bluuebunny/crossref_metadata_2025 huggingface dataset:
P323 Virulence not required? Albumin promotes pathogenicity of (non)-damaging Candida strains
Authors: Hitzler Sophia , Austermeier Sophie , Pekmezović Marina , Brandt Philipp , Hube Bernhard , Vylkova Slavena , Gresnigt Mark Sebastian
Published: September 2022

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

The pathogenicity of the dimorphic yeast Candida albicans is associated with filamentation, adhesion, invasion, and production of the toxin Candidalysin. However, there are certain clinical isolates and other Candida spp., that cause infection independent of filamentation or the production of Candidalysin. Consequently, these strains and species are often non-damaging in vitro, this does not correlate with their potential to cause infection in patients. We hypothesize that specific host factors, which trigger pathogenicity, are absent in in vitro models, and thereby not reflecting the situation in the host.

 

To determine the impact of albumin, the most abundant protein in the human body, vaginal epithelial cells were infected with different C. albicans strains and Candida species. Interestingly, after prolonged infection (45 h) albumin increased the damage potential, even in otherwise non-damaging and non-filamentous strains. This included deletion mutants deficient in filamentation, als3 adhesin/invasin, thigmotropism, or Candidalysin production. Yet, the increased damage was likely not solely an effect of increased growth and nutrient competition between the fungus and epithelial cells. Reduced damage in presence of protease inhibitors and albumin hint toward the role of proteases in the utilization of albumin. Albumin enhanced C. albicans metabolism, by stimulating the utilization of various nitrogen sources. This metabolic adaption could explain the advantage and enhanced growth as a strain and species-independent feature.

 

Our data suggest that common host factors can impact C. albicans to cause damage independent of adhesion, invasion, filamentation, and toxin production. Possibly, also other host-derived factors can drive the pathogenic potential of fungi through unresolved mechanisms.
P326 DNA replication initiator proteins stabilize the kinetochore in the human fungal pathogen Cryptococcus neoformans
Authors: Aggarwal Rashi , Sanyal Kaustuv
Published: September 2022

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

 

Objectives

DNA replication licensing ensures maintenance of the ploidy state by limiting DNA replication once per cell cycle. The mini-chromosome maintenance (MCM) complex is an evolutionarily conserved DNA helicase in eukaryotes that aids this process. Upon activation in the S phase by several protein kinases, the MCM complex unwinds the double-stranded DNA and moves away from DNA replication origins preventing re-initiation of replication in the remainder of the cell cycle. Deregulation of MCM function can lead to malignant transformation of proliferating cells as indicated by their upregulated expression in human cancer and pre-cancerous cells. MCMs, therefore, serve as important biomarkers and potential targets for anti-cancer drugs. This study aims to decipher the effect of deregulated expression of the MCM complex on the cell cycle events of the human fungal pathogen, Cryptococcus neoformans, which is more similar to metazoans than other budding yeast. Aneuploidy-mediated drug resistance is a common mechanism in many major human fungal pathogens including Cryptococcus and Candida.

Methods

We generated conditional mutants of individual subunits of the MCM complex in C. neoformans and assayed the impact of their altered expression on cell cycle events. We also tested the alternative role of MCM subunits in the assembly of the kinetochore, a vital component of the chromosome segregation machinery.

Results

Our screen with MCM conditional mutants identified two in vivo functional subcomplexes that comprise the MCM complex in C. neoformans. Although upregulated expression of either Mcm2 or Mcm3 does not affect cell cycle progression, overexpression of either Mcm6 or Mcm7 led to the accumulation of cells in the large bud stage with nuclear segregation defects. This work provides evidence for the first time for a mitotic role of pre-replication complex proteins, MCM 2-7 complex in Cryptococcus. Depletion of Mcm2 led to arrest of cells in the S and G2/M stages of the cell cycle with defects in nuclear segregation. Localization and expression of several kinetochore proteins upon depletion of Mcm2 established that Mcm2 is vital for kinetochore assembly/integrity. Although the centromeric histone H3 variant, CENP-A, remains largely clustered, the outer kinetochore did not mature indicating that Mcm2 alone or as part of the MCM complex plays a role in kinetochore assembly/integrity and thereby in chromosome segregation.

Conclusion

A conserved eukaryotic DNA helicase, MCM 2-7 complex, has an unexplored non-canonical role in kinetochore assembly/integrity and chromosome segregation.
P328 An overexpression screen identifies Csa25 as a novel cellular morphogenesis regulator in the human fungal pathogen Candida albicans
Authors: Brahma Priya , Jaitly Priya , Das Abhijit , Goyal Rohit , Legrand Melanie , d'Enfert Christophe , Sanyal Kaustuv
Published: September 2022

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

 

Objective

Morphological plasticity is one of the key attributes of microbial pathogens contributing to the successful establishment of infection in host tissues. Candida albicans, an opportunistic human fungal pathogen, lives as a commensal in the gut, skin, and genitourinary tracts of most healthy individuals. The budding yeast form helps it to disseminate easily in the host system, and the filamentous form (hypha and pseudohypha) is believed to invade the host tissue. Strikingly, alterations of gene expression that block cell cycle progression at different stages additionally lead to aberrant cellular morphology in C. albicans. While various morphological states of C. albicans have been well-studied, the search for key players bringing about these changes is far from complete. This is supported by the fact that ∼70% of the C. albicans proteome remains functionally uncharacterized. Thus, the primary objective of our study was to identify novel regulators contributing to cellular morphogenesis in C. albicans.

