bluuebunny/crossref_metadata_2025 huggingface dataset:
S1.5a Epidemiology of myotic keratitis in developing countries
Authors: Thomas Philip Aloysius
Published: September 2022

S1.5 Mycotic keratitis, September 21, 2022, 11:00 AM - 12:30 PM

 

 

Mycotic keratitis (corneal infection due to a fungal etiology) is a well-recognized ophthalmological emergency warranting rapid initiation of specific antifungal therapy. However, the magnitude of the problem of mycotic keratitis in the community, especially in the Indian subcontinent and the developing world, is, perhaps, less apparent. A minimal annual incidence estimate of 1051, 787 cases (23.6/100 000 population [popln]) globally has recently been reported, with the highest rates being in Asia (33.9/100 000 popln, an absolute number of 939 895) and Africa (13.5/100 000; 75 196); if all culture-negative cases are assumed to be fungal, especially where the incidence of mycotic keratitis is known to be high, then the annual incidence would be about 1480 916 cases. A fungal etiology has been found to account for a very high proportion (> 45%) of microbial keratitis cases in countries in the Indian subcontinent. Countries where a fungal etiology accounts for >25% of microbial keratitis mostly tend to abut the equator. Interestingly, the proportion of microbial keratitis patients with a proven fungal etiology shows a significant negative correlation with the gross domestic product per capita. Although it is clear that the most common fungal species are Fusarium, Aspergillus, and Candida species, marked regional variations in fungal etiology have been noted. It is important to realize that sensitivity of the culture of ocular fungal pathogens can vary, depending on the pathogen, as well as the competence of the testing laboratory. For some countries, multiple reports over time have been noted, with there being some evidence of an increasing trend in the proportion of all microbial keratitis cases being diagnosed as mycotic keratitis. Even in a single geographical location, cases of mycotic keratitis may be higher than the yearly average at certain times of the year, such as during the harvest or windy seasons, or when there is increased relative humidity. A disturbing statistic to note is that, in 8%-11% of patients with mycotic keratitis, the affected eye needs to be removed, representing an irreversible annual loss of 84 143-115 697 eyes. It is recognized that many people suffering from mycotic keratitis in rural distant communities never present to health care workers due to financial and other constraints. Hence, the actual number of people afflicted by mycotic keratitis, man-days lost due to the disease and during therapy, and reduced quality of life due to persistent disability (corneal scarring) in the Indian subcontinent and developing countries requires further study.
S1.5b The burden of mycotic keratitis in West Africa
Authors: Gugnani Harish
Published: September 2022

S1.5 Mycotic keratitis, September 21, 2022, 11:00 AM - 12:30 PM

 

Background

Fungal infection of the cornea, known as mycotic keratitis, can cause permanent corneal scarring and perforation resulting in the loss of the eye. This paper reviews the prevalence and epidemiology of mycotic keratitis in different countries in West Africa to estimate its burden.

Methods

An exhaustive search of the literature was made on Google, PubMed, MEDfacts, Cochrane Library, and Web of knowledge using different sets of keywords, viz. mycotic keratitis, ocular fungal infection, West Arica, risk factor, prevention, etc.

Results

A study in Nigeria over a period of 4 years (1974-1977) dealt with 42 confirmed cases of mycotic keratitis with Fusarium solani as the predominant etiological agent (14 cases) followed by Penicillium citrinum (8 cases) and Aspergillus fumigates (5 cases), Candida spp (3 cases). The remaining 12 cases were that of Fusarium moniliforme, Aspergillus spp, Penicillium sp, and Cladosporium spp. The predisposing factors identified were trauma from palm tree leaves, thorns, kernels, or other plant objects, mechanical tools, and frying oil. A 10-year review (2003-2012) of 152 cases of corneal ulcers at the University of Calabar Teaching Hospital, Calabar, Nigeria revealed only 2 (2.9%) cases due to Aspergillus sp, many patients in this study were farmers. Other studies from Nigeria only mentioned the prevalence of keratitis without any mention of fungal etiology. Of the two studies from Ghana, the one conducted in 1999 showed the predominant agents Fusarium spp. (52.3%) and Aspergillus spp. (15.3%), in the other one conducted in 1999-2001, these agents were represented by 42.2% and 17.4% respectively. In another prospective study of suppurative corneal ulcers in 290 cases in Ghana (June 1999-May 2001), the etiological agents identified in culturally proven 77 (85.5%) cases of mycotic keratitis were Fusarium spp-46, A. flavus-9, A. fumigates-7, A. niger-1, A. nidulans-1, and Aspergillus sp-1 A Siera Leonian study of cases of suspected infectious ulcerative keratitis from January 2005 to January 2006) detected 35.6% of mycotic keratitis and 13.7% of mixed fungal and bacterial etiology. A study on the burden of serious fungal infections in Togo mentioned an annual incidence of 951 cases of mycotic keratitis but no details of fungal etiology were mentioned.

Conclusion

Investigators have estimated the annual global incidence of fungal keratitis at over 1 million cases. Reports of cases reported from some countries represent only a tip of the true burden of mycotic keratitis in West Africa. There is a need for comprehensive surveys (involving collaboration between ophthalmologists and microbiologists) of mycotic keratitis in representative communities in collaboration with primary health centers and hospitals in different countries. It should be possible to produce a combined antifungal antibacterial preparation for widespread and immediate prophylactic first-aid use after corneal trauma, especially in rural areas.
S10.5a Fungal respiratory infections in cystic fibrosis patients in the Middle East
Authors: Hedayati Mohammad , Ghazanfari Mona , Ashrafi-Khozani Mahtab , sarae Sabrieh Asadi Shahi , Ghanbari Somayeh , Parsay Shima , Yaalimadad Sanaz , Shirvan Bahador Nikoueian
Published: September 2022

S10.5 Fungal respiratory infections in Cystic Fibrosis, September 24, 2022, 10:30 AM - 12:00 PM

Cystic Fibrosis (CF) is among the most common genetic disorders, which involves multiple organs including the respiratory tract. CF is thought to be an uncommon disease in the Middle East (ME). However, the prevalence is estimated at 1 in 30 000-50 000, while the incidence is estimated at 1 in 2000-5800 live births. Several studies from ME revealed that many children with CF in these populations probably remain undiagnosed due to lack of clinical suspicion and proper diagnostic facilities. According to the experts’ idea, CF may be more common in Iran than expected before.

