Antifungal Susceptibility Testing of Fusarium: A Practical Approach

Investigating the susceptibility profiles and in vitro combinations of caspofungin, itraconazole, fluconazole, voriconazole, clotrimazole, and amphotericin B against clinical isolates causing fungal keratitis

Fungal keratitis is a global cause of blindness, highlighting the need to assess antifungal treatment efficacy before clinical use. This study evaluates the synergistic and antagonistic effects of antifungal agents on fungal keratitis isolates. Susceptibility testing of 35 corneal isolates including Aspergillus spp., Neocosmospora spp., Candida albicans, Penicillium chrysogenum was performed with broth microdilution and checkerboard methods to test six antifungal agents (caspofungin, itraconazole, fluconazole, voriconazole, amphotericin B, clotrimazole). Among Aspergillus spp., the MIC ranges were reported as 0.01-1, 0.5-16, 32-64, 0.06-16, 0.125-8, and 0.25-4 µg/mL for caspofungin, amphotericin B, fluconazole, itraconazole, voriconazole, and clotrimazole, respectively. For Fusarium/Neocosmospora spp., these ranges varied to 0.01-8, 0.125-4, 64, 0.03-16, 0.25-8, and 0.5-8 µg/mL for the same drugs. In Candida spp., the MIC ranges were 0.01-0.03, 0.25, 64, ≥16, ≥16, and 0.5-1 µg/mL for the same antifungal agents. Notably, the combination of caspofungin and amphotericin B exhibited 100% synergistic effects against Aspergillus spp., while combinations of clotrimazole, fluconazole, or voriconazole with amphotericin B showed a 50% synergistic effect against Fusarium/Neocosmospora spp. Furthermore, fluconazole combined with voriconazole or itraconazole, as well as voriconazole and itraconazole, demonstrated 100% synergism against Candida spp. The results indicate that caspofungin is the most effective antifungal agent, while fluconazole exhibited the highest rates of resistance. The combination of caspofungin and amphotericin B proved most effective against Aspergillus spp., azole compounds combined with amphotericin B were most effective against Fusarium/ Neocosmospora spp., and combinations of fluconazole with voriconazole or itraconazole and voriconazole and itraconazole demonstrated synergistic effects against Candida spp.

Clinical aspects and recent advances in fungal diseases impacting human health

Fungal diseases are of growing clinical concern in human medicine as the result of changes in the epidemiology, diversity in clinical presentation, emergence of new pathogens, difficulties in diagnosis and increasing resistance to antifungals of current available classes. There is a need for high disease awareness among the public and healthcare physicians, improvement in diagnostic methods and the development of drugs from new therapeutic classes with an improved resistance profile. In this article, we will explore some key aspects of fungal diseases in humans and provide a general overview of this important topic.

Antifungal susceptibility, clinical findings, and biofilm resistance of Fusarium species causing keratitis: a challenge for disease control

Fusarium keratitis (FK) is an important clinical condition that can lead to blindness and eye loss, and is most commonly caused by the Fusarium solani species complex (FSSC). This study evaluated the susceptibility of planktonic cells and biofilms of FSSC (n = 7) and non-FSSC (n = 7) isolates obtained from patients with keratitis from a semi-arid tropical region to amphotericin B (AMB), natamycin (NAT), voriconazole (VRZ), efinaconazole (EFZ), and luliconazole (LCZ). Analysis of clinical data showed that trauma was the most common risk factor for FK patients. Disease onset was longer in non-FSSC group (3-30 days) than in the FSSC group (3-7 days). FSSC strains were less susceptible to AMB and VRZ than non-FSSC strains (p < 0.05). Susceptibility to NAT, LCZ and EFZ was similar between isolates of FSSC and non-FSSC groups. Overall, patients infected with non-FSSC showed a better response to antifungal treatment. Corneal transplantation was more common in patients infected with FSSC (3/7) than in those infected with non-FSSC (1/7). Mature biofilms showed a poor response to antifungal treatment. Patients infected with Fusarium strains capable of forming antifungal tolerant biofilms had more complex therapeutic management, requiring two antifungals and/or corneal transplantation (p < 0.05). This study highlights the importance of mycological diagnosis and the antifungal susceptibility testing in the clinical management of FK. The ability of Fusarium to form antifungal tolerant biofilms poses a challenge to clinicians and urges the development of new antibiofilm therapeutics.

Fungicide resistance in Fusarium species: exploring environmental impacts and sustainable management strategies

The agricultural productivity and world-wide food security is affected by different phytopathogens, in which Fusarium is more destructive affecting more than 150 crops, now got resistance against many fungicides that possess harmful effects on environment such as soil health, air pollution, and human health. Fusarium fungicide resistance is an increasing concern in agricultural and environmental contexts, requiring a thorough understanding of its causes, implications, and management approaches. The mechanisms of fungicide resistance in Fusarium spp., are reviewed in this article, including increased efflux pump activity, target-site mutations, and metabolic detoxification pathways. Fusarium is naturally resistant to some of the fungicides, on the other hand; it speedily develops resistance against the other fungicides groups. Most of the important plant pathogenic Fusarium species including F. oxysporum, F. psedogramanium, F. graminearium and Fusarium solani, which have shown resistance to major groups of fungicides including triazoles, phenylpyrole and benzimedazoles in various regions of the world. The review also covers a range of management techniques, including fungicide rotation, resistant cultivars, cultural methods, and biological control agents, to lessen fungicide resistance. By shedding light on the current state of knowledge concerning fungicide resistance in Fusarium spp., this review provides valuable information to researchers, policymakers, and practitioners to design long-term effective disease management approaches, as well as fungal menace control to preserve fungicides' effectiveness in agriculture and conservancy activities.

Molecular Identification and Antifungal Susceptibility of Fusarium spp. Clinical Isolates

BACKGROUND

Accurate identification of Fusarium species requires molecular identification. Treating fusariosis is challenging due to widespread antifungal resistance, high rates of treatment failure, and insufficient information relating antifungal susceptibility to the clinical outcome. Despite recent outbreaks in Mexico, there is limited information on epidemiology and antifungal susceptibility testing (AST).

OBJECTIVES

We aimed to analyse the distribution of Fusarium species from a referral centre in Mexico with DNA sequencing and to describe AST to the clinical outcome.

METHODS

We conducted a retrospective study on clinical isolates of Fusarium. They were identified by translation elongation factor-1α gene amplification and sequencing. AST was performed to determine minimal inhibitory concentrations (MICs).

RESULTS

A total of 35 Fusarium isolates from 26 patients were included. The most common was Fusarium solani species complex (FSSC) in 51.5%, of which Fusarium petroliphilum and Fusarium oxysporum species complex were the most frequent with 37% and 20%, respectively. AST did not show MICs above the epidemiological cut-off value. Fusariosis was diagnosed in 19 patients, mostly with hematologic neoplasm; the overall mortality rate was 32%.

CONCLUSIONS

Fusarium petroliphilum from the FSSC was found most frequently. Elevated mortality and MICs for all tested antifungals were found, with higher MIC50 among F. solani SC than F. oxysporum SC or F. fujikuroi SC.

