Changing epidemiology of systemic fungal infections

Epidemiology and risk factors of fungal pathogens in sepsis: a prospective nationwide multicenter cohort study

BACKGROUND

The incidence of sepsis with identified fungal pathogens is increasing and is associated with higher morbidity and mortality. Co-infection with fungal infections in COVID-19 patients is attracting clinical attention. This study examines the epidemiology, risk factors, and outcomes among sepsis patients with identified fungal pathogens.

METHODS

We conducted a nationwide cohort study of adult patients with sepsis from the Korean Sepsis Alliance Database in South Korea between September 2019 and December 2021. We identified 407 patients with documented fungal pathogens, categorized according to the presence of hemato-oncologic malignancies.

RESULTS

Of the 11,981 patients with sepsis, fungal pathogens were identified in 3.4% of cases. Among these patients, 38.3% had co-existing hematologic or solid organ cancer. Older age, higher clinical frailty scale scores, and underlying conditions, such as chronic kidney disease, cerebrovascular disease, and dementia, were more prevalent in patients without hemato-oncologic malignancies. The most common fungal pathogens were Candida albicans (47.9%), Candida glabrata (20.6%), and Candida tropicalis (13.5%). Only 6.6% of the patients with confirmed fungal pathogens received antifungal treatment. The presence of hemato-oncologic malignancies did not significantly affect patient outcomes. Factors associated with the presence of identified fungal pathogens included chronic kidney disease (Odds ratio [OR] 1.662; 95% confidence interval [CI] 1.216-2.273; p = 0.001), connective tissue disease (OR 1.885; 95% CI 1.058-3.358; p = 0.032), immunocompromised status (OR 2.284; 95% CI 2.186-3.753; p = 0.001), and invasive mechanical ventilation (OR 2.864; 95% CI 2.186-3.753; p < 0.001).

CONCLUSIONS

Sepsis identified fungal pathogen are associated with chronic kidney disease, immunocompromised status and other risk factors, demonstrating the need for early detection, targeted management and improved antifungal strategies to improve patient outcomes.

Dynamic characterization of the changes in intestinal fungi and fecal metabolites during the reproductive cycle of sows

Pregnancy-induced changes in the intestinal microbiota have been widely demonstrated. However, the research on the alterations of intestinal fungi and fecal metabolism during the reproductive cycle of sows is limited. In this study, fresh fecal samples were collected from 12 sows during the second day before fertilization (SBF), early pregnancy period (EEP; including gestational days 28, 42, and 56), late pregnancy period (LPP; including gestational days 70, 84, and 98), farrowing day (FD; collected after delivery), and lactation period (LAC, including days 7, 14, and 21 postpartum) for Internal Transcribed Space amplicon sequencing and untargeted metabolomics sequencing. The results indicated that intestinal fungi and fecal metabolites underwent significant dynamic changes during EPP and LPP, stabilizing after FD. Correlation analysis revealed a significant association between intestinal fungi and fecal metabolites, suggesting a potential role of intestinal fungi in the regulation of host health and reproductive performance. These results indicated that pregnancy may play a key role in driving the dynamic changes in intestinal fungi and fecal metabolites observed throughout the reproductive cycle. This study explores the dynamic changes and correlations of intestinal fungi and fecal metabolites in sows, providing theoretical insights for sow breeding production, feed management, and the development of microecological agents.

Novel Curvularia species causing disseminated phaeohyphomycosis in a dog

Phaeohyphomycosis is an uncommon disease caused by dematiaceous fungi that is almost exclusively found in immunocompromised dogs. Here we describe the case of a dog treated with prednisone (1.1 mg/kg/day) and cyclosporine (11.2 mg/kg/day) for immune thrombocytopenia that developed cutaneous/subcutaneous lesions affecting both forelimbs 29 days after initiation of immunosuppression. The owner elected conservative outpatient treatment that consisted of wound care, antibiotics, mirtazapine, maropitant, and a dose reduction of prednisone (0.3 mg/kg/day) in lieu of biopsies or cultures. The dog was subsequently euthanized 13 days later because of an acute onset of increased respiratory rate and effort, obtunded mentation, and an inability to ambulate. Postmortem examination revealed widespread fungal dissemination in the heart, pericardium, intercostal muscles, lymph nodes, skin, subcutis, kidneys, lungs, pleura, and nasal cavity. Histopathology of the widespread plaques and nodules revealed fungal hyphae that were 4-8 µm in diameter, pigmented, variably septate, non-parallel, and toruloid with acute branching and occasional terminal bulbous dilations up to 20 µm in diameter, resembling chlamydoconidia. Yeast-like cells had a thick, variably pigmented wall and internal, foamy to granular, pale amphophilic contents. Fungal culture of swabs from the right elbow subcutaneous granulomas and from the left lateral pleural nodules yielded pure growth of Curvularia sp. Genomic DNA was extracted from harvested mycelia and molecular sequencing confirmed the presence of a novel Curvularia sp., C. arizonensis.

Endophytic Fungi of Calea pinnatifida (Asteraceae): Dereplication of Crude Extracts, Antimicrobial Properties, and Identification of New Tetronic Acid Derivative Produced by Hypomontagnella barbarensis

Endophytic fungi are increasingly being recognized for their diverse metabolites that may exhibit antimicrobial properties. In our study, we isolated seven endophytic fungal strains from Calea pinnatifida, which were identified as Hypomontagnella barbarensis, Neopestalotiopsis clavispora, Nigrospora sacchari-officinarum, Annulohypoxylon moriforme, Colletotrichum siamense, and Colletotrichum karstii (with two isolates from the same species). Furthermore, the antimicrobial activity of the extracts was assessed, revealing that the extract from Hypomontagnella barbarensis demonstrated activity against Staphylococcus aureus. Further investigation of secondary metabolites, employing UHPLC-HR-ESI-MS/MS in combination with molecular networking, facilitated annotation of the nine compounds. Of these, five were identified based on matches with the GNPS spectral library, and four were predicted based on the molecular network. Notably, from the extract of Hypomontagnella barbarensis, two pairs of diastereoisomeric acyl-tetronic acid derivatives were isolated and characterized using MS and NMR spectroscopy. This study highlights the potential of endophytic fungi as a valuable source of novel antimicrobial agents.

Antibiotic use prior to attending a large diarrheal disease hospital among preschool children suffering from bloody or non-bloody diarrhea: A cross-sectional study conducted in Bangladesh

BACKGROUND

Among diarrheal children, injudicious use of antibiotics is a major public health concern particularly in low- and middle-income countries. There are evidence-based guidelines by the World Health Organization (WHO) to prescribe antibiotics for bloody diarrhea in children. There is a scarcity of published data regarding the judicious use of antibiotics for bloody diarrhea in children. So, we aimed to evaluate the presenting features of bloody diarrhea at hospital with prior antibiotic use at home and the prevalence of injudicious antibiotic use for bloody diarrhea in children.

METHODS

We screened 7,289 children aged 24-59 months with diarrhea (≥3 loose stools in the last 24 h) at Dhaka Hospital, International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), from December 5, 2021 to February 16, 2023. Antibiotic intake at home due to current diarrheal illness was evaluated and confirmed by direct observation of a prescription, the bottle of antibiotics, or asking the caregiver about the name of antibiotics.

