MRC Centre for Medical Mycology

CreA, and subsequently, the two newly identified sites S268 and T308, the previously identified but uncharacterized site S262, and the previously characterized site S319 were chosen to be mutated to nonphosphorylatable residues before their effect on CCR was characterized. Sites S262, S268, and T308 are important for CreA protein accumulation and cellular localization, DNA binding, and repression of enzyme activities. In agreement with a previous study, site S319 is not important for several here-tested phenotypes but is key for CreA degradation and induction of enzyme activities. This work characterized novel CreA phosphorylation sites under carbon catabolite-repressing conditions and showed that they are crucial for CreA protein turnover, control of carbohydrate utilization, and biotechnologically relevant enzyme production.

Candida auris is an emerging yeast that has been reported as a cause of human infections in over 30 countries and 6 continents since its first description 10 years ago Capable of causing large nosocomial outbreaks, usually in high-dependency units Whole-genome sequence (WGS) analyses have revealed the existence of at least 4 phylogenetically separate clonal lineages of C. auris, each with firm associations with distinct geographic regions: clade I (Southern Asia), clade II (East Asia), clade III (South Africa), and clade IV (South America) WGS has revealed minimal diversity between isolates within each clade but vast sequence divergence between different clades, consistent with their almost simultaneous and very recent emergence as human colonizers/pathogens in multiple geographic areas Subsequent outbreaks reported in the United Kingdom, Central and Southern Europe, and North America have all been seeded by isolates that can be mapped genetically to 1 of these 4 clonal lineages Interestingly, a potential fifth clade was recently described from a case of otitis in Iran [14], although to date, this has not been responsible for any nosocomial outbreaks.

The (1→3)-β-D-glucan (BDG) is a component of the fungal cell wall that can be detected in serum and used as an adjunctive tool for the diagnosis of invasive mold infections (IMI) in patients with hematologic cancer or other immunosuppressive conditions. However, its use is limited by modest sensitivity/specificity, inability to differentiate between fungal pathogens, and lack of detection of mucormycosis. Data about BDG performance for other relevant IMI, such as invasive fusariosis (IF) and invasive scedosporiosis/lomentosporiosis (IS) are scarce. The objective of this study was to assess the sensitivity of BDG for the diagnosis of IF and IS through systematic literature review and meta-analysis. Immunosuppressed patients diagnosed with proven or probable IF and IS, with interpretable BDG data were eligible. A total of 73 IF and 27 IS cases were included. The sensitivity of BDG for IF and IS diagnosis was 76.7% and 81.5%, respectively. In comparison, the sensitivity of serum galactomannan for IF was 27%. Importantly, BDG positivity preceded the diagnosis by conventional methods (culture or histopathology) in 73% and 94% of IF and IS cases, respectively. Specificity was not assessed because of lacking data. In conclusion, BDG testing may be useful in patients with suspected IF or IS. Combining BDG and galactomannan testing may also help differentiating between the different types of IMI.

The emergence of multidrug-resistant bacteria has driven the need for novel antibiotics. Our investigations have focussed on lichens as they naturally produce a wide range of unique and very effective defence chemicals. The aim of this study was to evaluate some of the antimicrobial properties of ten common British churchyard lichens. The lichen material was sampled from ten species, namely Caloplaca flavescens , Diploicia canescens , Cladonia fimbriata , Psilolechia lucida , Lecanora campestris subsp. Campestris , Lecanora sulphurea, Pertusaria amara f.amara , Lepraria incana , Porpidia tuberculosa and Xanthoria calcicola . Crude acetone extracts of these lichens were tested against six bacteria ( Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonela typhimurium, Listeria monocytogenes and Lactobacillus acidophilus ) and two fungi ( Trichophyton interdigitale and Aspergillus flavus ) by the disc-diffusion susceptibility test method. Extracts of Diploicia canescens, Psilolechia lucida, Lecanora sulphurea, Pertusaria amara and Lepraria incana showed clear inhibition of the Gram-positive bacteria tested ( S. aureus, L. monocytogenes, L. plantarum ). Diploicia canescens, Pertusaria amara and Lepraria incana extracts also inhibited the dermatophyte fungi tested. The Lepraria incana sample tested here was the only extract that showed activity against any of the Gram-negative bacteria tested; it showed inhibition of Pseudomnas aeruginosa . Overall, our results showed that crude extracts of Diploicia canescens and Pertusaria amara had the most potent antimicrobial activity of all the extracts tested. Our results are in general agreement with published findings elsewhere. The activity of the Porpidia tuberculosa margin sample being different from that of the main colony material was an interesting and new finding reported here for the first time.

