Multicenter, International Study of MIC/MEC Distributions for Definition of Epidemiological Cutoff Values for Sporothrix Species Identified by Molecular Methods

The first autochthonous human case of sporotrichosis by Sporothrix brasiliensis in Paraguay

Sporotrichosis by Sporothrix brasiliensis is increasingly reported in South America. Here, we present the first autochthonous human case in Paraguay, transmitted by a local infected cat. After 63 days of clinical signs onset, the patient was correctly diagnosed and antifungal treatment started, highlighting the need to increase awareness for this emerging disease.

Therapeutic alternatives for sporotrichosis induced by wild-type and non-wild-type Sporothrix schenckii through in vitro and in vivo assessment of enilconazole, isavuconazole, posaconazole, and terbinafine

This study explores the effectiveness of various antifungal drugs in treating sporotrichosis caused by Sporothrix schenckii, especially in non-wild-type (non-WT) strains. The drugs tested include enilconazole (ENIL), isavuconazole (ISA), posaconazole (POS), terbinafine (TER), and itraconazole (ITC). The study involved in vitro and in vivo tests on 10 WT isolates and eight ITC non-WT isolates. Two isolates were assessed using time-kill assays, checkerboard assays, and Galleria mellonella infection models. In vitro studies have shown that all of these drugs were more effective than or equal to ITC against WT and non-WT isolates. No ITC resistance was observed with other azoles. All drugs inhibited fungal growth of WT and non-WT strains within 24 h at all incubations. ENIL and TER showed fungicidal effect against types at over 2x minimum inhibitory concentrations with no regrowth. POS was fungicidal against WT at high concentrations but not against non-WT. ISA was only fungicidal for non-WT. ITC did not exhibit any fungicidal activity. In checkerboard experiments, the combination of POS or ISA with TER showed enhanced activity against WT and non-WT strains, surpassing the combination of ITC with TER. In vivo model experiments demonstrated significantly reduced mortality rates with ENIL, POS, and TER against WT and with ENIL, ISA, POS, and TER against non-WT. The study concludes that monotherapy with ENIL, ISA, POS, and TER, and combinations of POS/TER or ISA/TER, show promise as effective antifungal treatments against S. schenckii, including ITC-non-WT isolates.

Zoonotic feline sporotrichosis: a small case cluster in Perth, Western Australia, and a review of previous feline cases from Australia

Sporotrichosis is caused by species of the fungus Sporothrix that affect human and several animal species. The transmission of sporotrichosis is classically from an environmental source following penetrating injury. The alternative zoonotic route has gained attention due to the rapid and significant spread of cat-transmitted sporotrichosis in South America and Malaysia, resulting in several thousand human and feline cases in recent decades, especially in Brazil. In Australia, sporotrichosis is sporadic and mainly related to environmental sources. Although feline sporotrichosis is rare in Australia, zoonotic transmission occurred in two of five reported cases, including a recent case cluster, which is reported in this article. The investigation of such cases in Australia is important, as cats not only represent a source of infection living in close proximity with humans, but also, they may represent sentinels for the environmental presence of the fungus. To encourage the investigation and reporting of new veterinary cases, we have reviewed Australian sporotrichosis cases in humans and cats and report a new case cluster of feline sporotrichosis in Perth, WA, Australia, with zoonotic transmission. The index case was a kitten who developed severe facial sporotrichosis with prominent involvement of the nasal planum. Two human cases - one suspected and one confirmed - are also described in the owner, who was a veterinary nurse, and the attending veterinarian, respectively, probably from handling the kitten while not wearing gloves. Later, another mature cat in the same household also became infected. The affected cats were successfully treated using combination of itraconazole and terbinafine. To the best of our knowledge, this is only the second case of cat-transmitted sporotrichosis reported from Australia.

Milteforan, a promising veterinary commercial product against feline sporotrichosis

Sporotrichosis, the cutaneous mycosis most commonly reported in Latin America, is caused by the Sporothrix clinical clade species, including Sporothrix brasiliensis and Sporothrix schenckii sensu stricto. Due to its zoonotic transmission in Brazil, S. brasiliensis represents a significant health threat to humans and domestic animals. Itraconazole, terbinafine, and amphotericin B are the most used antifungals for treating sporotrichosis. However, many strains of S. brasiliensis and S. schenckii have shown resistance to these agents, highlighting the importance of finding new therapeutic options. Here, we demonstrate that milteforan, a commercial veterinary product against dog leishmaniasis, whose active principle is miltefosine, is a possible therapeutic alternative for the treatment of sporotrichosis, as observed by its fungicidal activity in vitro against different strains of S. brasiliensis and S. schenckii. Fluorescent miltefosine localizes to the Sporothrix cell membrane and mitochondria and causes cell death through increased permeabilization. Milteforan decreases S. brasiliensis fungal burden in A549 pulmonary cells and bone marrow-derived macrophages and also has an immunomodulatory effect by decreasing TNF-α, IL-6, and IL-10 production. Our results suggest milteforan as a possible alternative to treat feline sporotrichosis.

IMPORTANCE

Sporotrichosis is an endemic disease in Latin America caused by different species of Sporothrix. This fungus can infect domestic animals, mainly cats and eventually dogs, as well as humans. Few drugs are available to treat this disease, such as itraconazole, terbinafine, and amphotericin B, but resistance to these agents has risen in the last few years. Alternative new therapeutic options to treat sporotrichosis are essential. Here, we propose milteforan, a commercial veterinary product against dog leishmaniasis, whose active principle is miltefosine, as a possible therapeutic alternative for treating sporotrichosis. Milteforan decreases S. brasiliensis fungal burden in human and mouse cells and has an immunomodulatory effect by decreasing several cytokine production.

Non-Zoonotic Transmission of Sporotrichosis: A Translational Study of Forty-Three Cases in a Zoonotic Hyperendemic Area

Over the past two decades, zoonotic sporotrichosis transmitted by naturally infected cats has become hyperendemic in Rio de Janeiro, Brazil. Sporothrix brasiliensis is the main agent involved. However, there are other forms of transmission of sporotrichosis. The aim of this study was to evaluate and associate the epidemiological, clinical and therapeutic data and the susceptibility of Sporothrix spp. to antifungal drugs in 43 non-zoonotic sporotrichosis cases. Forty-three clinical strains of Sporothrix were identified by partial sequencing of the calmodulin gene. An antifungal susceptibility test of amphotericin B, terbinafine, itraconazole, posaconazole and isavuconazole was performed according to the broth microdilution method. Most patients were male (55.8%). Regarding the source of infection, 21 patients (48.8%) reported trauma involving plants and/or contact with soil. Sporothrix brasiliensis was the predominant species (n = 39), followed by S. globosa (n = 3) and S. schenckii (n = 1). Sporothrix brasiliensis was associated with all the sources of infection, reinforcing previous data showing the presence of this species in environmental sources, as well as with all the clinical forms, including severe cases. One clinical strain of Sporothrix brasiliensis was classified as a non-wild-type strain for amphotericin B and another for itraconazole. S. schenckii was classified as non-WT for all the antifungals tested. In this context, it is important to emphasize that non-zoonotic sporotrichosis still occurs in the state of Rio de Janeiro, with S. brasiliensis as the main etiological agent, primarily associated with infections acquired after traumatic inoculation with plants and/or soil contact, followed by S. globosa and S. schenckii. In addition, non-WT strains were found, indicating the need to monitor the antifungal susceptibility profile of these species. It is crucial to investigate other natural sources of S. brasiliensis to better understand this fungal pathogen and its environment and host cycle.