 

Chronic colonization of the airways of CF patients and infections due to a wide variety of opportunistic fungal pathogens including Aspergillus, Candida, Scedosporium species, Exophiala dermatitidis, Rasamsonia argillacea complex, and Lomentospora prolificans are currently increasing. On the other hand, the resistance of these opportunistic pathogens to commonly available antifungals challenges therapeutic options and consequently endanger the CF patients’ life.

 

Dissimilar to bacterial colonization or infections, the epidemiology and pathogenicity of colonization and fungal respiratory infections in CF are less known. According to our recent study, the prevalence rate of respiratory colonization was reported as 73.3%. Among mold isolates, Aspergillus was also the most common genus followed by Scedosporium species. In contrast to the reports from western countries, A. flavus was also identified as the most prevalent species of Aspergillus from ME countries including Iran and India.

 

In some studies, allergic bronchopulmonary aspergillosis (ABPA) in CF patients from ME was evaluated. In our recent experience from Iran, of 86 patients with CF, 9 (10.5%) cases were met ABPA diagnosis. A. flavus was the most common agent followed by A. fumigatus, A. terreus and A. tubingensis.

 

A significant resistance of Scedosporium and Aspergillus isolates from CF patients against the main antifungal agents in invasive fungal infections therapy was reported in different studies.

 

According to these realities, there are a few reports on the Research Topic ‘Fungal Respiratory Infections and Colonization in CF’ from Iran and some other ME countries. Therefore, in this presentation, we are going to highlight our experiences and other published data from Iran and ME in this field including clinical presentations, fungal species involved, diagnosis strategies, and in vitro antifungal susceptibility patterns of fungal isolates from CF patients, and common treatments and prophylactic strategies.
S10.5b Bacterial and fungal coinfections in cystic fibrosis
Authors: Briard Benoit
Published: September 2022

S10.5 Fungal respiratory infections in Cystic Fibrosis, September 24, 2022, 10:30 AM - 12:00 PM

Lung infections due to Aspergillus fumigatus are in constant augmentation in cystic fibrosis (CF) patients. Up to 55% of CF patients show respiratory complications and exacerbated inflammation due to A. fumigatus. Allergic bronchopulmonary aspergillosis is the major complication found in up to 15% of these CF patients. Moreover, up to 60% of CF patients who are already infected chronically by Pseudomonas aeruginosa are also colonized by A. fumigatus. The interactions between A. fumigatus and P. aeruginosa showed a balance between inhibitory and stimulatory effects on fungal growth in mixed A. fumigatus-P. aeruginosa cultures.

 

Moreover, the interaction between the bacteria and A. fumigatus modulates exposure to fungal patterns and the innate immune response to the pathogens. Indeed, superinfection by A. fumigatus of patients already colonized by P. aeruginosa leads to hyperinflammation. Therefore, studying the interaction between bacteria and fungus in cystic fibrosis is crucial.
S2.5a Magnusiomyces spp.
Authors: Hamprecht Axel
Published: September 2022

S2.5 Rare yeasts, September 21, 2022, 3:00 PM - 4:30 PM

 

 

Magnusiomyces clavatus and Magnusiomyces capitatus are emerging yeasts with intrinsic resistance to many commonly used antifungal agents. Identification is difficult, and the determination of susceptibility patterns with commercial and reference methods is equally challenging. For this reason, few data on invasive infections by Magnusiomyces spp. are available. We, therefore, determined the epidemiology and susceptibility of Magnusiomyces isolates from bloodstream infections (BSI) isolated in Germany and Austria from 2001 to 2020. A total of 34 Magnusiomyces BSI were analyzed; isolates were identified by internal transcribed spacer (ITS) sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Antifungal susceptibility was determined by EUCAST broth microdilution and gradient tests. Of the 34 isolates, M. clavatus was more common (n = 24) than M. capitatus (n = 10). BSI by Magnusiomyces spp. were more common in men (62%) and mostly occurred in patients with hemato-oncological malignancies (79%). The highest in vitro antifungal activity against M. clavatus/M. capitatus was observed for voriconazole (MIC50, 0.03/0.125 mg/l), followed by posaconazole (MIC50, 0.125/0.25 mg/l). M. clavatus isolates showed overall lower MICs than M. capitatus. With the exception of amphotericin B, a low essential agreement between gradient test and microdilution was recorded for all antifungals (0%-70%). Both species showed distinct morphologic traits on ChromAgar Orientation medium and Columbia blood agar, which can be used for differentiation if no MALDI-TOF MS or molecular identification is available. In conclusion, most BSI were caused by M. clavatus. The lowest MICs were recorded for voriconazole. Gradient tests demonstrated unacceptably low agreement and should preferably not be used for susceptibility testing of Magnusiomyces spp.
S2.5c Exophiala spp.
Authors: Steinmann Joerg
Published: September 2022

S2.5 Rare yeasts, September 21, 2022, 3:00 PM - 4:30 PM

 