Method

In our current study, we screened an overexpression library of C. albicans ORFeome generated to identify novel regulators contributing to chromosome stability (CSA) in C. albicans. The screen involved overexpression of each gene using a tetracycline-inducible promoter for a duration of 12 h, followed by microscopy-based observations to identify associated aberrant cellular morphologies.

Results

Screening of overexpression library of the C. albicans ORFeome identified 14 unique Candidate genes from 1389 genes screened. While the functions of half of them have been verified in C. albicans, the remaining seven genes are not functionally characterized. Each of the seven uncharacterized genes was predicted to be non-essential for viability in C. albicans. Bioinformatic analysis predicts one of these proteins, Csa25, to be carrying a point centromere-specific kinetochore protein Ndc10-like DNA-binding domain at its N-terminus spanning over a region of 273 amino acids. Sub-cellular localization indicates this protein to be present throughout the nucleus at all stages of the cell cycle. Strikingly, overexpression of this protein led to yeast cells forming chains connected by septa, as visualized by calcofluor staining, without hampering nuclear segregation. In addition, a large proportion of cells overexpressing Csa25 were unable to exhibit hyphal morphology when subjected to hyphae-inducing conditions.

Conclusion

In conclusion, our study identified Csa25 as a novel morphogenesis regulator involved in the negative regulation of yeast-hyphae transition in C. albicans. Further studies based on host-pathogen interaction will identify the critical role of Csa25 in the pathobiology of C. albicans and its survival in host-specific niches.
P340 Detection of emerging genotypes in Trichophyton mentagrophytes complex: a proposal for handling biodiversity in dermatophytes
Authors: Tang Chao
Published: September 2022

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

 

Objective

The resistant and hypervirulent dermatophytes, which were found in India, have been described as a taxonomic novelty. It is urgent to detect the dermatophytes and their closely related clinical species fast and efficiently. Therefore, we evaluate the efficacy of diagnostic methods for the rapid detection of closely related clinical species.

Methods

Members of the Trichophyton mentagrophytes species complex were analyzed using Realtime-PCR, Dermagenius, LAMP, and MALDI-TOF in comparison with ITS sequencing.

Results

Dermagenius correctly recognized genotypes IV, VII, and IX as belonging to Trichophyton mentagrophytes, and all strains of T. interdigitale. However, genotype III and III* of T. mentagrophytes were recognized as T. interdigitale. The real-time PCR cannot distinguish these genotypes. In LAMP assay, T. indotineae, T. mentagrophytes III*, III, and IV, and T. interdigitale were positive. Trichophyton mentagrophytes genotype VII, and one strain of T. mentagrophytes genotype IX. In MALDI-TOF tree, the most of T. indotineae strains can be clustered in one clade. The rest of the genotypes are irregular.

Conclusion

Dermagenius, real-time PCR, and LAMP cannot adequately distinguish among T. indotianeae, T. interdigitale, and T. mentagrophytes. Only T. indotineae from the Indian outbreak was approximately distinguishable with MALDI-TOF other than sequencing. We recommend to distinguish species only when they show an appreciable degree of adaptation and thus are clinically significant. Distinction of remaining clonal diversity is an epidemiological query and can be solved by haplotype numbering.
P342 Lactobacillus rhamnosus protection against Candida-induced vaginal epithelial cell damage is Candida albicans strain-dependent
Authors: Valentine Marisa , Alonso-Román Raquel , Abdul-Rahman Shameema , Bougnoux Marie-Elisabeth , d'Enfert Christophe , Hube Bernhard , Gresnigt Mark S
Published: September 2022

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

Microbial dysbiosis can lead to vulvovaginal candidiasis (VVC) which is characterized by a pathogenicity-induced inflammatory response progressing to neutrophil-driven immunopathology. Probiotic treatment has varied success rates and some women still experience VVC despite being colonized by lactobacilli. It is, therefore, imperative to identify factors that influence the success of probiotic treatment for VVC.

 

We aimed to evaluate how Candida albicans strain differences contribute to the varying degrees to which probiotics such as Lactobacillus rhamnosus protect against Candida-induced epithelial tissue damage. We screened the commonly used highly virulent C. albicans laboratory strain SC5314, 24 C. albicans strains from different clades, and several vaginal C. albicans isolates. L. rhamnosus was used to colonize vaginal epithelial cells prior to C. albicans infection and vaginal epithelial cell damage was measured.

 

Compared to SC5314, most C. albicans strains induced relatively low or no epithelial cell damage. Even increased multiplicities of infection did not increase epithelial damage to the level of SC5314. Three groups were identified based on the effect of L. rhamnosus on Candida-induced epithelial cell damage. Bacterial colonization decreased, did not affect, or even increased tissue damage during infection.

 

The different C. albicans clades showed no correlation with the protective phenotypes. However, increased epithelial tissue damage in the presence of lactobacilli was generally observed with strains that alone were unable to damage the epithelium. Some strains had an enhanced potential to grow at low pH, yet growth at low pH alone was not able to distinguish the three groups.