<title>Abstract</title> This book chapter describes the advantages and limitations of the ITS Region as a universal barcode for fungal identification. The ITS region offers several practical advantages as a universal fungal barcode region. The region encompasses segments that permit resolution at different taxonomic levels as it includes the highly conserved 5.8S rRNA gene, the moderately rapidly evolving ITS2 region and the rapidly evolving ITS1 region, flanked by the highly conserved SSU and LSU genes which permit design of PCR primers that are almost panfungal. Over the last two decades the sequence-based identification of fungi has certainly come of age. The ITS region is universally accepted as the primary fungal barcoding region owing to the high barcode gap with the locus for many groups of fungi. Since the species-resolution power of ITS is poor for certain groups of fungi, and higher-level taxonomic resolution is greater with proteincoding genes, the TEF1α locus has been proposed as the universal secondary barcode region. In addition, the historical problems surrounding the reliability of fungal DNA sequences in centralized repositories are slowly being resolved by the development of an increasing number of publicly accessible, curated databases.

Abstract Candida albicans : a fungal pathogen, can cause superficial and fatal infections in humans. An important virulence factor in C. albicans dissemination is the transformation from yeast to an invasive hyphal form, which is favoured at human body temperature. Zebrafish, a useful model for studying C. albicans infections, cannot survive at 37°C. Arabian killifish, Aphanius dispar , an emerging teleost model can tolerate temperatures up to 40 °C for up to 12 days (independent feeding time) allowing for longer analysis compared to zebrafish. This study introduces A. dispar as a thermo-relevant and a more accurate reporter of the virulence mechanisms relevant to C. albicans as a human pathogen. Using A. dispar , we tested virulence at human skin (30 °C), body temperature (37 °C) and a high fever condition (40°C). Infection by C. albicans at 37°C and 40°C significantly increased virulence, reduced survival of AKF embryos and formed invasive hyphal network compared to 30 °C. Two mutant strains of C. albicans. pmr1Δ (with aberrant cell surface glycans) exhibited reduced virulence at 37°C, whereas rsr1 Δ (lacking a cell polarity marker) showed less virulence at 30 °C. Additionally, anti-fungal treatment rescued AKF survival in a dose-dependent manner, indicating AKF’s potential for in vivo drug testing. Our data indicates the quantitative and qualitative importance of examining virulence traits at physiologically relevant temperatures and demonstrates an equivalence to findings for systemic infection derived in mouse models. The A. dispar embryo therefore provides an excellent in vivo model system for assessing virulence, drug-testing, and real-time imaging of host-pathogen interactions. Significance Statement The virulence of many pathogens is dependent on host temperature. We demonstrate that the A. dispar embryo provides an excellent new thermo-relevant alternative to zebrafish and mouse models, which have limitations in terms of the range of temperatures that can be assessed in real-time. In this study, we have assessed C. albicans temperature-based virulence, focusing on human body and human skin temperatures (37, 40 and 30 °C, respectively) by examining different genetic backgrounds of C. albicans strains. The results indicate different C. albicans strains with genetic background show varied virulence depending on temperature indicating importance of examination of virulence mechanisms at physiological temperatures.

Abstract A 10‐year‐old, male, farm‐based springer spaniel that presented with subacute progressive left‐sided central vestibular signs was diagnosed with meningoencephalitis of unknown origin. The patient received prednisolone (2 mg/kg/day orally), ciclosporin (5 mg/kg orally twice a day) and a single infusion of cytarabine (200 mg/m 2 ). Six weeks later, neurological signs had resolved, but multiple cutaneous nodules developed on the limbs, trunk and face. Lesions discharged a dark purulent material without tissue grains. A ‘filamentous fungus’ was isolated, but discarded without identification. Aspirates from nodules showed pigmented, septate fungal hyphae, and culture of aspirates yielded Trematosphaeria grisea . Itraconazole (5 mg/kg once a day) and gradual tapering of immunosuppressive drugs led to resolution of nodular lesions over 4 months without neurological relapse. A fungal granuloma developed transiently 8 months after starting itraconazole. Immunosuppressive drugs were stopped 15 months after introduction without neurological relapse. Itraconazole was withdrawn 8 weeks later, 5 months after last relapse of skin disease.