 

The black yeast Exophiala dermatitidis is an opportunistic pathogen, causing phaeohyphomycosis in immunosuppressed patients, chromoblastomycosis, and fatal infections of the central nervous system in otherwise healthy Asian patients. In addition, it is also regularly isolated from respiratory samples from cystic fibrosis patients, with rates varying between 1% and 19%. Melanin, as part of the cell wall of black yeasts, is one major factor known to contribute to the pathogenicity of E. dermatitidis and increased resistance against host defense and anti-infective therapeutics. Further virulence factors, e.g., the capability to adhere to surfaces and to form biofilm were reported.
S4.2d Efficacy of LD Bio Aspergillus ICT lateral flow assay for serodiagnosis of chronic pulmonary aspergillosis
Authors: Ray Animesh , Chowdhary Mohit , Sachdeva Janya , Singh Gagandeep , Xess Immaculata , Sinha Sanjeev , Vyas Surabhi , Dennings David W , Wig Naveet , Kabra Sunil Kumar
Published: September 2022

S4.2 Advances in diagnosis of invasive fungal infection, September 22, 2022, 10:30 AM – 12:00 PM

 

Background

The diagnosis of chronic pulmonary aspergillosis (CPA) relies on the detection of IgG Aspergillus antibody which is not freely available, especially in resource-poor settings. Point-of-care tests like LDBio, evaluated in only a few studies, have shown promising results for the diagnosis of CPA. However, no study has compared the diagnostic performances of LDBio in the setting of tuberculosis endemic countries and has compared it with that of IgG Aspergillus.

Objectives

This study aimed to evaluate the diagnostic performances of LDBio in CPA and compare it with the existing diagnostic algorithm utilizing ImmunoCAP IgG Aspergillus.

Methods

Serial patients presenting with respiratory symptoms (cough, hemoptysis, fever, etc) for >4 weeks were screened for eligibility. Relevant investigations including respiratory secretions stain/culture, IgG Aspergillus, chest imaging, etc were done according to the existing algorithm. Serum of all patients was tested by LDBio and IgG Aspergillus (ImmunoCAP) and their diagnostic performances were compared.

Results

A total of 218 patients were screened and 174 patients were included in the study with ∼ 66.7% of patients having a past history of tuberculosis. A diagnosis of CPA was made in 74 (42.5%) patients. The estimated sensitivity and specificity of LDBio was 67.6% [95% confidence interval (CI), 55.7%-78%] and 81% (95% CI, 71.9%-81%) respectively which increased to 73.3% (95% CI, 60.3%-83.9%), and 83.9% (95% CI, 71.7%-92.4%) respectively in patients with past history of tuberculosis. The sensitivity and specificity of IgG Aspergillus was 82.4% (95% CI, 71.8%-90.3%) and 82% (95% CI, 73.1-89%); 86.7% (95% CI, 75.4%-94.1%), and 80.4% (95% CI, 67.6%-89.8%) in the whole group and those with past history of tuberculosis respectively. The baseline characteristics and diagnostic accuracies are listed in Tables 1 and 2 respectively.

Conclusions

LDBio is a point-of-care test with reasonable sensitivity and specificity. However, further tests may have to be done to rule-in or rule-out the diagnosis of CPA in the appropriate setting.
S5.1b Antifungal r esistance
Authors: Seidel Danila
Published: September 2022

S5.1 Antifungal resistance, September 22, 2022, 3:00 PM - 4:30 PM

Resistance to clinical antimycotics in Aspergillus fumigatus has become an increasing threat in healthcare worldwide over the past two decades. Factors that contribute to this continuing trend are manifold, among others resistance emerge in environmental fungi through selection pressure due to fungicides widely used in agriculture and farming, resistant clones are diffused around the world through global travel and shipping routes, as well as prophylactic and long-term administration of antifungal agents in patients with chronic fungal disease creating selection pressure.

 

Physicians face particular challenges in their patients with invasive aspergillosis, with emerging resistance adding another layer of therapeutic complexity. We are beginning to gain an understanding of the clinical implications of the different patterns of resistance. First international studies have shown that resistance of A. fumigatus to clinical antifungal agents significantly hampers the successful treatment of patients.

 

This presentation aims to highlight the difficulties associated with antifungal resistance in A. fumigatus with a focus on hematological oncological patients.
S5.1d Mechanisms of azole antifungal resistance in clinical isolates of Candida tropicalis
Authors: Ghosh Anup , Paul Paul , Shaw Dipika , Joshi Himanshu , Singh Shreya , Chakrabarti Arunaloke , Rudramurthy Shivaprakash M , Kaur Harsimran
Published: September 2022

S5.1 Antifungal resistance, September 22, 2022, 3:00 PM - 4:30 PM

 

Objectives

In tropical countries, the azole resistance in Candida tropicalis is on the rise. There are limited studies available regarding the azole resistance mechanisms in C. tropicalis. This study was designed to understand the molecular mechanisms of azole resistance in C. tropicalis by using genetic and bioinformatics approaches.

Methods

A total of 32 azole-resistant (R) and 10 azole-susceptible (S) clinical isolates of C. tropicalis were included in this study. All the isolates were subjected to complete gene sequencing of azole target genes including ERG11 to analyze the mutations which could lead the azole resistance. Four fragments were amplified, sequenced, and aligned to get full-length ERG11 gene. Inducible expression analysis of 17 other genes potentially associated with azole resistance was also evaluated. Homology modeling and molecular docking analysis were performed to study the effect of amino acid alterations in mediating azole resistance.