 

The protective potential of L. rhamnosus is highly C. albicans strain-dependent. Our data hint toward a potential multifactorial effect involving stress-resistance and metabolic interplay. Elucidating the processes that lead to epithelial protection or enhanced damage will be crucial to predict whether probiotic lactobacilli may be beneficial or detrimental for a patient and may help to design generally protective probiotics.
P351 Genetic recombination between the main human skin commensal fungus, Malassezia restricta, and M. globosa using an Agrobacterium tumefaciens-mediated gene transfer system
Authors: Cho Otomi , Matsumoto Yasuhiko , Yamada Tsuyoshi , Sugita Takashi
Published: September 2022

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

 

Objects

Malassezia restricta and M. globosa cause or exacerbate Malassezia -associated skin, seborrheic, and atopic dermatitis, as well as pityriasis versicolor, but the virulence factors remain unclear because between-species genetic recombination has not yet been achieved. We built an Agrobacterium tumefaciens-mediated gene transfer (ATMT) system that generated gene-knockout mutants of both Malassezia species.

Materials and Methods

The binary vector pAg1-Δfkb1::NAT1 was introduced into M. restricta CBS 7877 and M. globosa CBS 7966 via ATMT; FKB1 was replaced. Then, FKB1 was re-introduced into the mutants to counteract the deficiencies.

Results and Discussion

The medium acetosyringone concentration and temperature, as well as the co-cultivation ratios of A. tumefaciens and the Malassezia strains, affected recombination efficacy. We generated a mutant of the FKB1 gene (which encodes the FKBP12 protein that binds to the calcineurin inhibitor tacrolimus). Wild-type M. restricta and M. globosa were tacrolimus-sensitive, while the FKB1 mutants were tacrolimus-resistant; drug susceptibility was restored by reintroducing FKB1.

Conclusion

Studies on recombination between M. restricta and M. globosa will aid elucidation of the molecular mechanisms underlying Malassezia -associated dermatitis.
P357 Update on risk factors for Candida krusei-Fungemia
Authors: Jansen Julia C. , Verhasselt Hedda Luise , Rath Peter Michael
Published: September 2022

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

Institut für Medizinische Mikrobiologie der Universitätsmedizin Essen, Robert Koch Haus, Virchow Straße 179, 45147 Essen, Germany

Objectives

Infection with Candida species have been an increasing threat to hospital patients worldwide. During the last decade research has shown high mortality rates associated with candidemia and progressing drug resistance to NAC (non-albicans Candida) species. This study aims to solidify risk factors for C. krusei fungemia.

Patients and Methods

We retrospectively analyzed patient data with at least one C. krusei or C. albicans positive blood culture at Essen University Hospital between 2008–2020.

Relevant categories consisted of age, gender, underlying condition, central venous catheters (CVC), steroids, leukopenia <4000/μl, diabetes, antifungal treatment, hospital ward, and outcome.

We used the Chi-Squared test to compare categorical valuables. P-values were considered significant <.05 and highly significant <.01.

Results

From 1380 patients who tested positive for Candida spp. between 2008–2020, 40 were positive for C. krusei and 786 for C. albicans.

Candida albicans presented as the leading species (57.0%), followed by C. glabrata (23.5%), C. parapsilosis (5.8%), C. tropicals (5.1%), and C. krusei (2.9%). A total of 67.6% of patients were located at ICU. Incidence rates for Candida positive blood cultures increased from 1.0% to 10.0%. Candida krusei was most common in patients 51–60 years of age.

In both groups, overall survival was identical (52.2% C. krusei/54.3% C. albicans). For C. krusei correlation between outcome and antifungal treatment was highly significant (P .044). A total of 20% more C. krusei infected hemato-oncology patients died than in the C. albicans group (62.5%

C. krusei/46.5% C. albicans). In all, 60.0% of C. krusei patients on ICU died. In the C. krusei group all patients with CVC died and all patients without survived.

Conclusion

Candida-positive blood cultures increased from 1% in 2008 to 10% in 2020.

Three major risk factors for C. krusei fungemia were found: CVC, hemato-oncology malignancies, and leukocytopenia.
P361 Demystifying the NIH grant application process for international investigators
Authors: Love Dona
Published: September 2022

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

 

 

The National Institute of Allergy and Infectious Diseases (NIAID) funds one of the largest medical mycology research portfolios. The portfolio includes the major human fungal pathogens and covers basic fungal biology and the more translational areas of therapeutics, vaccines, and diagnostics. NIAID utilizes many granting mechanisms that are open to US and international researchers. These include investigator-initiated applications (R01, R21, and R03s) and targeted announcements for fungal research. Additionally, NIAID has a suite of preclinical services supporting therapeutic, diagnostic, and vaccine development. These services are free and available to investigators in academia, not-for-profit organizations, industry, or governments worldwide. The NIAID granting mechanism can be complicated. Tips and tricks for navigating the NIAID application process and preclinical services will be discussed.
P370 Low rate of Sporothrix spp. recovery from storage in mineral oil: along period study
Authors: Poester Vanice , Roca Beatriz , Vieira Mariana , Trápaga Mariana , Munhoz Lívia , Klafke Gabriel , Xavier Melissa
Published: September 2022

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

Fungus collection is an essential approach to allow future studies, including molecular, and epidemiological characteristics, virulence factors, susceptibility profile, and others. Ideal methods should keep the isolates viable for long periods of storage. The mineral oil method is theoretically a secure and efficient method for the storage of filamentous and dimorphic fungi, including Sporothrix spp., for long periods.