Abstract Erythropoiesis occurs through several waves during embryonic development. Although the source of the primitive wave is well characterized, the origin of erythrocytes later in embryogenesis is less clear due to overlaps between the different erythroid waves. Using the miR144/451-GFP mouse model to track cells expressing the erythroid microRNAs miR144/451, we identified cells co-expressing VE-Cadherin and GFP in the yolk sac between E9.5 and E12. This suggested the existence of hemogenic endothelial cells committed to erythropoiesis (Ery-HEC). We showed that these cells were capable of generating erythrocytes ex vivo and we demonstrated that the formation of Ery-HEC was independent of the Runx1 gene expression. Using transcriptome analysis, we demonstrated that these cells coexpressed endothelial and erythroid genes such as Hbb-bh1 and Gata1 but we were surprised to detect the primitive erythroid genes Aqp3 and Aqp8 suggesting the formation of primitive erythrocytes at a much later time point than initially thought. Finally, we showed that enforced expression of Gata1 in endothelial cells was enough to initiate the erythroid transcriptional program.

Abstract: Histoplasmosis is a dimorphic fungal infection, which is rare outside endemic pockets in North, Central, and South America, Asia, and Africa. Herein, we describe a woman in her 80s living in the Scottish Borders region of the United Kingdom with a recent diagnosis of granulomatous rosacea, who on receiving escalating immunosuppression for suspected sarcoidosis, and long-standing rheumatoid arthritis developed a striking eruption involving her eyelids along with painful ulceration of the oral and nasal mucosa. Histopathologic examination of the skin and mucosal lesions demonstrated granulomatous inflammation with numerous yeast forms of fungal organisms with morphological characteristics of Histoplasma species. This was confirmed to be H. capsulatum on fungal culture and direct panfungal polymerase chain reaction assay. Although the patient had not left the United Kingdom for more than 20 years, she gave a travel history involving multiple trips to countries where histoplasmosis is known to occur, before that. This case exemplifies the challenges involved in making a diagnosis of histoplasmosis in nonendemic regions for both clinicians and pathologists alike. In this particular patient, the diagnostic difficulties were compounded by the clinicopathological overlap with other cutaneous and systemic granulomatous disorders like granulomatous rosacea and suspected sarcoidosis and also the exceptionally long latency period between the purported historical primary infection and recent recrudescence. We highlight this unusual case to increase an awareness of histoplasmosis, which is very rare in nonendemic regions like the United Kingdom and involves cases acquired during residence in or travel to endemic areas, to ensure its prompt recognition and treatment.

Introduction: Rhizopus homothallicus is a new emerging pathogen causing Mucormycosis.Case Presentation: We report a case of pneumonia caused by Rhizopus homothallicus in a 54 year old type 2 diabetic patient. The organism was isolated from bronchoalveolar lavage fluid and preliminary identified by fungal morphology and finally by sequencing of the internal transcribed spacer region.Conclusion: Mucormycosis may be associated with cavitary lung lesions in the backdrop of poorly controlled diabetes or other immunosuppressed states. Pulmonary mucormycosis may have variable clinical and radiological presentations. Therefore, strong clinical suspicion and prompt management can prevent high fatality associated with the disease.

Mycetohabitans MAGs identified and assembled from public Mucorales SRA data.