RESULTS

Out of 7,289 children presented with diarrhea, 3,823 (52.45%) children consumed antibiotics before visiting hospital. 254 (3.48%) children presented with bloody diarrhea, among which 162 ingested antibiotics. Among 162 children, 88 (54.32%) received inappropriate antibiotics due to bloody diarrhea, according to the WHO guidelines. The most prevalent single antibiotic consumed in bloody diarrhea was metronidazole (n = 45, 27.78%), followed by ciprofloxacin (n = 39, 24.07%) and azithromycin (n = 32, 19.75%). After adjusting for relevant covariates like age, sex, presence of straining/tenesmus, fever during admission, history of cough, stunting, wasting, and underweight; children suffering from bloody diarrhea had 1.55 times higher odds of using metronidazole alone or in combination with other antibiotics (aOR:1.55, 95% CI: 1.10-2.19, p-value = 0.012) and 1.93 times higher odds of using multiple antibiotics (aOR:1.93, 95% CI: 1.23-3.02, p-value = 0.004) compared to children with non-bloody diarrhea.

CONCLUSION

The study underscores the excessive use of antimicrobials among children with diarrheal illnesses. It is also evident that metronidazole use and multiple antibiotic use are increasing among children due to bloody diarrhea, which is alarming and calls for antibiotic stewardship by regulating bodies in the country.

Review of neuroimaging findings of intracranial angioinvasive fungal infections

With increasing use of broad-spectrum antibiotics, advances in organ and stem-cell transplant therapy, and the continued diabetes mellitus II epidemic, as well as other risk factors, reports of fungal infections of the CNS have been increasing. The most lethal subset is the angioinvasive fungal infection. Aspergillus fumigatus, Mucor, and Fusarium tend to affect immunocompromised individuals depending on their risk factors. Exserohilum rostratum and Cladophialaphora species tend to infect immunocompetent individuals. Early diagnosis and treatment are imperative for improved outcomes and reduced morbidity and mortality. Clinical presentation is often nonspecific, while neuroimaging can be helpful for accurate diagnosis. CT of the head and/or the maxillofacial structures is the primary imaging modality. Once the infection begins to proliferate, areas of vasogenic and cytotoxic edema, with regional mass effect and shift of the midline structures may be seen. These findings, however, are often nonspecific and may also be seen in underlying neoplasm, inflammatory processes, and other intracranial infections. Characteristic findings on T1, T2, diffusion-weighted imaging (DWI), and gradient echo sequences (GRE) may help to further narrow the differential diagnoses. We present a review of neuroimaging findings that will aid the neuroradiologist in distinguishing intracranial angioinvasive fungal infections and lead to improved patient outcomes.

Ru-terpyridine complexes containing clotrimazole as potent photoactivatable selective antifungal agents

The overuse of antimicrobial agents in medical and veterinary applications has led to the development of antimicrobial resistance in some microorganisms and this is now one of the major concerns in modern society. In this context, the use of transition metal complexes with photoactivatable properties, which can act as drug delivery systems triggered by light, could become a potent strategy to overcome the problem of resistance. In this work several Ru complexes with terpyridine ligands and the clotrimazole fragment, which is a potent antimycotic drug, were synthesized. The main goal was to explore the potential photoactivated activity of the complexes as antifungal agents and evaluate the effect of introducing different substituents on the terpyridine ligand. The complexes were capable of delivering the clotrimazole unit upon irradiation with visible light in a short period of time. The influence of the substituents on the photodissociation rate was explained by means of TD-DFT calculations. The complexes were tested against three different yeasts, which were selected based on their prevalence in fungal infections. The complex in which a carboxybenzene unit was attached to the terpyridine ligand showed the best activity against the three species under light, with minimal inhibitory concentration values of 0.88 μM and a phototoxicity index of 50 achieved. The activity of this complex was markedly higher than that of free clotrimazole, especially upon irradiation with visible light (141 times higher). The complexes were more active on yeast species than on cancer cell lines.

Mechanisms of action of Lactobacillus spp. in the treatment of oral candidiasis

Candida albicans is often associated with oral candidiasis, and drug-resistance profiles have contributed to an increase in morbidity and mortality. It is known that Lactobacillus spp. acts by competing for adhesion to the epithelium, absorption of nutrients and modulation of the human microbiota. Therefore, they are important to assist in the host's microbiological balance and reduce the growth of Candida spp. Until now, there have been no reports in the literature of reviews correlating to the use of Lactobacillus spp. in the treatment of oral candidiasis. Thus, this review aims to highlight the mechanisms of action of Lactobacillus spp. and methods that can be used in the treatment of oral candidiasis. This is a study carried out through the databases PubMed Central and Scientific Electronic Library Online, using the following keywords: Oral Candidiasis and Lactobacillus. Original articles about oral candidiasis were included, with both in vitro and in vivo analyses, and published from 2012 to 2022. Lactobacillus rhamnosus was the most common microorganism used in the experiments against Candida, acting mainly in the reduction of biofilm, filamentation, and competing for adhesion sites of Candida spp. Among in vivo studies, most researchers used immunosuppressed mouse modelsof Candida infection. The studies showed that Lactobacillus has a great potential as a probiotic, acting mainly in the prevention and treatment of mucosal diseases. Thus, the use of Lactobacillus may be a good strategy for the treatment of oral candidiasis.

Clinical Mycology Today: Emerging Challenges and Opportunities

The Mycoses Study Group Education and Research Consortium is a collective of clinicians, researchers, and educators with the common goal to advance awareness, diagnosis, and management of invasive fungal diseases. Clinical Mycology Today, the Mycoses Study Group Education and Research Consortium's biennial meeting, is dedicated to discussing the most pressing contemporary issues facing the field of clinical mycology, promoting clinical, translational, and basic science collaborations, and mentoring the next generation of clinical mycologists. Here, we review the current opportunities and challenges facing the field of mycology that arose from discussions at the 2022 meeting, with emphasis on novel host risk factors, emerging resistant fungal pathogens, the evolving antifungal pipeline, and critical issues affecting the advancement of mycology research.

Fungal ball due to a species of the Scedosporium apiospermum complex in a post-tuberculosis patient

BACKGROUND

Scedosporium species are considered emerging pathogens causing illness in immunocompetent and immunocompromised hosts.

CASE REPORT

A case of non-invasive pulmonary (fungal ball) infection by Scedosporium apiospermum complex in a 49-year-old female with bronchiectasis and cavities secondary to tuberculosis is described. The patient had a history of three years of cough and hemoptysis. A computed tomography scan of the thorax revealed the presence of a cavity in the lower lobe of the right lung, associated with bronchiectasis. A combination of surgical debridement and antifungal therapy (voriconazole) was the treatment of choice. Pulmonary resection (right lower lobectomy) was performed, and samples were sent for microbiological culture and histopathological examination; by means of the latter technique, hyphae were shown. The identification of Scedosporium angustum, a phylogenetic species of the S. apiospermum complex, was obtained by amplifying and sequencing the β-tubulin locus. Voriconazole therapy was started at a loading dose of 800mg/12h for the first 24h, followed by 200mg/12h for 6 months. The patient responded favorably to the treatment and remained asymptomatic.

CONCLUSIONS

This case emphasizes the importance of considering Scedosporium species in the differential diagnosis of fungal balls by Aspergillus. .