Results

Of the 32 resistant isolates, 12 (37.5%) showed A395T and C461T mutations in the ERG11 gene. The mean overexpression of CDR1, CDR3, TAC1, ERG1, ERG2, ERG3, ERG11, UPC2, and MKC1 in resistant isolates without mutation (R-WTM) was significantly higher (P <.05) than those with mutation (R-WM) and the sensitive isolates (3.2-11 vs. 0.2-2.5, and 0.3-2.2 folds, respectively). Although the R-WTM and R-WM had higher (P <.05) CDR2 and MRR1 expression compared to S isolates, noticeable variation was not seen among the other genes. Protein homology modeling and molecular docking revealed that the mutations in the ERG11 gene were responsible for structural alteration and low binding efficiency between ERG11p and ligands. Isolates with ERG11 mutations also presented A220C in ERG1 and together T503C, G751A mutations in UPC2.

Conclusions

Nonsynonymous mutations in the ERG11 gene and coordinated overexpression of various genes including different transporters, ergosterol biosynthesis pathway, transcription factors, and stress-responsive genes are associated with azole resistance in clinical isolates of C. tropicalis.
S6.4c Primary cutaneous implantation coccidioidomycosis
Authors: Bonifaz Alexandro , Araiza Javier , Arce Martin
Published: September 2022

S6.4 One health approach for endemic mycoes in the Americas, September 22, 2022, 4:45 PM - 6:15 PM

 

Objective

To present a series of cases of primary cutaneous coccidioidomycosis, to highlight this mycosis that can start as cutaneous implantation, after trauma, and to emphasize the classification criteria.

Methods

A series of cases of primary cutaneous coccidioidomycosis will be presented, all of them confirmed by mycological studies, fresh examinations, stains, and cultures, as well as their molecular identification; also confirmed by histopathology.

Results

A series of 22 cases of primary cutaneous coccidioidomycosis is presented, 16 (72.8%) in men, 6 (27.2%) in women. With an average age of 35.2 years, with the lowest case in a 14-year-old child and the highest at 72 years. All from rural and endemic areas. A total of 11 (50%) with fieldwork and the rest due to various injuries. The etiological agent was isolated in all of them: Coccidiodes posadasii in 16 (72.8%), C. immits in 3 and one by Coccidiodes sp. 20 cases were managed with itraconazole, with an average of 8 months and two more with a cycle of amphotericin B and subsequent itraconazole. Clinical and mycological cure was obtained in all.

Discussion

Primary cutaneous coccidioidomycosis, is considered an implantation mycosis, similar to other endemic ones, it occurs between 2%-10% of cases. It begins after trauma that inoculates the fungus, such as a primary chancre. To confirm that it is a primary form, Wilson's criteria must be met: the presence of skin trauma, regional lymphadenopathy, no evidence of pulmonary involvement, positive intradermal reaction, and low antibody titers. It may present auto involution and in immunosuppressed patients, it can spread.

Conclusion

The initial cutaneous form of coccidioidomycosis is rare, usually seen in patients living in endemic areas, and usually present in patients with rural occupations. It has a variety of clinical forms, being confused with many diseases. Its diagnosis is simple, being the biopsy the most used, and it must be confirmed by mycological tests. It has a good prognosis and its main management is with itraconazole.
S6.5b Genomics and metagenomics of Madurella mycetomatis
Authors: Litvintseva Anastasia , Bakhiet Sahar , Gade Lalitha , Bagal Ujwal , Wagner Darlene , Siddig Emmanuel Edwar , Mhmoud Najwa Adam , Fahal Ahmed
Published: September 2022

S6.5 Efforts of improving the management of mycetoma: working towards the 2030 goals, September 22, 2022, 4:45 PM - 6:15 PM

 

 

Mycetoma is a debilitating disease recognized as a neglected tropical disease by the World Health Organization. The etiology of mycetoma is poorly understood; ∼ 60% of cases are caused by fungi and the rest are bacterial, although this varies by region. The pathogenic fungus, Madurella mycetomatis, is most frequently identified in mycetoma cases. Here, we present a high-quality genome assembly of M. mycetomatis and the results of the whole genome sequence analysis of 25 isolates from Sudan. We demonstrate evidence of at least seven genetically diverse lineages and extreme clonality among isolates within these lineages. Shotgun metagenomic analysis of DNA from mycetoma grains confirmed that M. mycetomatis was the predominant causative agent of eumycetoma Sudan; however, 10% of grains also contained bacterial reads suggestive of secondary infections. A thorough understanding of the genetic structure and diversity of fungi causing mycetoma is essential for the development of new diagnostic methods and for identifying potential drug targets.
S6.5c MycetOS: identifying drugs which can penetrate the mycetoma grain
Authors: Van de Sande Wendy
Published: September 2022

S6.5 Efforts of improving the management of mycetoma: working towards the 2030 goals, September 22, 2022, 4:45 PM - 6:15 PM

Mycetoma is a neglected tropical disease characterized by large subcutaneous swellings and the formation of grains. Madurella mycetomatis is the most common causative agent. Currently, mycetoma is treated with a combination of itraconazole therapy and surgery with low success rates, resulting often in amputation and social sigma. To improve the current therapeutic success rates a novel drug is needed. Due to the lack of interest in the pharmaceutical industry, an open-source drug discovery program for mycetoma was established called MycetOS.

 

In total 1360 compounds were screened for in vitro activity against M. mycetomatis, and many more are currently being screened. Compounds that were able to inhibit growth at 100 μm, 25 μm, and had an IC50 <8 μm were selected for studying the in vivo efficacy in an M. mycetomatis grain model in the invertebrate Galleria mellonella.