A total of 10 non-dermatophytic molds isolated from both symptomatic and asymptomatic cattle skin which includes Penicillumcitrinum, Aspergillus welwitschiae, Aspergillus aculeatus, Curvulariakusanol, Cladosporium teniussmum, Pestalotiopsis microspora, Fusarium oxysporum, Fusarium linchenicola, Absidia sp. and Aspergillus fumigatus were subjected to a pathogenecity test using albino mice. These isolates were also screened for five enzymes using standard plate method. Result from pathogenecity test showed that Absidiasp, C.tenuissimum and Aspergillus welwitschiae were able to elicit discolouration, lesion production and alopecia on the albino mice skin respectively which are evidences of clinical symptoms associated of cutaneous mycoses. For enzyme screening&#160; result revealed the highest zone of activity for keratinase (65mm), amylase (86mm), protease (60mm), lipase (60mm) and cellulase (86mm) which were observed on P.microspora, A.welwitschiae, C.tenuissimum, A.welwitschiae and&#160; A. welwitschiae respectively.&#160; Pathogenecity test from this study shows that some of these molds are highly virulent and that can be attributed to their ability to posses some virulent factors which includes secretion of hydrolytic enzyme.

Introduction: Malassezia globosa is a yeast species that belongs to the mycobiota of humans and animals, associated with dermatological disorders such as dandruff. This is a chronic scalp skin disorder characterized by flaking and itching. Treatments include commercial shampoo with different formulations that contain antifungal activities like Zinc pyrithione or Piroctone Olamine. The effectiveness of these formulations have been evaluated for decades &#160;for dandruff symptom relief of volunteers. To date, non-mammalian, in-vivo methods exist to test formulations of these actives.Aim:&#160;To evaluate in vivo in Galleria mellonella larva, two commercial antifungal shampoos (Shampoo with 1% ZPT &amp; 1.6% Zinc Carbonate and shampoo with 0.5% PO) against this species.Methodology: G. mellonella larvae were inoculated with M. globosa on abraded cuticular surface. Then, integument cell viability, histological changes, and fungal burden were evaluated. Results. Larvae inoculated with M. globosa&#160;showed higher lesion melanization and tissue damage. In addition, M. globosa population showed to increase over time. Concerning the shampoo’s effectiveness, both formulations significantly reduced M. globosa&#160;burden and tissue damage.Conclusion:&#160;G. mellonella larvae were allowed to evaluate M. globosa superficial infection and antifungal effectiveness. Shampoos with ZPT and PO showed a positive effect on inoculated larvae.

Raw data files linked to publication "Commensal yeast Malassezia produces tryptophane metabolites to promote tissue homeostasis via the aryl hydrocarbon receptor." (Nature Microbiology 2026)

Invasive fungal infections (IFI) such as mucormycosis are causing devastating morbidity and mortality in immunocompromised patients as anti-fungal agents do not work in the setting of suppressed immune system. COVID-19 pandemic has created a novel landscape for IFI in post-pandemic patients, which results from severe immune suppression caused by COVID-19 infection, comorbidities (diabetes, obesity) and immunosuppressive treatments such as steroids. The antigen-antibody interaction has been employed in radioimmunotherapy (RIT) to deliver lethal doses of ionizing radiation emitted by radionuclides to targeted cells and has demonstrated efficacy in several cancers. One of the advantages of RIT is its independence of immune status of a host which is crucial for immunosuppressed post-COVID-19 patients. In present work we targeted with RIT fungal pan-antigens 1,3-beta-glucan and melanin pigment, which are present in the majority of pathogenic fungi, thus making such targeting pathogen-agnostic. We demonstrated in experimental murine mucormycosis in immunocompetent and immunocompromised mice that 177Lutetium-labeled antibodies to these two antigens effectively decreased the fungal burden in major organs including the brain. These results are encouraging because they show the effectiveness of pathogen-agnostic RIT in significantly decreasing fungal burden in vivo, while they can be also potentially applied to treat the broad range of invasive fungal infections which express pan-antigens 1,3-beta-glucan or melanin.

raw data files linked to https://doi.org/10.1128/mbio.00415-26

Mucormycosis is found in co-infection with bacteria in &gt;50% of the cases. Most of these cases were reported among people with haematological diseases. The two most frequent bacteria found were Pseudomonas aeruginosa and Klebsiella pneumoniae. Almost 40% of the identified bacteria were reported as multidrug resistant (MDR).