Clinico-Demographic Parameters of Oral Fungal Infections: An Institutional Retrospective Study

Introduction Most fungal infections are responsive to antifungal therapy. However, failure to diagnose the same can significantly affect the quality of lives of patients. Timely identification of fungal infections and their association with varied demographic and clinical parameters will help in improving the prognosis of the patient. The present study aims to evaluate the prevalence of fungal infections among various age groups and genders and also to evaluate the association of fungal infections with demographic parameters. Methods This study included a sample size of n = 600. The demographic and clinical details were compiled and transferred to IBM SPSS Version 23 software (IBM Corp., Armonk, NY) for statistical analysis. Descriptive and Pearson chi-square tests were used to analyze the association of the type of fungal infection with gender, age, and comorbidities. A p-value of less than 0.05 is considered statistically significant. Results Angular cheilitis (40%, 240), followed by denture stomatitis (37.5%, 225), were the most common type of fungal infection among the sample population, and the elderly age group (51-72 years) was the most affected. Angular cheilitis was the most common infection among both males (21.4%, 128) and females (18.6%, 112), but candidiasis was reported more in females (18%, 108) than males (3%, 18) (p = 0.00). Angular cheilitis (32%, 192) and candidiasis (18%, 108) were more observed in association with anemia; however, denture stomatitis (34%, 204) was significantly higher among diabetics (p = 0.00). Conclusion The identification of associated systemic and demographic factors is as important as the treatment of fungal infection itself. The recognition of fungal infections and the role of parameters like age, gender, and systemic comorbidities in the development of fungal infections will have valuable implications for public health. Future research is required for a clear understanding of the same.

Clinicomycological Study of the Spectrum of Pulmonary Aspergillosis at a Tertiary Care Hospital in Central India

Knowing the spectrum, prevalence, and modes of diagnosis of pulmonary aspergillosis (PA) will be beneficial to clinicians for its early diagnosis and management. This study aims to estimate the prevalence, spectrum, and role of serological tests and radiological findings in the diagnosis of PA. A total of 150 patients were suspected of having PA after obtaining relevant clinical history and radiological imaging. The patients were grouped into each spectrum of PA as invasive PA (IPA), chronic necrotizing PA (CNPA), aspergilloma, allergic bronchopulmonary aspergillosis (ABPA) based on predisposing factors, clinical and radiological findings, and the guidelines of the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG). Samples (bronchoalveolar lavage (BAL), sputum, blood) were collected from these patients and processed in a microbiology lab. BAL and sputum were subjected to microscopy by potassium hydroxide mount, calcofluor white mount, and culture. The serum was separated from blood by centrifugation and subjected to specific serological tests based on the spectrum of PA that the patient was suspected to have. For IPA, serum and BAL galactomannan antigen enzyme-linked immunosorbent assay (ELISA) was performed. For CNPA and aspergilloma, the anti-Aspergillus IgG antibody ELISA was performed. For ABPA, the tests performed were total immunoglobulin E (IgE) ELISA, Aspergillus fumigatus-specific IgE ELISA, and anti-Aspergillus immunoglobulin G (IgG) antibody ELISA. After compiling the clinical, radiological, culture, and serological findings, patients were diagnosed to have a particular spectrum of PA. The prevalence of IPA was 1.4%, CNPA was 4%, ABPA was 3.2%, and aspergilloma was 2.9%. CNPA was the predominant spectrum of PA in our study. Culture positivity for Aspergillus species was seen the highest in aspergilloma patients, followed by IPA, ABPA, and CNPA patients. A. fumigatus was the most common causative agent of PA, except for IPA for which Aspergillus flavus was the most common causative. Aspergillus niger and Aspergillus terreus were less the frequent causes of PA. A combination of radiological, microbiological, and serological tests along with clinical correlation is needed to confirm the diagnosis of PA.

Validation of diagnoses of liver disorders in users of systemic azole antifungal medication in Sweden

BACKGROUND

Liver disorders are important adverse effects associated with antifungal drug treatment. However, the accuracy of Clinical International Classification of Diseases (ICD)-10 codes in identifying liver disorders for register based research is not well-established. This study aimed to determine the positive predictive value (PPV) of the ICD-10 codes for identifying patients with toxic liver disease, hepatic failure, and jaundice among patients with systemic antifungal treatment.

METHODS

Data from the Swedish Prescribed Drug Register and the National Patient Register were utilized to identify adult patients who received systemic azole antifungal drugs and had a recorded diagnosis of toxic liver disease (K71.0, K71.1, K71.2, K71.6, K71.8, K71.9), hepatic failure (K72.0, K72.9), or jaundice (R17) between 2005 and 2016. The medical records of all included patients were reviewed. Prespecified criteria were used to re-evaluate and confirm each diagnosis, serving as the gold standard to calculate PPVs with 95% confidence intervals (95% CI) for each diagnostic group.

RESULTS

Among the 115 included patients, 26 were diagnosed with toxic liver disease, 58 with hepatic failure, and 31 with jaundice. Toxic liver disease was confirmed in 14 out of 26 patients, yielding a PPV of 53.8% (95% CI 33.4-73.4%). Hepatic failure was confirmed in 26 out of 38 patients, resulting in a PPV of 62.1% (95% CI 48.4-74.5%). The highest PPV was found in jaundice, with 30 confirmed diagnoses out of 31, yielding a PPV of 96.8% (95% CI 83.3-99.9%).

CONCLUSION

Among patients who received azole antifungal treatment and were subsequently diagnosed with a liver disorder, the PPV for the diagnosis of jaundice was high, while the PPVs for toxic liver disease and hepatic failure were lower.

Structure, function and biogenesis of the fungal proton pump Pma1

The fungal plasma membrane proton pump Pma1 is an integral plasma membrane protein of the P-type ATPase family. It is an essential enzyme responsible for maintaining a constant cytosolic pH and for energising the plasma membrane to secondary transport processes. Due to its importance for fungal survival and absence from animals, Pma1 is also a highly sought-after drug target. Until recently, its characterisation has been limited to functional, mutational and localisation studies, due to a lack of high-resolution structural information. The determination of three cryo-EM structures of Pma1 in its unique hexameric state offers a new level of understanding the molecular mechanisms underlying the protein's stability, regulated activity and druggability. In light of this context, this article aims to review what we currently know about the structure, function and biogenesis of fungal Pma1.

Our current clinical understanding of Candida biofilms: where are we two decades on?

Clinically we have been aware of the concept of Candida biofilms for many decades, though perhaps without the formal designation. Just over 20 years ago the subject emerged on the back of progress made from the bacterial biofilms, and academic progress pace has continued to mirror the bacterial biofilm community, albeit at a decreased volume. It is apparent that Candida species have a considerable capacity to colonize surfaces and interfaces and form tenacious biofilm structures, either alone or in mixed species communities. From the oral cavity, to the respiratory and genitourinary tracts, wounds, or in and around a plethora of biomedical devices, the scope of these infections is vast. These are highly tolerant to antifungal therapies that has a measurable impact on clinical management. This review aims to provide a comprehensive overight of our current clinical understanding of where these biofilms cause infections, and we discuss existing and emerging antifungal therapies and strategies.

Sepsis heterogeneity

BACKGROUND

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, with extremely high mortality. Notably, sepsis is a heterogeneous syndrome characterized by a vast, multidimensional array of clinical and biologic features, which has hindered advances in the therapeutic field beyond the current standards.

DATA SOURCES

We used PubMed to search the subject-related medical literature by searching for the following single and/or combination keywords: sepsis, heterogeneity, personalized treatment, host response, infection, epidemiology, mortality, incidence, age, children, sex, comorbidities, gene susceptibility, infection sites, bacteria, fungi, virus, host response, organ dysfunction and management.

RESULTS

We found that host factors (age, biological sex, comorbidities, and genetics), infection etiology, host response dysregulation and multiple organ dysfunctions can all result in different disease manifestations, progression, and response to treatment, which make it difficult to effectively treat and manage sepsis patients.