Objective

We aimed to evaluate the recovery rate of isolates of Sporothrix spp. maintained for years through the mineral oil technique in a fungal collection.

Methods

Sporothrix spp. isolates were originally cultivated in tubes with potato dextrose agar, incubated at 30°C for at least 7 days, and covered by mineral oil, until around 1 cm above the surface, after the growth and sporulation of the colonies. Tubes were maintained at room temperature (∼25°C). A total of 238 isolates of Sporothrix spp. (mostly S. brasiliensis) maintained for 4-108 months (mean of 49.7 months) were included in the study, being 191 isolates from cats (80%), 31 from humans (13%), 14 from dogs (6%), and 2 (1%) from the environment. To evaluate the rate of recovery, a fragment of the colonies was cultivated in duplicate in plates with Sabouraud dextrose agar and incubated at 25°C until the fungal growth or for 30 days. To analyze the results, frequency, mean, and standard deviation (SD) were calculated, as well and the Kruskal-Wallis test was performed, using the SPSS statistical program.

Results

Only 14% (n = 34) of the fungal isolates were recovered from oil minerals after a mean of 64 months of storage (SD = 18.4), being 82% (n = 28) of the recovered isolates from cats, 12% (n = 4) from humans, and 6% (n = 2) from dogs (n = 1), or environment (n = 1). The 204 isolates that could not be recovered, were stored for a mean of 47 months (SD = 25.5) (P ˃ 0.05).

Conclusion

Disagreeing with previous reports, mineral oil was a failure method to keep Sporothrix spp. isolates viable independently of the period of storage. Therefore, optimization of this methodology is necessary, and/or other methods must be implemented to guarantee the preservation of Sporothrix spp. isolates in fungal collections.
P371 The relation of mating type (MAT) preference and source in the opportunistic pathogen Talaromyces marneffei
Authors: Lu Sha , Sha Lu , Liyan Xi , Zhou Xin
Published: September 2022

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

 

Background

Genome-wide comparisons have shown Talaromyces marneffei possessed a stable mating type locus in its meiosis genes. But the function of the mating-type locus in T. marneffei is not clear. The potential sex recombination might lead to problems in clinical, such as the evolution of increased resistance to antifungal drugs and virulence.

Objectives

To determine mating type in a sample of 107 strains and to explore the possible relationship between mating-type and fungus virulence.

Methods

We used PCR analysis to determine the distribution of mating-type genes in 107 T. marneffei strains. We also analyzed the relationship between mating-type and isolated sources (including HIV-positive patients, HIV-negative patients, bamboo rats, and environment). Further, Drosophila melanogaster model of infection was used to compare the virulence difference between different mating-type and source strains.

Results

The results showed an entire sample population of T. marneffei with an overabundance of MAT1-2 alleles, but with a higher ratio of MAT1-1 in the isolates from HIV-negative patients. However, no significant differences in the survival of the Drosophila melanogaster infected neither with MAT1-1 (6.5 days) nor MAT1-2 (4 days) isolates. Similar results were also observed in virulence analysis tested with different sources of isolates.

Conclusions

All isolates bearing single mating type idiomorphs and unequal distribution. The distribution of the MAT genes seems related to different sources. And the pathogenicity differences are independent of mating type genotype and source.
P373 Does biofilm forming capacity of Candida tropicalis vary with echinocandin susceptibility?
Authors: Ritika  , Paul Raees A. , Kaur Harsimran , Ghosh Anup K. , Rudramurthy Shivaprakash M.
Published: September 2022

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

 

Objectives

Candida tropicalis is a common cause of nosocomial candidemia and candiduria. The role of biofilm formation in virulence and antimicrobial resistance in C. tropicalis remains under-investigated. We aimed to evaluate the biofilm-forming capacity of C. tropicalis isolates exhibiting resistance, borderline resistance, and sensitivity to echinocandins.

Methods

The echinocandin resistant, borderline resistant, and susceptible isolates of C. tropicalis were collected based on their minimum inhibitory concentration (MIC) values according to Clinical and Laboratory Standard Institute (CLSI) broth microdilution guidelines. The isolates were subjected to FKS1 gene sequencing. To estimate biofilm production, echinocandin resistant (n = 2), borderline resistant (n = 5), and susceptible isolates (n = 3) were seeded at the cell concentration of 1 × 10⁶ cells/mL in RPMI-1640 with 0.165 M MOPS in polystyrene 96-well microtiter plates and incubated for 24 and 48 h at 37°C. The biofilm was quantified by crystal violet/safranin-based spectrophotometric method and XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) reduction assay. Statistical analysis was performed using one-way ANOVA with Bonferroni's post-hoc test for multiple comparisons among the groups.

Results

FKS1 sequencing analysis revealed S654P mutation in HS1 in both resistant isolates while isolates exhibiting borderline MIC to echinocandins carried wild-type FKS1 gene. Biofilm formation in borderline echinocandin-resistant C. tropicalis isolates was significantly (P <.005) higher compared with resistant and susceptible isolates. However, no significant difference in biofilm formation was noted among resistant and susceptible isolates.