Is terbinafine an effective treatment for feline sporotrichosis?

BACKGROUND

Terbinafine has been successfully used in the treatment of human sporotrichosis; however, its effectiveness in the treatment of feline sporotrichosis is unknown. Therefore, this study aimed to describe the use of terbinafine in the treatment of feline sporotrichosis.

METHODS

A cohort study was conducted in cats with sporotrichosis to assess the effectiveness and safety of terbinafine (30‒60 mg/kg/day). Clinical examination and analysis of laboratory parameters were performed monthly until clinical signs resolved or terbinafine treatment was discontinued.

RESULTS

Of the 54 cats with sporotrichosis included in the study, 19 were lost during follow-up and five were withdrawn from the study due to switching to treatment with another prescription drug. Of the remaining 30 cats, 10 achieved clinical cure, with a median treatment time of 18.5 weeks. Treatment failed in 18 cases, and two cats died. Twenty-two cats had adverse reactions to terbinafine treatment, and 10 cats showed elevation of serum transaminases.

LIMITATION

Loss during follow-up was high, which makes it difficult to draw accurate conclusions regarding clinical outcomes.

CONCLUSION

The low rate of clinical cure observed suggests that terbinafine does not represent an effective treatment option for cases of feline sporotrichosis.

What are the 100 most cited fungal genera?

The global diversity of fungi has been estimated between 2 to 11 million species, of which only about 155 000 have been named. Most fungi are invisible to the unaided eye, but they represent a major component of biodiversity on our planet, and play essential ecological roles, supporting life as we know it. Although approximately 20 000 fungal genera are presently recognised, the ecology of most remains undetermined. Despite all this diversity, the mycological community actively researches some fungal genera more commonly than others. This poses an interesting question: why have some fungal genera impacted mycology and related fields more than others? To address this issue, we conducted a bibliometric analysis to identify the top 100 most cited fungal genera. A thorough database search of the Web of Science, Google Scholar, and PubMed was performed to establish which genera are most cited. The most cited 10 genera are Saccharomyces, Candida, Aspergillus, Fusarium, Penicillium, Trichoderma, Botrytis, Pichia, Cryptococcus and Alternaria. Case studies are presented for the 100 most cited genera with general background, notes on their ecology and economic significance and important research advances. This paper provides a historic overview of scientific research of these genera and the prospect for further research. Citation: Bhunjun CS, Chen YJ, Phukhamsakda C, Boekhout T, Groenewald JZ, McKenzie EHC, Francisco EC, Frisvad JC, Groenewald M, Hurdeal VG, Luangsa-ard J, Perrone G, Visagie CM, Bai FY, Błaszkowski J, Braun U, de Souza FA, de Queiroz MB, Dutta AK, Gonkhom D, Goto BT, Guarnaccia V, Hagen F, Houbraken J, Lachance MA, Li JJ, Luo KY, Magurno F, Mongkolsamrit S, Robert V, Roy N, Tibpromma S, Wanasinghe DN, Wang DQ, Wei DP, Zhao CL, Aiphuk W, Ajayi-Oyetunde O, Arantes TD, Araujo JC, Begerow D, Bakhshi M, Barbosa RN, Behrens FH, Bensch K, Bezerra JDP, Bilański P, Bradley CA, Bubner B, Burgess TI, Buyck B, Čadež N, Cai L, Calaça FJS, Campbell LJ, Chaverri P, Chen YY, Chethana KWT, Coetzee B, Costa MM, Chen Q, Custódio FA, Dai YC, Damm U, de Azevedo Santiago ALCM, De Miccolis Angelini RM, Dijksterhuis J, Dissanayake AJ, Doilom M, Dong W, Alvarez-Duarte E, Fischer M, Gajanayake AJ, Gené J, Gomdola D, Gomes AAM, Hausner G, He MQ, Hou L, Iturrieta-González I, Jami F, Jankowiak R, Jayawardena RS, Kandemir H, Kiss L, Kobmoo N, Kowalski T, Landi L, Lin CG, Liu JK, Liu XB, Loizides M, Luangharn T, Maharachchikumbura SSN, Makhathini Mkhwanazi GJ, Manawasinghe IS, Marin-Felix Y, McTaggart AR, Moreau PA, Morozova OV, Mostert L, Osiewacz HD, Pem D, Phookamsak R, Pollastro S, Pordel A, Poyntner C, Phillips AJL, Phonemany M, Promputtha I, Rathnayaka AR, Rodrigues AM, Romanazzi G, Rothmann L, Salgado-Salazar C, Sandoval-Denis M, Saupe SJ, Scholler M, Scott P, Shivas RG, Silar P, Souza-Motta CM, Silva-Filho AGS, Spies CFJ, Stchigel AM, Sterflinger K, Summerbell RC, Svetasheva TY, Takamatsu S, Theelen B, Theodoro RC, Thines M, Thongklang N, Torres R, Turchetti B, van den Brule T, Wang XW, Wartchow F, Welti S, Wijesinghe SN, Wu F, Xu R, Yang ZL, Yilmaz N, Yurkov A, Zhao L, Zhao RL, Zhou N, Hyde KD, Crous PW (2024). What are the 100 most cited fungal genera? Studies in Mycology 108: 1-411. doi: 10.3114/sim.2024.108.01.

Bimodal distribution of azole susceptibility in Sporothrix brasiliensis isolates in Brazil

Sporothrix brasiliensis is an emerging zoonotic fungal pathogen that can be difficult to treat. Antifungal susceptibility testing was performed on the mold phase of a convenience sample of 61 Sporothrix spp. isolates from human and cat sporotrichosis cases in Brazil using the Clinical and Laboratory Standards Institute standard M38. A bimodal distribution of azole susceptibility was observed with 50% (28/56) of S. brasiliensis isolates showing elevated itraconazole minimum inhibitory concentrations ≥16 µg/mL. Phylogenetic analysis found the in vitro resistant isolates were not clonal and were distributed across three different S. brasiliensis clades. Single nucleotide polymorphism (SNP) analysis was performed to identify potential mechanisms of in vitro resistance. Two of the 28 resistant isolates (MIC ≥16 mg/L) had a polymorphism in the cytochrome P450 gene, cyp51, corresponding to the well-known G448S substitution inducing azole resistance in Aspergillus fumigatus. SNPs corresponding to other known mechanisms of azole resistance were not identified in the remaining 26 in vitro resistant isolates.

