Report of terbinafine resistant Trichophyton spp. in Italy: Clinical presentations, molecular identification, antifungal susceptibility testing and mutations in the squalene epoxidase gene

BACKGROUND

Numerous reports of resistance to terbinafine in Trichophyton spp. from all over the world are arousing justified attention and concern. Point mutations in the gene that encodes the squalene epoxidase (SQLE) enzyme are responsible for these therapeutic resistances.

OBJECTIVES

Primary objective of the study was to describe first isolates of Trichophyton spp. resistant to terbinafine among the patients treated between September 2019 and June 2022 at the Dermatology Units of Ospedale Maggiore Policlinico and San Bortolo Hospital. Secondary objective was to study the resistance mechanism.

METHODS

Patients with confirmed Trichophyton spp. infection has been treated with systemic and topical terbinafine. Patients were then re-evaluated 12 weeks after the therapy. Patients with incomplete or absent response to terbinafine underwent a new skin scraping for direct mycological examination, new identification of dermatophyte species from culture and MALDI-TOF, molecular species identification, antifungal susceptibility testing and molecular analysis of SQLE gene.

RESULTS

We identified five patients without clinical response to treatment with terbinafine. The DNA sequencing of the ITS region identified one Trichophyton rubrum and four Trichophyton indotineae. The T. rubrum strain showed minimum inhibitory concentration (MIC) (90% growth inhibition) of 4 mg/L for terbinafine. The four T. indotineae strains showed a MICs range of 0.25-4 mg/L for terbinafine. The analysis of the SQLE gene in the T. rubrum strain showed a nucleotide substitution generating a missense mutation (L393F). The SQLE gene sequencing in the T. indotineae strains showed a nucleotide substitution generating a missense mutation (F397L) in two strains, a nucleotide substitution L393S in one strain and a nucleotide substitution F415C in another strain.

CONCLUSIONS

We report the first cases of terbinafine-resistant Trichophyton isolates in the Italian population. Solid antifungal management programs will be needed to promote more responsible use of antimycotics and preserve their therapeutic efficacy to control antifungal resistance.

Yeast Bloodstream Infections in the COVID-19 Patient: A Multicenter Italian Study (FiCoV Study)

Fungemia is a co-infection contributing to the worsening of the critically ill COVID-19 patient. The multicenter Italian observational study FiCoV aims to estimate the frequency of yeast bloodstream infections (BSIs), to describe the factors associated with yeast BSIs in COVID-19 patients hospitalized in 10 hospitals, and to analyze the antifungal susceptibility profiles of the yeasts isolated from blood cultures. The study included all hospitalized adult COVID-19 patients with a yeast BSI; anonymous data was collected from each patient and data about antifungal susceptibility was collected. Yeast BSI occurred in 1.06% of patients, from 0.14% to 3.39% among the 10 participating centers. Patients were mainly admitted to intensive or sub-intensive care units (68.6%), over 60 years of age (73%), with a mean and median time from the hospitalization to fungemia of 29 and 22 days, respectively. Regarding risk factors for fungemia, most patients received corticosteroid therapy during hospitalization (61.8%) and had a comorbidity (25.3% diabetes, 11.5% chronic respiratory disorder, 9.5% cancer, 6% haematological malignancies, 1.4% organ transplantation). Antifungal therapy was administered to 75.6% of patients, mostly echinocandins (64.5%). The fatality rate observed in COVID-19 patients with yeast BSI was significantly higher than that of COVID-19 patients without yeast BSI (45.5% versus 30.5%). Candida parapsilosis (49.8%) and C. albicans (35.2%) were the most fungal species isolated; 72% of C. parapsilosis strains were fluconazole-resistant (range 0-93.2% among the centers). The FiCoV study highlights a high prevalence of Candida BSIs in critically ill COVID-19 patients, especially hospitalized in an intensive care unit, a high fatality rate associated with the fungal co-infection, and the worrying spread of azole-resistant C. parapsilosis.

Environmental and bioclimatic factors influencing yeasts and molds distribution along European shores

The present study employed data collected during the Mycosands survey to investigate the environmental factors influencing yeasts and molds distribution along European shores applying a species distribution modelling approach. Occurrence data were compared to climatic datasets (temperature, precipitation, and solar radiation), soil datasets (chemical and physical properties), and water datasets (temperature, salinity, and chlorophyll-a concentration) downloaded from web databases. Analyses were performed by MaxEnt software. Results suggested a different probability of distribution of yeasts and molds along European shores. Yeasts seem to tolerate low temperatures better during winter than molds and this reflects a higher suitability for the Northern European coasts. This difference is more evident considering suitability in waters. Both distributions of molds and yeasts are influenced by basic soil pH, probably because acidic soils are more favorable to bacterial growth. Soils with high nitrogen concentrations are not suitable for fungal growth, which, in contrast, are optimal for plant growth, favored by this environment. Finally, molds show affinity with soil rich in nickel and yeasts with soils rich in cadmium resulting in a distribution mainly at the mouths of European rivers or lagoons, where these metals accumulate in river sediments.

Fungal diversity in lake and sea beaches of Italy: Relevance to human health

Fungal diseases correlated to beach sand or water have not yet been demonstrated due to the lack of epidemiological studies. This study aims to illustrate the fungal population in beach sands of the two largest Italian lakes and in sands and waters of Mediterranean coasts of Southern Italy to contribute to the identification and assessment of causes of microbiological pollution that might impair bathers health. A great difference was observed between the two lakes, where the total of colony-forming units (CFU) ranged from 33.3 to 1049.9 CFU/g. For coastal sands, the total CFU ranged from 216.7 to 538.8 CFU/g, and for coastal waters the total ranged from 185 to 368.7 CFU/ml. The survey revealed the prevalence of opportunistic pathogenic moulds, mainly Aspergillus spp. (A. niger and A. fumigatus) and Penicillium spp., both in freshwater and costal bathing sites. Dermatophytes and yeasts were not detected in the freshwater sands while they were found at low load in coastal waters (3.3 CFU/ml) and sands (1.7 CFU/g). Differences were observed between urban and non-urban coastal beaches with regard to isolation of dermatophytes only from one urban beach. The present study reports a great diversity of fungi in sand and water of bathing beaches confirming that the Mediterranean region has a greater variety of fungal species.

