Nosocomial Fungal Infections

Antibiotic resistance of bioaerosols in particulate matter from indoor environments of the hospitals in Dhaka Bangladesh

The emergence and spread of antibiotic resistance in microorganisms pose significant challenges to public health, especially in hospitals. This study investigated the existence or occurrence of bacterial bioaerosol and their antibiotic resistance patterns in particulate matter (PM) collected from hospitals in the greater Dhaka region, Bangladesh. The real-time particulate matter concentrations (PM1.0, PM2.5, and PM10) were measured in four hospitals and two ambient locations. Air sampling was conducted using a filter-based method with a low-volume air sampler, while AEROCET-531 S (USA) was employed to monitor particulate matter concentrations. Bacterial bioaerosol concentration was determined using a culture-based method, and eleven bacterial species, including nine individual species, i.e., Staphylococcus aureus, Pseudomonas aeruginosa, P. stutzeri, Bacillus cereus, Acinetobacter schindleri, Proteus vulgaris, B. subtilis, Escherichia coli, and B. aerius, were isolated. Antibiotic susceptibility testing was conducted using the Kirby-Bauer disk diffusion method with 21 antibiotics. Bacterial isolates were detected using partial sequencing of the 16 S rRNA gene. Bioaerosol concentration ranged from 194.65 ± 22.48 CFU/m3 to 948.39 ± 84.14 CFU/m3, showing significant correlations with PM1.0 and PM2.5 concentrations (R2 = 0.80 and 0.85, respectively). All bacterial isolates collected from the hospitals exhibited resistance against four or more antibiotics, indicating multidrug resistance (MDR). Notably, the bacterial isolates displayed the highest resistance rate against ampicillin (90.90%), azithromycin (81.81%), erythromycin (81.81%), cefixime (81.81%), and cotrimoxazole (54.54%), among the tested antibiotics. Except B. aerius, all other bacterial isolates were associated with hospital-acquired infections (HAIs). These findings highlight the high rates of antibiotic resistance, underscoring the pressing requirement for infection control measures and continuous surveillance strategies in hospital settings. These findings emphasize the necessity for global hospital infection control strategies focusing airborne multidrug-resistant microorganisms.

Anti-fungal peptides: an emerging category with enthralling therapeutic prospects in the treatment of candidiasis

Candida infections, particularly invasive candidiasis, pose a serious global health threat. Candida albicans is the most prevalent species causing candidiasis, and resistance to key antifungal drugs, such as azoles, echinocandins, polyenes, and fluoropyrimidines, has emerged. This growing multidrug resistance (MDR) complicates treatment options, highlighting the need for novel therapeutic approaches. Antifungal peptides (AFPs) are gaining recognition for their potential as new antifungal agents due to their diverse structures and functions. These natural or recombinant peptides can effectively target fungal virulence and viability, making them promising candidates for future antifungal development. This review examines infections caused by Candida species, the limitations of current antifungal treatments, and the therapeutic potential of AFPs. It emphasizes the importance of identifying novel AFP targets and their production for advancing treatment strategies. By discussing the therapeutic development of AFPs, the review aims to draw researchers' attention to this promising field. The integration of knowledge about AFPs could pave the way for novel antifungal agents with broad-spectrum activity, reduced toxicity, targeted action, and mechanisms that limit resistance in pathogenic fungi, offering significant advancements in antifungal therapeutics.

The Road Ahead: Advancing Antifungal Vaccines and Addressing Fungal Infections in the Post-COVID World

In impoverished nations, the COVID-19 pandemic has led to a widespread occurrence of deadly fungal diseases like mucormycosis. The limited availability of effective antifungal treatments and the emergence of drug-resistant fungal strains further exacerbate the situation. Factors such as systemic steroid use, intravenous drug misuse, and overutilization of broad-spectrum antimicrobials contribute to the prevalence of hospital-acquired infections caused by drug-resistant fungi. Fungal infections exploit compromised immune status and employ intricate mechanisms to evade immune surveillance. The immune response involves the innate and adaptive immune systems, leading to phagocytic and complement-mediated elimination of fungi. However, resistance to antifungals poses a challenge, highlighting the importance of antifungal prophylaxis and therapeutic vaccination. Understanding the host-fungal immunological interactions and developing vaccines are vital in combating fungal infections. Further research is needed to address the high mortality and morbidity associated with multidrug-resistant fungal pathogens and to develop innovative treatment drugs and vaccines. This review focuses on the global epidemiological burden of fungal infections, host-fungal immunological interactions, recent advancements in vaccine development and the road ahead.

Multi-state evaluation of Candida infections in burn patients

BACKGROUND

Burn patients are at high risk of developing secondary invasive fungal infections due to their compromised skin barrier, extensive use of antibiotics, and immunosuppression.

OBJECTIVES

We investigated demographic characteristics and clinical factors associated with Candida infections in intensive care unit (ICU) burn patients, and the in vitro antifungal susceptibility of species of isolates.

METHODS

A total of 353 burn patients admitted to three major ICUs of burn centers in Iran were evaluated between 2021 and 2023. Patients were considered as colonisation and candidemia. Demographic characteristics, burn-related factors, and clinical conditions were compared among the groups. Furthermore, we identified fungi at the species level and performed antifungal susceptibility testing according to CLSI guidelines.

RESULTS

Overall, 46.2% of patients were colonised with a Candida species, leading to candidemia in 15.3%. The most frequently isolated species from candidemia and burn wound colonisation were Candida parapsilosis (37.0%) and Candida albicans (31.9%), respectively. Risk factors linked to candidemia included larger total body surface area (TBSA) (>50%), older patients, indwelling catheters, diabetes, and an extended ICU stay. Mortality rate was higher among candidemia patients (82.5%) compared to colonised patients (7.3%). The resistance rate of the strains isolated from candidemia to fluconazole and voriconazole was 28% and 18.2%, respectively.

CONCLUSION

We found that a higher percentage of TBSA burn injuries, longer hospital stays, and catheterization are important predictors of candidemia. The mortality rate was significantly higher in people infected with non-albicans Candida species. Prevention and treatment strategies for candidemia should be based on updated, regional epidemiological data.

Compilation of regulations and procedures for monitoring filamentous fungi in hospital environments

Air and surfaces in the hospital environment are a potential source of exposure to filamentous fungi (FF) that could cause invasive fungal diseases (IFD) in severely immunocompromised patients. The prevalent FF in IFD are species from the genera Aspergillus, Fusarium, Scedosporium, and those within the order Mucorales. We have compiled regulations and described the procedures used in the clinical mycology laboratory to assess the presence of FF in areas at risk for the development of IFD. The infection control committees of each establishment implement hospital policies to regulate and control processes aimed at preventing infections. Fungal load monitoring is an important step in this process to validate air quality in order to ensure a clean and protected environment for severely immunocompromised patients.