Fusarium spp. causing invasive disease in humans: A case series from north India

Owing to their inherent resistance to different classes of antifungals, early identification of Fusarium spp. is crucial. In this study, 10 clinical isolates were included from patients with invasive fusariosis involving lungs, sinuses, or both. Clinico-radiological data were collected. Samples were processed by standard laboratory procedures. Three gene regions (ITS, TEF1, and RPB2) were amplified by PCR for multilocus sequencing. Fusarium MLST, FUSARIUM-ID, and FUSARIOID-ID databases were used for final identification. Antifungal susceptibility testing was performed by broth microdilution following CLSI M38-A3 and Sensititre™ YeastOne™ YO9 plate. Pulmonary involvement was seen in all patients, and sino-nasal involvement was present in six. Radiologically, consolidations and cavitations were present in eight and six cases, respectively. Halo sign was present in six; reverse halo sign was also found in three of them. Direct microscopy showed septate hyphae that were morphologically different from those found in aspergillosis. Results of the molecular identification were as follows: two Fusarium irregulare, one Fusarium pernambucanum, one Fusarium incarnatum, one Fusarium sp. FIESC 30, two Fusarium keratoplasticum, one Fusarium falciforme, one Fusarium pseudonygamai, and one Fusarium delphinoides. For both Fusarium solani (FSSC) and Fusarium incarnatum-equiseti (FIESC) species complexes, amphotericin B had the lowest minimum inhibitory concentrations (MICs). Importantly, for terbinafine, all FIESC isolates had low MICs, while FSSC isolates had high MICs. In some cases, early identification of Fusarium spp. is possible by means of morphology of hyphae on direct microscopy and findings on radiology. Molecular identification, at least to the species complex level, is crucial for the choice of antifungals.

Formulation Strategies to Overcome Amphotericin B Induced Toxicity

Fungal infection poses a major global threat to public health because of its wide prevalence, severe mortality rate, challenges involved in diagnosis and treatment, and the emergence of drug-resistant fungal strains. Millions of people are getting affected by fungal infection, and around 3.8 million people face death per year due to fungal infection, as per the latest report. The polyene antibiotic AmB has an extensive record of use as a therapeutic moiety against systemic fungal infection and leishmaniasis since 1960. AmB has broad-spectrum fungistatic and fungicidal activity. AmB exerts its therapeutic activity at the cellular level by binding to fungal sterol and forming hydrophilic pores, releasing essential cellular components and ions into the extracellular fluid, leading to cell death. Despite using AmB as an antifungal and antileishmanial at a broad scale, its clinical use is limited due to drug-induced nephrotoxicity resulting from binding the aggregated form of the drug to mammalian sterol. To mitigate AmB-induced toxicity and to get better anti-fungal therapeutic outcomes, researchers have developed nanoformulations, self-assembled formulations, prodrugs, cholesterol- and albumin-based AmB formulations, AmB-mAb combination therapy, and AmB cochleates. These formulations have helped to reduce toxicity to a certain extent by controlling the aggregation state of AmB, providing sustained drug release, and altering the physicochemical and pharmacokinetic parameters of AmB. Although the preclinical outcome of AmB formulations is quite satisfactory, its parallel result at the clinical level is insignificant. However, the safety and efficacy of AmB therapy can be improved at the clinical stage by continuous investigation and collaboration among researchers, clinicians, and pharmaceutical companies.

Antarctic Streptomyces: Promising biocontrol agents for combating Fusarium oxysporum f. sp. cubense

Fusarium wilt of Banana (FWB) caused by Fusarium oxysporum f. sp. cubense (Foc) poses a significant threat to the banana industry, with current inadequate control measures. This study evaluated the antifungal potential of nine Streptomyces strains isolated from Antarctic soil samples, using Casein-Starch media to stimulate the production of antifungal compounds. The inhibition spectrum against Foc was assessed under laboratory conditions using the well diffusion on Mueller-Hinton agar, with antifungal activity measured in arbitrary units (AU/mL) and minimum inhibitory concentration (MIC) tested using ethyl acetate extracts. Among the nine isolates, K6 and E7 were closely related to Streptomyces polyrhachis and Streptomyces fildesensis, exhibited significant antifungal activity, with K6 and E7 showing 320 and 80 AU/mL, and MIC values of 250 and >500 ppm, respectively. These findings highlight K6 and E7 as potential biocontrol agents against Foc, offering new avenues for sustainable Fusarium wilt management in banana cultivation.

Identification and antifungal sensitivity of Fusarium species isolated from piscine hosts

Fusarium is a huge genus of filamentous fungi that has the potential to cause emerging diseases. Members of this genus can cause infections in plants, animals and humans. Here, we report the isolation of F. oxysporum and F. equiseti from 2 important fish species, Oncorhynchus mykiss (rainbow trout) and Tor putitora (golden mahseer), respectively. F. oxysporum has emerged as a significant fungal pathogen causing infection in many fish. However, F. equiseti has been isolated mainly from plants. As far as the available literatures are concerned, this is the first report on the isolation of F. oxysporum and F. equiseti from these hosts. The isolates were identified based on growth morphology and microscopic observation. F. oxysporum produced violet pigmentation on potato dextrose agar, while F. equiseti had yellow colouration. F. oxysporum produced 1- to 2-celled microconidia along with straight or curved macroconidia having 3 to 4 septa. F. equiseti produced abundant macroconidia with 4 or more septa. Species were further confirmed based on the nucleotide sequences of the internal transcribed spacer region. In a molecular phylogeny analysis, F. oxysporum and F. equiseti formed 2 different clades. In an antifungal sensitivity assay, F. oxysporum was found to be susceptible to clotrimazole with a minimum inhibitory concentration of 1.0 µg ml-1, whereas F. equiseti was susceptible to clotrimazole, ketoconazole and fluconazole. Overall, the main findings of this study are the infection of new hosts by Fusarium species and the limited activity of many antifungal drugs against these pathogens.

Advancements in Green Nanoparticle Technology: Focusing on the Treatment of Clinical Phytopathogens

Opportunistic pathogenic microbial infections pose a significant danger to human health, which forces people to use riskier, more expensive, and less effective drugs compared to traditional treatments. These may be attributed to several factors, such as overusing antibiotics in medicine and lack of sanitization in hospital settings. In this context, researchers are looking for new options to combat this worrying condition and find a solution. Nanoparticles are currently being utilized in the pharmaceutical sector; however, there is a persistent worry regarding their potential danger to human health due to the usage of toxic chemicals, which makes the utilization of nanoparticles highly hazardous to eukaryotic cells. Multiple nanoparticle-based techniques are now being developed, offering essential understanding regarding the synthesis of components that play a crucial role in producing anti-microbial nanotherapeutic pharmaceuticals. In this regard, green nanoparticles are considered less hazardous than other forms, providing potential options for avoiding the extensive harm to the human microbiome that is prevalent with existing procedures. This review article aims to comprehensively assess the current state of knowledge on green nanoparticles related to antibiotic activity as well as their potential to assist antibiotics in treating opportunistic clinical phytopathogenic illnesses.

Fusarium Keratitis on the Rise - a Clinical Review

Fungal keratitis due to Fusarium species is a rare but serious ocular disease. Due to its rapid progression, often late diagnostic confirmation as well as limited topical treatment options, this is potentially sight threatening. Increasing contact lens use and global climate change have been suggested to be factors leading to an increase in cases of fusarium keratitis, even in regions with moderate climate. Early recognition and initiation of antimycotic treatment, as well as early surgical treatment by penetrating keratoplasty are decisive for the outcome.

