologies were identified. Our PJ-PCR assay was at least equivalent to IFA, fostering studies aimed at defining a qPCR-based standard for PCP diagnosis in the future.

Disseminated Geosmithia argillacea Infection in a Patient with Ph-Positive Acute Lymphoblastic Leukemia. Case Report and Literature Review.

Invasive fungal infection (IFI) remains the major complication in patients with either acute leukemia, allogeneic stem cell transplantation setting, or both, especially regarding pulmonary localization. We report an experience of a 74-year-old Caucasian male with a Philadelphia-positive (BCR-ABL p190) Common B-acute lymphoblastic leukemia (ALL) who developed a pulmonary infection due to Geosmithia argillacea. Furthermore, we describe the management of this complication and the results of microbiological tests useful to guide the treatment. All cases reported show failure of voriconazole treatment. In the majority of cases a good susceptibility to posaconazole has been reported, which seems to have a good clinical impact; however, only L-AmB shows a clinical effect to produce quick clinical improvement and so it should be a drug of choice. A literature revision shows that only a few papers have thus far described this infection, at present only one case was reported in a hematological setting like a gastrointestinal graft versus host disease in an allogeneic HSCT recipient. The severity of clinical conditions in hematological malignancy settings requires improving the management of this emerging invasive fungal infection. Indeed, a molecular diagnostic approach with a tight laboratory collaboration and targeted therapy should become the gold standard.

Are We Ready for Nosocomial Candida auris Infections? Rapid Identification and Antifungal Resistance Detection Using MALDI-TOF Mass Spectrometry May Be the Answer.

The occurrence of multidrug-resistant Candida auris isolates and the increased mortality associated with invasive infections or outbreaks due to this Candida species have been reported in many healthcare settings. Therefore, accurate and rapid identification at the species level of clinical C. auris isolates as well as their timely differentiation as susceptible or resistant to antifungal drugs is mandatory. Aims of the present study were to implement the MALDI-TOF mass spectrometry (MS) Bruker Daltonics Biotyper® database with C. auris spectrum profiles and to develop a fast and reproducible MS assay for detecting anidulafungin (AFG) resistance in C. auris isolates. After creation of main C. auris spectra, a score-oriented dendrogram was generated from hierarchical cluster analysis, including spectra of isolates from C. auris and other Candida (C. glabrata, C. guilliermondii, C. haemulonii, C. lusitaniae, and C. parapsilosis) or non-Candida (Rhodotorula glutinis) species. Cluster analysis allowed to group and classify the isolates according to their species designation. Then, a three-hour incubation antifungal susceptibility testing (AFST) assay was developed. Spectra obtained at null, intermediate, or maximum AFG concentrations were used to create composite correlation index matrices for eighteen C. auris isolates included in the study. All six resistant C. auris isolates were detected as resistant whereas 11 of 12 susceptible C. auris isolates were detected as susceptible by the MS-AFST assay. In conclusion, our MS-based assay offers the possibility of rapidly diagnosing and appropriately treating patients with C. auris infection.

Considerations on antimicrobial prophylaxis in patients with lymphoproliferative diseases: A SEIFEM group position paper.

The therapeutic armamentarium for the treatment of patients with lymphoproliferative diseases has grown considerably over the most recent years, including a large use of new immunotherapeutic agents. As a consequence, the epidemiology of infectious complications in this group of patients is poorly documented, and even more importantly, the potential benefit of antimicrobial prophylaxis remains a matter of debate when considering the harmful effect from the emergence of multidrug resistant pathogens. The present position paper is addressed to all hematologists treating patients affected by lymphoproliferative malignancies with the aim to provide clinicians with a useful tool for the prevention of bacterial, fungal and viral infections.

Pan-Echinocandin-Resistant Candida glabrata Bloodstream Infection Complicating COVID-19: A Fatal Case Report.