P352 Molds and yeasts on the beach: environmental factors influencing distribution of fungi along european shores

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM

 

Objectives

The present study employed data collected during the Mycosands survey to investigate the environmental factors influencing yeasts and molds distribution along European shores by applying a species distribution modeling approach.

Methods

Occurrence data were compared to climatic datasets (temperature, precipitation, and solar radiation), soil datasets (chemical and physical properties), and water datasets (temperature, salinity, and chlorophyll concentration) downloaded from web databases. All dataset layers were edited and formatted by QGIS software and analyses were performed by MaxEnt software.

Results

The distribution maps inferred comparing occurrence data on shores for Aspergillus spp., Aspergillus fumigatus, A. flavus, A. niger, Fusarium spp., dematiaceous fungi, and considering all molds, to climatic datasets showed the highest probability of presence along Eastern and South-Central Mediterranean coasts, whereas comparison of water occurrence data to water features identified a high suitability along Eastern Mediterranean coasts, Gulf of Lion, Southern coasts of Spain, and Southern and Central Atlantic coast of Portugal, Southern Atlantic coast of France, Netherlands coasts, the mouth of Danube, coasts of the Ireland sea, and Kuri Lagoon in Lithuania. The main variables contributing to the models were minimum temperatures in winter, water temperature during spring, and chlorophyll concentration. The comparison with soil datasets showed a high tolerance of soils with a high concentration of CaCO3 and basic pH. Nitrogen concentration was tolerated at values below 1 g/kg and phosphorus concentration at values <20 mg/kg and >40 mg/kg. In addition, the model identified a high tolerance to soils rich in nickel.

The same analyses were performed for the following groups of occurrence data: Candida spp., Rhodotorula spp., and all yeasts. Results showed the highest probability of presence on shores located along the coasts of Eastern Mediterranean Sea, Southern-Central Mediterranean Sea, Northern Adriatic Sea coasts, Kuri Lagoon, and Northern European coasts from France to Denmark. In waters, high suitability areas were located along the coasts of Northern Black Sea, Northern Adriatic Sea, coasts of Ireland Sea, Western Atlantic coast of France, and the Northern European coasts from France to western Denmark. The most relevant variables contributing to the model were minimum temperatures during winter and water chlorophyll concentration. The comparison with soil features showed similar results to those obtained for molds, except a high tolerance for soils rich in cadmium.

Conclusions

All together our results suggest a different probability of distribution of yeasts and molds along European shores. Yeasts seem to tolerate low temperatures better during winter than molds and this reflects a higher suitability for the Northern European coasts. This difference is more evident considering suitability in waters. Both distributions of molds and yeasts are influenced by basic soil pH, probably because acidic soils are more favorable to bacterial growth. Soils with high nitrogen concentrations are not suitable for fungal growth, which, in contrast, are optimal for plant growth, favored by this environment. Finally, molds show affinity with soil rich in nickel and yeasts with soils rich in cadmium resulting in a distribution mainly at the mouths of European rivers or lagoons, where these metals accumulate in river sediments.

P039 Cross-resistance to clinical and agricultural azoles among Aspergillus fumigatus strains isolated from humans and environment in Italy

 

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM

Objectives

In Italy, a prevalence of 16.9% of resistance to clinical azoles was observed among Aspergillus fumigatus isolates from an agricultural environment. This spread of azole-resistance is attributed to the widespread use of 14a-demethylase inhibitors (DMIs).

The aims of the present study were to investigate: the DMIs resistance in Italian A. fumigatus strains of clinical and environmental origin, both susceptible and resistant to clinical azoles; the molecular mechanism of resistance in strains susceptible to clinical azoles but resistant to at least one of the tested DMIs; the in vitro DMI resistance induced by prolonged exposure to DMIs in susceptible clinical and environmental strains, and the molecular mechanism of resistance.

Methods

A total of 54 A. fumigatus strains were selected: 23 susceptible to clinical azoles (CAS) and 31 resistant (CAR) with and without mutations in the CYP51A gene (TR34/L98H, F219I, G54R, G54E, D269Y, M220I, or F46Y/M172V/N248T/D255E/E427K). Antifungal susceptibility testing was performed for 8 DMIs (tebuconazole, epoxiconazole, difenoconazole, propiconazole, tetraconazole, flusilazole, fenbuconazole, and prochloraz) using broth microdilution method according to EUCAST and CLSI methods. Mutations in CYP51A, CYP51B, and HMG1 genes were investigated in CAS with DMI high MIC values. In vitro induction of resistance was performed using the 8 DMIs on 11 (6 clinical and 5 environmental) A. fumigatus strains susceptible both to clinical azoles and DMIs. A suspension of 106 conidia was inoculated on glucose-yeast extract-peptone agar plates containing different DMIs at different concentrations and incubated at 37°C for 72 h for six repeated passages.

Results

Comparable results were obtained using EUCAST and CLSI methods.