Screening of alkaloids and withanolides isolated from Solanaceae plants for antifungal properties against non-wild type Sporothrix brasiliensis

Antifungal resistance has often been found in animal sporotrichosis in Southern Brazil. The biological potential of compounds from plants of the Solanaceae family against infectious diseases is known, however, it is still unknown against Sporothrix brasiliensis. This study evaluated the anti-Sporothrix brasiliensis activity, synergism, cytotoxicity, and action mechanism of steroidal lactones (withanolides) and alkaloids isolated from these plants. Pure compounds of withanolide D (WNOD), physalin F (PHYF), withanicandin (WNIC), nicandin B (NICB), solasonine (SSON), and solamargine (SMAR) were tested against 12 Sporothrix brasiliensis isolated from cats (n = 11) and dogs (n = 2) through M38-A2 CLSI. For the compounds with the best activity, a checkerboard assay for synergism, sorbitol protection, and ergosterol effect for action mechanism; and MTT test for cytotoxicity were performed. The withanolides WNOD, PHYF, WNIC, and NICB were not antifungal, but SSON (MIC 0.125-1 mg/mL) and SMAR (MIC 0.5-1 mg/mL) were both fungistatic and fungicidal (MFC 0.5-1 mg/mL for both) against wild-type (WT) and non-WT isolates. The activity of SSON and SMAR was indifferent when combined with itraconazole. In the mechanism of action, cell wall and plasma membrane by complexation with ergosterol seemed to be two target structures of SSON and SMAR. SSON was selected for cytotoxicity, whose cell viability in MDBK cells ranged from 28.85 % to 101.75 %, and was higher than 87.49 % at concentrations ≤0.0015 mg/ml. Only the steroidal alkaloids SSON and SMAR were active against non-WT isolates, being promising antifungal candidates for the treatment of feline and canine sporotrichosis with low susceptibility to itraconazole.

Case Report: Osteomyelitis Due to Sporothrix brasiliensis in Two Immunocompetent Patients Requiring Surgical Amputation

Sporotrichosis is the most frequent subcutaneous mycosis in Latin America. Sporothrix brasiliensis is the most virulent species, responsible for the majority of human and animal cases in Brazil. Osteomyelitis was described as a potential comorbidity of S. brasiliensis infection; however, surgical amputation resulting from an extracutaneous form is a rare outcome. In such cases, immunodeficiency and alcoholism must be investigated. We present two unusual cases of surgical amputation as a severe morbidity resulting from osteomyelitis by S. brasiliensis in immunocompetent nonalcoholic patients.

Amlodipine and lufenuron as repurposing drugs against Sporothrix brasiliensis

Background

Sporotrichosis caused by Sporothrix brasiliensis is a globally emerging infectious disease with limited therapeutic options. Thus, we aimed to evaluate the in vitro activity of amlodipine (AML) and lufenuron (LUF) alone and their interaction with itraconazole (ITZ), the first-choice drug against S. brasiliensis.

Methods

Twenty clinical isolates of S. brasiliensis from two hyperendemic regions were tested through a microdilution assay to evaluate the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of AML and LUF. Checkerboard assay was performed with 10 isolates for both drug interactions with ITZ.

Results

AML showed inhibitory and fungicidal activity against all isolates included, with MIC values ranging from 32 to 256 µg/mL, and MFC from 64 to 256 µg/mL. However, none of the S. brasiliensis isolates were inhibited by the highest soluble concentration of LUF (MIC >64 µg/mL for all strains). Synergic interaction of AML and LUF with ITZ occurred in 50% and 40% of the isolates tested, without any antagonistic effects.

Conclusion

Both repurposing drugs evaluated in our study showed a promising in vitro activity, especially in synergy with ITZ against S. brasiliensis, warranting future in vivo investigations regarding its activity.

Antifungal efficacy of imidazo[1,2-a]pyrazine-based thiosemicarbazones and thiazolidinediones against Sporothrix species

Aim: To evaluate antifungal potential of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids based on thiosemicarbazones and thiazolidinediones against pathogenic Sporothrix species. Methods: Antifungal activity of nine compounds were assessed by broth microdilution. Interactions between active compounds and itraconazole were evaluated by the checkerboard assay using non-wild-type isolates. Cytotoxicity of the compounds was determined. Results: Four C-3 substituted analogs showed antifungal activity, unrelated to thiosemicarbazone or thiazolidinedione functions. Synergistic interactions between the four compounds and itraconazole, and low toxicity on mouse fibroblast cells were observed. Activity of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids against Sporothrix depended on the substitution on the imidazopyrazine ring. Conclusion: Antifungal potential, overcoming itraconazole resistance and low toxicity indicate the possible use of that series of compounds in a therapeutic alternative for treatment of sporotrichosis.

Human and Feline Sporotrichosis in a Reference Center of Southeastern Brazil: Genetic Differentiation, Diversity, and Antifungal Susceptibility of Sporothrix Species

Sporotrichosis is a neglected subcutaneous fungal infection that affects humans and animals worldwide caused by species belonging to the genus Sporothrix. This study aims to examine the range of genetic variations, assess molecular epidemiology significance, and explore potential modes of transmission of the Sporothrix species associated with the current sporotrichosis outbreaks in Espírito Santo, Brazil. In this investigation, 262 samples were evaluated, including 142 from humans and 120 from felines, collected between 2016 and 2021. The isolates were identified based on morphological and molecular characteristics. Sexual idiomorphs were determined by mating-type PCR using primers specific to the MAT1-1 and MAT1-2 loci. Amplified fragment length polymorphism (AFLP) was employed to assess the genetic variability of Sporothrix spp. Finally, antifungal susceptibility testing was performed following the CLSI M38-A2 protocol. Of the 142 human samples, 125 were identified as S. brasiliensis and 17 as S. schenckii s. str. The presence of S. brasiliensis was overwhelming (100%) during outbreaks, highlighting the significant role of domestic cats in the emergence of this species. Heterothallism was the only observed mating strategy. However, the MAT1-2 idiomorph was predominant in cases of cat-transmitted sporotrichosis (χ2 = 202.976; p < 0.0001). Our AFLP results show significant intraspecific variability observed among S. brasiliensis isolates in Espírito Santo. Different genotypes forming subgroups within the same population suggest that these isolates do not originate from a single ancestor, indicating multiple emergences. Furthermore, terbinafine was the antifungal with the best results in vitro. However, in clinical practice, itraconazole remains the primary treatment choice. Sporotrichosis continues to advance in the state; therefore, the health system must outline one-health strategies to contain the disease to prevent future epidemics.