Coinfections with bacteria or fungi may be a frequent complication of COVID-19, but coinfections with Candida species in COVID-19 patients remain rare. We report the 53-day clinical course of a complicated type-2 diabetes patient diagnosed with COVID-19, who developed bloodstream infections initially due to methicillin-resistant Staphylococcus aureus, secondly due to multidrug-resistant Gram-negative bacteria, and lastly due to a possibly fatal Candida glabrata. The development of FKS-associated pan-echinocandin resistance in the C. glabrata isolated from the patient after 13 days of caspofungin treatment aggravated the situation. The patient died of septic shock shortly before the prospect of receiving potentially effective antifungal therapy. This case emphasizes the importance of early diagnosis and monitoring for antimicrobial drug-resistant coinfections to reduce their unfavorable outcomes in COVID-19 patients.

(1,3)-ß-D-Glucan-based empirical antifungal interruption in suspected invasive candidiasis: a randomized trial.

BACKGROUND: (1,3)-ß-D-Glucan has been widely used in clinical practice for the diagnosis of invasive Candida infections. However, such serum biomarker showed potential to guide antimicrobial therapy in order to reduce the duration of empirical antifungal treatment in critically ill septic patients with suspected invasive candidiasis. METHODS: This was a single-centre, randomized, open-label clinical trial in which critically ill patients were enrolled during the admission to the intensive care unit (ICU). All septic patients who presented invasive Candida infection risk factors and for whom an empirical antifungal therapy was commenced were randomly assigned (1:1) in those stopping antifungal therapy if (1,3)-ß-D-glucan was negative ((1,3)-ß-D-glucan group) or those continuing the antifungal therapy based on clinical rules (control group). Serum 1,3-ß-D-glucan was measured at the enrolment and every 48/72 h over 14 days afterwards. The primary endpoint was the duration of antifungal treatment in the first 30 days after enrolment. RESULTS: We randomized 108 patients into the (1,3)-ß-D-glucan (n = 53) and control (n = 55) groups. Median [IQR] duration of antifungal treatment was 2 days [1-3] in the (1,3)-ß-D-glucan group vs. 10 days [6-13] in the control group (between-group absolute difference in means, 6.29 days [95% CI 3.94-8.65], p < 0.001). Thirty-day mortality was similar (28.3% [(1,3)-ß-D-glucan group] vs. 27.3% [control group], p = 0.92) as well as the overall rate of documented candidiasis (11.3% [(1,3)-ß-D-glucan group] vs. 12.7% [control group], p = 0.94), the length of mechanical ventilation (p = 0.97) and ICU stay (p = 0.23). CONCLUSIONS: In critically ill septic patients admitted to the ICU at risk of invasive candidiasis, a (1,3)-ß-D-glucan-guided strategy could reduce the duration of empirical antifungal therapy. However, the safety of this algorithm needs to be confirmed in future, multicentre clinical trial with a larger population. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03117439 , retrospectively registered on 18 April 2017.

Comparative performance evaluation of Wako ß-glucan test and Fungitell assay for the diagnosis of invasive fungal diseases.

The Fungitell assay (FA) and the Wako ß-glucan test (GT) are employed to measure the serum/plasma 1,3-ß-D-glucan (BDG), a well-known invasive fungal disease biomarker. Data to convincingly and/or sufficiently support the GT as a valuable alternative to the FA are yet limited. In this study, we evaluated the FA and the GT to diagnose invasive aspergillosis (IA), invasive candidiasis (IC), and Pneumocystis jirovecii pneumonia (PJP). The FA and GT performances were compared in sera of patients with IA (n = 40), IC (n = 78), and PJP (n = 17) with respect to sera of control patients (n = 187). Using the manufacturer's cutoff values of 80 pg/mL and 11 pg/mL, the sensitivity and specificity for IA diagnosis were 92.5% and 99.5% for the FA and 60.0% and 99.5% for the GT, respectively; for IC diagnosis were 100.0% and 97.3% for the FA and 91.0% and 99.5% for the GT, respectively; for PJP diagnosis were 100.0% and 97.3% for the FA and 88.2% and 99.5% for the GT, respectively. When an optimized cutoff value of 7.0 pg/mL for the GT was used, the sensitivity and specificity were 80.0% and 97.3% for IA diagnosis, 98.7% and 97.3% for IC diagnosis, and 94.1% and 97.3% for PJP diagnosis, respectively. At the 7.0-pg/mL GT cutoff, the agreement between the assays remained and/or became excellent for IA (95.1%), IC (97.3%), and PJP (96.5%), respectively. In conclusion, we show that the GT performed as well as the FA only with a lowered cutoff value for positivity. Further studies are expected to establish the equivalence of the two BDG assays.