 

Out of the 1360 compounds screened against M. mycetomatis, 302 were able to inhibit growth at 100 μm, and 23 of those met all criteria to be screened in vivo. Of these 23, nine did prolong larval survival. These included 3/7 azoles tested, olorofim, fenbendazole, MMV006357, MMV022478, MMV675968, and MMV1782387. Based on these results, 6 compound series were selected for further studying, these included the fenarimols (series 1), the aminothiazoles (series 2), the phenotiazines (series 3), dihydrofolate reductase inhibitors (series 4), benzimidazoles (series 5) and the ketoximines (series 6). For series 1 in total 185 additional compounds were screened. By analyzing the in vitro activity and in vivo efficacy in relation to the chemical properties of the molecules it appears that the LogD value of a compound was important for penetrating into the mycetoma grain.

 

In conclusion, using an open source drug discovery approach for mycetoma we were able to identify novel lead compounds. Some of these compounds were highly active against M. mycetomatis only (fenarimols, aminothiazoles, phenotiazines, and ketoximines), while other compounds such as the benzimidazoles also were active against other causative agents as well. Screening more analogs of identified compounds allowed us also to identify chemical properties which are favorable for grain penetration in vivo. This will allow us to chemically design more active compounds for this difficult to treat infection.
S6.5d Molecular identification of mycetoma causative agents from patients in ahospital setting in Senegal
Authors: Sow Doudou , Deh Aminata , Minlékib Carole Pab , Ndiaye Maodo , Manga Isaac , Lelo Souleye , Fall Cheikh Bintou , Sylla Khadime , Ndiaye Magatte , Tine Roger , Dieng Thérèse , Faye Babacar
Published: September 2022

S6.5 Efforts of improving the management of mycetoma: working towards the 2030 goals, September 22, 2022, 4:45 PM - 6:15 PM

 

Background

Mycetoma is a chronic granulomatous inflammatory disease that is caused either by bacteria or fungi. The diagnosis of species is important to guide the therapeutic management of patients particularly for white and yellow grains. However, the identification of the causative agents using mycological and histological techniques is a real problem in our countries. This study aims to identify etiologic agents using molecular techniques in Senegal.

Methods

A prospective study was carried out to compare mycological and histological techniques with molecular methods in patients attending hospital settings. Biopsy specimens and/or grains obtained from these patients were examined by PCR targeting the ITS (fungal agents) and 16S (actinomycosis agents) genes. Sequencing with the SANGER method allowed us to identify the species.

Results

Preliminary results were obtained from 30 patients. The grains collected were black (38%), red (4.7%), white (47.6%), and yellow (9.5%). Discriminative PCR ITS vs 16S identified 5 actinomycosis agents including white and yellow grains and 1 fungal agent. The fungal agent was identified after sequencing as Microsporum langeronii.

Conclusion

The preliminary results of this study show the importance of discriminative PCR to guide the therapeutic choice of clinicians. Its widespread use could improve the detection and management of mycetoma cases in Senegal.
S7.2d Divergent EGFR/MAPK-mediated immune responses to clinical Candida pathogens in vulvovaginal candidiasis
Authors: Zhang Jingyun , Peng Jingwen , Li Dongmei , Mei Huan , Yu Yu , Li Xiaofang , She Xiaodong , Liu Weida
Published: September 2022

S7.2 More than just candidemia: clinical aspects, diagnosis and treatment, and pathogenesis of deep-seated candidiasis, September 23, 2022, 10:30 AM - 12:00 PM

 

Objectives

Vulvovaginal candidiasis (VVC) is characterized by symptomatic inflammatory responses in the vagina caused by Candida albicans and non-albicans Candida (NAC) species. The epidermal growth factor receptor (EGFR) -mitogen-activated protein kinase (MAPK) signaling pathway has been linked to immune responses of oral epithelial cells upon C. albicans exposure, but whether this pathway plays a similar response in vaginal epithelial cells is not determined.

Methods

The activation of EGFR and MAPK signaling pathways in vaginal epithelial cells infected with C. albicans was determined by RNA sequencing and Western blot. The relationship between EGFR and MAPK signaling was verified via inhibition of EGFR and construction of EGFR-overexpressing cells. Enzyme-linked immunosorbent assay (ELISA) and Real Time Cellular Analysis (RTCA) techniques were used to detect the effect of EGFR-MAPK signaling pathway on regulating the secretion of inflammatory cytokines and cell damage induced by C. albicans. The mouse model of VVC infected by C. albicans was constructed, and the role of EGFR signaling pathway in regulating fungal burden, vaginal inflammation, and epithelial damage was determined by Periodic Acid-Schiff stain and immunofluorescence.

Results

We observed that phosphorylation of EGFR and p38 was continuously activated in vaginal epithelial cells by C. albicans strain SC5314. The response is not in a biphasic manner that is critical for oral epithelial cells to discriminate the morphology of C. albicans. When compared with SC5314, a highly azole-resistant C. albicans isolate 1052 can induce a stronger phosphorylated signal of EGFR and p38, while clinically-isolated NAC strains including C. tropicalis, C. glabrata, C. parapsilosis, and C. auris triggered higher levels of phosphorylated ERK1/2 and c-Fos than C. albicans. Consistently, inhibition of EGFR significantly reduced inflammatory response and epithelial damage induced by C. albicans in vitro and in vivo, while inhibition of p38 led to great loss of epithelial damage triggered by both C. albicans and NAC species.