Resistance (MIC ≥16) to tetraconazole and fenbuconazole was observed in 100% of isolates, both CAR and CAS. On the contrary, a statistically significant difference in tebuconazole, epoxiconazole, difenoconazole, propiconazole, and flusilazole MICs between CAR strains and CAS strains was observed with higher geometric means (GM) in CAR (range 4.9-9.3 mg/L) than in CAS (1.5-2.7 mg/L) strains. Prochloraz showed the lowest GMs: 0.6 and 0.25 mg/L in CAR and CAS strains, respectively.

A significant difference of the GMs for all the DMIs tested, except prochloraz, was observed between the isolates harboring a TR34/L98H or a M220I mutation (GM range 10.4-16 mg/L) and those with other CYP51A mutations (GM range 1-4.6 mg/L).

In the CAS showing high DMI MICs, the absence of CYP51A mutations was confirmed, while a synonymous mutation P394P, was identified in CYP51B. No mutations in HMG1 gene were found.

In the induction tests, the prolonged exposure to DMIs showed an induced phenotypic resistance of 100% (11/11 isolates) for epoxiconazole, of 72.7% (8/11) for propiconazole, of 54% (6/11) for tebuconazole and difenoconazole, and of 9.1% (1/11) for prochloraz.

Molecular analysis to understand if the phenotypic resistance corresponds to induced mutations in CYP51A, CYP51B, and HMG1 genes is in progress.

Conclusions

Preliminary results confirm cross-resistance between clinical azoles and DMIs, with MIC differences between CAR and CAS and between strains with different mutations in the CYP51A gene. Furthermore, the ability of DMIs to induce resistance in vitro was highlighted.

Exploring Mitogenomes Diversity of Fusarium musae from Banana Fruits and Human Patients

Fusarium musae has recently been described as a cross-kingdom pathogen causing post-harvest disease in bananas and systemic and superficial infection in humans. The taxonomic identity of fungal cross-kingdom pathogens is essential for confirming the identification of the species on distant infected hosts. Understanding the level of variability within the species is essential to decipher the population homogeneity infecting human and plant hosts. In order to verify that F. musae strains isolated from fruits and patients are part of a common population and to estimate their overall diversity, we assembled, annotated and explored the diversity of the mitogenomes of 18 F. musae strains obtained from banana fruits and human patients. The mitogenomes showed a high level of similarity among strains with different hosts’ origins, with sizes ranging from 56,493 to 59,256 bp. All contained 27 tRNA genes and 14 protein-coding genes, rps3 protein, and small and large ribosomal subunits (rns and rnl). Variations in the number of endonucleases were detected. A comparison of mitochondrial endonucleases distribution with a diverse set of Fusarium mitogenomes allowed us to specifically discriminate F. musae from its sister species F. verticillioides and the other Fusarium species. Despite the diversity in F. musae mitochondria, strains from bananas and strains from human patients group together, indirectly confirming F. musae as a cross-kingdom pathogen.

Catheter-related blood stream infection caused by Millerozyma farinosa in an immunocompetent patient: a case report and a brief review of the literature

Millerozyma farinose is a halotolerant yeast that has recently been described as an emerging human pathogen, especially in immunocompromised patients. Both the diagnostic process and treatment options are still unclear. Here, we report a case of an immunocompetent oncological patient who developed a catheter-related bloodstream infection (CRBSI) with a concomitant respiratory tract infection caused by M. farinosa. In this report, we discuss how prompt microbiological identification and attentive evaluation of the patient's clinical status can play a significant role in the appropriate management of infections caused by uncommon fungi. MALDI-TOF technology has also substantially improved the timely diagnosis of rare fungi. Furthermore, our diagnosis was subsequently confirmed by 5.8S rRNA sequencing. In our patient, the rapid diagnosis of fungaemia was crucial, together with catheter removal and the initiation of antifungal treatment, for the patient's clinical improvement.

ICU ENVIRONMENTAL SURFACES ARE A RESERVOIR OF FUNGI: SPECIES DISTRIBUTION IN NORTHERN ITALY

BACKGROUND

Preventing and reducing nosocomial infections is a public health goal. Concern about healthcare-associated fungal infections has increased in recent years, due to the emergence and spread of new pathogens, increasing antifungal resistance and outbreaks in hospital settings.

AIM

This study investigated the presence of medically-relevant fungal species on environmental surfaces in 12 intensive care units of 8 hospitals in Milan, Italy.

METHODS

Environmental samplings, using contact plates on surfaces near bed stations and medical workstations, were conducted between November 2019 and January 2020. Fungi isolated were identified and some were tested in vitro for antifungal susceptibility.

FINDINGS

A total of 401 environmental samples were collected from 61 bed stations and 17 medical workstations. Positive samples were found in all hospitals except one, with positivity rates ranging from 4% to 24.2%. Filamentous fungi were found mainly on infusion pumps (23.2%) and patient tables (21.2%), whereas yeasts were mainly on computers (25%) and floors (10.9%). Fungi were isolated from 12% of total samples. Filamentous fungi, mainly Aspergillus fumigatus, grew in 70.8% of positive samples, and yeasts in 27.1%, mainly Candida parapsilosis (42.8%) and C. glabrata (28.6%). Fungi were detected both near patients' beds and on surfaces at workstations, indicating potential for environment-to-patient, patient-to-patient and healthcare workers-to-patient transmission CONCLUSIONS: This study highlights that surveillance in hospital settings through environmental sampling may be an important component of fungal infection prevention.