Conclusion

This study suggests differential biofilm-formation capacity among C. tropicalis isolates with reduced susceptibility to echinocandins. However, this warrants further studies before any definitive inference can be made.
P378 Insecticidal potential of isolated fungal species in targeting Drosophila melanogaster and Zaprionus indianus
Authors: Sharma Aanchal
Published: September 2022

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

 

Objectives

Fruit flies are polyphagous insects that attack a variety of commercially significant plants, which resulted in the build-up of insecticide resistance making the research focus shift toward alternative pest management tools in order to reduce risks to humans, environment, and non-target organisms.

Methods

Fungal species were isolated and molecularly characterized from Drosophila culture medium. Virulence assay was conducted against third instar larvae and adults of Drosophila melanogaster and Zaprionus indianus. Percent adult emergence and larval mortality were calculated.

Results

Three species: Meyerozyma caribbica, Pichia kudriavzevii, and Aspergillus flavus were identified by ITS region sequencing. A. flavus was the most virulent against larvae and adults of D. melanogaster and Z. indianus followed by P. kudriavzevii and M. caribbica (44%-100% mortality). Lethal time to 90% mortality (LT90) ranged from 4.5 to 7 days (P. kudriavzevii) and 3.2 to 4.5 days (A. flavus).

Conclusion

These preliminary findings suggest that the isolated fungal species can be deployed in targeting the developmental life stages of Drosophila species and hence, controlling invasive insect pests in an eco-friendly way. The use of these biological control agents could further minimize the use of harmful insecticides which has substantial global health benefits.
P383 ‘It's not Fungus, its Nocardia’—an elementary diagnostic challenge for draining sinus on abdominal wall (rare): a case report
Authors: Tigga Richa Anjleen , Keche Archana Y , Ganguly Satyaki , Chand Anjali
Published: September 2022

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

 

Introduction

A rare finding of abdominal wall clinical presentation of persistent progressive tumefaction with draining sinus with no granules caused by Nocardia brasiliensis.

Methods

History: A 22-year-old presented to the Dermatology OPD with complaints of swelling and tenderness and discharging sinuses with no granules around the periumbilical region in the lower abdominal area for three years. His initial fine needle aspiration cytology specimen report was inconclusive. He received anti-Kochs treatment based on a positive Montoux test and family history from outside the hospital.

Initially punch biopsy samples were sent for fungal processing to our laboratory which was inconclusive. Repeat pus aspirate and punch biopsy samples were subjected to conventional techniques. The sample was inoculated on Sabouraud's Dextrose agar, Brain heart Infusion agar, and Lowenstein-Jensen media. Direct Smear was subjected to Gram stain and Modified Zeihl Neelson stain with 1% Sulfuric acid as decoloriser.

Results

Conclusion
P386 Molecular identification and antifungal susceptibility of fungi causing sinusitis in arid climate region
Authors: Zhou Shaoqin , Ismail Mawahib , Kang Yingqian , Gabr Aida , de Hoog Sybren , Mahgoub Elsheikh , Ahmed Sarah
Published: September 2022

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

 

Objectives

Fungal sinusitis is a common problem worldwide with an increasing burden in arid climate regions. Clinical presentations of the disease range from allergic to acute invasive or chronic forms. In the present study, we aim to identify the etiology of fungal sinusitis in an arid climate region of Africa using molecular methods and to determine the antifungal susceptibility of the clinical isolates.

Methods

A total of 60 isolates collected from patients diagnosed with fungal sinusitis in Khartoum, Sudan were included. Direct microscopic examination and culture from nasal biopsies were performed at the mycology reference laboratory in Khartoum. To confirm the presence of fungal elements in tissue, histology was performed for all samples. Cultured isolates were then identified by sequencing the internal transcribed spacer (ITS), β-tubulin, and calmodulin gene regions. Antifungal susceptibility was tested using the protocol of the European Committee on Antimicrobial Susceptibility Testing (EUCAST).

Results

Sequencing of the three genes identified the following species: Aspergillus flavus (n = 48), A. citrinoterreus (n = 3), A. caespitosus (n = 2), A. sydowii (n = 2), Exserohilum sp. (n = 2), Purpureocillium lilacinum (n = 1), Trichosporon asahii (n = 1), and Fusarium chlamydosporum (n = 1).

Conclusion

The fungi associated with sinusitis are of high diversity; the 60 isolates were found to belong to 8 different species. With the exception of cryptic species, a large concordance was found between molecular and phenotypic identification methods. Aspergillus is the most commonly reported genus with A. flavus as the most prevalent species.
P388 High rate of chronic pulmonary aspergillosis in active TB patients in Indonesia with GeneXpert positive
Authors: Setianingrum Findra , Rozaliyani Anna , Adawiyah Robiatul , Sjam Ridhawati , Tugiran Mulyati , Sari Cut Yulia Indah , Wahyuningsih Retno , Richardson Riina R , Denning David W
Published: September 2022

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

 

Objectives

Chronic pulmonary aspergillosis (CPA) commonly affects post-tuberculosis (TB) patients. However, the existence of this slowly destructive disease is also increasingly being reported in patients with active TB. The study aimed to identify the clinical, radiological, and serological characteristics of probable CPA patients between proven TB with GeneXpert positive and clinically diagnosed TB (GeneXpert negative) in early TB therapy.

Methods

All patients were on anti-tuberculous therapy in the early phase (0–2 months). Clinical profiles and radiology findings were collected from hospitals in Jakarta and Depok, Indonesia. Aspergillus antibodies were measured using Immulite automated ELISA. Sputum was tested for TB with GeneXpert MTB/RIF assay.