Phenotypic and Genotypic Characterization and Antifungal Susceptibility of Sporothrix schenckii sensu stricto Isolated from a Feline Sporotrichosis Outbreak in Bangkok, Thailand

Sporotrichosis, an invasive fungal infection caused by Sporothrix schenckii, has emerged in Southeast Asia, affecting cats and posing a potential zoonotic risk to humans. We evaluated 38 feline sporotrichosis cases in and around Bangkok, Thailand, from 2017 to 2021. The isolates were phenotypically and genotypically characterized. The cats infected with sporotrichosis were mainly young adults, males, and domestic short hairs with uncontrolled outdoor access, and they lived in Bangkok. All isolates showed low thermotolerance and converted to the yeast phase at 35 °C. Based on the internal transcribed spacer region of rDNA sequences, our strains belonged to S. schenckii sensu stricto and clustered with clinical clade D. Based on the concatenated tree of calmodulin and beta-tubulin genes, five groups of S. schenckii were generated, and the monophyletic clade, Group II, of Thai strains was recognized. In vitro antifungal susceptibility testing demonstrated that the MIC50 of our isolates to amphotericin B, itraconazole, and posaconazole were within the limit of the species-specific epidemiological cutoff values, suggesting that the organisms were the wild type. Addressing the outbreak of feline sporotrichosis in Thailand by providing guidelines for diagnosis and effective treatment may help control the spread of disease and reduce the risk of cat-transmitted sporotrichosis to humans.

High-Throughput Microsatellite Markers Development for Genetic Characterization of Emerging Sporothrix Species

Sporotrichosis is the main subcutaneous mycosis worldwide transmitted by animal or plant vectors and often escalates to outbreaks or epidemics. The current cat-transmitted sporotrichosis driven by Sporothrix brasiliensis has become a significant public health issue in South America. Transmission dynamics remain enigmatic due to the lack of development of polymorphic markers for molecular epidemiological analysis. This study used a high-throughput mining strategy to characterize simple sequence repeat (SSR) markers from Sporothrix genomes. A total of 118,140-143,912 SSR loci were identified (82,841-98,369 unique markers), with a 3651.55-3804.65 SSR/Mb density and a majority of dinucleotides motifs (GC/CG). We developed a panel of 15 highly polymorphic SSR markers suitable for genotyping S. brasiliensis, S. schenckii, and S. globosa. PCR amplification revealed 240 alleles in 180 Sporothrix isolates with excellent polymorphic information content (PIC = 0.9101), expected heterozygosity (H = 0.9159), and discriminating power (D = 0.7127), supporting the effectiveness of SSR markers in uncovering cryptic genetic diversity. A systematic population genetic study estimated three clusters, corresponding to S. brasiliensis (population 1, n = 97), S. schenckii (population 2, n = 49), and S. globosa (population 3, n = 34), with a weak signature of mixed ancestry between populations 1 and 2 or 3 and 2. Partitioning of genetic variation via AMOVA revealed highly structured populations (ΦPT = 0.539; Nm = 0.213; p < 0.0001), with approximately equivalent genetic variability within (46%) and between (54%) populations. Analysis of SSR diversity supports Rio de Janeiro (RJ) as the center of origin for contemporary S. brasiliensis infections. The recent emergence of cat-transmitted sporotrichosis in northeastern Brazil indicates an RJ-Northeast migration resulting in founder effects during the introduction of diseased animals into sporotrichosis-free areas. Our results demonstrated high cross-species transferability, reproducibility, and informativeness of SSR genetic markers, helping dissect deep and fine-scale genetic structures and guiding decision making to mitigate the harmful effects of the expansion of cat-transmitted sporotrichosis.

Are γ-terpinene, 1,8-cineole, p-coumaric acid, and quercetin active against wild-type and non-wild-type Sporothrix brasiliensis to itraconazole?

The emergence of itraconazole (ITZ)-resistant Sporothrix brasiliensis in feline and canine cases in southern Brazil has hampered the clinical cure of animal sporotrichosis, encouraging the search for therapeutic alternatives. The promising use of plants extracts from Lamiaceae family is known; however, there are no studies with its major compounds, as γ-terpinene (γTER), 1,8-cineole (1,8CIN), p-coumaric acid (pCOU), and quercetin (QUER). For the first time, we evaluated the antifungal, synergistic, cytotoxic activities and action mechanism of these compounds against S. brasiliensis. For this, 28 S. brasiliensis from cats (n = 24) and dogs (n = 4) and standard strains of S. brasiliensis and S. schenckii (n = 4) were tested by M38-A2 (CLSI), revealing non-wild-type (WT) isolates to ITZ on 54.2% (13/24) and 75% (03/04) of feline and canine isolates, respectively. Of the compounds, γTER stood out against all isolates (MIC/MFC 0.75 to > 3 mg/ml; MIC50 3 mg/ml). However, 1,8CIN, pCOU, and QUER showed little or no activity (MIC50 > 3 mg/ml). Thus, γTER was selected for checkerboard assay, whose combination with ITZ showed synergistic (WT isolates) and indifferent (non-WT isolates) interaction. For action mechanism (sorbitol protection and ergosterol effect), γTER acted in membrane by complexing with fungal ergosterol and at the cell wall level, showing two possible pathways as antifungal target. Finally, cytotoxicity (MTT assay) showed that γTER was the safest compound on MDBK cells, even at a concentration of 3 mg/ml (90.16%). Our findings support that γTER is a potent antifungal candidate for the control of sporotrichosis, including against non-WT S. brasiliensis.

Ethyl acetate fractions of Myrciaria floribunda, Ocotea pulchella, and Ocotea notata exhibit promising in vitro activity against Sporothrix brasiliensis isolates with low susceptibility to itraconazole

Sporothrix brasiliensis with low susceptibility isolates were described from the Brazilian zoonotic sporotrichosis hyperendemics. The aim of this work was to evaluate distinct fractions of Ocotea pulchella, Ocotea notata, Myrciaria floribunda, and Hypericum brasiliense plant extracts against itraconazole-sensitive and low susceptibility S. brasiliensis isolates. Crude extracts were tested against clinical isolates and the ATCC MYA4823 to determine the minimum inhibitory concentrations (MICs) and fungicidal or fungistatic activities (MFC). A high MICs and MFCs amplitude (1 - > 128 µg/mL) were obtained for seven extracts. The highest antimicrobial activities against sensitive S. brasiliensis were displayed by the ethyl acetate extracts of O. notata (MIC = 2-128 μg/mL) and M. floribunda (MIC = 1-8 μg/mL). A fungicidal effect was observed for all fraction extracts. Ocotea spp. and M. floribunda ethyl acetate extracts provide promising profiles against itraconazole-sensitive or low susceptibility S. brasiliensis. Future studies will determine if these extracts can contribute as alternative therapies to this neglected zoonosis.