Fusarium musae from Diseased Bananas and Human Patients: Susceptibility to Fungicides Used in Clinical and Agricultural Settings

Fusarium musae belongs to the Fusarium fujikuroi species complex. It causes crown rot disease in banana but also keratitis and skin infections as well as systemic infections in immunocompromised patients. Antifungal treatments in clinical and agricultural settings rely mostly on molecules belonging to the azole class. Given the potential risk of pathogen spread from food to clinical settings, the goal of the work was to define the level of susceptibility to different azoles of a worldwide population of F. musae. Eight fungicides used in agriculture and five antifungals used in clinical settings (4 azoles and amphotericin B) were tested using the CLSI (Clinical and Laboratory Standards Institute) protocol methodology on 19 F. musae strains collected from both infected patients and bananas. The level of susceptibility to the different active molecules was not dependent on the source of isolation with the exception of fenbuconazole and difenoconazole which had a higher efficiency on banana-isolated strains. Minimal inhibitory concentrations (MICs) of the different molecules ranged from 0.12–0.25 mg/L for prochloraz to more than 16 mg/L for tetraconazole and fenbuconazole. Compared to the F. verticillioides, F. musae MICs were higher suggesting the importance of monitoring the potential future spread of this species also in clinical settings.

Phylogenomic Analysis of a 55.1-kb 19-Gene Dataset Resolves a Monophyletic Fusarium that Includes the Fusarium solani Species Complex

Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.

Tobacco and e-cigarette smoking habits among Italian healthcare students

BACKGROUND

Healthcare professionals might play a significant role in tobacco control. The aims of this study were to investigate tobacco cigarette and electronic cigarette (e-cigarette) consumption among university students enrolled in courses of the healthcare area, and to understand whether training in healthcare could induce to smoking cessation.

STUDY DESIGN

Cross-sectional survey using a self-administered, structured questionnaire.

METHODS

Tobacco smoking habits of 560 students of four different medical area courses at the University of Milan, enrolled both in the first and in the last course year during the 2017-2018 academic year, were collected.

RESULTS

The prevalence of smokers was 34.8%, almost the same for males and females, and higher in Italian students compared to foreigners. Smoking prevalence was higher among employed (46.9%) than unemployed (35.1%) students, without differences between healthcare and non-healthcare workers. The influence of family, and particularly friends, is confirmed to be relevant. About 25% of respondents tried e-cigarettes, mainly smokers (44.6%) and former smokers (38.6%) with the goal of quitting smoking. More than 44% were dual users of both tobacco cigarettes and e-cigarettes. Comparing smoking habits between first-year and final-year students, only students of healthcare assistance course showed a significant drop in smoking during the university studies.

CONCLUSIONS

The implementation of specific educational curricula on smoking dangers and on smoking cessation techniques might have the double effect of supporting students in quitting smoking and of properly preparing them for their future task of helping people to quit smoking.

Prospective multicentre study on azole resistance in Aspergillus isolates from surveillance cultures in haematological patients in Italy

OBJECTIVES

This study was conducted to assess the prevalence of azole resistance in Aspergillus isolates from patients with haematological malignancies or who were undergoing haematopoietic stem cell transplantation and to identify the molecular mechanism of resistance.

METHODS

In this 28-month prospective study involving 18 Italian centres, Aspergillus isolates from surveillance cultures were collected and screened for azole resistance, and mutations in the cyp51A gene were identified. Resistant isolates were genotyped by microsatellite analysis, and the allelic profiles were compared with those of resistant environmental and clinical isolates from the same geographical area that had been previously genotyped.

RESULTS

There were 292 Aspergillus isolates collected from 228 patients. The isolates belonged mainly to the section Fumigati (45.9%), Nigri (20.9%), Flavi (16.8%) and Terrei (4.8%). Three isolates showed itraconazole resistance: Aspergillus fumigatus sensu stricto, Aspergillus lentulus (section Fumigati) and Aspergillus awamori (section Nigri). The itraconazole resistance rates were 1% and 1.48% considering all Aspergillus spp. isolates and the Aspergillus section Fumigati, respectively. The prevalence of azole resistance among all the patients was 1.3%. Among patients harbouring A. fumigatus sensu stricto isolates, the resistance rate was 0.79%. The A. fumigatus isolate, with the TR₃₄/L98H mutation, was genotypically distant from the environmental and clinical strains previously genotyped.

CONCLUSIONS

In this study, the Aspergillus azole resistance rate was 1% (3/292). In addition to A. fumigatus sensu stricto, A. lentulus and A. awamori azole-resistant isolates were identified. Therefore, it is important have a correct identification at the species level to address a rapid therapy better, quickly understand the shift towards cryptic species and have an updated knowledge of the local epidemiology.

Yeast-like filamentous fungi: Molecular identification and in vitro susceptibility study

Yeast-like filamentous fungi, collected in Italy from 1985 to 2018, were submitted to molecular identification and antifungal susceptibility testings. Clinical isolates were identified as Magnusiomyces capitatus (28), M. clavatus (18), and Geotrichum candidum (2). M. clavatus was prevalent among blood isolates (18/24), M. capitatus among isolates from other biological materials. The intrinsic echinocandin resistance was confirmed. Both species had low minimum inhibitory concentrations (MICs) of itraconazole, posaconazole, and voriconazole, while M. clavatus had lower MIC of flucytosine and higher MIC of isavuconazole than M. capitatus. The intrinsic resistance of these species to echinocandins could be the reason of the recent increase of M. clavatus bloodstream infections.