Result

A total of 70 patients with a median age of 37 years were studied. Overall, 29% (n = 20) met the criteria for proven or probable CPA. The rate of CPA in GeneXpert positive was 50%, whereas it was only 14% in GeneXpert negative patients (P = .001). Most of CPA patients had GeneXpert result intermediate (n = 7, 35%), 4 of them (6%) had a high load of TB proven by GeneXpert. Cough was the most common symptom in GeneXpert positive groups (n = 11, 39%). Fatigue was frequently founded in GeneXpert negative groups (n = 8, 19%). The proportion of cavities (90% vs 44%), paracavitary fibrosis (70% vs 26%), and pleural thickening (60% vs 24%) were significantly higher in CPA patients. The median score of Aspergillus antibody in non-CPA patients was lower (7.7, range 3.1-15.2 mg/L) compare with CPA patients (11.9, range 4.3-344 mg/L) (P = .024).

Conclusion

Aspergillus spp is a fatal fungal pathogen that might cause co-infection in active TB patients. The measurement of Aspergillus antibodies is a hallmark for the diagnosis of CPA. The coexistence of CPA in active TB patients is underdiagnosed.
P398 COVID-19-associated pulmonary aspergillosis: Species distribution and susceptibility profiles
Authors: Fakhim Hamed , vaezi Afsane , nasri Elahe , Sadeghi Somayeh , Shelerangkon Mahsa , Rizi Mahnaz Hosseini , Ghafel Safiyeh , Badali Hamid , Mirhendi Hossein
Published: September 2022

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

 

Objectives

This study aimed to investigate the species distribution and susceptibility profiles of Aspergillus species isolated from patients admitted to the intensive care unit with severe COVID-19 in Isfahan, Iran, between April 2021 and March 2022.

Methods

This retrospective study included intubated patients with COVID-19 in three referral COVID-19 hospitals. Tracheal aspirate (TA) samples were taken from 267 patients to investigate pulmonary co-infections. COVID-19-associated aspergillosis (CAPA) was defined according to the 2020 European Confederation of Medical Mycology/International Society of Human and Animal Mycosis consensus criteria. Aspergillus species obtained from samples were characterized based on conventional and molecular assays. In vitro antifungal susceptibility testing was performed on the obtained isolates according to the guidelines from the Clinical and Laboratory Standards Institute.

Results

The mean age of the patients was 61.73 ± 12.69 years. The mean length of hospitalization and admission in ICU were 18.77 ± 12.94 and 13.51 ± 9.83 days, respectively. A total of 61 (22.9%) patients presented with a single cavity lesion. Pulmonary artery pseudoaneurysm was seen in seven patients and post-COVID-19 changes were seen in all patients. Based on the conventional and molecular techniques, 72 isolates of Aspergillus species (26.9%), including A. flavus (10.1%%), A. fumigatus (8.6%%), A. niger (3.3%), A. tubingensis (2.9%), A. terreus (1.1%), A. luchuensis (0.37%) A. quadrillineatus, and (0.37%), were obtained from 267 patients. MIC results showed that all Aspergillus species were susceptible to all tested antifungal drugs.

Conclusion

Access to priority clinical groups, improving the care of patients with simultaneous pulmonary aspergillosis with COVID-19, and identifying Aspergillus species are essential steps in the care cascade to manage those affected by them.
P410 Aspergillus fumigatus sensitization among the patients with chronic obstructive pulmonary disease (COPD)— a cross sectional study
Authors: Subhagan Haritha , Padaki Priyadarshini , Savio Jayanthi , Ramachandran Priya , Rajeshwari V. , Raj John Michael
Published: September 2022

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

 

Objectives

Allergic bronchopulmonary aspergillosis (ABPA) caused by hypersensitivity to A. fumigatus complicates the course of asthma. Fungal sensitization due to A. fumigatus among asthmatic patients and their progression to ABPA is well studied. Similar data on Aspergillus sensitization among patients with COPD and their progression are still not well established. The objective of this study was to evaluate the Total serum IgE (TIgE) and A. fumigatus specific IgE (Af sp IgE) levels among patients with COPD.

Method

A total of 100 stable patients with COPD above 40 years of age from the Department of Pulmonary Medicine were included. TIgE and Af sp IgE levels were detected using VIDAS total IgE assay and M3 ImmunoCap with Phadia 100 respectively. The subjects were grouped into three (TIgE <500 IU/l, 500-1000 IU/l, and >1000 IU/l) based on the TIgE values. They were also categorized based on Af sp IgE levels as sensitization likely (AS ≥0.35 kUA/l), sensitization indeterminate (AI 0.1-0.35 kUA/l), and sensitization unlikely (AU ≤0.1 kUA/l). This categorization was based on the kit manufacturer's guidelines that sensitization is unlikely with specific IgE <0.1 kUA/l and the proposed ISHAM ABPA working group criteria of >0.35 kUA/l for diagnosis of sensitization. A comparison of Asf sp IgE with TIgE was done using the Fischer exact test.

Result

Among 100 patients, the prevalence of elevated TIgE [>150 IU/l (kit cutoff)] and Aspergillus sensitization [Af Sp IgE >0.35kUA/l (ISHAM cutoff)] was 47% and 6%, respectively. A total of 5% of subjects satisfied the criteria for serological ABPA. The results of the comparison of Asf sp IgE with total IgE using the Fischer exact test are given in Table 1.