Sporotrichosis Outbreak Due to Sporothrix brasiliensis in Domestic Cats in Magallanes, Chile: A One-Health-Approach Study

Sporotrichosis is an implantation mycosis with subcutaneo-lymphatic or, more rarely, a viscerally disseminated affection; it can be acquired through traumatic percutaneous inoculation of the fungus present in soil or plant matter, or by feline scratching. Among the causative agents, Sporothrix brasiliensis is considered the most virulent species with a high prevalence in Brazil and recently in Argentina.

OBJECTIVE

To describe a S. brasiliensis outbreak in domestic and feral cats detected in the Magallanes region of southern Chile.

MATERIALS AND METHODS

Between the months of July and September 2022, three cats presented with suppurative subcutaneous lesions located mainly on the head and thoracic limbs. The cytology revealed the presence of yeasts with morphological characteristics suggestive of Sporothrix spp. The histopathology confirmed pyogranulomatous subcutaneous lesions associated with the presence of the same yeasts. The fungal culture followed by the partial gene sequence and analysis of the ITS region confirmed the diagnosis of the S. brasiliensis as the causative agent. The cats were treated with itraconazole associated in one case with potassium iodide. The evolution of the patients was favorable in all cases.

CONCLUSIONS

An outbreak caused by S. brasiliensis was detected in domestic and feral cats in austral Chile. The correct identification of this fungus and antifungigram is essential for treatment decisions and for designing dissemination control and prevention programs under a one health approach that consider the health of people, animals, and the environment.

Mucosal Sporotrichosis from Zoonotic Transmission: Descriptions of Four Case Reports

BACKGROUND

Sporotrichosis is a subacute or chronic mycosis caused by a dimorphic fungus of the genus Sporothrix. Zoonotic-transmitted sporotrichosis has become a major public health concern and is characterised by a different clinical pattern from the traditional epidemiology of sporotrichosis.

CASE PRESENTATION

We present the details of four patients with mucosal sporotrichosis with regional lymphadenopathy (three cases of granulomatous conjunctivitis and one case of nasal sporotrichosis). The patients' age range was between 23 to 46 years old and their gender was three female and one male patient. All four patients shared the same ethnicity, Malay, and they had a common history of owning domestic cats as pets. Sporothrix schenckii were isolated from all the culture samples and its antifungal susceptibility patterns were compared in the mycelial and yeast phases. All four patients recovered with oral itraconazole treatment, but the treatment duration was variable among patients.

CONCLUSIONS

People who have a history of contact with domestic cats should be aware of the possibility of sporotrichosis infection. It can present in cutaneous, lymphocutaneous, disseminated, or systemic forms. Early treatment and the prevention of disease progression are more beneficial to patients. The published data concludes that antifungal treatment is highly efficacious, although the reported treatment duration is variable.

Severe Sporotrichosis Caused by Sporothrix brasiliensis: Antifungal Susceptibility and Clinical Outcomes

Itraconazole is the first choice for treating sporotrichosis. Amphotericin B is indicated for severe and disseminated forms. The aim of the study was to evaluate the antifungal susceptibility of Sporothrix brasiliensis strains isolated from patients with severe sporotrichosis treated with amphotericin B and correlate with clinical outcomes. Clinical and epidemiological data were obtained from severe sporotrichosis cases caused by S. brasiliensis. Antifungal susceptibility tests against amphotericin B, itraconazole, terbinafine, posaconazole, and 5-flucytosine were performed. Moreover, possible synergisms between amphotericin B and posaconazole or 5-flucytosine were assessed. Relationships between clinical and laboratorial data were then analyzed. Forty-six S. brasiliensis isolates from 37 patients were studied. Clinical forms included disseminated (94.6%) and disseminated cutaneous sporotrichosis (5.4%). The median treatment time was 784 days (range: 7 to 3115 days). Cure occurred in 45.9% of the cases and death due to sporotrichosis in 24.3%. Forty-three (93.5%) S. brasiliensis isolates were classified as wild-type for all the antifungals tested according to their in vitro antifungal susceptibility. There was no synergism for the combinations studied. Finally, we found no association between higher Minimal Inhibitory Concentration (MIC) values of amphotericin B or itraconazole with unfavorable outcomes; however, there were higher MIC values of itraconazole in strains isolated from alcoholic patients. Possibly, clinical factors, such as the extent of dissemination, immunosuppression, and late treatment onset, are the main determinants of patient outcomes, rather than antifungal resistance. The current study suggests that the need to use amphotericin B therapy is not associated with the emergence of S. brasiliensis resistant strains.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Epidemiological cut-off values for itraconazole and ravuconazole for Madurella mycetomatis, the most common causative agent of mycetoma

BACKGROUND

Eumycetoma is a neglected tropical disease. It is a chronic inflammatory subcutaneous infection characterised by painless swellings which produce grains. It is currently treated with a combination of itraconazole and surgery. In an ongoing clinical study, the efficacy of fosravuconazole, the prodrug of ravuconazole, is being investigated. For both itraconazole and ravuconazole, no clinical breakpoints or epidemiological cut-off values (ECV) to guide treatment are currently available.

OBJECTIVE

To determine tentative ECVs for itraconazole and ravuconazole in Madurella mycetomatis, the main causative agent of eumycetoma.

MATERIALS AND METHODS

Minimal inhibitory concentrations (MICs) for itraconazole and ravuconazole were determined in 131 genetically diverse clinical M. mycetomatis isolates with the modified CLSI M38 broth microdilution method. The MIC distributions were established and used to determine ECVs with the ECOFFinder software. CYP51A sequences were sequenced to determine whether mutations occurred in this azole target gene, and comparisons were made between the different CYP51A variants and the MIC distributions.

RESULTS

The MICs ranged from 0.008 to 1 mg/L for itraconazole and from 0.002 to 0.125 mg/L for ravuconazole. The M. mycetomatis ECV for itraconazole was 1 mg/L and for ravuconazole 0.064 mg/L. In the wild-type population, two CYP51A variants were found for M. mycetomatis, which differed in one amino acid at position 499 (S499G). The MIC distributions for itraconazole and ravuconazole were similar between the two variants. No mutations linked to decreased susceptibility were found.

CONCLUSION

The proposed M. mycetomatis ECV for itraconazole is 1 mg/L and for ravuconazole 0.064 mg/L.