Fusariosis in burn patients: A systematic review of case reports

Burns can cause skin damage, facilitating the entry of fungi and other microorganisms into the body, leading to infections. Fusarium is a fungus capable of infecting individuals with burn injuries. Diagnosing and treating Fusarium infections in burn patients can be challenging due to the manifestation of nonspecific symptoms. This study aims to investigate case reports and case series from published literature describing Fusarium infection in burned patients, in order to assess treatment regimens, clinical outcomes, and make recommendations for future management. We conducted searches on Web of Science, PubMed, ScienceDirect, and Medline for all case reports and case series containing keywords 'Burn', 'Burns', 'Burned', 'Fusarium', or 'Fusariosis' in the title or abstract. All burn patients who developed Fusarium fungal infections between January 1974 and March 2023 were included in the study. Demographic and clinical data were analyzed retrospectivity. The final analysis incorporates 24 case reports encompassing a total of 87 burn patients with Fusarium infection. Patient ages ranged from one to 85 years, with the majority being male (53%). The median percentage of burn surface area was 78%, and the skin in the face, upper limbs, and lower limbs were the most commonly infected sites. Fungal infections appeared around 10 days after the burn injury on average. The majority of the patients were identified through culture or histopathology. The Fusarium dimerum species complex, which was found in nine patients, was the most frequently identified Fusarium species complex. Amphotericin B was the most preferred treatment drug, followed by voriconazole, and 62% of patients underwent debridement. In our study, 23 patients (37%) died from fungal infections. Implementing early and effective treatment protocols targeting Fusarium spp. in burn treatment units can significantly reduce mortality rates. It is critical to enhance the understanding of fusariosis epidemiology and emphasize the importance of maintaining a high clinical suspicion for this condition in burn patients.

Trans-kingdom fungal pathogens infecting both plants and humans, and the problem of azole fungicide resistance

Azole antifungals are abundantly used in the environment and play an important role in managing fungal diseases in clinics. Due to the widespread use, azole resistance is an emerging global problem for all applications in several fungal species, including trans-kingdom pathogens, capable of infecting plants and humans. Azoles used in agriculture and clinics share the mode of action and facilitating cross-resistance development. The extensive use of azoles in the environment, e.g., for plant protection and wood preservation, contributes to the spread of resistant populations and challenges using these antifungals in medical treatments. The target of azoles is the cytochrome p450 lanosterol 14-α demethylase encoded by the CYP51 (called also as ERG11 in the case of yeasts) gene. Resistance mechanisms involve mainly the mutations in the coding region in the CYP51 gene, resulting in the inadequate binding of azoles to the encoded Cyp51 protein, or mutations in the promoter region causing overexpression of the protein. The World Health Organization (WHO) has issued the first fungal priority pathogens list (FPPL) to raise awareness of the risk of fungal infections and the increasingly rapid spread of antifungal resistance. Here, we review the main issues about the azole antifungal resistance of trans-kingdom pathogenic fungi with the ability to cause serious human infections and included in the WHO FPPL. Methods for the identification of these species and detection of resistance are summarized, highlighting the importance of these issues to apply the proper treatment.

Invasive fusariosis in patients with leukaemia in the era of mould-active azoles: increasing incidence, frequent breakthrough infections and lack of improved outcomes

OBJECTIVES

Historically, patients with leukaemia and invasive fusariosis (IF) have experienced poor outcomes in the setting of persistent immunosuppression. Herein, we retrospectively reviewed the incidence, presentation and outcomes of IF that are scarcely studied in contemporary cohorts of leukaemia patients.

METHODS

We identified adult leukaemia patients with proven or probable IF at MD Anderson Cancer Center during 2009-21. Independent risk factors for 42 day mortality after IF diagnosis were determined using a multivariable logistic regression model. Combined with historical data, the annual IF incidence density over the past 23 years was estimated using Poisson regression analysis.

RESULTS

Among 140 leukaemia patients with IF (114 proven), 118 patients (84%) had relapsed/refractory leukaemia and 124 (89%) had neutropenia at IF diagnosis. One hundred patients (71%) had pulmonary IF, 88 (63%) had disseminated IF and 48 (34%) had fungaemia. Coinfections were common (55%). Eighty-nine patients (64%) had breakthrough IF to mould-active triazoles. Most patients (84%) received combination antifungal therapy. Neutrophil recovery [adjusted OR (aOR), 0.04; 95% CI, 0.01-0.14; P < 0.0001], pulmonary IF (aOR, 3.28; 95% CI, 1.11-9.70; P = 0.032) and high SOFA score (aOR, 1.91 per 1-point increase; 95% CI, 1.47-2.50; P < 0.0001) were independent predictors of 42 day mortality outcomes. From 1998 to 2021, IF incidence density increased significantly at an annual ratio of 1.03 (95% CI, 1.01-1.06; P = 0.04).

CONCLUSIONS

IF is predominantly seen in patients with relapsed/refractory leukaemia and increasingly seen as a breakthrough infection to mould-active triazoles. Despite frequent combination antifungal therapy, high mortality rates have persisted in patients with lasting neutropenia.

Clinical spectrum of fusariosis from a tertiary care center in India- a retrospective study

Background and Objectives

Fusarium spp. is an emerging pathogen that presents with varied clinical presentations but there are very few studies from India that elaborate on the spectrum of infection caused by the fungus. Hence, the present study was conducted in our institute to understand the clinical spectrum of fusariosis.

Materials and Methods

The present study was a retrospective study conducted at a tertiary care institute, in Hyderabad, Telangana, India for four years from January 2018 to December 2022. All the patients with clinically significant isolation of Fusarium spp. from various samples were included in the study.

Results

There were 25 cases of fusariosis diagnosed during the study period. Fusarium was isolated predominantly from debrided tissue following road traffic accidents in 12/25 (84%) of the cases, nails in 3/25 (12%) and superficial leg ulcer in 1/25 (4%) of the cases. Speciation was done for four patients. Three were Fusarium incarnatum and one was Fusarium solani. The patients were treated surgically and with/without antifungal therapy and were discharged in a stable condition.

Conclusion

Traumatic injuries were the major cause of infections in the present study. As Fusarium is a virulent and highly resistant pathogen, an early suspicion and an appropriate diagnosis would lead to a better outcome in these patients.

Update on therapeutic approaches for invasive fungal infections in adults

Invasive fungal infections are increasingly encountered with the expansion of iatrogenic immunosuppression, including not only solid organ and hematopoietic stem cell transplant recipients but also patients with malignancies or autoimmune diseases receiving immunomodulatory therapies, such as Bruton Tyrosine Kinase (BTK) inhibitor. Their attributable mortality remains elevated, part of which is a contribution from globally emerging resistance in both molds and yeasts. Because antifungal susceptibility test results are often unavailable or delayed, empiric and tailored antifungal approaches including choice of agent(s) and use of combination therapy are heterogeneous and often based on clinician experience with knowledge of host's net state of immunosuppression, prior antifungal exposure, antifungal side effects and interaction profile, clinical severity of disease including site(s) of infection and local resistance data. In this review, we aim to summarize previous recommendations and most recent literature on treatment of invasive mold and yeast infections in adults to guide optimal evidence-based therapeutic approaches. We review the recent data that support use of available antifungal agents, including the different triazoles that have now been studied in comparison to previously preferred agents. We discuss management of complex infections with specific emerging fungi such as Scedosporium spp., Fusarium spp., Trichosporon asahii, and Candida auris. We briefly explore newer antifungal agents or formulations that are now being investigated to overcome therapeutic pitfalls, including but not limited to olorofim, rezafungin, fosmanogepix, and encochleated Amphotericin B. We discuss the role of surgical resection or debridement, duration of treatment, follow-up modalities, and need for secondary prophylaxis, all of which remain challenging, especially in patients chronically immunocompromised or awaiting more immunosuppressive therapies.