Conclusion

These results confirm the importance of the EGFR-MAPK signaling in VVC pathogenesis and highlight the remarkable immunogenic differences between C. albicans and NAC species in host-microbe interactions.
S8.2a Trends in epidemiology of pediatric Candida infections
Authors: Roilides Emmanuel
Published: September 2022

S8.2 What is new in pediatric mycology?, September 23, 2022, 3:00 PM - 4:30 PM

 

 

Invasive Candida infections are a cause of increased morbidity and excessive mortality in immunocompromised and critically ill patients including premature neonates. In the pediatric setting, they are more frequent in the neonatal intensive care unit (ICU), in the pediatric ICU, and in the pediatric oncology/hematology departments. Its frequency in other pediatric departments, such as gastroenterology, surgery, and nephrology is less of a problem. Candida albicans remains the most frequent Candida species, whereas other non-albicans Candida spp. are less frequent. Candida parapsilosis is second in frequency, but in certain pediatric settings and countries, it may be first. While C. albicans is almost entirely susceptible to azoles, C. parapsilosis has started to manifest increasing resistance to fluconazole and this is of concern. However, due to improved infection control and prevention measures and to use of fluconazole prophylaxis in a number of neonatal ICUs, its incidence has been shown to decrease in a multi-state study conducted by the Centers of Disease Control and Prevention in the United States. Another large multinational study that was conducted in many European countries showed no changes in epidemiology over a number of years, and more non-albicans Candida, particularly C. parapsilosis, in South Europe. The epidemiology of Candida in pediatric ICU has been less studied. Similar epidemiology and risk factors exist in PICU as in neonates. Abdominal surgery and multi-site colonization with Candida of patients are risk factors for developing invasive Candida infections, mainly candidemia. In the patients with hematological malignancies, antifungal prophylaxis for mold infections is also active against Candida, therefore, the incidence of invasive candidiasis is relatively low. However, non-Candida albicans species with reduced susceptibility to azoles, such as C. glabrata, are found more frequently. In pediatric patients with solid organ transplantation, invasive candidiasis is the most frequent fungal infection, mainly in those with liver transplantation. Candida causes infection in the first weeks after transplantation earlier than other fungal infections.
S8.3b How fungal cell wall glycans modulate the activation of platelets ?
Authors: Jawhara Samir
Published: September 2022

S8.3 How the fungal cell wall glycan can modulate the immune response?, September 23, 2022, 3:00 PM - 4:30 PM

 

 

Platelets are the first circulating blood cells that interact and adhere to vascular lesions. They play an important role in vascular repair and maintenance of blood homeostasis. Platelets are involved in the immune defense of the host against many infections caused by bacteria, viruses, and fungi. Following infection, these microorganisms can alter platelet function leading to platelet activation. During fungal infection, β-glucans, mannan, and chitin, are critical components of Candida albicans, an opportunistic pathogenic yeast of humans. These fungal glycans play an important role in the modulation of the host response. They are released into the bloodstream and can be detected up to 10 days before the onset of clinical signs of invasive candidiasis. However, their role in the modulation of platelet activities is unknown. In our studies, we observed that β -glucans and chitin decrease platelet activation and modulate the production of inflammatory mediators, mediated by TLR4 or TLR8 respectively. These glycans also reduce platelet adherence to C. albicans and to polynuclear neutrophils, suggesting a process by which C. albicans can escape from cells of innate immunity by releasing cell wall polysaccharides into the close environment or the blood circulation. This study provides evidence that fungal glycans play a role in the modulation of the immune response and how C. albicans can escape from the innate immune response.
S8.3c Cell wall glycans as targets for the development of new antifungals
Authors: Aimanianda Vishukumar , Wong Sarah Sze Wah , Delliere Sarah , Schiefermeier-Mach Natalia , Lechner Lukas , Perkhofer Susanne , Bomme Perrine , Fontaine Thierry , Schlosser Anders , Sorensen Grith , Madan Taruna , Kishore Uday
Published: September 2022

S8.3 How the fungal cell wall glycan can modulate the immune response?, September 23, 2022, 3:00 PM - 4:30 PM

 

 

Being an extracellular organelle, the cell wall plays a crucial role in fungal life, by protecting fungal cells from a hostile environments and providing cells with mechanical strength. Exploiting the essentiality of this cell wall, available antifungal drugs target cell wall biosynthesis directly or by altering the fungal cell membrane. However, the emergence of resistance to antifungal drugs, new at risk-cohorts, and drug-drug interaction issue with antifungals demand new/alternative therapeutic strategy. In this regard, we have identified that surfactant protein-D (SP-D; a host humoral immune component) has growth inhibitory activity on Aspergillus fumigatus, a ubiquitous airborne opportunistic pathogen. SP-D, a soluble pattern recognition receptor of the collection family, targets galactosaminogalactan and galactomannan, the cell wall glycans of A. fumigatus hyphae, as the ligands. Hyphae grown in presence of SP-D show a significant decrease in the growth and are hyperbranched compared to control hyphae. SP-D treatment alters surface exposure of hyphal cell wall polysaccharides, thereby modifying hyphal immunoreactivity. SP-D pre-treatment increases the efficacy of the echinocandin and azole classes of antifungals against A. fumigatus. Interestingly, SP-D show hyphal growth inhibitory activity against multi-/pan-azole-resistant isolates of A. fumigatus. Overall, SP-D seems to target A. fumigatus cell wall glycans to execute its fungistatic activity. We are currently investigating the exact mechanism of anti-A. fumigatus activity associated with SP-D.
S8.5c MLST genotyping and phylogenetics of AD-hybrids
Authors: Cogliati Massimo , Chen Min , Xu Jianping , Hitchcock Megan , Chung June Kwon , Yang Dong-Hoon , Rickerts Volker , Ollivier Marie Desnos , Silva Joao Inacio , Meyer Wieland , Florek Magdalena , Nawrot Urszula , Escandon Patricia , Puime Andrés , Roger Frederic , Bertout Sébastien
Published: September 2022

S8.5 Genotyping of Cryptococcus neoformans and C. gattii, September 23, 2022, 3:00 PM - 4:30 PM

 

Objectives

In a previous study a set of new molecular-type specific primers were designed to apply the standard ISHAM consensus multi-locus sequence typing (MLST) scheme to Cryptococcus neoformans AD hybrids. In the present study, we report the preliminary results of the investigation by MLST of a large number of AD hybrids with the aim to identify the circulating genotypes, their phylogenesis, and population genetics.