CONCLUSIONS

Herein, we have summarized contributing factors to sepsis heterogeneity, including host factors, infection etiology, host response dysregulation, and multiple organ dysfunctions, from the key elements of pathogenesis of sepsis. An in-depth understanding of the factors that contribute to the heterogeneity of sepsis will help clinicians understand the complexity of sepsis and enable researchers to conduct more personalized clinical studies for homogenous patients.

A Comprehensive Review of Identification Methods for Pathogenic Yeasts: Challenges and Approaches

Given the increasing incidence of yeast infections and the presence of drug-resistant isolates, accurate identification of the pathogenic yeasts is essential for the management of yeast infections. In this review, we tried to introduce the routine and novel techniques applied for yeast identification. Laboratory identification methods of pathogenic yeast are classified into three categories; I. conventional methods, including microscopical and culture-base methods II. biochemical/physiological-processes methods III. molecular methods. While conventional and biochemical methods require more precautions and are not specific in some cases, molecular diagnostic methods are the optimum tools for diagnosing pathogenic yeasts in a short time with high accuracy and specificity, and having various methods that cover different purposes, and affordable costs for researchers. Nucleotide sequencing is a reference or gold standard for identifying pathogenic yeasts. Since it is an expensive method, it is not widely used in developing countries. However, novel identification techniques are constantly updated, and we recommend further studies in this field. The results of this study will guide researchers in finding more accurate diagnostic method(s) for their studies in a short period of time.

Elevated Temperature, Nitrate and Diesel Oil Enhance the Distribution of the Opportunistic Pathogens Scedosporium spp

Scedosporium infections mainly occur after aspiration of contaminated water or inoculation with polluted environmental materials. Scedosporium spp. have been isolated from anthropogenic environments frequently. To understand their propagation and routes of infection, possible reservoirs of Scedosporium spp. should be explored. In this study, the impact of temperature, diesel and nitrate on Scedosporium populations in soil is described. Soil was treated with diesel and KNO₃ and incubated for nine weeks at 18 and 25 °C. Isolation of Scedosporium strains was done using SceSel+. For the identification of 600 isolated strains, RFLP and rDNA sequencing were used. Scedosporium apiospermum, S. aurantiacum, S. boydii and S. dehoogii were isolated at the beginning and/or the end of incubation. Temperature alone had a minor effect on the Scedosporium population. The combination of 25 °C and nitrate resulted in higher Scedosporium numbers. Treatment with 10 g diesel/kg soil and incubation at 25 °C resulted in even higher abundance, and favored S. apiospermum and S. dehoogii. The results of this study show that diesel-polluted soils favor dispersal of Scedosporium strains, especially S. apiospermum and S. dehoogii. Higher temperature force the effect of supplementations.

Oral Candidiasis of Tobacco Smokers: A Literature Review

The mouth is a vital point of entry into the human body, the health of the mouth entails mental, physical as well as social well-being. Studying diseases, microbiota and environmental conditions of the mouth is important to maintain oral health and all body. The smoke of tobacco cigarettes is one of the worst habits that affect the health of the mouth and the body. Therefore, this review has been conducted to study the effect of smoking on the balance of the oral microbiota and the opportunistic organisms, one of the most important of them &lt;i&gt;Candida&lt;/i&gt;. Although a few studies have found that cigarette smoking does not influence carriage by &lt;i&gt;Candida&lt;/i&gt; significantly. However, most of the studies had results completely contrary to that, smoking cigarettes affect &lt;i&gt;Candida&lt;/i&gt; pathogenic characteristics such as a transition from yeast to hyphal form, biofilm formation and, virulence-related gene expressions. Tobacco is not only an inducer of the transition process but it considers an excellent medium for this process. Furthermore, smoking was significantly associated with &lt;i&gt;Candida&lt;/i&gt; pathogenicity in patients with clinically suspected oral leukoplakia and smoking worsens oral candidiasis and dampens epithelial cell defense response. Nicotine significantly altered the composition and proportion of yeast cells, as well as the extracellular polysaccharide amounts which increase biofilm matrix and thickness which could promote oral candidiasis. Smoking has the potential to alter the oral condition and cause severe oxidative stress, thereby damaging the epithelial barrier of the mouth. These oxidative molecules during smoking activate epithelial cells proteins called oxidative stress-sensing proteins. If some of these proteins induced, widely thought to have anti-inflammatory properties, inhibit the secretion of pro-inflammatory cytokines and are linked to inflammation and oxidative stress is thought to be a possible therapeutic objective and a crucial regulator for smoking-related oral diseases and mouth candidiasis for instance leukoplakia. Also, it is transported into the cell nucleus in the existence of additional electrophilic chemicals to activate antioxidant enzyme gene expression. Therefore, smoking cigarettes destroys oral health and consequently destroys the health of the whole body.

A Current Overview of Cyclodextrin-Based Nanocarriers for Enhanced Antifungal Delivery

Fungal infections are an extremely serious health problem, particularly in patients with compromised immune systems. Most antifungal agents have low aqueous solubility, which may hamper their bioavailability. Their complexation with cyclodextrins (CDs) could increase the solubility of antifungals, facilitating their antifungal efficacy. Nanoparticulate systems are promising carriers for antifungal delivery due to their ability to overcome the drawbacks of conventional dosage forms. CD-based nanocarriers could form beneficial combinations of CDs and nanoparticulate platforms. These systems have synergistic or additive effects regarding improved drug loading, enhanced chemical stability, and enhanced drug permeation through membranes, thereby increasing the bioavailability of drugs. Here, an application of CD in antifungal drug formulations is reviewed. CD-based nanocarriers, such as nanoparticles, liposomes, nanoemulsions, nanofibers, and in situ gels, enhancing antifungal activity in a controlled-release manner and possessing good toxicological profiles, are described. Additionally, the examples of current, updated CD-based nanocarriers loaded with antifungal drugs for delivery by various routes of administration are discussed and summarized.

Growth Performance and Recovery of Nosocomial Aspergillus spp. in Blood Culture Bottles

Theoretically, Aspergillus spp. grow in culture media, but frequently, blood cultures of patients with invasive Aspergillosis are negative, even if until now, the reasons are not clear. This aspect underlines the lack of a good strategy for the cultivation and isolation of Aspergillus spp. In order to develop a complete analytical method to detect Aspergillus in clinical and pharmaceutical samples, we investigated the growth performance of two blood culture systems versus the pharmacopeia standard method. At <72 h, all test systems showed comparable sensitivity, about 1−2 conidia. However, the subculture analysis showed a suboptimal recovery for the methods, despite the positive growth and the visualization of the “Aspergillus balls” in the culture media. To investigate this issue, we studied three different subculture approaches: (i) the use of a sterile subculture unit, (ii) the use of a sterile subculture unit and the collection of a larger aliquot (100 µL), following vigorous agitation of the vials, and (iii) to decapsulate the bottle, withdrawing and centrifuging the sample, and aliquot the pellet onto SDA plates. Our results showed that only the third procedure recovered Aspergillus from all positive culture bottles. This work confirmed that our strategy is a valid and faster method to culture and isolate Aspergillus spp. from blood culture bottles.

Medical Mycology dissertation topics require prioritisation among Postgraduate Microbiology trainees of Makerere University, Uganda

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Only 5 (3.3%) of the postgraduate dissertations were on medical mycology.

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Cryptococcal meningitis (40%, n = 2) was the most researched topic.

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The most common method for studying fungal diseases was culture (60%, n = 3).

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There is limited research on medical mycology at Makerere University, Uganda.