AS category: TIgE was >1000 IU/l in 5 (83.3%) of the 6 subjects. One (16.7%) had between 500-1000 IU/l. None of them had TIgE <500IU/l. Aspergillus sensitization was higher in 3/5 subjects with TIgE >1000 IU/ml (Asf sp IgE values of 2.55KUA/l, 12KUA/l, 14KUA/l, 0.38KUA/l, and 0.45KUA/l) compared with the one subject with TIgE <1000IU/l (Asf sp IgE of 0.73KUA/l). The clinical characteristics of subjects in the AS category is given in Table 2.

AI category: A total of 7 (50%) of the 14 subjects had the TIgE value >1000 IU/l, 5 (35.7%) had the TIgE between 500-1000 IU/l, and 2 subjects had the TIgE <500 IU/l.

AU category: In all, 1 (1.25%) had the TIgE value >1000 IU/l, 5 (6.25%) had the TIgE between 500-1000 IU/l. TIgE was <500 IU/l in 74 (92.5%) subjects.

Conclusion

The study results suggest the co-existence of COPD and Aspergillus sensitization/ABPA. Patients in the AI group (Af sp IgE level 0.1-0.35 kUA/l) must be evaluated and monitored to prevent the progression of the disease. Studies involving a larger patient population are warranted.
P416 Efficient and accurate diagnosis of otomycosis using an ensemble deep learning model
Authors: Chenggang Mao , Aimin Li , Juehui Wang , Yi Sun , Dan Peng
Published: September 2022

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

 

Objectives

Otomycosis accounts for ˃15% of the cases with external otitis worldwide. And otomycosis is more frequently observed in humid regions and people enjoying the culture of ear cleaning in China. Aspergillus and Candida are the major pathogens that could cause long-term infection. Early endoscopic and microbiological examinations are important for appropriate medical treatment to otomycosis. However, accurate diagnosis always needs experts such as otologist and microbiologist. Deep learning model is a novel efficient method to provide quick diagnosis which is an automatically diagnostic program using a large database of images acquired in the cliniC. This paper puts forward a mechanic learning model to address the diagnosis of otomycosis caused by Aspergillus and Candida accurately and quickly.

Methods

We proposed a computer-aided decision system that is based on a deep learning model consisting of two subsystems, a java-based web application, and picture classification. The web application subsystem mainly provides a user-friendly page for collecting consulted pictures as well as displaying the calculation results. The picture classification subsystem mainly uses trained neural network models for end-to-end data inference. The end user only needs to upload a few pictures of the ear endoscope, and the system will return the classification results to the user in the form of category probability value.

In order to accurately diagnose otomycosis, we generally kept endoscopic images and took the secretion for fungal culture for further identification. Positive fluorescence fungal staining, culture, and further DNA sequencing were taken to confirm the pathogens, Aspergillus or Candida sp. In addition, impacted cerumen, external otitis, and normal external auditory canal endoscopic images are retained for reference. We merged these four types of images into an endoscopic images gallery.

Results

In order to achieve better accuracy and generalization ability after model training, we selected 2750 samples from nearly 4000 ear endoscopic images as training samples and 454 as validation samples. On the selection of deep neural network models, we tested the resnet, senet, and efficientnet neural network models with different numbers of layers. Considering the accuracy and operation speed, we finally chose the efficientnet-b6 model and output the probability values of the four categories of otomycosis, external otitis, impacted cerumen, and normal cases. After multiple iterative sample training, the overall validation sample accuracy reached 94.71%, and the average cross-validation accuracy of the 4 classifications reached 94.3%.

Conclusion

The results suggest that the system can be used as a reference for general practitioners to make better decisions in the diagnosis of otomycosis.
P417 Evaluation of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)-Bruker Biotyper Sirius for identification of invasive molds
Authors: Dalvi Mousami , Patwardhan Sampada , Prayag Parikshit , Purandhare Bharat , Soman Rajeev
Published: September 2022

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

 

Objectives

Susceptibility to various antifungal drugs varies between different species and subspecies within the same genus. Phenotypic identification of fungi has limitations for species-level identification. Correct identification of species and subspecies in invasive mold infections is important to initiate the appropriate antifungal therapy. Matrix Assisted Laser Desorption Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS) with its proteomic analysis overcomes this limitation and helps in administering the correct anti-fungal therapy. A total of seven mold isolates from invasive fungal infections were evaluated for identification by MALDI-TOF MS and conventional morphological methods.

Methods

Total of seven isolates from invasive mold infections were identified by the conventional method of culturing specimens on Sabouraud's dextrose agar and Potato Dextrose agar with incubation at room temperature and 37°C in Biological oxygen demand (BOD) incubator. Micro-morphological identification of the fungus was done by Lacto Phenol Cotton Blue (LPCB) mount. Same isolates were processed on MALDI-TOF MS Bruker Biotyper Sirius (Bruker Daltonics, Bremen Germany) following recommended extraction protocol using ethanol absolute, acetonitrile, and 70% formic acid.

Results

As per the below Figure.

