Host-driven subspeciation in the hedgehog fungus, Trichophyton erinacei, an emerging cause of human dermatophytosis.

Trichophyton erinacei is a main cause of dermatophytosis in hedgehogs and is increasingly reported from human infections worldwide. This pathogen was originally described in the European hedgehog (Erinaceus europaeus) but is also frequently found in the African four-toed hedgehog (Atelerix albiventris), a popular pet animal worldwide. Little is known about the taxonomy and population genetics of this pathogen despite its increasing importance in clinical practice. Notably, whether there are different populations or even cryptic species associated with different hosts or geographic regions is not known. To answer these questions, we collected 161 isolates, performed phylogenetic and population-genetic analyses, determined mating-type, and characterised morphology and physiology. Multigene phylogeny and microsatellite analysis supported T. erinacei as a monophyletic species, in contrast to highly incongruent single-gene phylogenies. Two main subpopulations, one specific mainly to Atelerix and second to Erinaceus hosts, were identified inside T. erinacei, and slight differences in the size of microconidia and antifungal susceptibilities were observed among them. Although the process of speciation into two lineages is ongoing in T. erinacei, there is still gene flow between these populations. Thus, we present T. erinacei as a single species, with notable intraspecies variability in genotype and phenotype. The data from wild hedgehogs indicated that sexual reproduction in T. erinacei and de novo infection of hedgehogs from soil are probably rare events and that clonal horizontal spread strongly dominates. The molecular typing approach used in this study represents a suitable tool for further epidemiological surveillance of this emerging pathogen in both animals and humans. The results of this study also highlighted the need to use a multigene phylogeny ideally in combination with other independent molecular markers to understand the species boundaries of dermatophytes. Citation: Cmoková A, Kolarík M, Guillot J, et al. 2022. Host-driven subspeciation in the hedgehog fungus, Trichophyton erinacei, an emerging cause of human dermatophytosis. Persoonia 48: 203-218. https://doi.org/10.3767/persoonia.2022.48.06.

Nosocomial candidemia in the Czech Republic in 2012-2015: results of a microbiological multicentre study.

  Background: Candidemia is a severe and often life-threatening infection frequently occurring in critically ill patients. During the last decade, new therapeutic and prophylactic strategies influenced (at least in some patient subgroups) the epidemiological situation and the spectrum of causative Candida strains. The present multicentre study aimed to assess the current epidemiological situation of Candida strains causing invasive candidiasis (IC) in patients of tertiary care hospitals in the Czech Republic. MATERIAL AND METHODS: Clinical and microbiological data on patients with bloodstream yeast isolates collected in 11 tertiary care hospitals in the Czech Republic between 2012 and 2015 were analysed. The incidence of cases and species distribution were assessed by study year, age, and specialty. Moreover, an association with the Candida colonization and presence of toxigenic strains of Clostridium difficile in stool prior to blood culture positivity was analysed. For some of the strains, minimum inhibitory concentrations (MICs) of systemic antifungals were determined using standard methods. RESULTS: A total of 886 episodes of candidemia (921 yeast strains) were identified during the study period. The overall incidence per 1000 admissions was 0.40 (range 0.21-1.22 depending on the hospital). Almost half of the isolates belonged to the species Candida albicans (49.7 %), followed by Candida glabrata (15.3 %) and Candida parapsilosis (11.2 %). Non-albicans species of Candida significantly predominated in oncology wards (71.6 %) as compared to surgery (40.4 %) or internal medicine (52.0 %) departments. More than 70.0 % of patients stayed in intensive care units at the time of positive culture; in 65.0 % of patients, colonization with the same yeast species preceded blood culture positivity. In only 5.1 % of all patients, the previous presence of toxigenic strains of Clostridium difficile in stool was found. Fifty-six of the 921 yeast strains were tested for antifungal susceptibility, with an increase in MICs to azoles being observed for C. glabrata. CONCLUSION: The incidence of candidemia in the Czech Republic did not vary significantly between 2012 and 2015, and C. glabrata was the second most common yeast species after C. albicans isolated from blood.

Diagnostic value of serum galactomannan, (1,3)-ß-d-glucan, and Aspergillus fumigatus-specific IgA and IgG assays for invasive pulmonary aspergillosis in non-neutropenic patients.