Background

Objective

Methods

Results

Conclusion

Posaconazole oral suspension for secondary antifungal prophylaxis in allogeneic stem cell transplantation recipients: a retrospective study

Background

There is no consensus on the optimal secondary antifungal prophylaxis (SAP) regimen in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT). The purpose of this study was to evaluate the efficacy and safety of posaconazole oral suspension as secondary prophylaxis of invasive fungal disease (IFD) for allo-HSCT patients.

Methods

We retrospectively reviewed clinical data from prior IFD patients who received posaconazole oral suspension as systemic antifungal prophylaxis between June 2016 and January 2021 and have a follow-up period of 1 year after HSCT. The clinical outcomes of patients with a prior history of IFD (n = 30) and those without (n = 93) were compared.

Results

The 1-year cumulative incidence of prophylaxis failure was 58.3% in the group with prior history of IFD and 41.6% in the group without a prior history of IFD (p = 0.459). The cumulative incidence of proven, probable or possible IFD within 1 year after allo-HSCT was 23.1% in the group with prior history of IFD and 14.1% in the group without prior history of IFD (p = 0.230). There was no significant difference between the cumulative incidence of proven or probable IFD within 1-year after allo-HSCT in the group with a prior history of IFD and the group without (p = 0.807). Multivariate logistic regression revealed cytomegalovirus disease as risk factor for post-transplantation IFD occurrence in posaconazole oral suspension prophylaxis. There was not a significant difference in overall survival between the patients with IFD history and those without (P = 0.559).

Conclusions

Our study support that allo-HSCT recipients with a prior history of IFD and normal GI absorption can choose posaconazole oral suspension as a safe and effective SAP option.

Invasive Aspergillus outbreak in inhalation injury: a case presentation and literature review

Background

Invasive pulmonary aspergillosis often occurs in patients with poor immune function, who abuse steroids or broad-spectrum antibiotics, or who use intravenous drugs. Among the Aspergillus genus of pulmonary infection, Aspergillus fumigatus is the most important pathogen, followed by Aspergillus flavus, Aspergillus niger, and Aspergillus terreus. Inhalation injury complicated by Aspergillus infection has atypical clinical manifestations. Diagnosis is difficult, and it is easy to make mistakes in treatment. Moreover, there are few cases of burn inhalation injury complicated with pulmonary Aspergillus.

Case presentation

We report a case of severe burns combined with severe inhalation injury, early pulmonary aspergillosis, and severe respiratory failure due to treatment discontinuation. Through analyzing the processes of diagnosis and treatment in the present case and performing a literature review, we explore feasible diagnosis and treatment plans.

Conclusions

Early application of a variety of diagnostic measures can be used to identify Aspergillus infection, and targeted anti-infection treatment is likely to reverse a severe adverse prognosis.

Non-Dermatophyte Mold Dominated Onychomycosis in Patients Attending a Rank Higher Specialized Dermatology Clinic in Addis Ababa, Ethiopia

Background

Onychomycosis is a common refractory fungal infection associated with significant morbidity. The objective of this study was to determine the prevalence of onychomycosis, and the diversity and species composition of fungal etiological agents.

Materials and Methods

A clinic-based, prospective, non-randomized cross-sectional study was carried out between October 2018 and June 2019 at Rank Higher Specialized Dermatology Clinic, Addis Ababa, Ethiopia. Nail scrapings were collected aseptically from 200 patients clinically identified with nail disorders of fungal origin by dermatologists. Fungal etiological agents were identified microscopically and by culture method following standard procedures.

Results

Among 200 nail scrapings, 161 (80.5%) samples were found out to be culture positive. Of these, 135 (83.9%) samples yielded single colonies while 26 (16.1%) mixed colonies gave a total of 190 isolates. Among the isolates, 25.8% were dermatophytes while 61.1% were non- dermatophytes molds, and 13.1% were yeasts. Females were more likely to present dystrophic nails than men. Patients in the middle age group were more affected. Trichophyton interdigitale, Aspergillus spp, and Candida albicans were the dominant species.

Conclusion

The prevalence rate of onychomycosis in the present study was high. The isolation rate of non-dermatophyte molds was higher than dermatophytes and yeasts. Trichophyton interdigitale, Aspergillus spp, and Candida albicans were the dominant etiological agents. Females and patients in the middle age group were more affected. An increase in the prevalence of non-dermatophyte molds in nail infections dictates further investigation demonstrating how this group of fungi causes onychomycosis.

Characterization of Aspergillus nidulans Biofilm Formation and Structure and Their Inhibition by Pea Defensin Psd2

Approximately four million people contract fungal infections every year in Brazil, primarily caused by Aspergillus spp. The ability of these fungi to form biofilms in tissues and medical devices complicates treatment and contributes to high rates of morbidity and mortality in immunocompromised patients. Psd2 is a pea defensin of 5.4 kDa that possesses good antifungal activity against planktonic cells of representative pathogenic fungi. Its function depends on interactions with membrane and cell wall lipid components such as glucosylceramide and ergosterol. In the present study, we characterized Aspergillus nidulans biofilm formation and determined the effect of Psd2 on A. nidulans biofilms. After 4 hours, A. nidulans conidia adhered to polystyrene surfaces and formed a robust extracellular matrix-producing biofilm at 24 h, increasing thickness until 48 h Psd2 inhibited A. nidulans biofilm formation in a dose-dependent manner. Most notably, at 10 μM Psd2 inhibited 50% of biofilm viability and biomass and 40% of extracellular matrix production. Psd2 significantly decreased the colonized surface area by the biofilm and changed its level of organization, causing a shortening of length and diameter of hyphae and inhibition of conidiophore formation. This activity against A. nidulans biofilm suggests a potential use of Psd2 as a prototype to design new antifungal agents to prevent biofilm formation by A. nidulans and related species.

Development of a Sensitive and Specific Novel qPCR Assay for Simultaneous Detection and Differentiation of Mucormycosis and Aspergillosis by Melting Curve Analysis

Molecular diagnostic assays can expedite the diagnosis of fungal infections, and subsequently help in early interventions and appropriate management of patients. The aim of this study was to develop a single set of primers for a real-time quantitative polymerase chain reaction (qPCR) assay to detect and identify commonly reported, clinically relevant molds i.e., Aspergillus spp, Mucorales and Fusarium spp., up to genus level by melting curve analysis. This assay was evaluated in whole blood from patients with suspected invasive aspergillosis (IA), and in tissue biopsy, bronchoalveolar lavage (BAL) fluid and other site-specific samples from patients with suspected invasive mucormycosis (IM). The limit of detection (LoD) was determined as 10 copies/μl for all three molds. The mean coefficient of variation (CV) across all sets of intra- and inter-assay data was 0.63% (ranging from 0.42 to 1.56%), showing high reproducibility of the assay. Sensitivity and specificity of the assay were 93.3 and 97.1% respectively for diagnosis of IA, and 99.29 and 83.84% respectively for diagnosis of IM. Fusarium was not detected in any of the clinical samples included and the few laboratory confirmed cases of fusariosis did not meet the inclusion criteria of the study. Hence no ROC curve or cutoff value could be generated for the same. This newly developed qPCR assay therefore appears to be a promising tool in detection of IA and IM.

Molecular characterisation of Candida auris isolates from immunocompromised patients in a tertiary-care hospital in Kuwait reveals a novel mutation in FKS1 conferring reduced susceptibility to echinocandins

BACKGROUND

Candida auris is an emerging, potentially multidrug-resistant pathogen that exhibits clade-specific resistance to fluconazole and also develops resistance to echinocandins and amphotericin B easily. This study analysed 49 C auris isolates for alterations in hotspot-1 and hotspot-2 of FKS1 for the detection of mutations conferring reduced susceptibility to echinocandins.