Developments in identifying and managing mucormycosis in hematologic cancer patients.

INTRODUCTION: Mucormycoses represent a rare but very aggressive class of mold infections occurring in patients with hematological malignancies (HMs). In the past, patients at high risk of invasive mucomycosis (IM) were those affected by acute myeloid leukemia but over the last ten years the prophylaxis with a very effective mold-active drug, such as posaconazole, has completely modified the epidemiology. In fact, IM is now observed more frequently in patients with lymphoproliferative disorders who do not receive antifungal prophylaxis. AREAS COVERED: The attention was focused on the epidemiology, diagnosis, prophylaxis and treatment of IM in HMs. Authors excluded pediatric patients considering the different epidemiology and differences in treatment given the limitation of the use of azoles in the pediatric field. A systematic literature review was performed using PubMed database listings between February 2014 and February 2020 using the following MeSH terms: leukemia, hematological malignancies, stem cell transplantation, mucormycosis, molds, prophilaxis, treatment. EXPERT OPINION: The epidemiology of mucormycosis in HMs is changing in the last years. The availability of drugs more effective than in the past against this infection has reduced the mortality; however, a timely diagnosis remains a relevant problem potentially influencing the outcome of hematologic patients with IM.

Prevalence and Clonal Distribution of Azole-Resistant Candida parapsilosis Isolates Causing Bloodstream Infections in a Large Italian Hospital.

The most prevalent cause of nosocomial bloodstream infection (BSI) among non-C. albicans Candida species, Candida parapsilosis, may not only be resistant to azole antifungal agents but also disseminate to vulnerable patients. In this survey of BSIs occurring at a large Italian hospital between May 2014 and May 2019, C. parapsilosis accounted for 28.5% (241/844) of all Candida isolates causing BSI episodes. The majority of episodes (151/844) occurred in medical wards. Across the 5 yearly periods, the rates of azole non-susceptibility were 11.8% (4/34), 17.8% (8/45), 28.6% (12/42), 32.8% (19/58), and 17.7% (11/62), respectively, using the Sensititre YeastOne® method. Among azole non-susceptible isolates (54/241; 22.4%), 49 were available for further investigation. Using the CLSI reference method, all 49 isolates were resistant to fluconazole and, except one (susceptible dose-dependent), to voriconazole. Forty (81.6%) isolates harbored the Erg11p Y132F substitution and nine (18.4%) isolates the Y132F in combination with the Erg11p R398I substitution. According to their genotypes, as defined using a microsatellite analysis based on six short tandem repeat markers, 87.7% of isolates (43/49) grouped in two major clusters (II and III), whereas 4.1% of isolates (2/49) belonged to a separate cluster (I). Interestingly, all the isolates from cluster II harbored the Y132F substitution, and those from cluster III harbored both Y132F and R398I substitutions. Of 56 non-Italian isolates included as controls, two Indian isolates with the Y132F substitution had a genotype clearly differing from that of the isolates from clusters II and I. In conclusion, these findings show the dominance of clonal Y132F isolates in our hospital and suggest detection of the Y132F substitution as helpful tool to prevent transmission among hospitalized patients at risk of BSI.