Single nucleotide polymorphisms and chromosomal copy number variation may impact the Sporothrix brasiliensis antifungal susceptibility and sporotrichosis clinical outcomes

Feline-transmitted sporotrichosis has garnered attention due to the recent high incidence and the lack of efficient control in the epicenter of the epidemic, Rio de Janeiro, Brazil. Sporothrix brasiliensis is the major pathogen involved in feline-to-human sporotrichosis in Brazil and displays more virulent genotypes than the closely related species S. schenckii. Over the last two decades, several reports of antifungal-resistant strains have emerged. Sequencing and comparison analysis of the outbreak strains allowed us to observe that the azole non-wild-type S. brasiliensis strain CFP 1054 had significant chromosomal variations compared to wild-type strains. One of these variants includes a region of 231 Kb containing 75 duplicated genes, which were overrepresented for lipid and isoprenoid metabolism. We also identified an additional strain (CFP 1055) that was resistant to itraconazole and amphotericin B, which had a single nucleotide polymorphism in the tac1 gene. The patients infected with these two strains showed protracted clinical course and sequelae. Even though our sample size is modest, these results suggest the possibility of identifying specific point mutations and large chromosomal duplications potentially associated with antifungal resistance and clinical outcomes of sporotrichosis.

Sporotrichosis: A Review of a Neglected Disease in the Last 50 Years in Brazil

Sporotrichosis is caused by fungi belonging to the genus Sporothrix, which saprophytically are found in plants and organic matter. However, cats are highly susceptible to contamination with fungal spores and, when they become sick, they can transmit it to other animals and to man. The objective of this study is to carry out a systematic review on the emergency, diagnosis, clinical symptoms, therapeutics, and control of zoonotic sporotrichosis. Published data covering the last 50 years using a combination of keywords were selected to answer the question: Why has the zoonotic sporotrichosis been a neglected disease up to now? A total of 135 studies were included in this review. The studies emphasize that in recent decades, Brazil has experienced an unprecedented zoonotic outbreak of sporotrichosis. Advances on the genus Sporothrix allowed one to associate thermotolerance, capacity for melanin synthesis, potential for adhesion to tissue macromolecules, ergosterol peroxide production, and expression of virulence proteins as tools for infection and invasion in S. brasiliensis, the main species involved, although cases with S. schenckii or S. lurei were also reported. Correct diagnosis, early treatment, basic educational measures that emphasize responsible ownership of animals and reproductive control programs for felines can contribute to the control of zoonosis.

Trends in Molecular Diagnostics and Genotyping Tools Applied for Emerging Sporothrix Species

Sporotrichosis is the most important subcutaneous mycosis that affects humans and animals worldwide. The mycosis is caused after a traumatic inoculation of fungal propagules into the host and may follow an animal or environmental transmission route. The main culprits of sporotrichosis are thermodimorphic Sporothrix species embedded in a clinical clade, including S. brasiliensis, S. schenckii, S. globosa, and S. luriei. Although sporotrichosis occurs worldwide, the etiological agents are not evenly distributed, as exemplified by ongoing outbreaks in Brazil and China, caused by S. brasiliensis and S. globosa, respectively. The gold standard for diagnosing sporotrichosis has been the isolation of the fungus in vitro. However, with the advance in molecular techniques, molecular assays have complemented and gradually replaced the classical mycological tests to quickly and accurately detect and/or differentiate molecular siblings in Sporothrix. Nearly all techniques available for molecular diagnosis of sporotrichosis involve PCR amplification, which is currently moving towards detecting Sporothrix DNA directly from clinical samples in multiplex qPCR assays. From an epidemiological perspective, genotyping is key to tracing back sources of Sporothrix infections, detecting diversity in outbreak areas, and thus uncovering finer-scale epidemiological patterns. Over the past decades, molecular epidemiological studies have provided essential information to policymakers regarding outbreak management. From high-to-low throughput genotyping methods, MLSA, AFLP, SSR, RAPD, PCR-RFLP, and WGS are available to assess the transmission dynamics and sporotrichosis expansion. This review discusses the trends in the molecular diagnosis of sporotrichosis, genotyping techniques applied in molecular epidemiological studies, and perspectives for the near future.

Current Progress on Epidemiology, Diagnosis, and Treatment of Sporotrichosis and Their Future Trends

Sporotrichosis, a human and animal disease caused by Sporothrix species, is the most important implantation mycosis worldwide. Sporothrix taxonomy has improved in recent years, allowing important advances in diagnosis, epidemiology, and treatment. Molecular epidemiology reveals that S. brasiliensis remains highly prevalent during the cat-transmitted sporotrichosis outbreaks in South America and that the spread of S. brasiliensis occurs through founder effects. Sporothrix globosa and S. schenckii are cosmopolitan on the move, causing major sapronoses in Asia and the Americas, respectively. In this emerging scenario, one-health approaches are required to develop a creative, effective, and sustainable response to tackle the spread of sporotrichosis. In the 21st century, it has become vital to speciate Sporothrix, and PCR is the main pillar of molecular diagnosis, aiming at the detection of the pathogen DNA from clinical samples through multiplex assays, whose sensitivity reaches remarkably three copies of the target. The treatment of sporotrichosis can be challenging, especially after the emergence of resistance to azoles and polyenes. Alternative drugs arising from discoveries or repositioning have entered the radar of basic research over the last decade and point to several molecules with antifungal potential, especially the hydrazone derivatives with great in vitro and in vivo activities. There are many promising developments for the near future, and in this review, we discuss how these trends can be applied to the Sporothrix-sporotrichosis system to mitigate the advance of an emerging and re-emerging disease.

A Spotlight on Sporothrix and Sporotrichosis

Sporothrix (order Ophiostomatales) comprises a genus with 53 species, of which S. brasiliensis, S. schenckii, S. globosa, and S. luriei cause skin infections in humans and other mammals. Remarkably, closely related Sporothrix can follow different strategies in epidemics. For example, during the cat-transmitted sporotrichosis, there is an increased prevalence of the highly virulent S. brasiliensis in South America, whereas S. schenckii and S. globosa are generally associated with a sapronotic route worldwide. Therefore, species-specific types of transmission may require distinct public health strategies to mitigate the advance of sporotrichosis, including early diagnosis, isolation of new animal cases, administration of adequate antifungal therapy, and population education on the main aspects of the disease. Here, we shed light on the system Sporothrix-sporotrichosis covering hot topics in the epidemiology and diagnosis of this important neglected disease.

Sporotrichosis Caused by Non-Wild Type Sporothrix brasiliensis Strains

The zoonotic transmission of sporotrichosis due to Sporothrix brasiliensis occurs largely in Rio de Janeiro state, Brazil since the 1990´s. Most patients infected with S. brasiliensis respond well to itraconazole or terbinafine. However, a few patients have a slow response or do not respond to the treatment and develop a chronic infection. The aim of this study was to analyze strains of S. brasiliensis against five different drugs to determine minimal inhibitory concentration distributions, to identify non-wild type strains to any drug evaluated and the clinical aspects of infections caused by them. This study evaluated 100 Sporothrix spp. strains obtained from 1999 to 2018 from the Evandro Chagas National Institute of Infectious Diseases, Fiocruz, which were identified through a polymerase chain reaction using specific primers for species identification. Two-fold serial dilutions of stock solutions of amphotericin B, itraconazole, posaconazole, ketoconazole and terbinafine prepared in dimethyl sulfoxide were performed to obtain working concentrations of antifungal drugs ranging from 0.015 to 8.0 mg/L. The broth microdilution reference method was performed according the M38-A2 CLSI guideline. All strains were identified as S. brasiliensis and thirteen were classified as non-wild type, two of them against different drugs. Non-wild type strains were identified throughout the entire study period. Patients infected by non-wild type strains presented prolonged treatment times, needed increased antifungal doses than those described in the literature and one of them presented a permanent sequel. In addition, three of them, with immunosuppression, died from sporotrichosis. Despite the broad use of antifungal drugs in hyperendemic areas of sporotrichosis, an emergence of non-wild type strains did not occur. The results of in vitro antifungal susceptibility tests should guide sporotrichosis therapy, especially in immunosuppressed patients.