METHODS

C auris isolates (n = 49) obtained from 18 immunocompromised patients during June 2016-December 2018 were analysed. Antifungal susceptibility testing was performed by Etest and broth microdilution-based MICRONAUT-AM assay. Mutations in hotspot-1 and hotspot-2 regions of FKS1 were detected by PCR sequencing and fingerprinting of the isolates was done by short tandem repeat typing.

RESULTS

The patients had multiple comorbidities/risk factors for Candida spp. infection including cancer/leukaemia/lymphoma/myeloma (n = 16), arterial/central line (n = 17), urinary catheter (n = 17), mechanical ventilation (n = 14) and major surgery (n = 9) and received antifungal drugs as prophylaxis and/or empiric treatment. Seven patients developed C auris candidemia/breakthrough candidemia, nine patients had candiduria with/without candidemia and four patients developed surgical site/respiratory infection. Resistance to fluconazole and amphotericin B was detected in 44 and four isolates, respectively. Twelve C auris isolates from eight patients showed reduced susceptibility to echinocandins. Seven isolates contained hostspot-1 mutations and three isolates from a candidemia patient contained R1354H mutation in hotspot-2 of FKS1. Ten patients died, five were cured, two were lost to follow-up and treatment details for one patient were not available.

CONCLUSIONS

Our findings describe development of a novel mutation in FKS1 conferring reduced susceptibility to echinocandins in one patient during treatment and unfavourable clinical outcome for many C auris-infected patients.

Recent advances in fungal serine protease inhibitors

Four types of antifungal drugs are available that include inhibitors of ergosterol synthesis, of fungal RNA biosynthesis, and of cell wall biosynthesis as well as physiochemical regulators of fungal membrane sterols. Increasing resistance to antifungal drugs can severely limit treatment options of fungal nail infections, vaginal candidiasis, ringworm, blastomycosis, histoplasmosis, and Candida infections of the mouth, throat, and esophagus, among other infections. Development of strategies focused on new fungicides can effectively help tackle troublesome fungal diseases. The virulence and optimal growth of fungi depend on various extracellular secreted factors, among which proteases, such as serine proteases, are of particular interest. A specific extracellular proteolytic system enables fungi to survive and penetrate the tissues. Given the role of fungal proteases in infection, any molecule capable of selectively and specifically inhibiting their activity can lead to the development of potential drugs. Owing to their specific mode of action, fungal protease inhibitors can avoid fungal resistance observed with currently available treatments. Although fungal secreted proteases have been extensively studied as potential virulence factors, our understanding of the substrate specificity of such proteases remains poor. In this review, we summarize the recent advances in the design and development of specific serine protease inhibitors and provide a brief history of the compounds that inhibit fungal serine protease activity.

Effect of Cannabis Smoke Condensate on C. albicans Growth and Biofilm Formation

The most common use of cannabis is smoking. The oral ecosystem, among other constituents, can be deregulated by the presence of cannabis smoke in the oral cavity. We evaluated the effect of cannabis smoke condensate (CSC) on the behavior of Candida albicans, a common yeast found in the oral cavity. The yeast was first cultured with different concentrations of CSC, and its growth was evaluated. The transition from the blastospore to the hyphal form and the hyphae size were assessed after 3 and 6 h, along with biofilm formation after 72 h of contact with CSC. The response of C. albicans to oxidative (H₂O₂) stress was also examined. Our results show that CSC contained high amounts of THC (about 1055 ppm), CBN (63 ppm), and CBG (about 47 ppm). The presence of various concentrations of CSC in the culture medium increased C. albicans growth. CSC also contributed to increases in both the hyphal length and biofilm mass. Following oxidative stress (H₂O₂ at either 100 or 500 μM), CSC prevented the damaging effect of H₂O₂ on both C. albicans shape and growth. These findings support clinical observations demonstrating that cannabis may promote C. albicans growth and oral candidiasis.

Structure of the hexameric fungal plasma membrane proton pump in its autoinhibited state

The fungal plasma membrane H+-ATPase Pma1 is a vital enzyme, generating a proton-motive force that drives the import of essential nutrients. Autoinhibited Pma1 hexamers in the plasma membrane of starving fungi are activated by glucose signaling and subsequent phosphorylation of the autoinhibitory domain. As related P-type adenosine triphosphatases (ATPases) are not known to oligomerize, the physiological relevance of Pma1 hexamers remained unknown. We have determined the structure of hexameric Pma1 from Neurospora crassa by electron cryo-microscopy at 3.3-Å resolution, elucidating the molecular basis for hexamer formation and autoinhibition and providing a basis for structure-based drug development. Coarse-grained molecular dynamics simulations in a lipid bilayer suggest lipid-mediated contacts between monomers and a substantial protein-induced membrane deformation that could act as a proton-attracting funnel.

The Flo Adhesin Family

The first step in the infection of fungal pathogens in humans is the adhesion of the pathogen to host tissue cells or abiotic surfaces such as catheters and implants. One of the main players involved in this are the expressed cell wall adhesins. Here, we review the Flo adhesin family and their involvement in the adhesion of these yeasts during human infections. Firstly, we redefined the Flo adhesin family based on the domain architectures that are present in the Flo adhesins and their functions, and set up a new classification of Flo adhesins. Next, the structure, function, and adhesion mechanisms of the Flo adhesins whose structure has been solved are discussed in detail. Finally, we identified from Pfam database datamining yeasts that could express Flo adhesins and are encountered in human infections and their adhesin architectures. These yeasts are discussed in relation to their adhesion characteristics and involvement in infections.

Photofungizides Based on Curcumin and Derivates Thereof against Candida albicans and Aspergillus niger

Fungal infections in humans, contamination of food and structural damage to buildings by fungi are associated with high costs for the general public. In addition, the increase in antifungal resistance towards conventional treatment raises the demand for new fungicidal methods. Here, we present the antifungal use of Photodynamic Inactivation (PDI) based on the natural photosensitizer curcumin and a water-soluble positively charged derivative thereof (SA-CUR 12a) against two different model organisms; Candida albicans grown in a liquid culture and photo treated with a 435 nm LED light followed by counting of the colony-forming units and photoinactivation of tissue-like hyphal spheres of Aspergillus niger (diameter ~5 mm) with subsequent monitoring of colony growth. Curcumin (50 µM, no incubation period, i.p.) supplemented with 10% or 0.5% DMSO as well as SA-CUR 12a (50 µM no i.p or 5 min i.p.) triggered a photoantifungal effect of >4 log units towards C. albicans. At 100 µM, SA-CUR 12a (0 min or 5 min i.p.) achieved a reduction of >6 log units. Colonies of A. niger shrunk significantly during PDI treatment. Photoinactivation with 50 µM or 100 µM curcumin (+0.5% DMSO) resulted in complete growth inhibition. PDI using 20, 50 or 100 µM SA-CUR 12a (with or without 10% DMSO) also showed a significant reduction in colony area compared to the control after 48 h, although less pronounced compared to curcumin. In summary, PDI using curcumin or SA-CUR 12a against C. albicans or A. niger is a promising alternative to currently used fungicides, with the advantage of being very unlikely to induce resistance.