Cryptococcus neoformans and Cryptococcus gattii Species Complex Isolates on the Slopes of Mount Etna, SICILY, Italy

This study investigated the presence of Cryptococcus neoformans and Cryptococcus gattii species complex isolates on olive trees growing in the Eastern part of Sicily (Italy) characterized by the presence of the volcano Etna and the ability of these fungal pathogens to sexually reproduce on medium containing volcanic soil. Samples from 124 olive trees were collected from 14 different sites around Mount Etna. Eighteen trees (14.5%) resulted colonized by C. neoformans VNI-αA isolates, one (0.8%) by VNIV-αD isolates, and two (1.6%) by C. gattii VGI-αB isolates. The ability of environmental and reference strains belonging to VNI, VNIV, and VGI molecular types to sexually reproduce on a medium containing volcanic soil was also tested. VNI and VNIV strains were able to produce filaments and basiodiospores more vigorously than on the control medium, whereas VGI strains were not fertile. In conclusion, the present study identified which C. neoformans and C. gattii species complex genotypes are circulating in Eastern Sicily and confirmed the ecological role of olive trees as environmental reservoir of these pathogens. It also showed that Cryptococcus is able to colonize and sexually reproduce in inhospitable environments such as the slopes of a volcano.

Evolution of fungemia in an Italian region

BACKGROUND

Fungemia represents a public health concern. Knowing aetiology and activity of the antifungals is critical for the management of bloodstream infections. Therefore, surveillance on local/international levels is desirable for a prompt administration of appropriate therapy.

METHODS

Data on fungi responsible for fungemia and antifungal susceptibility profiles were collected from a laboratory-based surveillance over 2016-2017 in 12 hospitals located in Lombardia, Italy. The trend of this infection in twenty years was analysed.

RESULTS

A total of 1024 episodes were evaluated. Rate of candiaemia progressively increased up to 1.46/1000 admissions. C.albicans was the most common species (52%), followed by C. parapsilosis (15%) and C glabrata (13%). As in the previous surveys the antifungal resistance is rare (echinocandins<2%, fluconazole 6%, amphotericin B 0.6%). Fungi other than Candida were responsible for 18 episodes: Cryptococcus neoformans (5 cases), Fusarium spp. (4), Magnusiomyces clavatus (3), Saccharomyces cerevisiae (3), Rhodotorula spp. (2), Exophiala dermatitidis (1). All fungi, except S.cerevisiae, were intrinsically resistant to echinocandins. Some isolates showed also elevated azole MIC.

CONCLUSIONS

No particular changes in terms of species distribution and antifungal susceptibility patterns was noted. However, surveillance programs are needed to monitor trends in antifungal resistance, steer stewardship activities, orient empirical treatment.

Epidemiological trends of cryptococcosis in Italy: Molecular typing and susceptibility pattern of Cryptococcus neoformans isolates collected during a 20-year period

In the present study clinical data and isolates from cases of cryptococcosis recorded during clinical surveys carried out in Italy from 1997 to 2016, were investigated. Molecular typing and antifungal susceptibility testing were performed in order to delineate the epidemiological trend of cryptococcosis in Italy and to define wild-type population for four different antifungal compounds. During the studied period, a total of 302 cases collected from 32 centers of 11 Italian regions were recorded. Analysis of clinical data showed a significant increase of frequency (from 7% to 38%) of cryptococcosis in human immunodeficiency virus (HIV)-negative patients primarily with hematologic malignancies and solid organ transplantations. The prevalence of the molecular types has significantly changed during the study period, showing an increase of VNIII isolates from 11% to 41% in HIV-negative patients, and a decrease of VNIV isolates from 36% to 16%. Antifungal susceptibility testing allowed us to calculate the epidemiological cut-off for flucytosine (1 mg/l), fluconazole (8 mg/l), itraconazole (0.5 mg/l), and voriconazole (0.25 mg/l). Most of the isolates were wild-type strains. Comparison of the MIC distributions according to molecular types showed that VNIV isolates had lower MICs for fluconazole and itraconazole than the VNI and VIII isolates. The current study emphasizes that the epidemiology of cryptococcosis in Italy has significantly changed over the last decades.

Magnusiomyces clavatus infection in a child after allogeneic hematotopoetic stem cell transplantation: Diagnostic and therapeutic implications

Magnusiomyces clavatus is an ascomycetous fungus causing invasive disease in immuno-compromised patients. Neutropenia, contaminated venous catheters, previous antifungal treatment are risk factors for this infection. We report a case of Magnusiomyces clavatus fungemia with pulmonary, renal and skin localizations in a 6-year-old boy with prolonged neutropenia because of three allogeneic hematopoietic stem cell transplantations. The infection was controlled by aggressive and strictly monitored combination therapy with voriconazole and liposomial-ampthotericine-B along with durable recover from neutropenia.

Azole Resistance in Aspergillus fumigatus Clinical Isolates from an Italian Culture Collection

The aims of the study were to investigate the prevalence of azole resistance among Aspergillus fumigatus clinical isolates. A total of 533 clinical isolates that had been collected between 1995 and 2006, from 441 patients, were screened. No resistance was detected in isolates collected between 1995 and 1997. Starting in 1998, the resistance rate was 6.9%; a total of 24 patients (6.25%) harbored a resistant isolate. The TR34/L98H substitution was found in 21 of 30 tested isolates.

Trichophyton concentricum in skin lesions in children from the Salomon Islands

AIM

Aim of the paper was to report cases of Tinea imbricata, a mycosis caused by the anthropophilic dermatophyte Trichophyton concentricum, observed in 2012 in Guadalcanal, the largest of the Salomon islands.

METHODS

During 2012, several cases of Tinea imbricata, called bakwa by local people, were observed in the Little Samaritan Hospital in Guadalcanal. Skin scrapings collected from three young patients were examined in Italy to confirm the clinical diagnosis. The fungus grown on culture was morphologically identified and submitted to sequencing of the ITS1-ITS2 region.