Detection of serum galactomannan (GM) and (1,3)-ß-d-glucan (BG) is considered useful for non-culture diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients. Only few studies evaluated these seromarkers in non-neutropenic patients suspected of having IPA. The aim of this study was to evaluate both tests together with the Aspergillus fumigatus-specific serum IgG and IgA (IgAG) test for serological IPA diagnosis in non-neutropenic patients. Sera from 87 patients suspected of having IPA were retrospectively analysed. Patients were categorised into groups of proven IPA (n = 10), putative IPA (n = 31) and non-IPA colonisation (n = 46). When the GM, BG and IgAG assays were used for patients included in the study, the sensitivity/specificity/positive predictive value (PPV)/negative predictive value (NPV) were 48.8%/91.3%/83.3%/66.7%, 82.9%/73.9%/73.9%/82.9% and 75.6%/95.7%/93.9%/81.5%, respectively. Thus, the highest specificity and PPV were confirmed for the IgAG assay. Improvements in the sensitivity and NPV were achieved by "at least one positive" analysis with the GM and BG assays, with the sensitivity/specificity/PPV/NPV values being 85.0%/69.6%/71.4%/84.2%. Nevertheless, the highest sensitivity and NPV were achieved by the "at least one positive" analysis combining the GM, BG and IgAG tests (97.6% and 96.8%, respectively). The involvement of the IgAG assay could improve IPA diagnosis in non-neutropenic patients by increasing the sensitivity and NPV when combined with the GM or BG assays. Furthermore, improvement was achieved by combining the GM, BG and IgAG assays using the "at least one positive test" strategy, especially if doubt exists.

High frequency of Candida fabianii among clinical isolates biochemically identified as Candida pelliculosa and Candida utilis.

Clinical yeast isolates belonging to Candida pelliculosa, Candida utilis and Candida fabianii are difficult to distinguish in a routine mycology laboratory using common biochemical tests. The aims of this study were to determine the prevalence of C. pelliculosa, C. utilis and C. fabianii in clinical samples and to compare their minimum inhibitory concentrations (MICs) to systemic antifungals. Two hundred and forty-eight clinical yeast isolates obtained from eight large hospitals in the Czech Republic were included in this study. Identification was performed biochemically using ID 32C kit and by MALDI-TOF MS. MICs were determined using colorimetric broth dilution Sensititre YeastOne panels. From a total number of 248 isolates, 175 were identified as C. pelliculosa and 73 as C. utilis using the biochemical kit. In contrast, MALDI-TOF MS identified 222 isolates as C. fabianii, 20 as C. pelliculosa and 6 as C. utilis. The highest mean MICs were found in C. fabianii and, regardless of the studied species, in isolates from blood cultures and central venous catheters. MALDI-TOF MS revealed C. fabianii to be most prevalent in clinical samples as compared with the other studied species. Higher MIC values in C. fabianii support the importance of correct identification of this species.

[Invasive candidiasis in selected heamatology departments in the Czech Republic and Slovakia - microbiological results of the CAN CELL project]. / Invazivní kvasinkové infekce na vybraných hematoonkologických oddeleních Czech Republic and Slovakia - microbiological results of the CAN CELL project]

BACKGROUND: The aim of our study was to analyze the spectrum and characteristic of invasive candidiasis in selected haematological departments in the Czech and Slovak Republics, and to compare minimum inhibitory concentrations (MIC) of some antifungal agents for isolates obtained. MATERIAL AND METHODS: Between 1 March 2009 and 31 October 2010, Candida strains from clinically important material obtained from patients with haematological malignancies were collected. Each isolate was biochemically identified and tested for in vitro susceptibility to three known echinocandins and amphotericin B and selected azoles using the E-test. Relevant clinical data were collected. RESULTS: The study included 63 isolates from 61 patients. The most frequently isolated species were C. albicans and C. glabrata (28 % and 19 %, respectively). However, after exclusion of isolates from bronchoalveolar lavage fluid, the percentage changed in favour of C. albicans and C. parapsilosis (25 % and 17 respectively). The MIC data showed a high susceptibility of yeasts to echinocandins and amphotericin B. Ten (16 %) strains were cross-resistant to azoles (mostly C. glabrata). CONCLUSION: Invasive candidiasis is not frequent infection complication in patients with haematological malignancies in the Czech Republic and Slovakia. Moreover, the spectrum of pathogens was similar to that described in recent international studies. However, identification of susceptible and resistant strains according to MIC could be beneficial for choice of antifungal treatment.