Synthesis, In Silico Study, and In Vitro Antifungal Activity of New 5-(1,3-Diphenyl-1H-Pyrazol-4-yl)-4-Tosyl-4,5-Dihydrooxazoles

The increase in multi-drug resistant Candida strains has caused a sharp rise in life-threatening fungal infections in immunosuppressed patients, including those with SARS-CoV-2. Novel antifungal drugs are needed to combat multi-drug-resistant yeasts. This study aimed to synthesize a new series of 2-oxazolines and evaluate the ligands in vitro for the inhibition of six Candida species and in silico for affinity to the CYP51 enzymes (obtained with molecular modeling and protein homology) of the same species. The 5-(1,3-diphenyl-1H-pyrazol-4-yl)-4-tosyl-4,5-dihydrooxazoles 6a-j were synthesized using the Van Leusen reaction between 1,3-diphenyl-4-formylpyrazoles 4a-j and TosMIC 5 in the presence of K2CO3 or KOH without heating, resulting in short reaction times, high compound purity, and high yields. The docking studies revealed good affinity for the active site of the CYP51 enzymes of the Candida species in the following order: 6a-j > 4a-j > fluconazole (the reference drug). The in vitro testing of the compounds against the Candida species showed lower MIC values for 6a-j than 4a-j, and for 4a-j than fluconazole, thus correlating well with the in silico findings. According to growth rescue assays, 6a-j and 4a-j (like fluconazole) inhibit ergosterol synthesis. The in silico toxicity assessment evidenced the safety of compounds 6a-j, which merit further research as possible antifungal drugs.

Environmental surveillance of fungi and susceptibility to antifungal agents in tertiary care hospitals

IMPORTANCE

Saprophytic fungi can cause nosocomial infections in high-risk patients. These infections are related to high mortality and cost. In the current study, different species of filamentous fungi and yeast were isolated from the environment of the studied hospitals. Some species were resistant to antifungal drugs. We suggest that the future work concentrates on the relationship between the level/quantification of saprophytic contamination in the environment of hospitals and fungal infections in patients.

Does Streptococcus oralis supernatant influence on the proliferation and virulence of Candida albicans?

OBJECTIVE

To evaluate the influence of Streptococcus oralis supernatant on the proliferation and virulence of Candida albicans.

DESIGN

S. oralis supernatant was obtained by filtration of overnight cultures. Single or dual-species cultures of C. albicans and S. oralis were cultivated in both planktonic and biofilm-based models. Planktonic culture growth was measured, and mature biofilms formed on resin disks were collected to measure biofilm metabolic activity, total biomass, and cell counts. Hyphae formation (virulence factor) and biofilm thickness were analyzed by confocal laser scanning microscopy. Data were analyzed by a one-way ANOVA test followed by the Tukey posthoc test (α = 0.05).

RESULTS

We found that S. oralis supernatant did not influence C. albicans proliferation in planktonic cultures. However, biofilms containing S. oralis supernatant showed higher cell metabolism than C. albicans monoculture biofilms and C. albicans-S. oralis dual-culture biofilms (p < 0.05). Though S. oralis supernatants did increase biofilm metabolic activity, they did not affect the total biomass and cell counts of C. albicans (p > 0.05). However, biofilm imaging revealed enhanced C. albicans hyphae formation in biofilms containing S. oralis supernatant compared to C. albicans monoculture biofilms.

CONCLUSIONS

Secreted metabolites in S. oralis supernatant may contribute to C. albicans metabolism and virulence.

Relationship Between Airborne Fungi Presence and the Position of the High Efficiency Particulate Air Filter in the Heating, Ventilation, and Air Conditioning System

AIM

Establish the influence of the terminal or nonterminal position of High Efficiency Particulate Air (HEPA) filters in the Heating, Ventilation, and Air Conditioning (HVAC) system on the presence of airborne fungi in controlled environment rooms.

BACKGROUND

Fungal infections are an important cause of morbidity and mortality in hospitalized patients.

METHODS

This study was realized from 2010 to 2017, in rooms with terminal and nonterminal HEPA filters, in eight Spanish hospitals. In rooms with terminal HEPA filters, 2,053 and 2,049 samples were recollected, and in rooms with nonterminal HEPA filters, 430 and 428 samples were recollected in the air discharge outlet (Point 1) and in the center of the room (Point 2), respectively. Temperature, relative humidity, air changes per hour, and differential pressure were recollected.

RESULTS

Multivariable analysis showed higher odds ratio (OR) of airborne fungi presence when HEPA filters were in nonterminal position (OR: 6.78; 95% CI [3.77, 12.20]) in Point 1 and (OR: 4.43; 95% CI [2.65, 7.40]) in Point 2. Other parameters influenced airborne fungi presence, such as temperature (OR: 1.23; 95% CI [1.06, 1.41]) in Point 2 differential pressure (OR: 0.86; 95% CI [0.84, 0.90]) and (OR: 0.88; 95% CI [0.86, 0.91]) in Points 1 and 2, respectively.

CONCLUSIONS

HEPA filter in terminal position of the HVAC system reduces the presence of airborne fungi. To decrease the presence of airborne fungi, adequate maintenance of the environmental and design parameters is necessary in addition to the terminal position of the HEPA filter.

The Clinical Characteristics of Bloodstream Infections Due to Candida spp. in Patients Hospitalized in Intensive Care Units during the SARS-CoV-2 Pandemic: The Results of a Multicenter Study

Candidemia is a serious health threat. Whether this infection has a greater incidence and a higher mortality rate in patients with COVID-19 is still debated. In this multicenter, retrospective, observational study, we aimed to identify the clinical characteristics associated with the 30-day mortality in critically ill patients with candidemia and to define the differences in candidemic patients with and without COVID-19. Over a three-year period (2019-2021), we identified 53 critically ill patients with candidemia, 18 of whom (34%) had COVID-19 and were hospitalized in four ICUs. The most frequent comorbidities were cardiovascular (42%), neurological (17%), chronic pulmonary diseases, chronic kidney failure, and solid tumors (13% each). A significantly higher proportion of COVID-19 patients had pneumonia, ARDS, septic shock, and were undergoing an ECMO procedure. On the contrary, non-COVID-19 patients had undergone previous surgeries and had used TPN more frequently. The mortality rate in the overall population was 43%: 39% and 46% in the COVID-19 and non-COVID-19 patients, respectively. The independent risk factors associated with a higher mortality were CVVH (HR 29.08 [CI 95% 3.37-250]) and a Charlson's score of > 3 (HR 9.346 [CI 95% 1.054-82.861]). In conclusion, we demonstrated that candidemia still has a high mortality rate in patients admitted to ICUs, irrespective of infection due to SARS-CoV-2.

Conjugated carbon monoxide-releasing molecules have broad-spectrum antimicrobial activity

Aim: To test the antimicrobial effect of carbon monoxide-releasing molecules (CORMs) conjugated with azoles on different microorganisms. Methods & results: We used broth microdilution, checkerboard and cytotoxicity assays, as well as imaging, fluorescence and bioluminescence experiments to study [Re(CO)3(2,2'-bipyridyl)(Ctz)]+ (also known as ReBpyCtz). ReBpyCtz exhibits a low minimum inhibitory concentration value, increases the intracellular formation of reactive oxygen species and causes significant alterations on Staphylococcus aureus's membrane. ReBpyCtz is active against fungi, having a more prolonged fungicidal effect on Candida glabrata than clotrimazole and is selectively active on blood-stage malaria parasites, at a concentration that is not toxic to kidney epithelial cells. Conclusion: Conjugated CORMs have the potential to be active against different types of pathogens, thus constituting a promising class of broad-spectrum antimicrobials.

Characterization and susceptibility of non-albicans Candida isolated from various clinical specimens in Lebanese hospitals

Background

Invasive fungal infections have presented a challenge in treatment. In the past, it was known that the frontrunner in such infections is Candida albicans with little emphasis placed on non-albicans Candida species (NAC). Studies worldwide have shown a rise in fungal infections attributed to non-albicans Candida species. The aim of this study is to describe the epidemiology of NAC infections along with an overview of resistance in Lebanese hospitals.