Methods

A total of 50 AD-hybrid isolates from different parts of the world and from different sources were genotyped by MLST. Minimum spanning trees using GoeBurst algorithm were generated by comparing hybrid genotypes and by comparing separately either allele-A and allele-D portions of the hybrid genotypes to the haplotypes recorded in the MLST global database.

Results

Analysis identified 32 hybrid genotypes grouped in three distinct main clusters (CC12, CC21, and CC30) including 12 isolates each. Both CC12 and CC21 clusters included isolates from different countries and continents but the former grouped only isolates with mating type aADalpha whereas the latter those with mating type alphaADa. Cluster CC30 included only isolates from Ivory Coasts. Heterozygous allelic combinations in each of the seven MLST loci presented two or three combinations more frequent than the other ones. In some isolates, one or more alleles were not amplified after multiple attempts, and therefore, they were considered as lacking. A total of 22 MLST profiles were identified by analyzing separately the allele-A combinations of the hybrids. Comparison with all MLST profiles of VNI, VNII, and VNB included in the MLST global database showed that the allele-A portion of the hybrid genotypes was grouped in few VNI or VNB clusters. In none of the investigated hybrids, the allele-A portion originated from VNII genotypes. Similarly, when the MLST profile of allele-D portion of hybrids was compared to all VNIV genotypes present in the global MLST database, few clusters were identified but, in this case, mostly originated from genotypes not yet found among VNIV haplotypes.

Conclusions

These preliminary results suggest that the AD hybrids here investigated originated from the mating of A haploids very common in both clinical and environmental isolates and D haploids that are not circulating at present or are very rare. Therefore, it is likely that hybrids originated in the environment where VNIV genotypic diversity is higher and suitable AD combinations can occur. Sequencing of further AD hybrids is in progress to confirm these results.
S9.2d Directed evolution of voriconazole resistance in Aspergillus fumigatus identifies novel mutations responsible for triazole resistance
Authors: Handelman Mariana , Kandil Amar Abo , Shadkchan Yona , Osherov Nir
Published: September 2022

S9.2 Azole resistance in Aspergillus fumiagatus: how hot is your hotspot?, September 23, 2022, 4:45 PM - 6:15 PM

Aspergillus fumigatus is the leading invasive mold pathogens in humans. The first line of treatment for invasive A. fumigatus infections are the triazole antifungals that inhibit Erg11/Cyp51 lanosterol demethylase activity, blocking ergosterol biosynthesis.

 

In recent years, triazole resistance of A. fumigatus has been increasingly reported, both as a result of widespread agricultural use of fungicidal triazoles and long-term treatment in patients with chronic aspergillosis. To date, the most common triazole resistance mechanisms in A. fumigatus are alterations in the erg11A/cyp51A gene or promoter, followed by overexpression of efflux pumps and mutations in hmg1, encoding HMG-CoA reductase. To identify novel triazole resistance mechanisms, we passaged A. fumigatus wild type and cyp51A-null strains under increasing concentrations of voriconazole (0.25 μg/ml-20 μg/ml) to generate resistant strains. Resistant isolates were whole-genome sequenced and compared with untreated controls. We identified known cyp51A and cyp51B mutations, and novel mutations in HMG1 and in previously uncharacterized genes in the ergosterol biosynthesis pathway as well as several efflux pumps. We identified at which stage of evolution each of the mutations occurred as well as their contribution to the resistance phenotype by re-introduction, alone and in combination, into the susceptible parental strain. Our study identified novel genes conferring triazole resistance and helps outline the complex stepwise evolutionary paths by which A. fumigatus develops resistance.
S9.4a Ocular infections by melanized fungi Curvularia lunata and Lasiodiplodia theobromae: Antifungal susceptibility and clinical outcome
Authors: Mitra Sanchita , Garg Prashant , Murthy Somasheila , Dave Vivek Pravin
Published: September 2022

S9.4 Free oral presentations (late breaking), September 23, 2022, 4:45 PM - 6:15 PM

 

Purpose

To report antifungal susceptibility and clinical correlations in melanized fungal isolates of Curvularia lunata and Lasiodiplodia theobromae from ocular infections.

Methods

Antifungal susceptibility testing was performed by broth microdilution testing, following Clinical and Laboratory Standard Institute guidelines, of 17 C. lunata and 13 L. theobromae isolates from monomicrobial infections of microbial keratitis or fungal endophthalmitis patients. Isolates resistant to ≥2 classes of antifungals were considered as multidrug-resistant (MDR). The panel of antifungals tested were amphotericin B, natamycin, voriconazole, ketoconazole, fluconazole, itraconazole, posaconazole, and caspofungin.

Results

Voriconazole showed the highest susceptibility (83.3% isolates) followed by natamycin (80%), fluconazole (80%), itraconazole (76.7%), ketoconazole (70%), posaconazole, and caspofungin (66.7% each) and lastly amphotericin B (63.3%). For treatment, all patients received topical natamycin, and few received additional oral ketoconazole or intraocular voriconazole. MDR isolates led to the poorer clinical outcomes (P=.015) in patients. But natamycin resistance alone did not show unfavorable outcomes (P=.28), though this was the most frequent drug used topically in fungal ocular infections.