Co-Delivery of Doxycycline and Hydroxychloroquine Using CdTe-Labeled Solid Lipid Nanoparticles for Treatment of Acute and Chronic Brucellosis

Brucellosis is a systemic disease in both acute and chronic forms which can affect any organ or tissue in the body. One of the biggest issues in treating this disease is its relapse. In this study, a complete treatment of brucellosis was evaluated using enhanced performance of doxycycline and hydroxychloroquine drugs by using solid lipid nanoparticles (SLN) conjugated cadmium-telluride quantum dots. The double emulsion method was used to prepare SLN and cadmium-telluride quantum dots. The physicochemical properties of NPs were determined. The effect of nanoparticle-loaded antibiotics against Brucella melitensis was determined by well diffusion, minimum inhibitory concentration (MIC), cell culture, and animal studies. The means of particle size, PDI, zeta potential, drugs loading, and encapsulation efficiency were 214 ± 25 nm, 0.385 ± 0.022, −18.7 ± 2.3 mV, 17.7 ± 1.5%, and 94.15 ± 2.6%, respectively. The results of FTIR and DSC showed that no chemical reaction occurred between the components of the NPs. The effect of free drug and NPs on bacteria was the same by well diffusion and MIC method. Drug-loaded NPs significantly reduced the number of CFUs in the cell line and acute and chronic brucellosis compared to the free drug. In conclusion, the synthesized nanoparticles were safe and green. With the slow release of the drug (100 h), the accumulation of the drug at the bacterial site increases and causes a greater effect on the B. melitensis and improves the disease of brucellosis. The use of synthesized nanodrugs in this study had promising therapeutic results.

Severe Sporotrichosis Treated with Amphotericin B: A 20-Year Cohort Study in an Endemic Area of Zoonotic Transmission

Although rare, disseminated sporotrichosis is increasing in several countries. Despite its limiting toxic potential, amphotericin B is the only intravenous antifungal available to treat severe sporotrichosis. We aimed to describe the effectiveness and safety of amphotericin B treatment for severe sporotrichosis. Clinical records of patients with disseminated sporotrichosis at a reference center were reviewed. This study included 73 patients. Most (53.4%) were men and non-white. HIV coinfection was the main comorbidity (52.1%). Most reported contact with cats (76.7%). Sporothrix brasiliensis was the causative species. Affected sites were skin (98.6%), osteoarticular system (64.4%), upper airway (42.5%), central nervous system (20.5%), eyes (12.3%), and lungs (8.2%). Median doses of amphotericin B used were 750 mg and 4500 mg for deoxycholate and lipid complex formulations, respectively. Amphotericin B discontinuation occurred in 20.5% due to adverse events, mainly azotemia. The outcomes included cure (52.1%), death due to sporotrichosis (21.9%), death due to other causes (9.6%), and loss to follow-up (8.2%). Survival analysis showed an association between cure and the absence of bone, upper airway, and central nervous system involvement. Amphotericin B is the first-choice treatment for disseminated sporotrichosis; however, the severity of systemic dissemination might predict its response. Favorable clinical results depend on prompt diagnosis, investigation of fungal dissemination, and early therapy initiation.

Old and New Insights into Sporothrix schenckii Complex Biology and Identification

Sporothrix schenckii is a worldwide-distributed thermally dimorphic fungus, which usually causes a subacute to chronic infection through traumatic implantation or inoculation of its infectious propagules. The fungus encompasses a group of phylogenetically closely related species, thus named the S. schenckii complex, of which S. schenckii sensu stricto and S. brasiliensis are main causative species of sporotrichosis. Owing to a multifaceted molecular dynamic, the S. schenckii complex can switch between the mycelium and the yeast form. This characteristic along with a varying cell wall composition account for significant species-specific differences in the host range, virulence, and susceptibility to antifungal drugs. While culture remains the gold standard to diagnose sporotrichosis, polymerase chain reaction (PCR) or matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry-based methods have become an essential for accurate species identification in many clinical laboratories. If directly applied on tissue samples, molecular methods are helpful to improve both sensitivity of and time to the etiological diagnosis of sporotrichosis. This mini-review aims to put together the old and new knowledge on the S. schenckii complex biology and identification, with particular emphasis on the laboratory diagnosis-related aspects of disease.

Treatment of Human Sporotrichosis Caused by Sporothrix brasiliensis

We describe the successful treatment of a series of 30 zoonotic sporotrichosis cases from southern Brazil. Sporothrix brasiliensis was the species genotypically identified in all 25 confirmed cases. Five other cases were classified as probable, without laboratory confirmation, but with clinical and epidemiological data of cat-transmitted sporotrichosis. Two isolates were sequenced by translation elongation factor-1 alpha (EF1α) loci in order to compare their sequences, and both of them showed distinct genotypes from S. brasiliensis strains from other Brazilian states. Itraconazole (ITZ) or potassium iodide (KI) were the first choice treatment in 28 and 2 cases, respectively. Microdilution assay showed a wild-type profile of S. brasiliensis isolates to ITZ. However, a lack of clinical response occurred in 42% of cases, especially those treated with ITZ 100 mg/day, and treatment needed modifications, by either increased doses or antifungal combinations. Clinical cure required a mean of 187 days of treatment, which was dependent on the clinical form of the disease and age of patients. Therapy, including dosages and durations, for cutaneous forms of sporotrichosis requires re-evaluation, since cases caused by S. brasiliensis may influence treatment efficacy.

Human sporotrichosis: recommendations from the Brazilian Society of Dermatology for the clinical, diagnostic and therapeutic management

BACKGROUND

The increase in the zoonotic epidemic of sporotrichosis caused by Sporothrix brasiliensis, which started in the late 1990s in Rio de Janeiro and is now found in almost all Brazilian states, has been equally advancing in neighboring countries of Brazil. Changes in the clinical-epidemiological profile, advances in the laboratory diagnosis of the disease, and therapeutic difficulties have been observed throughout these almost 25 years of the epidemic, although there is no national consensus. The last international guideline dates from 2007.

OBJECTIVES

Update the clinical classification, diagnostic methods and recommendations on the therapeutic management of patients with sporotrichosis.