Methods

This is a two-year observational multi-central descriptive study. Between September 2016 and May of 2018, a total of 1000 isolates were collected from 10 different hospitals distributed all over the country. For the culture, Sabouraud Dextrose Agar was used. Antifungal Susceptibility was evaluated by determining the Minimum Inhibitory Concentration (MIC) in broth (microdilution) of the different antifungal treatments.

Results

Out of the 1000 collected isolates, Candida glabrata, being the most isolated species (40.8%), followed by Candida tropicalis: 231(23.1%), Candida parapsilosis: 103(10.3%), and other NAC species at lower percentage. Most of these isolates (88.67%) were susceptible to posaconazole, 98.22% were susceptible to micafungin, and 10% were susceptible to caspofungin.

Conclusion

The change of etiology of fungal infections involving a significant increase in NAC cases is alarming due to the different antifungal susceptibility patterns and the lack of local guidelines to guide the treatment. In this context, proper identification of such organisms is of utmost importance. The data presented here can help in establishing guidelines for the treatment of candida infections to decrease morbidity and mortality. Future surveillance data are needed.

Health risk posed by direct ingestion of yeasts from polluted river water

River water is an essential human resource that may be contaminated with hazardous microorganisms. However, the risk of yeast infection through river water exposure is unclear because it is highly dependant on individual susceptibility and has therefore not been well-studied, to date. To evaluate this undefined risk, we analysed the fungal communities in less polluted (LP) and highly polluted (HP) river water, as determined using principal coordinate analysis of pollution indicators. We enumerated culturable yeasts using a thermally selective isolation procedure (37 °C) and thus promoted the growth of potentially opportunistic species. Yeast species identified as clinically relevant were then tested for antifungal resistance. In addition, we propose a quantitative microbial risk assessment (QMRA) framework to quantitatively assess the potential risk of yeast infection. Our results indicated that pollution levels significantly altered fungal communities (p = 0.007) and that genera representing opportunistic and pathogenic members were significantly more abundant in HP waters (p = 0.038). Additionally, the yeast species Candida glabrata and Clavispora lusitaniae positively correlated with other pollution indicators, demonstrating the species' indicator potential. Our QMRA results further indicate that higher risk of infection is associated with increased water pollution levels (considering both physicochemical and bacterial indicators). Furthermore, yeast species with higher pathogenic potential present an increased risk of infection despite lower observed concentrations in the river water. Interestingly, the bloom of Meyerozyma guilliermondii during the wet season suggests that other environmental factors, such as dissolved oxygen levels and water turbulence, might affect growth characteristics of yeasts in river water, which consequently affects the distribution of annual infection risks. The presence of antifungal resistant yeasts, observed in this study, could further contribute to variation in risk distribution. Research on the ecophysiology of yeasts in these environments is therefore necessary to ameliorate the uncertainty and sensitivity of the proposed QMRA model. In addition to the vital knowledge on opportunistic and pathogenic yeast occurrence in river water and their observed association with pollution, this study provides valuable methods and insights to initiate future QMRAs of yeast infections.

Endogenous Fungal Endophthalmitis following COVID-19 Hospitalization: Evidence from a Year-Long Observational Study

PURPOSE

To describe cases of endogenous fungal endophthalmitis (EFE) post-recovery from or hospitalization for coronavirus disease 2019 (COVID-19).

METHODS

This prospective audit involved patients with suspected endophthalmitis referred to a tertiary eye care center over a one-year period. Comprehensive ocular examinations, laboratory studies, and imaging were performed. Confirmed cases of EFE with a recent history of COVID-19 hospitalization±intensive care unit admission were identified, documented, managed, followed up, and described.

RESULTS

Seven eyes of six patients were reported; 5/6 were male, and the mean age was 55. The mean duration of hospitalization for COVID-19 was approximately 28 days (14-45); the mean time from discharge to onset of visual symptoms was 22 days (0-35). All patients had underlying conditions (5/6 hypertension; 3/6 diabetes mellitus; 2/6 asthma) and had received dexamethasone and remdesivir during their COVID-related hospitalization. All presented with decreased vision, and 4/6 complained of floaters. Baseline visual acuity ranged from light perception (LP) to counting fingers (CF). The fundus was not visible in 3 out of 7 eyes; the other 4 had "creamy-white fluffy lesions" at the posterior pole as well as significant vitritis. Vitreous taps were positive for Candida species in six and Aspergillus species in one eye. Anti-fungal treatment included intravenous amphotericin B followed by oral voriconazole and intravitreal amphotericin B. Three eyes underwent vitrectomy; the systemic health of two patients precluded surgery. One patient (with aspergillosis) died; the others were followed for 7-10 months - the final visual outcome improved from CF to 20/200-20/50 in 4 eyes and worsened (hand motion to LP) or did not change (LP), in two others.

CONCLUSION

Ophthalmologists should maintain a high index of clinical suspicion for EFE in cases with visual symptoms and a history of recent COVID-19 hospitalization and/or systemic corticosteroid use - even without other well-known risk factors.

Biosynthesis of silver nanoparticles from Syzygium cumini leaves and their potential effects on odontogenic pathogens and biofilms

This study analyzed the antimicrobial and antibiofilm action and cytotoxicity of extract (HEScL) and silver nanoparticles (AgNPs-HEScL) from Syzygium cumini leaves. GC–MS, UV–Vis, EDX, FEG/SEM, DLS and zeta potential assays were used to characterize the extract or nanoparticles. Antimicrobial, antibiofilm and cytotoxicity analyses were carried out by in vitro methods: agar diffusion, microdilution and normal oral keratinocytes spontaneously immortalized (NOK-SI) cell culture. MICs of planktonic cells ranged from 31.2–250 (AgNPs-HEScL) to 1,296.8–10,375 μg/ml (HEScL) for Actinomyces naeslundii, Fusobacterium nucleatum, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Streptococcus oralis, Veillonella dispar, and Candida albicans. AgNPs-HEScL showed antibiofilm effects (125–8,000 μg/ml) toward Candida albicans, Streptococcus mutans and Streptococcus oralis, and Staphylococcus aureus and Staphylococcus epidermidis. The NOK-SI exhibited no cytotoxicity when treated with 32.8 and 680.3 μg/ml of AgNPs-HEScL and HEScL, respectively, for 5 min. The data suggest potential antimicrobial and antibiofilm action of HEScL, and more specifically, AgNPs-HEScL, involving pathogens of medical and dental interest (dose-, time- and species-dependent). The cytotoxicity of HEScL and AgNPs-HEScL detected in NOK-SI was dose- and time-dependent. This study presents toxicological information about the lyophilized ethanolic extract of S. cumini leaves, including their metallic nanoparticles, and adds scientific values to incipient studies found in the literature.

Design, Synthesis, and Biological Evaluation of Dual-Target COX-2/CYP51 Inhibitors for the Treatment of Fungal Infectious Diseases

The design of novel dual-target (COX-2/CYP51) inhibitors was proposed in the study, and three series of compounds were constructed though the pathway of skeleton screening and combination; their molecular structures were synthesized and evaluated. Most of the compounds exhibited significant antifungal ability. Among them, potential compounds (10a-2, 16b-3) with excellent antifungal and anti-drug-resistant fungal ability (MIC₅₀, 0.125-2.0 μg/mL) were selected for the subsequent mechanistic study. On the one hand, these compounds could block the ergosterol biosynthesis pathway by inhibiting CYP51 and influence the internal physiological function of fungal cells, which included the increase of the ROS level, the anomaly of ΔΨ_m, and the emergence of an apoptotic state. On the other hand, these compounds also effectively showed COX-2 inhibition ability, eliminated the inflammatory reaction of the infected region, and activated the body's immune function. In summary, this study not only provided a novel antifungal drug design pathway but also discovered excellent target compounds.