The First Case of Fusarium falciforme Eumycetoma in Sudan and an Extensive Literature Review about Treatment Worldwide

Eumycetoma is an infectious disease caused by various fungal pathogens. The disease is characterised by black and pale-yellowish grain discharge. In this communication, we report a case of eumycetoma with a pale grain foot-eumycetoma caused by Fusarium falciforme. The patient presented at the outpatient clinic of the Mycetoma Research Centre in Sudan. The causative agent was initially misidentified as Aspergillus nidulans based on its seemingly similar histopathological appearance. However, sequencing the internally transcribed spacer region of the extracted grain confirmed infection with Fusarium falciforme. Although the patient received Itraconazole and underwent surgical excision, the disease was recurrent. To our knowledge, this is the first report on Fusarium falciforme causing eumycetoma in Sudan, indicating the expansion of the geographical distribution of this pathogen. This calls for raising the awareness of healthcare providers and improving the diagnostic and surveillance systems in at-risk areas to improve the case management and reduce the threat of further spread. Considering the potential impacts of F. falciforme infection including threatening the global health, food security, and ecosystem balance, as well as loss of biodiversity and negative socioeconomic changes in endemic countries, we recommend the implementation of an integrated transdisciplinary One Health strategy for the prevention and control of emerging infectious diseases including F. falciforme.

Successful Use of Fosmanogepix for Treatment of Rare Highly Resistant Cutaneous Fusariosis in a Pediatric Patient With STAT3 Hyper-Immunoglobulin E Syndrome and End-Stage Kidney Disease

We describe the successful use of the novel antifungal drug fosmanogepix to treat a chronic case of multidrug-resistant cutaneous Fusarium suttonianum infection in a pediatric patient with STAT3 hyper-IgE syndrome and end-stage kidney disease on peritoneal dialysis.

Probiotics and their postbiotics for the control of opportunistic fungal pathogens: A review

During past twenty years the opportunistic fungal infections have been emerging, causing morbidity and mortality. The fungi belonging to Aspergillus, Mucor, Rhizopus, Candida, Fusarium, Penicillium, Dermatophytes and others cause severe opportunistic fungal infections. Among these Aspergillus and Candida spp cause majority of the diseases. The continuum of fungal infections will prolong to progress in the surroundings of the growing inhabitants of immunocompromised individuals. Presently many chemical-based drugs were used as prophylactic and therapeutic agents. Prolonged usage of antibiotics may lead to some severe effect on the human health. Also, one of the major threats is that the fungal pathogens are becoming the drug resistant. There are many physical, chemical, and mechanical methods to prevent the contamination or to control the disease. Owing to the limitations that are observed in such methods, biological methods are gaining more interest because of the use of natural products which have comparatively less side effects and environment friendly. In recent years, research on the possible use of natural products such as probiotics for clinical use is gaining importance. Probiotics, one of the well studied biological products, are safe upon consumption and are explored to treat various fungal infections. The antifungal potency of major groups of probiotic cultures such as Lactobacillus spp, Leuconostoc spp, Saccharomyces etc. and their metabolic byproducts which act as postbiotics like organic acids, short chain fatty acids, bacteriocin like metabolites, Hydrogen peroxide, cyclic dipeptides etc. to inhibit these opportunistic fungal pathogens have been discussed here.

In Vitro Evaluation of the Antifungal Effect of AgNPs on Fusarium oxysporum f. sp. lycopersici

The application of nanomaterials in the agri-food industry can lead us to the formulation of new sustainable and effective pesticides for the control of fungi such as Fusarium oxysporum f. sp. lycopersici (Fol). This is a fungal plant pathogen for the tomato plant. In this work, silver nanoparticles (AgNPs) were synthesized by a green methodology from Geranium leaf extract as a reducing agent. The poisoned food technique was used to determine the percentage of inhibition of Fol mycelial growth by the action of AgNPs. They were characterized by transmission electron microscopy (TEM, JEOL JEM-2100, Tokyo, Japan) and ultraviolet-visible spectroscopy (UV-VIS, DU 730 Beckman Coulter, Brea, CA, USA). Five different concentrations of AgNPs (10, 20, 40, 75, and 150 mg/L) were evaluated in vitro in order to determine the minimum inhibitory concentration (MIC) as well as the behavior of their antifungal activity in tomato fruit. Nanoparticles with spherical morphology and average diameters of 38.5 ± 18.5 nm were obtained. The maximum percentage of inhibition on the mycelial growth of Fol was 94.6 ± 0.1%, which was obtained using the AgNPs concentration of 150 mg/L and it was determined that the MIC corresponds to 75 mg/L. On the other hand, in a qualitative way, it was possible to observe an external inhibitory effect in the tomato fruit from the concentration of 10 mg/L. Finally, we can conclude that AgNPs are a viable alternative for alternative formulations applied in the agri-food industry as pesticide solutions.

In vitro antifungal susceptibility profile of Iranian Fusarium isolates: Emphasising on the potent inhibitory effect of efinaconazole compared to other drugs

BACKGROUND

Fusarium species are opportunistic human pathogens that remarkably cause fungal infections ranging from superficial to fatal invasive disseminated infections. Fusarium species are notoriously resistant to the majority of antifungal agents.

OBJECTIVES

Therefore, detailed studies regarding in vitro susceptibility are required and may lead to a better prognosis of severe infections.

METHODS

We evaluated 25 antifungal drugs in vitro against 282 clinical and environmental Fusarium isolates.

RESULTS

Fusarium species demonstrated high MICs/MECs values to the most commonly used antifungal drugs in clinical practice. The geometric mean (GM) MICs for luliconazole (0.004 μg/ml) and lanoconazole (0.012 μg/ml) were the lowest, followed by efinaconazole (0.98 μg/ml) and amphotericin B (1.04 μg/ml).

CONCLUSIONS

Efinaconazole, a novel triazole, may be a promising candidate for the treatment of superficial Fusarium infections. Furthermore, the development of systemic formulations of these drugs as well as further in vitro and in vivo investigations could aid in the treatment of systemic fusariosis.

Species Diversity in the Fusarium solani (Neocosmospora) Complex and Their Pathogenicity for Plants and Humans

The Fusarium solani species complex is a large group of soil saprotrophs with a broad adaptive potential, which allows the fungi to exist under various conditions and to parasitize on different hosts. The review analyzes the modern data concerning the genetic peculiarities of species from this complex by the example of F. solani f. sp. pisi and generalizes the data on the most widespread species pathogenic for both plants and humans. The enhanced resistance of the F. solani species complex to the most of modern antifungal agents and the need for novel therapeutic agents against fusariosis has been considered.

Fusarium proliferatum-induced chronic lip ulcer: successful treatment with itraconazole: a case report

Background

Fusarium species are saprophytic fungi with a worldwide distribution. These fungi cause various infections among immunocompromised patients; however, they can also involve immunocompetent individuals.