Abstract In both sickle cell disease (SCD) and malaria, red blood cells (RBCs) are phagocytosed in the spleen, but receptor-ligand pairs mediating uptake have not been identified. Here, we report that patches of high mannose N-glycans (Man 5-9 GlcNAc 2 ), expressed on diseased or oxidized RBC surfaces, bind the mannose receptor (CD206) on phagocytes to mediate clearance. Extravascular haemolysis in SCD correlates with high mannose glycan levels on RBCs. Infection of RBCs with Plasmodium falciparum expose surface mannose N-glycans on healthy RBCs, which occurred at significantly higher levels on RBCs from subjects with sickle cell trait compared to those lacking haemoglobin S. The glycans were associated with high molecular weight complexes and protease-resistant, lower molecular weight fragments containing spectrin. Recognition of surface N-linked high mannose glycans, a novel response to cellular stress, is the first molecular mechanism common to both the pathogenesis of SCD and resistance to severe malaria in sickle cell trait.

Asthma is a significant public health concern, particularly in children. Exacerbation of asthma (EOA) is life-threatening and respiratory infections (RIs) play a crucial role. Though viruses play a significant role in EOA, &#160;patients are empirically treated with antibiotics; in particular, macrolides are prescribed for unconfirmed M. pneumoniae infections. Although EOA and M. pneumoniae have been reported in many countries, no published data in Sri Lanka. The present study aimed to identify common respiratory viruses, typical respiratory bacterial pathogens, and M. pneumoniae in children with EOA &#160; and relate them with the compatibility of antimicrobial use.&#160;A case-control study was conducted in the pediatric unit of North Colombo Teaching Hospital, Sri Lanka, involving two groups of children between 5-15 years. Group-1: children with EOA, Group-2: children with stable asthma (SA). Each group consisted of 100 children. Sputum/throat swabs were tested for common respiratory viruses using specific &#160;fluoresceinated monoclonal antibodies (MAbs) with &#160;direct immunofluorescent staining, typical bacterial pathogens by routine culture and M. pneumoniae by RT-PCR. Macrolide-resistance in M. pneumoniae was detected using conventional PCR and sequencing for specific genetic mutations in the 23S rRNA gene. M. pneumoniae was genotyped using nested multilocus sequence typing (MLST), which targeted eight housekeeping genes &#160;(ppa, pgm, gyrB, gmk, glyA, atpA, arcC, adk). There was no significant difference in demographic data between the two groups.&#160;There was no statistically significant difference in age gender and geographical location between the two groups. In children with EOA, antibiotics were used in 66%, and macrolides in 42%. Samples consisted of 78% &#160;sputum and 22% throat swabs. Adenovirus virus was the most common respiratory virus identified, and it was significantly higher in children with EOA compared to those with SA, but no significant difference in typical bacteria findings between the two groups. &#160; M. pneumoniae was detected in one patient &#160; &#160;in the group of 100 children with EOA with none &#160;detected in the SA group. The &#160;M. pneumoniae was macrolide sensitive, and as per MLST analysis, it was ST14. The empiric use of antibiotics in children with asthma may be better targeted with pathogen screening to inform treatment to minimize antibiotic resistance.

The emergence of antibiotic resistance in food producing animals is of major public health significance arising from the risk of these bacteria entering the food chain. In this study, the genetic characteristics of antibiotic resistant Escherichia coli and Klebsiella spp. isolates from humans and poultry in Edo state, Nigeria were investigated. In April 2017, 45 Klebsiella spp. and 46 Escherichia coli isolates were obtained from urine, clinical wounds, nasal and chicken fecal samples. Isolates were recovered and identified as previously described. Species identification was achieved by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and ribosomal multilocus sequence typing. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer method for 12 antibiotics. Double disc synergy test was used to screen for ESBL production. Whole genome sequencing was performed for strain characterization of the isolates. Thirteen Klebsiella spp. isolates yielded positive results by the ESBL phenotypic test and harbored ESBL genes. Out of the 46 E. coli isolates, 21 human and 13 poultry isolates were resistant to at least one of the tested antibiotics. Four human E. coli isolates harbored ESBL genes and revealed positive results when applying ESBL double disc synergy tests. ESBL genes in the Klebsiella spp. and E. coli isolates include bla CTX-M-15 and bla SHV-28 . Whole genome based cgMLST of the Klebsiella spp. and E. coli isolates revealed a close relatedness among the isolates. An integrated "One Health" surveillance system is required to monitor transmission of antimicrobial resistance in Nigeria.