Risk Factors and Clinical Outcomes of Candidemia Associated With Severe COVID-19

COVID-19 can cause serious illness requiring multimodal treatment and is associated with secondary infections. Studies have suggested an increased risk of fungal infections, including candidemia following severe COVID-19 though understanding of risk factors and clinical outcomes remains unclear.

The discovery of novel antifungal phenylpyridines derivatives based on CYP53 binding model

Benzoates as toxic intermediate are naturally produced by fungal intracellular metabolism, and CYP53 can specific transform the substrates. In the study, we constructed the CYP53 homology model and analyzed the corresponding active region. At the same time, the molecular docking and the structure-based pharmacophore model (SBP) were performed to explore the bind mode of representative CYP53 inhibitors. On the basis, a series of phenylpyridines derivatives were designed as novel CYP53 inhibitors, and their molecular structures were synthesized and evaluated. Compared with the positive control groups, their antifungal activity showed the obvious upward trend. In particular, target compounds (13a, 15b) possessed the excellent biological activity against pathogenic fungi and drug-resistant fungi in vivo and in vitro. The preliminary action mechanism has confirmed that target compounds could inhibit CYP53 activity, and block the metabolism of toxic intermediates (Benzoates). This further induced the accumulation of reactive oxygen species (ROS) through the pattern of mitochondrial depolarization, which eventually caused fungal lysis and death. In summary, the study provided the reasonable computational models, and effectively guided the generation of novel CYP53 antifungal inhibitors.

Comparative efficacy and safety of systemic antifungal agents for candidemia: a systematic review with network meta-analysis and multicriteria acceptability analyses

AIM

Invasive candidiasis is the most common fungal infection in patients attending health services and is associated with high mortality rates and prolonged hospital stay. The aim of this review was to evaluate and compare efficacy and safety of antifungal agents for the treatment of candidemia.

METHODS

A systematic review with network meta-analysis (NMA), surface under the cumulative ranking analysis (SUCRA) and stochastic multicriteria acceptability analyses (SMAA) was performed (PROSPERO-CRD42020149264). Searches were conducted in PubMed and Scopus (Nov-2021). Randomised controlled trials evaluating the effect of oral antifungals (any dose or regimen) on mycological cure, discontinuation rates and adverse events were included.

RESULTS

Overall, 13 trials (n=3632) were analysed. There were no significant differences between therapies for the efficacy outcomes; however, caspofungin (50-150 mg), rezafungin (200-400 mg) and micafungin (100-150 mg) had higher rates of clinical and mycological responses (SUCRA overall response >60%) and were considered the most promising therapies. Fluconazole (400 mg) rated worst for overall response (17%). Rezafungin (200-400 mg) and micafungin (100 mg) were associated with lower discontinuation rates (<40%). Conventional amphotericin B (0.6-0.7 mg/kg) was more likely to be discontinued (odds ratio [OR] 0.08; 95% credibility interval [CrI] 0.00-0.95 vs. caspofungin 150 mg) and may impair liver function (87%).

CONCLUSION

Echinocandins are recommended as first-line treatments for invasive candidiasis following a priority order of caspofungin then micafungin. Rezafungin, an echinocandin under development, represents a potential option that should be further investigated. Azoles and liposomal amphotericin B can be used as second-line treatments in cases of fungal resistance or hypersensitivity.

Evaluation of the antifungal effect of chlorogenic acid against strains of Candida spp. resistant to fluconazole: apoptosis induction and in silico analysis of the possible mechanisms of action

Introduction. Candida spp. are commensal fungal pathogens of humans, but when there is an imbalance in the microbiota, or weak host immunity, these yeasts can become pathogenic, generating high medical costs.Gap Statement. With the increase in resistance to conventional antifungals, the development of new therapeutic strategies is necessary. This study evaluated the in vitro antifungal activity of chlorogenic acid against fluconazole-resistant strains of Candida spp. Mechanism of action through flow cytometry and in silico analyses, as well as molecular docking assays with ALS3 and SAP5, important proteins in the pathogenesis of Candida albicans associated with the adhesion process and biofilm formation.Results. The chlorogenic acid showed in vitro antifungal activity against the strains tested, causing reduced cell viability, increased potential for mitochondrial depolarization and production of reactive oxygen species, DNA fragmentation and phosphatidylserine externalization, indicating an apoptotic process. Concerning the analysis through docking, the complexes formed between chlorogenic acid and the targets Thymidylate Kinase, CYP51, 1Yeast Cytochrome BC1 Complex e Exo-B-(1,3)-glucanase demonstrated more favourable binding energy. In addition, chlorogenic acid presented significant interactions with the ALS3 active site residues of C. albicans, important in the adhesion process and resistance to fluconazole. Regarding molecular docking with SAP5, no significant interactions were found between chlorogenic acid and the active site of the enzyme.Conclusion. We concluded that chlorogenic acid has potential use as an adjuvant in antifungal therapies, due to its anti-Candida activity and ability to interact with important drug targets.

Inhibition of Galectin-3 Impairs Antifungal Immune Response in Fungal Keratitis

Galectin-3 is one of the galectin family members which are master regulators of immune homeostasis, especially in infectious diseases. However, its mechanism of immune regulation in fungal keratitis has not been thoroughly studied. Our study is aimed at clarifying the role of galectin-3 in the fungal keratitis mouse model in vivo, thereby providing a new biomarker of antifungal therapy. In our study, aspergillus, the most common pathogenic fungi of fungal keratitis, was identified and isolated by corneal tissue fungus culture. Then, the RNA expression levels of galectin family members in corneas of the mouse model with aspergillus fumigatus keratitis were screened by transcriptome sequencing (RNA-seq). The expression of the galectin-3 was detected by quantitative real-time Polymerase Chain Reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and immunofluorescence in the corneal tissue of the fungal keratitis mouse model. Recruitment of neutrophils and the co-immunofluorescence of galectin-3 and related markers in corneal tissue were determined by flow cytometry analysis and immunofluorescence staining. The regulatory role of galectin-3 for proinflammatory cytokines and neutrophils was validated by the knockout mouse model. Galectin-3 knockout deteriorated the condition for the inhibition of galectin-3 was benefecial for fungi to survive and thrive in corneal lesions. These results demonstrated that in the ocular fungal infection, galectin-3 is capable of regulating the pathogenesis of fungal keratitis by modulating neutrophil recruitment. The deterioration of fungal keratitis and increased fungal load in corneal lesions of galectin-3 knockout mice proved the regulatory role of galectin-3 in fungal keratitis. In conclusion, galectin-3 is going to be an essential target to modulate neutrophil recruitment and its related antifungal immune response in fungal keratitis.

Recent Advances in Fungal Infections: From Lung Ecology to Therapeutic Strategies With a Focus on Aspergillus spp

Fungal infections are estimated to be the main cause of death for more than 1.5 million people worldwide annually. However, fungal pathogenicity has been largely neglected. This is notably the case for pulmonary fungal infections, which are difficult to diagnose and to treat. We are currently facing a global emergence of antifungal resistance, which decreases the chances of survival for affected patients. New therapeutic approaches are therefore needed to face these life-threatening fungal infections. In this review, we will provide a general overview on respiratory fungal infections, with a focus on fungi of the genus Aspergillus. Next, the immunological and microbiological mechanisms of fungal pathogenesis will be discussed. The role of the respiratory mycobiota and its interactions with the bacterial microbiota on lung fungal infections will be presented from an ecological perspective. Finally, we will focus on existing and future innovative approaches for the treatment of respiratory fungal infections.