Case presentation

We report a case of a 41-year-old Iranian woman who presented with ulcerative lesions on her lips 10 months ago. She had a long history of anxiety but had no history of classical risk factors such as trauma, cosmetic lip tattoo, burning in her lips, smoking or use of alcohol and opium. A skin biopsy from the lower lip was performed and sent for microbiological examinations. Hyaline septate hyphae were seen on direct microscopy with potassium hydroxide. The clinical specimen was subcultured on sabouraud dextrose agar with chloramphenicol and prepared for antifungal susceptibility testing and molecular identification. Considering the minimum inhibitory concentrations (MIC) for antifungals, itraconazole (100 mg orally twice a day) was started for her, and after 2 months, the lesions were treated. She followed up for 3 months, and no signs of disease recurrence were observed.

Conclusions

Selecting an appropriate treatment strategy according to the laboratory assessments is essential in clinical practice and the management of rare infections to prevent related mortality and morbidity of opportunistic fungal infections.

In Vitro Antifungal Susceptibility Profile of Miltefosine against a Collection of Azole and Echinocandins Resistant Fusarium Strains

Fusarium species are filamentous fungi that cause a variety of infections in humans. Because they are commonly resistant to many antifungal drugs currently available in clinical settings, research into alternative targets in fungal cells and therapeutic approaches is required. The antifungal activity of miltefosine and four comparators, amphotericin B, voriconazole, itraconazole, and caspofungin, were tested in vitro against a collection of susceptible and resistant clinical (n = 68) and environmental (n = 42) Fusarium isolates. Amphotericin B (0.8 μg/mL) had the lowest geometric mean (GM) MICs/MECs values followed by miltefosine (1.44 μg/mL), voriconazole (2.15 μg/mL), caspofungin (7.23 μg/mL), and itraconazole (14.19 μg/mL). Miltefosine was the most effective agent against Fusarium isolates after amphotericin B indicating that miltefosine has the potential to be studied as a novel treatment for Fusarium infections.

Fusarium solani Necrotizing Fasciitis Complicating Treatment for Acute Lymphoblastic Leukemia: A Case Report

Fungal infections due to Fusarium species are serious albeit rare and mostly occur in severely immunocompromised patients. The prognosis of such infections, especially of disseminated manifestations, is poor as a result of multi-antifungal resistance, particularly to azoles. We report a case of a rapidly progressive necrotizing fasciitis of the foot secondary to Fusarium solani in a young female patient with acute lymphoblastic leukemia on consolidation therapy. Surgical debridement was undertaken and liposomal amphotericin was given as definitive therapy for a total of six weeks followed by secondary prophylaxis that resulted in remarked clinical and radiological improvement. High clinical suspicion, prompt surgical intervention, rapid diagnosis, and timely initiation of appropriate antifungal therapy are crucial for a favorable outcome in this relatively uncommon life-threatening infection.

A chloroacetamide derivative as a potent candidate for fusariosis treatment

Fusariosis has presented a significant increase in their incidence in the last years. This epidemiological panorama probably is due to the increasing profile of refractory susceptibility of Fusarium spp. to available drugs, especially in immunocompromised individuals. Thus, the development of new compounds with effectiveness on these organisms is a necessity. This study evaluated the antifungal potential of a chloroacetamide derivative (4-BFCA) against resistant Fusarium strains. As a result, the compound was effective against all strains (MIC range 12.5-50 μg/mL). The time kill assay demonstrated that 4-BFCA presents a concentration-dependent fungicidal action. Although its action mechanism has not yet been elucidated, it was possible to observe its efficacy through damages and alterations provoked along the hyphae of Fusarium spp. 4-BFCA maintained a high survival rate of Tenebrio molitor larvae, suggesting that it does not cause acute systemic toxicity on this host at the concentration evaluated. In addition, 4-BFCA was 83.33% effective in combating a fungal infection in vivo on the chorioallantoid membrane of embryonated eggs. Our results are very promising and arouse interest to investigate the action of 4-BFCA on Fusarium strains since it acts as a possible candidate for the development of new therapies for the treatment of fusariosis.

Competitiveness during Dual-Species Biofilm Formation of Fusarium oxysporum and Candida albicans and a Novel Treatment Strategy

During an infection, a single or multispecies biofilm can develop. Infections caused by non-dermatophyte molds, such as Fusarium spp. and yeasts, such as Candida spp., are particularly difficult to treat due to the formation of a mixed biofilm of the two species. Fusarium oxysporum is responsible for approximately 20% of human fusariosis, while Candida albicans is responsible for superficial mucosal and dermal infections and for disseminated bloodstream infections with a mortality rate above 40%. This study aims to investigate the interactions between C. albicans and F. oxysporum dual-species biofilm, considering variable formation conditions. Further, the ability of the WMR peptide, a modified version of myxinidin, to eradicate the mixed biofilm when used alone or in combination with fluconazole (FLC) was tested, and the efficacy of the combination of WMR and FLC at low doses was assessed, as well as its effect on the expression of some biofilm-related adhesin and hyphal regulatory genes. Finally, in order to confirm our findings in vivo and explore the synergistic effect of the two drugs, we utilized the Galleria mellonella infection model. We concluded that C. albicans negatively affects F. oxysporum growth in mixed biofilms. Combinatorial treatment by WMR and FLC significantly reduced the biomass and viability of both species in mature mixed biofilms, and these effects coincided with the reduced expression of biofilm-related genes in both fungi. Our results were confirmed in vivo since the synergistic antifungal activity of WMR and FLC increased the survival of infected larvae and reduced tissue invasion. These findings highlight the importance of drug combinations as an alternative treatment for C. albicans and F. oxysporum mixed biofilms.

Fungicide Activity of Culture Extract from Kocuria palustris 19C38A1 against Fusarium oxysporum

Secondary metabolites of actinomycetes are a potential source of bioactive compounds in the agricultural sector. This study aimed to determine the fungicidal properties of extracts of marine organism-derived actinomycetes. Actinomycetes were isolated from marine organisms using agar media with 1% colloidal chitin in artificial seawater. Then, the isolates were cultured on liquid media with 1% colloidal chitin in artificial seawater under static conditions for 14 days. The culture was extracted, the fungicide properties were evaluated using the microtiter 96-well plate method, and the influence of inhibition was visualized using apotome and SEM. Finally, the active extract was analyzed using LCMSMS. In the present study, 19 actinomycetes were isolated from marine organisms, and the isolates were examined with regard to their antifungal activities. Of these nineteen isolates, the isolate 19C38A1 was picked out from the rest. Hence, it showed significant control towards F. oxysporum. The prospective strain 19C38A1 was determined to be Kocuria palustris 19C38A1. The extract 19C38A1 was shown to cause damage to cell integrity, indicated by the shrinking form, and inhibited germination in the F. oxysporum; subsequently, the chemical characteristics of the compound produced by the potential isolate 19C38A1 indicated the presence of benzimidazole compounds in the active fraction of C38BK2FA. These results indicate that actinomycetes derived from marine organisms near the coast of Oluhuta, Tomini Bay, Gorontalo, related to strain 19C38A1, are not widely known as sources of valuable fungicides. This preliminary information is important, as it can be used as a basis for further development in the search for fungicides derived from marine actinomycetes.