Conclusion

Melanized fungi causing ocular infections have varying susceptibility to different antifungal agents. Most effective drug as seen in vitro in our study, was voriconazole. Significant resistance to amphotericin B, which is the most common antifungal used in intravitreal injections, was noted. MDR isolates overall, had poorer clinical outcomes.
S9.4c Diverse environmental inputs mediate changes in β-glucan exposure at the Candida albicans cell surface thereby influencing tissue colonisation during systemic infection
Authors: Pradhan Arnab , Ma Qinxi , Hickey Emer , Avelar Gabriela , Larcombe Daniel , Bain Judith , Childers Delma , Dambuza Ivy , Leaves Ian , de Assis Leandro Jose , Netea Mihai , Brown Gordon , Erwig Lars , Gow Neil A. R. , Brown Alistair J. P.
Published: September 2022

S9.4 Free oral presentations (late breaking), September 23, 2022, 4:45 PM - 6:15 PM

 

 

Candida albicans adaptation to host niches affects the exposure of key pathogen-associated molecular patterns (PAMPs) on its cell surface and, consequently, the detection of C. albicans cells by the immune system. Focusing on β-(1,3)-glucan, we screened for host inputs that influence the exposure of this immune-stimulatory PAMP on the C. albicans cell surface. We used a combination of fluorescent microscopy, flow cytometry, and cytokine assays, and then analyzed certain conditions in more detail using transmission electron microscopy and time-lapse video microscopy of C. albicans-phagocyte interactions. We found that some nutrients, micronutrient limitation, stresses, and antifungal drugs trigger β-glucan masking, whereas other inputs, such as nitrogen sources and quorum sensing molecules, exert limited effects on β-glucan exposure. In particular, host- or bacterial-derived L-lactate, hypoxia, or iron limitation induce β-glucan masking, and this leads to attenuation of phagocytic responses [Nature Micro 2, 16 238; mBio 9, e01318-18; Nature Comms 10, 5315]. Lactate signals through Gpr1 to activate Crz1 in a calcineurin-independent manner, whereas hypoxia signals via mitochondrial ROS, and iron limitation signals through Ftr1 and Sef1. β-glucan masking also depends upon downstream signaling via the cAMP-PKA pathway. We conclude that C. albicans has evolved to exploit a range of specific host-derived signals to modulate the exposure of a major PAMP at its cell surface in an attempt to evade phagocytic uptake. Using barcode-sequencing in direct competition assays in vivo, we showed that preadaptation to specific β-glucan masking signals affects the ability of this fungus to colonize particular tissues during systemic infection in a murine model. This reinforces the view that β-glucan masking promotes C. albicans infection.
S9.4d Main reservoirs of Trichophyton mentagrophytes Type V in Iran
Authors: Nikkholgh Sivash , Pchelin Ivan , Mahmoudabadi Ali Zarei , Shabanzadeh-Bardar Mahbubeh , Gharaghani Maral , Sharifzadeh Aghil , Mohammadi Rasoul , Noripour-Sisakht Sadegh , Katiraee Farzad , Rezaei-matehkolaei Ali
Published: September 2022

S9.4 Skin mycoses and microbiome, September 23, 2022, 4:45 PM - 6:15 PM

 

Objectives

Dermatophytosis in livestock receives attention because of its contagiousness, high treatment costs, and lack of control programs. Compared with cattle, mycological aspects of dermatophytosis in sheep and goats have been studied less frequently. Dermatophytosis in these animals (small ruminants) may lead to serious economic losses due to the negative impact on the growth of involved animals, as well as their milk and meat production. Recent studies showed that the old Trichophyton verrucosum var. verrucosum (which is known to have some African and Asiatic sheep as its reservoirs) is currently synonymous with T. mentagrophytes Type V, the most common genotype of T. mentagrophytes isolated from Iranian patients. But the animal reservoirs of this genotype are not well known in Iran and in this investigation, we aimed to determine them.

Methods

A total of 678 skin and hair samples from animals including sheep (n = 190), cows (n = 79), goats (n = 9), camels (n = 20), stray and domestic cats (n = 195), stray and pet dogs (n = 146), horses (n = 27), foxes (n = 2), hedgehogs (n = 2), and poultries (n = 8) were subjected to direct microscopy and culture on Mycobiotic agar. Most animals had skin lesions, though some stray cats and dogs were asymptomatic. Molecular identification of dermatophyte cultures was done by ITS-rDNA RFLP. To confirm the RFLP identification, 59 representative isolates from all studied animal species were subjected to ITS-rDNA sequencing. The likelihood for isolation of a specific species or genotype with regard to the type of infected animal was determined using the chi-square test.

Results

We obtained 334 dermatophyte cultures. ITS-RFLP and ITS region sequencing revealed the species T. verrucosum (n = 62; all from cows), T. mentagrophytes Type V (sheep = 95; goat = 6; cat = 1; horse = 2), T. mentagrophytes Type II* (cat = 2), T. mentagrophytes Type VII (dog = 2), Microsporum canis (cats, n = 94; dogs, n = 55; cow, n = 1; horse, n = 1), T. quinckeanum (fox, n = 1), Nannizzia gypsea (cats, n = 5; dogs, n = 4; cow, n = 1; horse, n = 1), and N. fulva (cow, n = 1). No dermatophytes were isolated from camels, hedgehogs, and poultries. There was a statistically significant difference in the isolation rate of T. mentagrophytes Type V between sampled animals meaning that with a high probability it is isolated from sheep and goats.

Conclusion

Purposive sampling from suspected animals confirmed that sheep are the main animal reservoir of T. mentagrophytes Type V, at least in Iran. Further international sequence-based investigations can test our conclusion.