Multicenter evaluation of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy-based method for rapid identification of clinically relevant yeasts

Fourier transform infrared (FTIR) spectroscopy has demonstrated applicability as a reagent-free whole-organism fingerprinting technique for both microbial identification and strain typing. For routine application of this technique in microbiology laboratories, acquisition of FTIR spectra in the attenuated total reflectance (ATR) mode simplifies the FTIR spectroscopy workflow, providing results within minutes after initial culture without prior sample preparation. In our previous central work, 99.7% correct species identification of clinically relevant yeasts was achieved by employing an ATR-FTIR-based method and spectral database developed by our group. In this study, ATR-FTIR spectrometers were placed in 6 clinical microbiology laboratories over a 16-month period and were used to collect spectra of routine yeast isolates for on-site identification to the species level. The identification results were compared to those obtained from conventional biochemical tests and/or matrix-assisted laser desorption/ionization time of flight mass spectrometry. Isolates producing discordant results were reanalyzed by routine identification methods, ATR-FTIR spectroscopy and PCR gene sequencing of the D1/D2 and ITS regions. Among the 573 routine clinical yeast isolates collected and identified by the ATR-FTIR-based method, 564 isolates (98.4%) were correctly identified at the species level while the remaining isolates were inconclusive with no misidentifications. Due to the low prevalence of Candida auris in routine isolates, additional randomly selected C. auris (n = 24) isolates were obtained for evaluation and resulted in 100% correct identification. Overall, the data obtained in our multicenter evaluation study using multiple spectrometers and system operators indicate that ATR-FTIR spectroscopy is a reliable, cost-effective yeast identification technique that provides accurate and timely (∼3 minutes/sample) species identification promptly after the initial culture.

Prophylactic vaccine delivery systems against epidemic infectious diseases

Prophylactic vaccines have evolved from traditional whole-cell vaccines to safer subunit vaccines. However, subunit vaccines still face problems, such as poor immunogenicity and low efficiency, while traditional adjuvants are usually unable to meet specific response needs. Advanced delivery vectors are important to overcome these barriers; they have favorable safety and effectiveness, tunable properties, precise location, and immunomodulatory capabilities. Nevertheless, there has been no systematic summary of the delivery systems to cover a wide range of infectious pathogens. We herein summarized and compared the delivery systems for major or epidemic infectious diseases caused by bacteria, viruses, fungi, and parasites. We also included the newly licensed vaccines (e.g., COVID-19 vaccines) and those close to licensure. Furthermore, we highlighted advanced delivery systems with high efficiency, cross-protection, or long-term protection against epidemic pathogens, and we put forward prospects and thoughts on the development of future prophylactic vaccines.

Epidemiology of Candidemia in Kuwait: A Nationwide, Population-Based Study

The Candida species cause a majority of invasive fungal infections. In this article, we describe the nationwide epidemiology of candidemia in Kuwait in 2018. Yeast bloodstream isolates submitted from all major hospitals and identified by phenotypic MALDI-TOF MS and/or by molecular methods were studied. Susceptibility testing was performed by Etest. Out of 313 bloodstream yeasts, 239 Candida spp. isolates (excluding duplicate isolates) were obtained during 234 candidemic episodes among 223 patients. Mixed-species candidemia and re-infection occurred in 5 and 11 patients, respectively. C. albicans (n = 74), C. parapsilosis (n = 54), C. tropicalis (n = 35), C. auris (n = 33), C. glabrata (n = 32), other Candida spp. (n = 11), and other yeasts (n = 9) caused fungemia. Nearly 50% of patients were in intensive care units. Candida spp. isolates (except C. glabrata) were susceptible to caspofungin and 27% of C. auris were amphotericin B-resistant. Resistance to fluconazole was 100% in C. auris, 17% in C. parapsilosis, 12% in C. glabrata, and 1% in C. albicans. Mortality was 47% for other Candida/yeast infections. Nationwide candidemia incidence in 2018 was 5.29 cases/100,000 inhabitants. Changes in species spectrum, increasing fluconazole resistance in C. parapsilosis, and the emergence of C. auris as a major pathogen in Kuwait are noteworthy findings. The data could be of help in informing decisions regarding planning, in the allocation of resources, and in antimicrobial stewardship.

Bloodstream infection by Saccharomyces cerevisiae in a COVID-19 patient receiving probiotic supplementation in the ICU in Brazil

Care-related infections (CRIs) have a negative impact on the morbidity and mortality of patients in intensive care. Among them, fungal infections (e.g. Candida spp. and Aspergillus spp.) have high mortality in critically ill patients, particularly those with acute respiratory distress syndrome (ARDS) and immunosuppression. Coronavirus disease 2019 (COVID-19) causes severe respiratory changes and deregulation of the immune system. Here, we describe a case of fungal infection in an intensive care unit (ICU) patient with COVID-19 caused by Saccharomyces cerevisiae, a yeast widely used in the baking and wine production industries. It is also used as a probiotic, both for prevention and as adjunctive therapy in patients with diarrhoea. The patient was admitted to the ICU with a diagnosis of COVID-19, respiratory failure, complications of ARDS and renal failure, and was being treated with antibiotics and vasoactive amines. Later, the patient had diarrhoea and, after supplementation with Saccharomyces, he developed a bloodstream infection with Saccharomyces. The patient died after 61 days of hospitalization due to thrombocytopenia and bleeding. This case report suggests avoiding the use of probiotics in intensive care patients under the administration of antibiotics and amines, and with damage to the intestinal mucosa and immunodeficiency caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), since these factors could favour the translocation of fungi.

Highly specific and rapid molecular detection of Candida glabrata in clinical samples

The most common nosocomial fungal infections are caused by several species of Candida, of which Candida glabrata is the second most frequently isolated species from bloodstream infections. C. glabrata displays relatively high minimal inhibitory concentration values (MIC) to the antifungal fluconazole and is associated with high mortality rates. To decrease mortality rates, the appropriate treatment must be administered promptly. C. glabrata contains in its genome several non-identical copies of species-specific sequences. We designed three pairs of C. glabrata-specific primers for endpoint PCR amplification that align to these species-specific sequences and amplify the different copies in the genome. Using these primers, we developed a fast, sensitive, inexpensive, and highly specific PCR-based method to positively detect C. glabrata DNA in a concentration-dependent manner from mixes of purified genomic DNA of several Candida species, as well as from hemocultures and urine clinical samples. This tool can be used for positive identification of C. glabrata in the clinic.

A 20-Year Antifungal Susceptibility Surveillance (From 1999 to 2019) for Aspergillus spp. and Proposed Epidemiological Cutoff Values for Aspergillus fumigatus and Aspergillus flavus: A Study in a Tertiary Hospital in China

The emergence of resistant Aspergillus spp. is increasing worldwide. Long-term susceptibility surveillance for clinically isolated Aspergillus spp. strains is warranted for understanding the dynamic change in susceptibility and monitoring the emergence of resistance. Additionally, neither clinical breakpoints (CBPs) nor epidemiological cutoff values (ECVs) for Aspergillus spp. in China have been established. In this study, we performed a 20-year antifungal susceptibility surveillance for 706 isolates of Aspergillus spp. in a clinical laboratory at Peking University First Hospital from 1999 to 2019; and in vitro antifungal susceptibility to triazoles, caspofungin, and amphotericin B was determined by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. It was observed that Aspergillus fumigatus was the most common species, followed by Aspergillus flavus and Aspergillus terreus. Forty isolates (5.7%), including A. fumigatus, A. flavus, A. terreus, Aspergillus niger, and Aspergillus nidulans, were classified as non-wild type (non-WT). Importantly, multidrug resistance was observed among A. flavus, A. terreus, and A. niger isolates. Cyp51A mutations were characterized for 19 non-WT A. fumigatus isolates, and TR34/L98H/S297T/F495I was the most prevalent mutation during the 20-year surveillance period. The overall resistance trend of A. fumigatus increased over 20 years in China. Furthermore, based on ECV establishment principles, proposed ECVs for A. fumigatus and A. flavus were established using gathered minimum inhibitory concentration (MIC)/minimum effective concentration (MEC) data. Consequently, all the proposed ECVs were identical to the CLSI ECVs, with the exception of itraconazole against A. flavus, resulting in a decrease in the non-WT rate from 6.0 to 0.6%.