Molecular Recognition of Citroflavonoids Naringin and Naringenin at the Active Site of the HMG-CoA Reductase and DNA Topoisomerase Type II Enzymes of Candida spp. and Ustilago maydis

Two agents from natural sources, citroflavonoids naringin and naringenin, can target enzymes in pathogenic yeasts responsible for hospital infections and crop failure. The aim of this study was to examine the molecular recognition site for naringin and naringenin on the HMGR and TOPOII enzymes of eleven Candida species and one phytopathogen, U. maydis, and evaluate yeast susceptibility to these flavonoids. The HMGR and TOPOII enzymes were analyzed in silico. The alignment of the two enzymes in the twelve pathogenic organisms with the corresponding enzyme of Homo sapiens revealed highly conserved amino acid sequences. Modeling studies of the enzymes indicated highly conserved structures. According to molecular docking simulations, both citroflavonoids recognized the amino acid residues of the active site of the enzymes. Binding energy values were higher for naringin (-10.75 and -9.38 kcal/mol, respectively) than simvastatin on HMGR (-9.9) and curcumin on TOPOII (-8.37). The appraisal of twenty-nine virtual mutations provided evidence of probable mechanisms of resistance (high binding energy) or susceptibility (low energy) to the drugs and emphasized the role of key residues. An in vitro susceptibility evaluation of the twelve yeasts demonstrated that the two flavonoids have similar or better MIC values than those reported for the reference compounds, obtaining the lowest with Candida dubliniensis (2.5 µg/ml) and U. maydis (5 µg/ml). Based on the present findings, naringin and naringenin could possibly be effective for treating diseases caused by pathogenic yeasts of the Candida species and U. maydis, presumably by inhibition of their HMGR and TOPOII enzymes.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12088-021-00980-0.

Machine-learning based prediction of prognostic risk factors in patients with invasive candidiasis infection and bacterial bloodstream infection: a singled centered retrospective study

Background

Invasive candidal infection combined with bacterial bloodstream infection is one of the common nosocomial infections that is also the main cause of morbidity and mortality. The incidence of invasive Candidal infection with bacterial bloodstream infection is increasing year by year worldwide, but data on China is still limited.

Methods

We included 246 hospitalised patients who had invasive candidal infection combined with a bacterial bloodstream infection from January 2013 to January 2018; we collected and analysed the relevant epidemiological information and used machine learning methods to find prognostic factors related to death (training set and test set were randomly allocated at a ratio of 7:3).

Results

Of the 246 patients with invasive candidal infection complicated with a bacterial bloodstream infection, the median age was 63 years (53.25–74), of which 159 (64.6%) were male, 109 (44.3%) were elderly patients (> 65 years), 238 (96.7%) were hospitalised for more than 10 days, 168 (68.3%) were admitted to ICU during hospitalisation, and most patients had records of multiple admissions within 2 years (167/246, 67.9%). The most common blood index was hypoproteinemia (169/246, 68.7%), and the most common inducement was urinary catheter use (210/246, 85.4%). Moreover, the most frequently infected fungi and bacteria were Candida parapsilosis and Acinetobacter baumannii, respectively. The main predictors of death prognosis by machine learning method are serum creatinine level, age, length of stay, stay in ICU during hospitalisation, serum albumin level, C-Reactive protein (CRP), leukocyte count, neutrophil count, Procalcitonin (PCT), and total bilirubin level.

Conclusion

Our results showed that the most common candida and bacteria infections were caused by Candida parapsilosis and Acinetobacter baumannii, respectively. The main predictors of death prognosis are serum creatinine level, age, length of stay, stay in ICU during hospitalisation, serum albumin level, CRP, leukocyte count, neutrophil count, PCT and total bilirubin level.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07125-8.

Nosocomial Infections in Non-COVID-19 Pediatric Patients Prior to and During the Pandemic in a Pediatric Intensive Care Unit

Background: Nosocomial infections are a global threat to human health worldwide.

Aim: This study aimed to investigate the change of nosocomial infection factors in equivalent historical periods in pediatric patients without COVID-19 before and during the pandemic in the pediatric intensive care unit.

Method: The study was planned retrospectively. Data on hospital infection rates, incidence densities, invasive device-associated infections, infectious agents, comorbid diseases, and invasive procedures in non-COVID-19 pediatric patients were obtained from the medical records for the periods of April-September 2019 and April-September 2020 in the pediatric intensive care unit. Hand hygiene compliance rates of healthcare workers were evaluated.

Results: Prior to the pandemic, the number of patients was 332, comprising 2,377 patient days with a nosocomial infection rate of 5.12, and an incidence density of 7.15. During the pandemic, the number of patients was 221, comprising 2,260 patient days with a nosocomial infection rate of 4.52, and incidence density of 4.43. Prior to the pandemic, there were 28.80% cases of Klebsiella pneumoniae, 23.81% of Pseudomonas aeruginosa, 9.52% of Enterococcus faecium, and 4.76% of Enterococcus faecalis. During the pandemic, there were decreased 14.29% cases of Klebsiella pneumoniae while Pseudomonas aeruginosa, Enterococcus faecium, and Enterococcus faecalis was not seen. Prior to the pandemic, the hand hygiene compliance rate was 94.83%, and during the pandemic, it was found to be 99.44%.

Conclusion: This study showed that the spread of bacteria such as Klebsiella pneumoniae, Pseudomonas aeruginosa, vancomycin-resistant enterococci, and Stenotrophomonas maltophilia, which are a major public health threat, can be decreased by applying simple standard methods.

Antifungal Polymeric Materials and Nanocomposites

Rising global populations due to medicinal advancements increases the patient population susceptible to superficial and severe fungal infections. Fungi often implicated in these diseases includes the dermatophytes (Microsporum spp., Epidermophtyon spp., Trichophyton spp.) as well as species of the Candida spp., Aspergillosis spp. and Cryptococcus spp. genera. In addition, increasing global populations leads to increasing agricultural demands. Thus, fungal infections of preharvested crops and stored food by plant pathogens such as Magnaporthe oryzae and Fusarium oxysporum can have detrimental socioeconomic effects due to food insecurity. Current antifungal strategies are based mainly on small molecule antifungal drugs. However, these drugs are limited by poor solubility and bioavailability. Furthermore, antifungal resistance against these drugs are on the rise. Thus, antimicrobial polymers offer an alternative antifungal strategy. Antifungal polymers are characterised by cationic and hydrophobic regions where the cationic regions have been shown to interact with microbial phospholipids and membranes. These polymers can be synthetic or natural and demonstrate distinct antifungal mechanisms ranging from fungal cell membrane permeabilisation, cell membrane depolarisation or cell entry. Although the relative importance of such mechanisms is difficult to decipher. Due to the chemical properties of these polymers, they can be combined with other antimicrobial compounds including existing antifungal drugs, charcoals, lipids and metal ions to elicit synergistic effects. In some cases, antifungal polymers and nanocomposites show better antifungal effects or reduced toxicity compared to the widely used small molecule antifungal drugs. This review provides an overview of antimicrobial polymers and nanocomposites with antifungal activity and the current understanding of their antifungal mechanisms.