Conclusion

In four out of seven isolates phenotypic identification upto species level based on LPCB micromorphology was confirmed on MALDI-TOF MS. In the remaining three isolates we could only give a genus level identification based on LPCB mount. These three isolates were further identified upto the level of species after processing on MALDI as Aspergillus tamarii, Phaeoacremonium cinerum, and Fusarium equiseti. All mold isolates were identified with good quality mass spectra. In our experience, mold identification by MALDI-TOF MS using the Bruker Biotyper Sirius platform definitely has an edge over conventional phenotypic methods in species-level differentiation of various molds, impacting targeted antifungal management.
P419 Galactomannan enzyme immunoassay in invasive pulmonary aspergillosis: a cross sectional study in 2021 in a New Delhi
Authors: Das Sutapa
Published: September 2022

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

 

Objective

This study aims to determine the role of GM EIA in the diagnosis of IPA as per revised EORTC/MSG 2019 criteria.

Material and Methods

A prospective cross-sectional study was performed on 87 children (from 1 to 12 years) admitted to pediatric hematology ward from Oct 2020 to February 2022. Serum of these patients was collected and GM EIA was performed using BIO-RAD Platelia™ Aspergillus Ag. Clinical, mycological workup (potassium-hydroxide mount, fungal culture) was done and furthermore, these patients were classified into proven, probable, and possible IA as per EORTC-MSG guidelines, 2019. Galactomannan indices (GMI) measured in terms of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were validated with revised EORTC -MSG, 2019 of IPA.

Results

A total of 53 patients out of 87 were categorized into probable IPA with routine mycological findings. On culture Aspergillus flavus was the most common pathogen, identified in 56% (25), followed by A. fumigatus 31.8% (14), A. niger 9% (4), etc. 44 (50.5%) had GMI value of >0.7, 9 (10.3%) in the range of 0.5-0.7 and 34 (39%) had GMI <0.5.

The maximal Youden index ‘J’ [95% confidence interval (CI) of 0.4167-0.6875] was calculated as 0.678 and sensitivity, specificity, PPV, and NPV in IPA were calculated corresponding to a GM index of >1.0, 0.7, 0.5 to determine the best cutoff point. The best cutoff was found to be 0.695 where in the 84.1% and specificity was 83.7% respectively.

Conclusion

GM EIA can prove as an excellent diagnostic test for IPA when done in addition to culture from nonsterile sites in high-risk populations like pediatric patients with hematological malignancy. This study reinforces the definition of the probable category of EORTC-MSG criteria, 2019 in overall diagnosis, prognosis, and management of IPA in pediatric patients with hematological malignancy.
P420 Fungal detection by means of HCR using 2D-Covalent Organic Framework Nanosheet
Authors: Gajjar Devarshi , Baghel Manoj Kumar , Thakkar Harshil , Thakore Sonal
Published: September 2022

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

The timely diagnosis of fungal infections is of prime importance for prescribing appropriate anti-fungal drugs. Current methods for fungal diagnosis involve culture-based methods, antibody-based detection using lateral flow assays and RT-PCR. In the present work, we devised a non-enzymatic amplification using 2D-Covalent Organic Framework (COF) nanosheet for the detection of fungal DNA.

Objectives

(1) Validation of exfoliated 2D COF Nanosheet as an efficient DNA detection tool via Hybridization chain reaction (HCR) triggered fluorescent assay. (2) Sequence retrieval and probe generation of fungal sample and detection of extracted target DNA via fluorescent assay.

Method

A novel COF was synthesized and characterization was done using FTIR, BET, TGA, XRD, and SEM. Probes for the detection of fungi (Candida, Aspergillus, and Mucor) were designed using NUPACK software. HCR was monitored for different time and probe concentrations and standardized reaction was used for the detection of fungal RNA.

Results

FTIR, BET, TGA, XRD, and SEM confirmed the structure and formation of COF-nanosheet. H1, H2 probes at a concentration of 1μm and in presence of Target DNA (0.001μm-1μm) showed HCR reaction at 1.5 h. Fluorescence quenching was observed when probes were mixed with both, bulk COF and COF-nanosheets but increased quenching

Conclusion

Fungal detection can be done by means of HCR using the Covalent nanosheets.
P422 EQUAL PCP Score 2022—an ECMM score derived from current guidelines to measure QUAlity of clinical Pneumocystis Pneumonia management
Authors: Grothe Jan
Published: September 2022

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

 

Background

Pneumocystis pneumonia (PCP) is a life-threatening opportunistic fungal infection requiring complex clinical management. Guidelines assist clinicians but can be challenging to comply with.

Objectives

To develop a scoring tool, that facilitates and quantifies adherence to guideline recommendations for PCP.

Methods

We reviewed current PCP guidelines and determined essential recommendations for diagnosis, treatment, and follow-up. These were weighted according to their strength of recommendation and level of evidence.

Results

The EQUAL PCP Score 2022 consists of 22 items. For diagnosis, weight was given to bronchoalveolar lavage and immunofluorescence assays as the gold standard for sampling and analysis. Beta-D-glucan was considered of similar importance due to its high negative predictive value. Trimethoprim/sulfamethoxazole and the addition of corticosteroids in respiratory failure got 3 points respectively. Alternative approaches received less points and the use of aerosolized pentamidine was discouraged with 1 minus point. HIV-specific considerations such as the start of secondary prophylaxis were factored in as well.

Conclusion

The EQUAL PCP Score 2022 weighs and aggregates factors recommended for optimal management of PCP. It provides a tool for antifungal stewardship as well as for measuring guideline adherence but remains to be correlated with patient outcomes.