Culture Cell Block Controls as a Tool to the Biomolecular Diagnosis of Infectious Diseases

The cell block (CB) technique has allowed easy obtainment of samples such as cellular and culture suspensions, to perform specific molecular tests such as immunohistochemistry and in situ hybridization. It has been improved along time, accuracy, and quality of the diagnoses, however, the cost of a commercial gel matrix for the preparation of CB is high and not suitable depending on the situation. The objective of this study is to test agarose as an alternative to the commercial gel matrix in the preparation of Aspergillus fumigatus' CB.

Challenges and Opportunities in Understanding Genetics of Fungal Diseases: Towards a Functional Genomics Approach

Infectious diseases are a leading cause of morbidity and mortality worldwide, and human pathogens have long been recognized as one of the main sources of evolutionary pressure, resulting in a high variable genetic background in immune-related genes. The study of the genetic contribution to infectious diseases has undergone tremendous advances over the last decades. Here, focusing on genetic predisposition to fungal diseases, we provide an overview of the available approaches for studying human genetic susceptibility to infections, reviewing current methodological and practical limitations. We describe how the classical methods available, such as family-based studies and candidate gene studies, have contributed to the discovery of crucial susceptibility factors for fungal infections. We will also discuss the contribution of novel unbiased approaches to the field, highlighting their success but also their limitations for the fungal immunology field. Finally, we show how a systems genomics approach can overcome those limitations and can lead to efficient prioritization and identification of genes and pathways with a critical role in susceptibility to fungal diseases. This knowledge will help to stratify at-risk patient groups and, subsequently, develop early appropriate prophylactic and treatment strategies.

Impact of antifungal stewardship interventions on the susceptibility of colonized Candida species in pediatric patients with malignancy

There is a worldwide concern regarding the antimicrobial resistance and the inappropriate use of antifungal agents, which had led to an ever-increasing antifungal resistance. This study aimed to identify the antifungal susceptibility of colonized Candida species isolated from pediatric patients with cancer and evaluate the clinical impact of antifungal stewardship (AFS) interventions on the antifungal susceptibility of colonized Candida species. Candida species colonization was evaluated among hospitalized children with cancer in a tertiary teaching hospital, Shiraz 2017–2018. Samples were collected from the mouth, nose, urine, and stool of the patients admitted to our center and cultured on sabouraud dextrose agar. The isolated yeasts identified by polymerase chain reaction–restriction fragment length polymorphisms (PCR–RFLP). DNA Extracted and PCR amplification was performed using the ITS1 and ITS4 primer pairs and Msp I enzyme. The broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) for amphotericin B, caspofungin, and azoles. The prevalence of Candida albicans in the present study was significantly higher than other Candida species. Candida albicans species were completely susceptible to the azoles. The susceptibility rate of C. albicans to amphotericin B and caspofungin was 93.1% and 97.1%, respectively. The fluconazole MIC values of Candida albicans decreased significantly during the post-AFS period (P < 0.001; mean difference: 72.3; 95% CI of the difference: 47.36–98.62). We found that ‏52.5% (53/117) of the isolated C. albicans were azole-resistant before AFS implementation, while only 1.5% (2/102) of the isolates were resistant after implementation of the AFS program (P < 0.001). C. albicans fluconazole and caspofungin resistant rate also decreased significantly (P < 0.001) after implementation of the AFS program [26 (32.9%) versus 0 (0.0%) and 11 (10.9%) versus 1 (0.9%), respectively]. Besides, fluconazole use (p < 0.05) and fluconazole expenditure reduced significantly (about one thousand US$ per year) after the AFS program. Our results confirm the positive effect of optimized antifungal usage and bedside intervention on the susceptibility of Candida species after the implementation of the AFS program. C. albicans and C. glabrata exhibited a significant increase in susceptibility after the execution of the AFS program.

Pattern recognition receptors as therapeutic targets for bacterial, viral and fungal sepsis

Sepsis remains to be a significant health care problem associated with high morbidities and mortalities. Recognizing its heterogeneity, it is critical to understand our host immunological responses to develop appropriate therapeutic approaches according to the type of sepsis. Because pattern recognition receptors are largely responsible for the recognition of microbes, we reviewed their role in immunological responses in the setting of bacterial, fungal and viral sepsis. We also considered their therapeutic potentials in sepsis.

Deciphering the epidemiology of invasive candidiasis in the intensive care unit: is it possible?

Invasive candidiasis (IC) has emerged in the last decades as an important cause of morbidity, mortality, and economic load in the intensive care unit (ICU). The epidemiology of IC is still a difficult and unsolved enigma for the literature. Accurate estimation of the true burden of IC is difficult due to variation in definitions and limitations inherent to available case-finding methodologies. Candidemia and intra-abdominal candidiasis (IAC) are the two predominant types of IC in ICU. During the last two decades, an increase in the incidence of candidemia has been constantly reported particularly in the expanding populations of elderly or immunosuppressed patents, with a parallel change in Candida species (spp.) distribution worldwide. Epidemiological shift in non-albicans spp. has reached worrisome trends. Recently, a novel, multidrug-resistant Candida spp., Candida auris, has globally emerged as a nosocomial pathogen causing a broad range of healthcare-associated invasive infections. Epidemiological profile of IAC remains imprecise. Though antifungal drugs are available for Candida infections, mortality rates continue to be high, estimated to be up to 50%. Increased use of fluconazole and echinocandins has been associated with the emergence of resistance to these drugs, which affects particularly C. albicans and C. glabrata. Crucial priorities for clinicians are to recognize the epidemiological trends of IC as well as the emergence of resistance to antifungal agents to improve diagnostic techniques and strategies, develop international surveillance networks and antifungal stewardship programmes for a better epidemiological control of IC.

In Vitro Confirmation of Siramesine as a Novel Antifungal Agent with In Silico Lead Proposals of Structurally Related Antifungals

The limited number of medicinal products available to treat of fungal infections makes control of fungal pathogens problematic, especially since the number of fungal resistance incidents increases. Given the high costs and slow development of new antifungal treatment options, repurposing of already known compounds is one of the proposed strategies. The objective of this study was to perform in vitro experimental tests of already identified lead compounds in our previous in silico drug repurposing study, which had been conducted on the known Drugbank database using a seven-step procedure which includes machine learning and molecular docking. This study identifies siramesine as a novel antifungal agent. This novel indication was confirmed through in vitro testing using several yeast species and one mold. The results showed susceptibility of Candida species to siramesine with MIC at concentration 12.5 µg/mL, whereas other candidates had no antifungal activity. Siramesine was also effective against in vitro biofilm formation and already formed biofilm was reduced following 24 h treatment with a MBEC range of 50-62.5 µg/mL. Siramesine is involved in modulation of ergosterol biosynthesis in vitro, which indicates it is a potential target for its antifungal activity. This implicates the possibility of siramesine repurposing, especially since there are already published data about nontoxicity. Following our in vitro results, we provide additional in depth in silico analysis of siramesine and compounds structurally similar to siramesine, providing an extended lead set for further preclinical and clinical investigation, which is needed to clearly define molecular targets and to elucidate its in vivo effectiveness as well.