Attributable Mortality of Candida Bloodstream Infections in the Modern Era: A Propensity Score Analysis

BACKGROUND

This study quantifies the mortality attributable to Candida bloodstream infections (BSI) in the modern era of echinocandins.

DESIGN

We conducted a retrospective cohort study of adult patients admitted to Barnes Jewish Hospital, a 1,368-bed tertiary care academic hospital, in Saint Louis, Missouri from 1/2/2012-4/30/2019. We identified 626 adult patients with Candida BSI that were frequency-matched with 6,269 control patients that had similar Candida BSI risk-factors. The 90-day all-cause mortality attributable to Candida BSI was calculated using three methods-propensity score matching, matching by inverse weighting of propensity score, and stratified analysis by quintile.

RESULTS

The 90-day crude mortality was 42.4% (269 patients) for Candida BSI cases and 17.1% (1,083 patients) for frequency-matched controls. Following propensity score-matching, the attributable risk difference for 90-day mortality was 28.4% with hazard ratio (HR) of 2.12 (95% CI, 1.98-2.25, p<0.001). In the stratified analysis, the risk for mortality at 90 days was highest in patients in the lowest risk quintile to develop Candida BSI (HR 3.13 (95% CI, 2.33-4.19). Patients in this lowest risk quintile accounted for 81(61%) of the 130 untreated patients with Candida BSI. Sixty nine percent of untreated patients (57/83) died versus 35% of (49/127) of treated patients (p<0.001).

CONCLUSIONS

Patients with Candida BSI continue to experience high mortality. Mortality attributable to Candida BSI was more pronounced in patients at lowest risk to develop Candida BSI. A higher proportion of these low-risk patients went untreated, experienced higher mortality, and should be the target of aggressive interventions to ensure timely, effective treatment.

Evaluation of a stewardship program of antifungal use at a Brazilian tertiary care hospital

Introduction

Stewardship programs have been developed to optimize the use of antibiotics, but programs focusing on antifungal agents are less frequent.

Objective

To evaluate the quality of antifungal prescriptions in a tertiary care hospital, and to test if a simple educational activity could improve the quality of prescriptions.

Methods

The study comprised three phases: 1) Retrospective audit of all antifungal prescriptions in a 6-month period, applying a score based on six parameters: indication, drug, dosage, route of administration, microbiologic adequacy after results of cultures, switching to an oral agent, and duration of treatment; 2) Creation of text boxes in the electronic medical records with information about antifungal agents, shown during prescription; 3) Retrospective audit of all antifungal prescriptions in a 6-month period, applying the same 6-parameters score, and comparison between the two periods.

Results

Among 333 prescriptions, fluconazole was the most frequently (80.5%) prescribed agent. Hematology (26.7%), Infectious Diseases Department (22.8%), Internal Medicine (15.9%) and Intensive Care Unit (14.4%) were the units with most antifungal prescriptions. The median score for the 333 prescriptions was 8.0 (range 0 – 10), and 72.7% of prescriptions were considered inappropriate. The median and mean scores in the first and second audit were 8.0 and 6.9, and 8.0 and 7.9, respectively (p<0.001). All items that comprised the score improved from the first to the second audit. Likewise, there was a reduction of inappropriate prescriptions (80.2% in the first audit vs. 64.6% in the second audit, p=0.001).

Conclusions

A large proportion of inappropriate prescriptions was observed, which improved with the implementation of simple educational activities.

Candida species biotypes and polyclonality of potentially virulent Candida albicans isolated from oral cavity of patients with orofacial clefts

OBJECTIVES

This study evaluated the incidence of Candida species, and the genetic diversity and virulence of C. albicans of the oral cavity from patients with cleft lip and palate (CLP).

MATERIALS AND METHODS

Oral samples were investigated by microbiological and species-specific PCR methods. The genetic diversity of C. albicans was established using isoenzyme markers, Nei's statistics, and clustering analysis. Hydrolytic enzymes (SAPs and PLs) were analyzed in vitro.

RESULTS

Oral colonization by Candida species was observed in 29 patients with CLP (65.9%), and C. albicans was highly prevalent. SAP and PL activities were observed in 100% and 51.9% of isolates, respectively. High genetic diversity and patterns of monoclonal and polyclonal oral colonization by C. albicans were observed among patients with CLP. Two major polymorphic taxa (A and B) and other minor polymorphic taxa (C to J) were identified. Only one of the 16 clusters (taxon A) harbored strains from patients with and without CLP, whereas other clusters harbored strains exclusively from CLP patients.

CONCLUSIONS

The anatomical conditions of the oral cavity of patients with CLP contribute to the high incidence of Candida species (C. albicans, C. krusei, C. tropicalis, and/or Candida spp.). Data suggest high genetic diversity of potentially virulent C. albicans strains in the oral cavity of CLP patients.

CLINICAL RELEVANCE

Microbiological niches in orofacial clefts can contribute to the emergence of a relative clinical genotypic identity of C. albicans. However, orofacial rehabilitation centers can contribute to the direct and indirect sources of transmission and propagation of Candida species.

Examining properties influencing infectious microbe associations with surfaces of four different thermoplastic radiation therapy masks

BACKGROUND

Previous testing revealed that four different microbes applied to face-only masks from Civco, Klarity Medical, Orfit, and Qfix demonstrated variation in the number recovered from each mask type after a 1-hour contact time. In all cases, the Orfit mask demonstrated the largest number of recovered microbes suggesting a preference by tested microbes to create associations with this mask type.

METHODS

The current study evaluated three physiochemical features of these thermoplastic masks to determine why the Orfit mask encouraged greater microbial associations. Measurements including water contact angle (WCA), surface topography, and available contact area were determined for each mask type, where feasible.

RESULTS

The Orfit mask exhibited the greatest difference in each of the 3 evaluated characteristics. Overall, it showed decreased hydrophobicity, increased surface roughness, and increased surface contact area. The WCA of both Orfit (50.8°) and Klarity (95.6°) masks showed decreased hydrophobicity when compared to native PCL (129.97°).

CONCLUSION

The Orfit mask's decreased hydrophobicity, increased roughness, and larger surface contact area appears to have contributed to its ability to support a larger number of microbe associations. The decreased hydrophobicity and altered topography of both Klarity and Orfit masks may have been due to their additional antimicrobial coatings.

Epidemiological Characterization of Clinical Fungal Isolates from Pauls Stradinš Clinical University Hospital, Latvia: A 4-Year Surveillance Report

Nosocomial fungal infections are an emerging global public health threat that requires urgent attention and proper management. With the limited availability of treatment options, it has become necessary to understand the emerging epidemiological trends, mechanisms, and risk factors. However, very limited surveillance reports are available in the Latvian and broader European context. We therefore conducted a retrospective analysis of laboratory data (2017-2020) from Pauls Stradinš Clinical University Hospital (PSCUH), Riga, Latvia, which is one of the largest public multispecialty hospitals in Latvia. A total of 2278 fungal isolates were analyzed during the study period, with Candida spp. comprising 95% of the isolates, followed by Aspergillus spp. and Geotrichum spp. Amongst the Candida spp., C. albicans and C. glabrata made up about 75% of the isolates. The Department of Lung Diseases and Thoracic Surgery had the highest caseload followed by Intensive Care Department. Majority of the fungal isolates were collected from the bronchoalveolar lavage (37%), followed by urine (19%) and sputum (18%) samples. A total of 34 cases of candidemia were noted during the study period with C. albicans being the most common candidemia pathogen. Proper surveillance of emerging epidemiological trends serve as the most reliable and powerful cornerstone towards tackling this emerging threat.