Antifungal Susceptibility of 182 Fusarium Species Isolates from 20 European Centers: Comparison between EUCAST and Gradient Concentration Strip Methods

We determined the susceptibility of 182 Fusarium species isolates to five antifungal drugs (amphotericin B, voriconazole, posaconazole, isavuconazole, and terbinafine) by the EUCAST method. Based on the latest taxonomic insights, isolates collected from 20 European centers were distributed into seven complexes and 27 species. The susceptibility was variable, depending on the species. Comparison with the gradient concentration strip method, which was used for 77 isolates, showed essential agreement values for voriconazole, posaconazole, isavuconazole, and amphotericin B of 17%, 91%, 83%, and 70%, respectively.

Fusarium musae from Diseased Bananas and Human Patients: Susceptibility to Fungicides Used in Clinical and Agricultural Settings

Fusarium musae belongs to the Fusarium fujikuroi species complex. It causes crown rot disease in banana but also keratitis and skin infections as well as systemic infections in immunocompromised patients. Antifungal treatments in clinical and agricultural settings rely mostly on molecules belonging to the azole class. Given the potential risk of pathogen spread from food to clinical settings, the goal of the work was to define the level of susceptibility to different azoles of a worldwide population of F. musae. Eight fungicides used in agriculture and five antifungals used in clinical settings (4 azoles and amphotericin B) were tested using the CLSI (Clinical and Laboratory Standards Institute) protocol methodology on 19 F. musae strains collected from both infected patients and bananas. The level of susceptibility to the different active molecules was not dependent on the source of isolation with the exception of fenbuconazole and difenoconazole which had a higher efficiency on banana-isolated strains. Minimal inhibitory concentrations (MICs) of the different molecules ranged from 0.12–0.25 mg/L for prochloraz to more than 16 mg/L for tetraconazole and fenbuconazole. Compared to the F. verticillioides, F. musae MICs were higher suggesting the importance of monitoring the potential future spread of this species also in clinical settings.

Diversity of Fusarium species causing invasive and disseminated infections

INTRODUCTION

Invasive fusariosis (IF) is considered an emerging fungal disease and an important problem worldwide that increasingly affects immunocompromised individuals. There is currently concern about establishing the genetic diversity and phylogenetic relationship of the species Fusarium causing invasive fusariosis.

MATERIALS AND METHODS

The aim of this study was to characterize the molecular profile and morphological characteristics of Fusarium species isolated from 21 patients with invasive fusariosis. Multilocus sequence typing was performed for molecular identification of the following genes: the second largest subunit of the RNA polymerase gene (RPB2) and elongation factor 1 alpha (EF-1α). The morphological features of different species were carefully described and revised by experienced mycologists.

RESULTS

Morphological and molecular analyses revealed that the F. solani species complex (FSSC) and F. oxysporum species complex (FOSC) were the most common species isolated from patients with invasive fusariosis; FSSC-2 h (5), FSSC-1 (2) and FOSC-183 (2) were the most frequent haplotypes. The macroscopic characterization revealed great variation in the tonalities of the FSSC colonies and particularities amongst the species in relation to the macroconidia structures, while the FOSC was more homogeneous and presented shades from white to lilac.

CONCLUSIONS

Our study characterized the diversity, haplotypes, and morphological aspects of Fusarium species and the haplotypes prevalent in patients with invasive fusariosis. FSSC and FSSC-2 h were the predominant species and haplotype, respectively. Although we have described interesting morphological aspects in Fusarium species, particularly haplotypes, their identification cannot rely on phenotypical aspects. Molecular biology techniques are necessary and should be introduced for routine use in mycology laboratories.

Case Report: Successful Management of Refractory Keratomycosis in an Alpaca Using Penetrating Keratoplasty and Combination Antifungal Therapy (Caspofungin 0.5% and Terbinafine 1%)

Fungal keratitis is a common disease in certain parts of the world and affects several species, including equids, camelids, and homo sapiens, leading to blindness or loss of the eye if the infection is not adequately controlled. Reports of clinical use of antifungals caspofungin and terbinafine are limited across both veterinary and human medical literature. The alpaca presented in this case demonstrates that deep keratomycosis can be caused by Scopulariopsis brevicaulis and Fusarium verticillioides, two previously unreported fungi to cause keratomycosis in camelids. This report demonstrates successful management with a combination of surgery and topical ophthalmic treatment with caspofungin 0.5% solution and terbinafine 1% dermatologic cream, after initially failing treatment with topical voriconazole 1% solution. Combination therapy appears more effective than monotherapy with some fungal organisms, and synergy between antifungal agents is thought to play a role in the success of combination therapy. Surgery to remove the bulk of the fungal infection is especially helpful in cases that fail initial medical therapy.

Azole antifungal resistance in fungal isolates from wastewater treatment plant effluents

Wastewater treatment plants (WWTPs) can be significant sources of antifungal resistant fungi, which can disseminate further in the environment by getting into rivers together with effluents discharged from WWTPs and pose a risk for human health. In this study, the presence of azole resistance was determined in fungal isolates from treated effluents of two WWTPs using the standard microdilution method from Clinical and Laboratory Standards Institute (CLSI). A total of 41 fungal isolates representing 23 fungal species and 16 fungal genera were obtained. Fungal genera related to the known human and/or plant pathogens such as Aspergillus, Fusarium, and Candida were detected. Among the observed species, the susceptibility of Aspergillus fumigatus and Fusarium oxysporum was tested against fluconazole (FCZ), ketoconazole (KTZ), itraconazole (ITZ), and voriconazole (VCZ). The isolate A. fumigatus was susceptible to KTZ, ITZ, and VCZ, while it showed resistance against FCZ. On the contrast, the isolate F. oxysporum showed resistance to KTZ, ITZ, and VCZ. Comparatively, VCZ showed highest activity against both A. fumigatus and F. oxysporum. Analysis of the gene Cyp51A for the A. fumigatus isolate showed no evidence of drug resistance that could be related to point mutations and/or tandem repeats in the gene. To the best of our knowledge, this is the first susceptibility test study on A. fumigatus and F. oxysporum isolates from the WWTPs of South Africa. In conclusion, this study indicated an urgent need for thorough investigation with larger group of fungal isolates from different regions of South Africa to broadly understand the role of WWTPs in the dissemination of azole antifungal drug resistance.

Ungual hyalohyphomycosis caused by Fusarium cugenangense

Fusarium onychomycosis is uncommon in the temperate climate zone of Japan. Based on the morphological characteristics and a gene analysis, we diagnosed a patient with ungual hyalohyphomycosis caused by Fusarium cugenangense belonging to the F oxysporum complex. This intractable disease was cured by 6-month treatment with efinaconazole 10% solution.

Amphotericin B and Other Polyenes-Discovery, Clinical Use, Mode of Action and Drug Resistance

Although polyenes were the first broad spectrum antifungal drugs on the market, after 70 years they are still the gold standard to treat a variety of fungal infections. Polyenes such as amphotericin B have a controversial image. They are the antifungal drug class with the broadest spectrum, resistance development is still relatively rare and fungicidal properties are extensive. Yet, they come with a significant host toxicity that limits their use. Relatively recently, the mode of action of polyenes has been revised, new mechanisms of drug resistance were discovered and emergent polyene resistant species such as Candida auris entered the picture. This review provides a short description of the history and clinical use of polyenes, and focusses on the ongoing debate concerning their mode of action, the diversity of resistance mechanisms discovered to date and the most recent trends in polyene resistance development.