RESULTS

The diagnosis obtained by visual inspection of the skin lesions, characterised by concentric and lamellar plaques of scale often involving large part of the body, was confirmed mycological investigations. A prevalence of 15% of Tinea imbricata in this population was hypothesized. The fungus grown on culture was morphologically identified as Trichophyton concentricum and identification was confirmed sequencing the ITS1-ITS2 region. Patients were treated with potassium permanganate solution soaked gauze followed by colloidal sulfur and salicylic acid cream application. However, the efficacy of the antifungal treatment was difficult to evaluate due to the poor compliance of the patients and the remoteness of the villages.

CONCLUSION

Italian clinicians and mycologists should be aware of this fungal infection because the increased number of international travels and of migration rise the spread of infections previously restricted to limited geographical areas.

Allergic fungal rhinosinusitis due to Curvularia lunata

We report a case of Curvularia lunata infection in an immunocompetent male with an initial diagnosis of suspected left side allergic fungal rhinosinusitis (AFRS), treated surgically. He had a relapse of nasal polyposis and underwent a surgical revision under local anaesthesia with endoscopic nasal polypectomy. The histological examination of the surgical specimen showed an inflammatory polyp of the paranasal sinuses, with eosinophil and lymphocyte infiltration, but without evidence of fungi. However, Curvularia spp fungus grew in cultures of nasal sinus drainage and bioptical specimens. The fungus was identified by DNA sequencing as C. lunata. The patient was then treated with itraconazole (200 mg BID for 4 weeks), mometasone furoate nasal spray (100 mcg BID for 6 months) and normal saline nasal irrigations. At the last follow-up endoscopic evaluation after 19 month from treatment, the patient was symptomless and free from disease. No polyp recurrence nor seromucous discharges were noticed. This first case of C. lunata-associated AFRS reported in Italy, highlights the difficulty of this diagnosis and the usefulness of molecular identification of the fungal species involved.

Azole-resistant Aspergillus fumigatus in the environment of northern Italy, May 2011 to June 2012

In recent years acquired azole resistance in Aspergillus fumigatus has been increasingly reported and a dominant mechanism of resistance (TR34/L98H) was found in clinical and environmental isolates. The aim of the present study was to investigate the prevalence of azole resistance in environmental A. fumigatus isolates collected in northern Italy. A. fumigatus grew from 29 of 47 soil samples analysed. Azole-resistant isolates were detected in 13% (6/47) of the soil samples and in 21% (6/29) of the soil samples containing A. fumigatus. High minimal inhibitory concentrations (MIC) of itraconazole (≥16 mg/L) and posaconazole (≥0.5 mg/L) were displayed by nine isolates from six different soil samples, namely apple orchard (1 sample), rose pot compost (2 samples), and cucurbit yields (3 samples). Seven isolates had a MIC=2 mg/L of voriconazole. Seven of nine itraconazole and posaconazole resistant isolates harboured the same TR34/L98H mutation of cyp51A. These findings, together with the occurrence of resistant clinical isolates, suggest that azole resistance should be considered in primary patient care.

Cryptococcus gattii serotype-C strains isolated in Bangalore, Karnataka, India

During a retrospective study on cryptococcosis carried out in Bangalore, Karnataka, India, four Cryptococcus gattii strains were isolated from one HIV-positive and three HIV-negative patients, two of which had unknown predisposing conditions. Serotyping and genotyping showed that the isolates were C. gattii serotype C, mating-type α and genotype VGIV. All the isolates were identical by multilocus sequence typing, but presented a low similarity compared with a set of 17 C. gattii global control strains. The comparison with a larger number of previously reported C. gattii strains, including African isolates, revealed a close relationship between Indian and African serotype-C isolates.

Consensus multi-locus sequence typing scheme for Cryptococcus neoformans and Cryptococcus gattii

This communication describes the consensus multi-locus typing scheme established by the Cryptococcal Working Group I (Genotyping of Cryptococcus neoformans and C. gattii) of the International Society for Human and Animal Mycology (ISHAM) using seven unlinked genetic loci for global strain genotyping. These genetic loci include the housekeeping genes CAP59,GPD1, LAC1, PLB1, SOD1, URA5 and the IGS1 region. Allele and sequence type information are accessible at http://www.mlst.net/ .

Electrophoretic karyotyping of Cryptococcus neoformans AD-hybrid strains

This study investigated the differences in genome structure between haploid serotype A and D isolates and AD-hybrid strains of Cryptococcus neoformans, and the correlation between the karyotype of A and D strains with their mating ability. The electrophoretic karyotyping of 16 AD-hybrid, eight haploid serotype-A MATalpha, and eight haploid serotype-D MATalphaC. neoformans isolates was performed. These 32 isolates presented, two by two, the same genotype and flow cytometry profile. Five clusters were identified, each including VNI (serotype A), VNIV (serotype D) haploid strains and VNIII AD hybrids. Similarly, mating types were also randomly distributed in the five clusters. In addition, AD-hybrid isolates, with double content of DNA, showed only a slight increase in both the number of chromosomal bands and the calculated genome size compared with haploid isolates. Data support the hypothesis that hybrid isolates are aneuploids (2n+x) rather than eudiploids (2n). In addition, a set of six mating type a strains were karyotyped and then used for mating experiments carried out crossing the haploid isolates with similar or different karyotype profile strains. Isolates with completely different karyotype were able to mate confirming that meiosis occurred even in the presence of chromosomes of different lengths.

Cryptococcus neoformans typing by PCR fingerprinting using (GACA)4 primers based on C. neoformans genome project data

Four (GACA)(4) PCR fingerprinting sequences, used as markers to identify serotypes A and D and AD hybrids, were retrieved in four Cryptococcus neoformans genome databases. Their locations, both in serotype A and D genomes, were confirmed by chromosomal hybridization with specific probes. Two sequences were recognized to code for hypothetical functional proteins.