Understanding the pathogenesis of infectious diseases by single-cell RNA sequencing

Infections are highly orchestrated and dynamic processes, which involve both pathogen and host. Transcriptional profiling at the single-cell level enables the analysis of cell diversity, heterogeneity of the immune response, and detailed molecular mechanisms underlying infectious diseases caused by bacteria, viruses, fungi, and parasites. Herein, we highlight recent remarkable advances in single-cell RNA sequencing (scRNA-seq) technologies and their applications in the investigation of host-pathogen interactions, current challenges and potential prospects for disease treatment are discussed as well. We propose that with the aid of scRNA-seq, the mechanism of infectious diseases will be further revealed thus inspiring the development of novel interventions and therapies.

The Use of a Three-in-One Practice-Management-Innovation Training Model in the Construction of an Infection Control Team

Objective

This study aims to explore the role of a three-in-one practice, management, and innovation training model (also called as three-in-one practice-management-innovation training model) in the construction of an infection control team.

Methods

This study retrospectively analyzed the position structure, mastery of professional knowledge, and working methods of the full-time and part-time personnel of the Changzhou Cancer Hospital, compared the training content of Jiangsu Hospital Infection Control Center with the actual situation of the hospital, and formulated and implemented a three-in-one practice-management-innovation training model. First, the team members were selected for the construction and management of the Hospital Infection Management Department according to the relevant responsibility and management requirements, and their learning and mastery of the basic knowledge and skills concerning infection control were completed based on their professional roles. In line with the regulations of the hospital and department, full-time personnel were ensured of having the opportunity to participate in provincial- and municipal-level academic exchanges and then learn from each other, through collaboration between doctors and nurses, how to exercise basic management skills. At the same time, a fair competitive incentive mechanism was established through the three-level network of the hospital infection committee, the hospital infection management department, and nosocomial infection management department to implement innovative project-based management and cultivate an awareness of hospital infection control in all employees.

Results

The professional structure of the full-time infection control personnel has been optimized, the awareness of the infection control team concerning active participation in practice has gradually increased, and infection control management and innovation has been significantly improved.

Conclusion

After the selection of an infection control management team and the delivery of well-planned training, the quality of infection control management has improved.

Role of Candida glabrata as nosocomial pathogen and its susceptibility to Fluconazole, Voriconazole, Caspofungin, Micafungin and Amphotericin B

Candida has different types that could cause bloodstream infections. A total number of 150 samples were collected from candidemia patients and examined. The Candida spp. Species isolated from blood samples were analysed. These were identified by culturing the species using different media, namely the chromogenic agar test. Then, the virulence factors of all samples were tested. The Candida glabrata isolates were tested with six commercial antifungal drugs. C. glabrata 67 (44.6%), C. albicans 34 (22.6%), C. krusei 18 (12%), C. tropicalis 17 (11.3%), and C. parasilosis 14 (9.3%). the production of phospholipase ranged between 0.63-0.99 mm. It was found that 96% of the species showed phospholipase activity in aerobic conditions. The protease activities of Candida spp. Isolates were experimentally tested by area of inhibition around the colonies, where 59.3% had the double (++) protease activity, 31.4% with (+) grade, and 9.3% had (–) grade or clear zone around the colony. The hemolytic capacity ranged from 0.69-0.89 in the optimum aerobic environments. Finally, 38.33% of the isolated Candida spp. were positive and 61.67% negative for biofilm formation. Out of the total positive Candida spp. for biofilm formation, 21.73% were strong biofilm producers, and 78.27% were weak. Minimum fungicidal concentration (MFC) of Fluconazole for C. glabrata isolates was not appropriate (NA) due to the occurrence of low inhibition tested for species. Micafungin exhibited the lowest fungicidal activity against C. glabrata ranging from 0.03 - 0.125, while Fluconazole showed the highest.

Risk factors of septic shock development and thirty-day mortality with a predictive model in adult candidemia patients in intensive care units

BACKGROUND

This study aimed to investigate factors associated with septic shock development and 30-day mortality outcome with a prediction model among adult candidemia patients in the intensive care unit (ICU).

METHODS

A retrospective study was conducted among patients admitted to the ICU from 2009 to 2018 at a tertiary care medical centre. The study subjects included adult patients ≥ 19 years with candidemia treated with antifungal agent for ≥ 3 days. Clinical variables were collected and analysed.

RESULTS

A total of 126 patients were included in the study. Of these patients, 32 patients (25.4%) had septic shock. Multivariate logistic regression analysis revealed that chronic liver disease was associated with septic shock (odds ratio [OR] 3.372, 95% confidence interval [CI] 1.057 - 10.057). The rate of 30-day mortality was 35.7% and the associated mortality risk factors were malignancy (OR 8.251, 95% CI 2.227 - 30.573), chronic liver disease (OR 3.605, 95% CI 0.913 - 14.227), haemodialysis (OR 8.479, 95% CI 1.801 - 39.924), mycological failure (OR 29.675, 95% CI 7.012 - 125.578), and septic shock (OR 3.980, 95% CI 1.238 - 12.796). A predictive model for 30-day mortality was created based on the mortality risk factor scores, which had an area of 0.862 under the receiver operating characteristic curve.

CONCLUSIONS

Adult candidemia patients in the ICU who have chronic liver disease may be at higher risk of developing septic shock. Furthermore, our predictive model for 30-day mortality based on the mortality risk factors may be useful for clinical assessment.

COVID-19 and Candida duobushaemulonii superinfection: A case report

Introduction

Critically ill COVID-19 patients are at high risk for nosocomial bacterial and fungal infections due to several predisposing factors such as intensive care unit stay, mechanical ventilation, and broad-spectrum antibiotics. Data regarding multidrug resistant (MDR) Candida species in COVID-19 patients is scarce, and nonexistent regarding Candida duobushaemulonii superinfections.

Case description

A 34-year-old male presented to our institution with acute respiratory distress syndrome (ARDS) due to COVID-19 infection and developed Candida duobushaemulonii fungemia after multiple courses of antibiotics and prolonged mechanical ventilation. He died after recurrent pneumothorax led to respiratory failure and cardiac arrest.

Discussion

Bacterial and fungal infections are common complications of viral pneumonia in critically ill patients. Data regarding these infections in COVID-19 patients has been poorly studied with only a few cases reporting secondary infection, mostly without identifying specific pathogens. Prolonged hospital stays, invasive interventions (central venous catheter, mechanical ventilation), and the use of broad-spectrum antibiotics in COVID-19 infections could carry a high risk of bacterial and/or fungal superinfections.

Conclusion

Strategies to improve outcome in COVID-19 ICU patients should include early recognition of candidemia and appropriate antifungal therapy.

Responses of Mast Cells to Pathogens: Beneficial and Detrimental Roles

Mast cells (MCs) are strategically located in tissues close to the external environment, being one of the first immune cells to interact with invading pathogens. They are long living effector cells equipped with different receptors that allow microbial recognition. Once activated, MCs release numerous biologically active mediators in the site of pathogen contact, which induce vascular endothelium modification, inflammation development and extracellular matrix remodeling. Efficient and direct antimicrobial mechanisms of MCs involve phagocytosis with oxidative and non-oxidative microbial destruction, extracellular trap formation, and the release of antimicrobial substances. MCs also contribute to host defense through the attraction and activation of phagocytic and inflammatory cells, shaping the innate and adaptive immune responses. However, as part of their response to pathogens and under an impaired, sustained, or systemic activation, MCs may contribute to tissue damage. This review will focus on the current knowledge about direct and indirect contribution of MCs to pathogen clearance. Antimicrobial mechanisms of MCs are addressed with special attention to signaling pathways involved and molecular weapons implicated. The role of MCs in a dysregulated host response that can increase morbidity and mortality is also reviewed and discussed, highlighting the complexity of MCs biology in the context of host-pathogen interactions.