A One Health Perspective to Recognize Fusarium as Important in Clinical Practice

Any strategy that proposes solutions to health-related problems recognizes that people, animals, and the environment are interconnected. Fusarium is an example of this interaction because it is capable of infecting plants, animals, and humans. This review provides information on various aspects of these relations and proposes how to approach fusariosis with a One Health methodology (a multidisciplinary, and multisectoral approach that can address urgent, ongoing, or potential health threats to humans, animals, and the environment). Here, we give a framework to understand infection pathogenesis, through the epidemiological triad, and explain how the broad utilization of fungicides in agriculture may play a role in the treatment of human fusariosis. We assess how plumbing systems and hospital environments might play a role as a reservoir for animal and human infections. We explain the role of antifungal resistance mechanisms in both humans and agriculture. Our review emphasizes the importance of developing interdisciplinary research studies where aquatic animals, plants, and human disease interactions can be explored through coordination and collaborative actions.

Antifungal Activity against Fusarium culmorum of Stevioside, Silybum marianum Seed Extracts, and Their Conjugate Complexes

Fusarium head blight (FHB) is a disease that poses a major challenge in cereal production that has important food and feed safety implications due to trichothecene contamination. In this study, the effect of stevioside-a glycoside found in the leaves of candyleaf (Stevia rebaudiana Bertoni)-was evaluated in vitro against Fusarium culmorum (W.G. Smith) Sacc., alone and in combination (in a 1:1 molar ratio) with polyphenols obtained from milk thistle seeds (Silybum marianum (L.) Gaertn). Different concentrations, ranging from 32 to 512 µg·mL^-1, were assayed, finding EC₅₀ and EC₉₀ inhibitory concentrations of 156 and 221 µg·mL^-1, respectively, for the treatment based only on stevioside, and EC₅₀ and EC₉₀ values of 123 and 160 µg·mL^-1, respectively, for the treatment based on the stevioside-polyphenol conjugate complexes. Colony formation inhibition results were consistent, reaching full inhibition at 256 µg·mL^-1. Given that synergistic behavior was observed for this latter formulation (SF = 1.43, according to Wadley's method), it was further assessed for grain protection at storage, mostly directed against mycotoxin contamination caused by the aforementioned phytopathogen, confirming that it could inhibit fungal growth and avoid trichothecene contamination. Moreover, seed tests showed that the treatment did not affect the percentage of germination, and it resulted in a lower incidence of root rot caused by the pathogen in Kamut and winter wheat seedlings. Hence, the application of these stevioside-S. marianum seed extract conjugate complexes may be put forward as a promising and environmentally friendly treatment for the protection of cereal crops and stored grain against FHB.

A comparative study of antibacterial and antifungal activities of extracts from four indigenous plants

A repetitive and wide use of chemical antibiotics has brought a serious threat in the biomedical and clinical sectors by the emergence of multidrug resistant pathogens. Plants have secondary metabolites that make them suitable candidate for natural antimicrobial agent without any side effect. In this study, we assessed comparative antibacterial and antifungal effects of extracts from four Indigenous plants (Nerium sp; Mentha sp; Aloe vera and Eucalyptus sp). Total phenolic and flavonoid content were extracted by microwave-assisted extractor and used for phytochemical assay. Antimicrobial experiment was done by micro dilution technique. A post hoc analysis inbuilt with one-way ANOVA test was used for the compilation of antibiotic sensitivity data and percent inhibition. Total phenolic content was significantly high in Mentha sp. and low in Nerium sp. (All p < 0.05). In antibacterial and antifungal activity higher concentrations of extracts showed a strong activity, which was as good as antibiotics used as control. Results from Eucalyptus sample showed a significant growth reducing capability even at lower concentrations. This study concludes that the plant extracts can be used to treat microbial infections with almost same efficacy as antibiotics and with a lower chance of resistance development.

Molecular identification of Fusarium species complex isolated from clinical samples and its antifungal susceptibility patterns

Background and Purpose:

More than 300 Fusarium species are grouped into approximately 23 species complexes out of which around 70 are involved in human infections. The nomenclature of these species has undergone considerable changes in recent years. These species cause localized infections in individuals while inducing systemic infections mainly in immunocompromised patients. The present study was conducted to identify Fusarium species in clinical isolates by molecular methods and determine their in vitro minimum inhibitory concentration (MIC) patterns to address the lack of data in this domain in Northern India.

Materials and Methods:

For the purpose of the study, Fusarium isolates obtained from various clinical samples were sent to the Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands, for molecular identification. The MIC testing was performed using the microbroth dilution method as per the Clinical and Laboratory Standards Institute reference method (M38-A2).

Results:

Fusarium was isolated from 33 patients (i.e., 1, 1, 2, 14, and 15 cases with endophthalmitis, sinusitis, pulmonary involvement, onychomycosis, and keratitis, respectively). These 33 isolates belonged to three species complexes, namely F. solani species complex (FSSC; n=13), F. fujikuroi species complex (FFSC; n=13), and F. incarnatumequiseti species complex (FIESC; n=7). The species identified within FSSC, FFSC, and FIESC included F. keratoplasticum (n=6)/F. falciforme (n=6)/F. solani (n=1), F. proliferatum (n=7)/F. sacchari (n=5)/F. anthophilum (n=1), and F. incarnatum SC species (n=6)/F. equiseti SC species (n=1), respectively. The MIC results showed that all isolates had a lower MIC against amphotericin B than against the other antifungal agents.

Antifungal Susceptibly Testing by Concentration Gradient Strip Etest Method for Fungal Isolates: A Review

Antifungal susceptibility testing is an important tool for managing patients with invasive fungal infections, as well as for epidemiological surveillance of emerging resistance. For routine testing in clinical microbiology laboratories, ready-to-use commercial methods are more practical than homemade reference techniques. Among commercially available methods, the concentration gradient Etest strip technique is widely used. It combines an agar-based diffusion method with a dilution method that determinates a minimal inhibitory concentration (MIC) in µg/mL. Many studies have evaluated the agreement between the gradient strip method and the reference methods for both yeasts and filamentous fungi. This agreement has been variable depending on the antifungal, the species, and the incubation time. It has also been shown that the gradient strip method could be a valuable alternative for detection of emerging resistance (non-wild-type isolates) as Etest epidemiological cutoff values have been recently defined for several drug-species combinations. Furthermore, the Etest could be useful for direct antifungal susceptibility testing on blood samples and basic research studies (e.g., the evaluation of the in vitro activity of antifungal combinations). This review summarizes the available data on the performance and potential use of the gradient strip method.

Shielding the Next Generation: Symbiotic Bacteria from a Reproductive Organ Protect Bobtail Squid Eggs from Fungal Fouling

Organisms must have strategies to ensure successful reproduction. Some animals that deposit eggs protect their embryos from fouling/disease with the help of microorganisms. Although beneficial bacteria are hypothesized to contribute to egg defense in some organisms, the mechanisms of this protection remain largely unknown, with the exception of a few recently described systems. Using both experimental and analytical approaches, we demonstrate that symbiotic bacteria associated with a cephalopod reproductive gland and eggs inhibit fungi. Chemical analyses suggest that these bacteria produce antimicrobial compounds that may prevent overgrowth from fungi and other microorganisms. Given the distribution of these symbiotic glands among many cephalopods, similar defensive relationships may be more common in aquatic environments than previously realized. Such defensive symbioses may also be a rich source for the discovery of new antimicrobial compounds.