Cryptococcus neoformans population includes hybrid strains homozygous at mating-type locus

Recent attempts to characterise the hybrid strains of Cryptococcus neoformans have led to the identification of a cryptic population of hybrid strains ('H strains') with double DNA content but only a single mating-type allele. To verify a set of hypotheses concerning their origin, we investigated 14 previously isolated H strains and ten F1-progeny strains arising from H99 and JEC20 mating. The double DNA content was tested by flow cytometry; the presence of only one mating type was tested by amplifying 12 mating-type-specific genes and one gene unlinked with the mating-type locus (URA5). Analysis of the F1 progeny identified two H strains, and electrophoretic karyotyping confirmed the occurrence of genetic recombination. The simultaneous presence of the homozygous and heterozygous loci, and the fact that all of the F1-progeny strains presented a recombinant karyotype, suggest that the H strains originated from the post-meiotic random fusion of two of the four recombinant nuclei. Further studies are required to elucidate the role of the homozygous mating-type loci in the virulence of C. neoformans.

Molecular analysis of 311Cryptococcus neoformansisolates from a 30-month ECMM survey of cryptococcosis in Europe

During a European Confederation of Medical Mycology (ECMM) prospective survey of cryptococcosis in Europe (from July 1997 to December 1999) 655 cases were reported from 17 countries; 565 of the completed questionnaires were evaluable. Cryptococcosis was associated with HIV infection in 77% of cases (range 57.5-94%). Assessment of the laboratory data highlighted the lack of defined standard procedures for the diagnosis of cryptococcosis: the antigen test was not usually used for screening, the disease was mainly recognised when meningitis occurred (65% of patients) and, with the exception of a few cases, the extent of the infection was not investigated. Cryptococcus neoformans was the etiological agent in all of the cases except for six caused by C. gattii and four by other Cryptococcus species. A total of 311 C. neoformans strains were serotyped by Crypto Check latex agglutination, genotyped by PCR-fingerprinting using the (GACA)4 oligonucleotide as a single primer, and their mating type was determined by PCR of the STE20 alleles. Serotype A was the most represented (51% of the isolates), followed by serotype D (30%) and serotype AD (19%). PCR-fingerprinting analysis significantly increased the percentage of hybrid strains to 30%, as 6% of the serotype A and 28% of the serotype D isolates were of the VN3 or VN4 hybrid genotype. In addition, the mating type determinations revealed the MATa serotype A allele in one haploid strain and 28 hybrids, and hybrid isolates with a single mating type (four Aalpha and two Dalpha) were also identified. This is the first prospective survey to be carried out in Europe which has attempted to investigate the epidemiology of cryptococcosis and the population structure of C. neoformans, and the results obtained thus far show the widespread involvement of AD hybrid strains in C. neoformans infections.

Four-year persistence of a single Candida albicans genotype causing bloodstream infections in a surgical ward proven by multilocus sequence typing

The present study represents the first application of multilocus sequence typing to retrospectively investigate a suspected outbreak of Candida albicans bloodstream infection cases that occurred in the same hospital ward between July 1987 and October 1991. Results demonstrated that eight bloodstream infections were caused by the same strain, endemic in the ward, over a 4-year period.

Comparative analysis of pathogenicity of Cryptococcus neoformans serotypes A, D and AD in murine cryptococcosis

OBJECTIVES

To characterize the pathogenicity of 15 strains of Cryptococcus neoformans belonging to several serotype/mating type allele patterns (Dalpha, Da, A(alpha), A(a), A(alpha)/D(a) and D(alpha)/A(a)) in experimental models of murine cryptococcosis.

METHODS

CD1-infected mice were examined for survival and fungal loads in either brain or lung during the course of infection.

RESULTS

All strains, with the exception of one Da strain, produced melanin in vitro. Similarly, all strains were encapsulated and produced phospholipase. When CD1 mice were challenged intravenously (i.v.) with 5x10(5)CFU/mouse and observed for 60 days post-infection, a significant variation of mortality rate was observed among mice infected with different strains. A(alpha) and A(alpha)/D(a) strains all produced 100% mortality within the study period with mean survivals significantly shorter than those of mice infected with strains belonging to any other allele type (P<0.0001). A wide range of pathogenicity was shown by haploid and diploid strains presenting D(alpha) allele. This finding was confirmed by an intranasal model of challenge. To investigate the progression of infection, the mice were challenged i.v. with 5x10(4)CFU/mouse and tissue burden experiments (brain and lung) were performed on days 6 and 12 post-infection. Only the mice infected with A(alpha) and A(alpha)/D(a) strains showed a >1 log(10) increase of CFU/g in both tissues throughout the study period.

CONCLUSIONS

Our results suggest that the presence of the A(alpha) mating type allele in either haploid or diploid strains is correlated with virulence, while the presence of the A(a) or D(a) allele in haploid strains is associated with moderate or no virulence. Finally, either haploid or diploid strains presenting D(alpha) allele vary in virulence.

Determination of Cryptococcus neoformans var. neoformans mating type by multiplex PCR

Mating type plays an important role in the epidemiology and virulence of Cryptococcus neoformans. The present study designed a multiplex PCR method to distinguish the six mating type patterns (Aa, Da, Aalpha, Dalpha, Aa/Dalpha, and Aalpha/Da) of C. neoformans var. neoformans. PCR amplification identified one fragment for Aa (860 bp), Dalpha (413 bp) and Da (645 bp) strains, two fragments for Aalpha (320 and 400 bp) and Aa/Dalpha (860 and 413 bp) strains, and three fragments (645, 400, 320 bp) for an Aalpha/Da strain. The method appears to be a valid, simple and relatively inexpensive tool for epidemiological and virulence studies.