Development of a stability-indicating assay method by HPLC-DAD and MS characterization of forced degradation products of ravuconazole

Ravuconazole (RAV) is a triazole antifungal with broad spectrum and a novel alternative in the treatment of systemic fungal infections. A stability-indicating method by high-performance liquid chromatography-diode array detection was developed and fully validated to assay ravuconazole in the presence of its degradation products. Separation was achieved with a Sunfire C18 column (250 mm × 4.6 mm id, 5 μm), mobile phase composed of acetonitrile and water (80:20), at 1 mL/min. The volume of injection was 5 μL and DAD detection was performed at 287 nm. RAV was well resolved from its degradation products and the method proved to be linear, selective, accurate, precise and robust. A forced degradation study was conducted on the pure drug under oxidative conditions in presence of H2O2 and metallic ions and under acid, alkaline and neutral hydrolysis. RAV was degraded mainly under alkaline hydrolysis, forming two main degradation products. The chemical structures were proposed according to the data obtained by liquid chromatography coupled to mass spectrometry (LC-MS) analysis. This study provided a new and selective stability-indicating method to evaluate the intrinsic stability of ravuconazole in active pharmaceutical ingredients. The developed method was found to be suitable for quality control routine analysis and to stability studies of ravuconazole.

Radionuclide Imaging of Fungal Infections and Correlation with the Host Defense Response

The human response to invading fungi includes a series of events that detect, kill, or clear the fungi. If the metabolic host response is unable to eliminate the fungi, an infection ensues. Some of the host response’s metabolic events to fungi can be imaged with molecules labelled with radionuclides. Several important clinical applications have been found with radiolabelled biomolecules of inflammation. ¹⁸F-fluorodeoxyglucose is the tracer that has been most widely investigated in the host defence of fungi. This tracer has added value in the early detection of infection, in staging and visualising dissemination of infection, and in monitoring antifungal treatment. Radiolabelled antimicrobial peptides showed promising results, but large prospective studies in fungal infection are lacking. Other tracers have also been used in imaging events of the host response, such as the migration of white blood cells at sites of infection, nutritional immunity in iron metabolism, and radiolabelled monoclonal antibodies. Many tracers are still at the preclinical stage. Some tracers require further studies before translation into clinical use. The application of therapeutic radionuclides offers a very promising clinical application of these tracers in managing drug-resistant fungi.

Nanoparticles as a Tool for Broadening Antifungal Activities

Fungal infections are diseases that are considered neglected although their infection rates have increased worldwide in the last decades. Thus, since the antifungal arsenal is restricted and many strains have shown resistance, new therapeutic alternatives are necessary. Nanoparticles are considered important alternatives to promote drug delivery. In this sense, the objective of the present study was to evaluate the contributions of newly developed nanoparticles to the treatment of fungal infections. Studies have shown that nanoparticles generally improve the biopharmaceutical and pharmacokinetic characteristics of antifungals, which is reflected in a greater pharmacodynamic potential and lower toxicity, as well as the possibility of prolonged action. It also offers the proposition of new routes of administration. Nanotechnology is known to contribute to a new drug delivery system, not only for the control of infectious diseases but for various other diseases as well. In recent years, several studies have emphasized its application in infectious diseases, presenting better alternatives for the treatment of fungal infections.

A novel use for an old drug: resistance reversal in Candida albicans by combining dihydroartemisinin with fluconazole

Aim: To investigate the effects of dihydroartemisinin combined with fluconazole against C. albicans in vitro and to explore the underlying mechanisms. Materials & methods: Checkerboard microdilution assay and time-kill curve method were employed to evaluate the static and dynamic antifungal effects against C. albicans. Reactive oxygen species (ROS) was measured by a fluorescent probe. Results: Combination of dihydroartemisinin and fluconazole exerted potent synergy against planktonic cells and biofilms of fluconazole-resistant C. albicans, with the fractional inhibitory concentration index values less than 0.07. A potent fungistatic activity of this drug combination could still be observed after 18 h. The accumulation of ROS induced by the drug combination might contribute to the synergy. Conclusion: Dihydroartemisinin reversed the resistance of C. albicans to fluconazole.

Evaluation of Nosocomial Infection Control Measures to Minimize the Risk of Aspergillus Dispersion During Major Demolition Work: A Case Study of a Japanese University Hospital

OBJECTIVES

To verify the effectiveness of our infection control measures based on the infection control risk assessment (ICRA) to minimize the risk of Aspergillus dispersion before, during, and after demolition work in a university hospital.

BACKGROUND

It is widely accepted that invasive aspergillosis is associated with construction, renovation, and demolition activities within or close to hospital sites. However, the risk is underestimated, and only limited preventive measures are taken in Japanese hospitals.

METHOD

The demolition process, carried out in July 2014, was supervised by our facility management in collaboration with the infection prevention team and followed an adapted ICRA tool. Dust containment measures were implemented to reduce the risk of airborne Aspergillus contamination. Air sampling was performed at four wards in the adjacent hospital buildings to assess the containment measures' effectiveness.

RESULTS

A high, undetermined number of colonies of bacteria and molds were detected on all outside balconies before demolition. During demolition, Aspergillus spp. was detected only in the ward closest to the demolition site. However, no case of aspergillosis was reported. The difference-in-difference analysis revealed that the interaction between the demolition activity, height of the ward, and distance of the air intake to the demolition activities resulted in a significant increase in the numbers of Aspergillus spp.

CONCLUSIONS

When large-scale demolition work occurs in hospital premises, Aspergillus spp. may increase in the ward where the vertical and horizontal distance of air intake from the demolition site is close, even though infection control measures based on the ICRA are implemented.

Neutrophil and Eosinophil DNA Extracellular Trap Formation: Lessons From Pathogenic Fungi

Fungal infections represent a worldwide health problem. Fungal pathogens are responsible for a variety of conditions, including superficial diseases, allergic pathologies and potentially lethal invasive infections. Neutrophils and eosinophils have been implicated as effector cells in several pathologies. Neutrophils are major effector cells involved in the control of fungal infections and exhibit a plethora of antifungal mechanisms, such as phagocytosis, reactive oxygen species production, degranulation, extracellular vesicle formation, and DNA extracellular trap (ET) release. Eosinophils are polymorphonuclear cells classically implicated as effector cells in the pathogenesis of allergic diseases and helminthic infections, although their roles as immunomodulatory players in both innate and adaptive immunity are currently recognized. Eosinophils are also endowed with antifungal activities and are abundantly found in allergic conditions associated with fungal colonization and sensitization. Neutrophils and eosinophils have been demonstrated to release their nuclear and mitochondrial DNA in response to many pathogens and pro-inflammatory stimuli. ETs have been implicated in the killing and control of many pathogens, as well as in promoting inflammation and tissue damage. The formation of ETs by neutrophils and eosinophils has been described in response to pathogenic fungi. Here, we provide an overview of the mechanisms involved in the release of neutrophil and eosinophil ETs in response to fungal pathogens. General implications for understanding the formation of ETs and the roles of ETs in fungal infections are discussed.