The importance of defensive symbioses, whereby microbes protect hosts through the production of specific compounds, is becoming increasingly evident. Although defining the partners in these associations has become easier, assigning function to these relationships often presents a significant challenge. Here, we describe a functional role for a bacterial consortium in a female reproductive organ in the Hawaiian bobtail squid, Euprymna scolopes. Bacteria from the accessory nidamental gland (ANG) are deposited into the egg jelly coat (JC), where they are hypothesized to play a defensive role during embryogenesis. Eggs treated with an antibiotic cocktail developed a microbial biomass primarily composed of the pathogenic fungus Fusarium keratoplasticum that infiltrated the JC, resulting in severely reduced hatch rates. Experimental manipulation of the eggs demonstrated that the JC was protective against this fungal fouling. A large proportion of the bacterial strains isolated from the ANG or JC inhibited F. keratoplasticum in culture (87.5%), while a similar proportion of extracts from these strains also exhibited antifungal activity against F. keratoplasticum and/or the human-pathogenic yeast Candida albicans (72.7%). Mass spectral network analyses of active extracts from bacterial isolates and egg clutches revealed compounds that may be involved in preventing microbial overgrowth. Several secondary metabolites were identified from ANG/JC bacteria and egg clutches, including the known antimicrobial lincomycin as well as a suite of glycerophosphocholines and mycinamicin-like compounds. These results shed light on a widely distributed but poorly understood symbiosis in cephalopods and offer a new source for exploring bacterial secondary metabolites with antimicrobial activity.

Vitek® MS v3.0 System in the Identification of Filamentous Fungi

Infections caused by filamentous fungi are rising in incidence and became a serious health concern. Their rapid and reliable identification in the clinical laboratory is essential for an early and accurate diagnosis to guide timely therapy. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reported as a rapid and reliable method for identification of bacteria and yeasts isolated from clinical samples. However, it has less used for molds identification. The aim of this study was to evaluate Vitek^® MS (a MALDI-TOF MS system) ability to identify molds and differentiate species within a complex. A collection of 90 filamentous fungi, 70 clinical and 20 environmental isolates, was studied by morphological and molecular methods and by Vitek^® MS. Seventy-four isolates (82.2%) were identified using Vitek^® MS v3.0 at Genus/Complex/Species group level; within these, 47/74 (63.5%) were correctly identified at species level and only one was misidentified. In contrast, 16/90 isolates (17.8%) were not identified, of which 13 were not present in the database. Results here expressed favor Vitek^® MS v3.0 as a very useful system for identification of most common clinical isolates of filamentous fungi. Accordingly, it may be an important tool for clinical microbiology laboratories in their task to answer to clinicians, adequately and rapidly, helping in proper patient's management.

Honokiol, magnolol and its monoacetyl derivative show strong anti-fungal effect on Fusarium isolates of clinical relevance

The antifungal activity of magnolol and honokiol, two naturally occurring hydroxylated biphenyls, and of their synthetic derivatives was evaluated on a collection of representative isolates of Fusarium oxysporum, F. solani and F. verticillioides of clinical and ecological concern. The tested compounds were proposed as a ‘natural’ alternative to conventional fungicides, even though a larger range of concentrations (5–400 μg/ml) was applied. The activity of magnolol and honokiol was compared with that of terbinafine (0.1–10 μg/ml), and fluconazole (1–50 μg/ml), two fungicides widely used in treating fungal infections on humans. Magnolol showed similar fungicidal activity compared to fluconazole, whereas honokiol was more effective in inhibiting mycelium growth compared to this fungicide on all tested clinical Fusarium spp. isolates. Compared to terbinafine, honokiol showed similar antifungal activity when tested on clinical F. solani isolates, whereas magnolol was less effective at all selected concentrations (5–400 μg/ml). The different position of the phenol-OH group, as well as its protection, explain different in vitro activities between magnolol, honokiol, and their derivatives. Furthermore, magnolol showed mycelium dry weight reduction at a concentration of 0.5 mM when tested on a set of agricultural isolates of Fusaria, leading to complete inhibition of some of them. Magnolol and honokiol are proposed as efficient and safe candidates for treating clinically relevant Fusaria.

An Omics Approach to Diagnosing or Investigating Fungal Keratitis

Fungal keratitis (FK) is one of the most severe corneal infectious diseases. FK often leads to poor visual prognosis and thus requires accurate diagnosis. Conventional approaches, including clinical diagnoses, smears, and cultures, often fail to provide reliable diagnostic value. Omics approaches, such as those using genomic, metagenomic, and tear proteomic data sources, provide promising features for improving the diagnosis and monitoring the progression of FK. Genomic approaches are based mainly on detecting amplicons of ribosomal RNA genes, and internal transcribed spacers are gradually gaining popularity in clinical practices. A metagenomic approach based on 16S rRNA genes may help monitor the dynamic change of conjunctival microbiota associated with an FK event, whereas that based on shot-gun and 18S rRNA target enrichment sequencing could have the potential to diagnose FK using clinical samples. A tear proteomic approach may provide comprehensive information about ocular surface defense and injury during FK. Representative up- and down-regulated proteins during FK could also be used as biomarkers to determine the clinical course and develop a treatment strategy in different stages of FK. Consequently, a personalized tear proteomic approach will soon play a key role in FK management.

Demonstration of Adventitious Sporulation in Fusarium Petroliphilum Onychomycosis

Fusarium petroliphilum is a recently described species within the Fusarium solani species complex. Some strains of Fusarium species are capable of forming yeast-like structures in tissue as well as in culture through a process known as "adventitious sporulation." Here, we describe the formation of these yeast-like reproductive structures in infected nail tissue obtained from a case of onychomycosis. These structures were also observed in culture grown on RPMI 1640 agar supplemented with 2% glucose. The isolate was resistant to azoles and echinocandins. To the best of our knowledge, this is the first report describing adventitious sporulation in F. petroliphilum and its etiologic role in onychomycosis.

Antimicrobial photodynamic therapy with phenothiazinium photosensitizers in non-vertebrate model Galleria mellonella infected with Fusarium keratoplasticum and Fusarium moniliforme

Fusarium keratoplasticum and Fusarium moniliforme are filamentous fungi common in the environment and cause mycosis in both animals and plants. Human infections include mycetoma, keratitis and onychomycosis, while deeper mycosis occurs in immunocompromised patients. Most of the Fusarium spp. are frequently resistant to treatment with currently used antifungals. The frequent occurrence of antifungal resistance has motivated the study of antimicrobial photodynamic therapy as an alternative treatment for fungal infections. Many studies have investigated the in vitro use of antimicrobial photodynamic therapy to kill fungi, but rarely in animal models of infection. Thus, here we employed the invertebrate wax moth Galleria mellonella to study the in vivo effects of antimicrobial photodynamic therapy with three different phenothiazinium photosensitizers, methylene blue, new methylene blue N and the pentacyclic S137 against infection with microconidia of Fusarium keratoplasticum and Fusarium moniliforme. The effect of antimicrobial photodynamic therapy using these photosensitizers and light-emitting diodes with an emission peak at 635 nm and an integrated irradiance from 570 to 670 nm of 9.8 mW cm^-2 was investigated regarding the toxicity, fungal burden, larval survival and cellular immune response. The results from this model indicate that antimicrobial photodynamic therapy with methylene blue, new methylene blue N and S137 is efficient for the treatment of infection with F. keratoplasticum and F. moniliforme. The efficiency can be attributed to the fungal cell damage caused by antimicrobial photodynamic therapy which facilitates the action of the host immune response.