Flucytosine and cryptococcosis: which in vitro test is the best predictor of outcome?

The combination of flucytosine and amphotericin B is first choice treatment for active cryptococcosis. Because of innate or acquired resistance of Cryptococcus neoformans to flucytosine, in vitro testing is mandatory. Yeast nitrogen base (YNB) at pH 7.0 is the recommended medium for the broth microdilution test (NCCLS M27-A) and for the E-test. In order to verify if minimum inhibitory concentrations (MICs) were able to predict treatment outcome, the susceptibility of 24 isolates from 21 patients treated with flucytosine alone or in combination was tested by the broth microdilution, agar dilution and E-test using YNB either at pH 7.0 or at pH 5.4. Only those MICs obtained on YNB pH 5.4 proved to correlate with treatment outcome. The present study suggests that in vitro susceptibility to flucytosine of C. neoformans isolates should be evaluated on YNB pH 5.4 and the test should be standardized accordingly.

Molecular and genetic characterization of a serotype A MATa Cryptococcus neoformans isolate

Cryptococcus neoformans comprises two varieties (neoformans and gattii) and four serotypes (A, B, C and D). Fertile isolates of both mating types have been identified in serotypes B, C and D; however, a fertile serotype A MATa strain has not been confirmed, although serotype A MATalpha strains will mate with serotype D MATa strains. Preliminary analysis of a recent Italian environmental isolate (IUM 96-2828) suggested that this strain was haploid, serotype A and MATa. In this study, IUM 96-2828 has been characterized in detail. A mating reaction between IUM 96-2828 and H99 (serotype A MATalpha) produced abundant spores with an equal distribution of MATa and MATalpha progeny, all of which were serotype A. Karyotypic analysis of F(1) spores revealed evidence of recombination, confirming that IUM 96-2828 was fertile. The MATa pheromone gene from IUM 96-2828 was sequenced and found to be most closely related to the serotype D MATa pheromone gene. Phylogenetic comparisons of other genes not linked to mating type also suggested IUM 96-2828 was most closely related to serotype A strains. Biochemical analysis showed that the carbon assimilation profiles of H99 and IUM 96-2828 were identical for 97 % (30/31) of the substrates while isozyme analysis showed 89 % (17/19) identity. Assays of major virulence factors found no difference between H99 and IUM 96-2828. Virulence studies using the mouse model demonstrated that IUM 96-2828 was virulent for mice, although it was less virulent than H99. These data strongly suggest that IUM 96-2828 is a true haploid serotype A MATa isolate that is fertile.

Origin of Cryptococcus neoformans var. neoformans diploid strains

The basidiomycetous yeast Cryptococcus neoformans is an important human fungal pathogen. Two varieties, C. neoformans var. neoformans and C. neoformans var. gattii, have been identified. Both are heterothallic with two mating types, MATa and MATalpha. Some rare isolates are self-fertile and are considered occasional diploid or aneuploid strains. In the present study, 133 isolates, mostly from Italian patients, were investigated to detect the presence of diploid strains in the Igiene Università Milano culture collection. All of the diploid isolates were further investigated by different methods to elucidate their origins. Forty-nine diploid strains were identified by flow cytometry. PCR fingerprinting using the (GACA)(4) primer showed that the diploid state was associated with two specific genotypes identified as VN3 and VN4. Determination of mating type on V8 juice medium confirmed that the majority of the strains were sterile. PCR and dot blotting using the two pheromone genes (MFa and MFalpha) as probes identified 36 of the 49 diploid isolates as MATa/alpha. The results of pheromone gene sequencing showed that two allelic MFalpha genes exist and are distinct for serotypes A and D. In contrast, the MFa gene sequence was conserved in both serotype alleles. Amplification of serotype-specific STE20 alleles demonstrated that the diploid strains contained one mating locus inherited from a serotype A parent and one inherited from a serotype D parent. The present results suggest that diploid isolates may be common among the C. neoformans population and that in Italy and other European countries serotype A and D populations are not genetically isolated but are able to recombine by sexual reproduction.

Isolation of a Cryptococcus neoformans serotype A MATa strain from the Italian environment

Cryptococcus neoformans is a heterothallic basidiomycete which possesses a bipolar mating system based on two mating type alleles, MATa and MATalpha. In the type variety, C. neoformans var. neoformans, both mating types have been found among strains of one serotype, serotype D, whereas only MATalpha was identified after extensive survey of serotype A strains. Serotype A MA Ta appeared to be extinct or to exist only in a vestigial, non-functional form. We report the isolation of a C. n. var. neoformans serotype A MATa strain from the Italian environment. The strain was serotyped by slide agglutination test, genotyped by polymerase chain reaction (PCR) fingerprinting using the (GACA)4 primer, and its haploid state was determined by flow cytometry. The mating type was identified by PCR amplification of the pheromone a gene. In addition, the amplification of the four STE20 alleles, specific for the mating type of serotypes A and D, showed that the strain contains only the MATa locus. By crossing experiments the strain was found to be fertile. The interest in the finding of this fertile isolate is related to the possibility to construct a congenic pair of serotype A MATa/MATalpha strains to be used in genetic and pathogenesis studies.

[Acute abdomen in the third trimester]

The authors report a case of acute abdomen in the third trimester of pregnancy as observed at the II Obstetrics and Gynecologic Department of Florence University. Emphasis is laid on the frequent abnormality of the symptomatology and therefore the difficult of early diagnosis. The conclusion is reached that a greater semeiologic accuracy on behalf of the specialist as well as memorization of the several clinical charts responsible for such pathology, allow an earlier diagnosis with consequent improvement of maternal and fetal prognosis.