METHODS

Twelve experts in human sporotrichosis were selected from different Brazilian regions, and divided into three work groups: clinical, diagnosis and treatment. The bibliographic research was carried out on the EBSCOHost platform. Meetings took place via electronic mail and remote/face-to-face and hybrid settings, resulting in a questionnaire which pointed out 13 divergences, resolved based on the opinion of the majority of the participants.

RESULTS

The clinical classification and laboratory diagnosis were updated. Therapeutic recommendations were made for the different clinical forms.

CONCLUSION

Publication of the first national recommendation, carried out by the Brazilian Society of Dermatology, aimed at the Brazilian scientific community, especially dermatologists, infectologists, pediatricians, family medicine personnel, and laboratory professionals who work in the management of human sporotrichosis.

Synthetic Derivatives against Wild-Type and Non-Wild-Type Sporothrix brasiliensis: In Vitro and In Silico Analyses

Recently, the well-known geographically wide distribution of sporotrichosis in Brazil, combined with the difficulties of effective domestic feline treatment, has emphasized the pressing need for new therapeutic alternatives. This work considers a range of synthetic derivatives as potential antifungals against Sporothrix brasiliensis isolated from cats from the hyperendemic Brazilian region. Six S. brasiliensis isolates from the sporotrichotic lesions of itraconazole responsive or non-responsive domestic cats were studied. The minimum inhibitory concentrations (MICs) of three novel hydrazone derivatives and eleven novel quinone derivatives were determined using the broth microdilution method (M38-A2). In silico tests were also used to predict the pharmacological profile and toxicity parameters of these synthetic derivatives. MICs and MFCs ranged from 1 to >128 µg/mL. The ADMET computational analysis failed to detect toxicity while a good pharmacological predictive profile, with parameters similar to itraconazole, was obtained. Three hydrazone derivatives were particularly promising candidates as antifungal agents against itraconazole-resistant S. brasiliensis from the Brazilian hyperendemic region. Since sporotrichosis is a neglected zoonosis currently spreading in Latin America, particularly in Brazil, the present data can contribute to its future control by alternative antifungal drug design against S. brasiliensis, the most virulent and prevalent species of the hyperendemic context.

In vitro activity of Schinus terebinthifolius extract and fractions against Sporothrix brasiliensis

BACKGROUND

Sporothrix brasiliensis is the causative agent of zoonotic cases of sporotrichosis in Brazil and is associated with atypical and severe presentations in cats, dogs, and humans. Sporotrichosis treatment is usually time- and cost-consuming, sometimes with poor response and host toxicity. Schinus terebinthifolius has proven efficacy against bacteria and fungi of clinical interest.

OBJECTIVE

To determine the in vitro activity of S. terebinthifolius against S. brasiliensis.

METHODS

Five S. brasiliensis isolates and three reference strains were subjected to a hydroethanol extract derived from the leaves of S. terebinthifolius and its fractions. The minimal inhibitory concentration (MIC) was determined using the broth microdilution method according to the M38-A2 CLSI guidelines. Also, the fungicidal/fungistatic activity of the extract and fractions was studied.

FINDINGS

The crude extract of S. terebinthifolius inhibited the growth of S. brasiliensis (MIC: 0.5-1.0 µg/mL), while the partitioned extracts dichloromethane, ethyl acetate, and butanol demonstrated growth inhibition at 8 µg/mL due to a fungistatic activity.

MAIN CONCLUSIONS

Due to its in vitro efficacy against S. brasiliensis and its known pharmacological safety, S. terebinthifolius is a candidate to be tested using in vivo models of sporotrichosis.

Bioisosteric modification on benzylidene-carbonyl compounds improved the drug-likeness and maintained the antifungal activity against Sporothrix brasiliensis

Considering the emergence of antifungal resistance on Sporothrix brasiliensis, we aimed to assess new benzylidene-carbonyl compounds against feline-borne S. brasiliensis isolates. The compounds were designed as bioisosteres from previously reported benzylidene-ketones generating the p-coumaric (1), cinnamic (2), p-methoxycinnamic (3) and caffeic acid (4) analogues. The corresponding compounds were tested against feline isolates of S. brasiliensis with sensitivity (n = 4) and resistance (n = 5) to itraconazole (ITZ), following the M38-A2 protocol (CLSI, Reference method for broth dilution antifungal susceptibility testing of filamentous fungi M38-A2 Guideline, 2008). Eleven analogues showed activity against all fungal strains with minimum inhibitory concentrations (MIC) ≤1 mg/ml (1a-d, 2e, 3b, 3e, 4, 4a and 5e) and fungicidal concentrations (MFC) ≤1 mg/ml (1b, 1d, 3e and 4a), whereas 3 was the less active with both MIC and MFC values above 1 mg/ml. Compound 3e (4-methoxy-N-butylcinnamamide) was the most potent (MIC_range 0.08-0.16 mg/ml; MFC_range 0.32-0.64 mg/ml) from the set, suggesting a different role of the substituents in ester and amide derivatives. The designed compounds proved to be important prototypes with improved drug-likeness to achieve compounds with higher activity against ITZ-resistant S. brasiliensis.

Can the essential oil of rosemary (Rosmarinus officinalis Linn.) protect rats infected with itraconazole-resistant Sporothrix brasiliensis from fungal spread?

INTRODUCTION

Itraconazole is the first-choice option to treat human and animal sporotrichosis. However, the emergence of itraconazole-resistant strains has encouraged research on new active antifungals. Among them, the essential oil of rosemary (Rosmarinus officinalis Linn., Lamiaceae) has shown antifungal activity in vitro.

OBJECTIVE

Assessing, for the first time, the effectiveness of rosemary essential oil in vivo in experimental cutaneous sporotrichosis, as well as its chemical composition and action mode.

METHODS

Itraconazole-resistant Sporothrix brasiliensis was inoculated in the left foot pad of 30 Wistar rats, which were randomized (n=10) for treatment with saline solution (control, CONT), itraconazole (ITRA, 10 mg/kg) and rosemary oil (ROSM, 250 mg/kg) for 30 days at an oral dose of 1 mL, daily. Clinical evolution, histopathology and fungal burden were investigated. GC-MS was used for chemical analysis; sorbitol protection and ergosterol effect were used to evaluate the action mechanism of rosemary oil.

RESULTS

ROSM was the only group evolving to skin lesion remission, lack of edema and exudate, and mild-to-absent yeast cells. Rosemary oil delayed fungal spreading and protected systemic organs, mainly liver and spleen. The ROSM group presented lower fungal load than that observed for the CONT and ITRA groups (p<0.05). Antifungal action took place at complexation level after ergosterol application. Most compounds were 1,8-cineole/eucalyptol (47.91%), camphor (17.92%), and α-pinene (11.52%).

CONCLUSIONS

These findings have evidenced that rosemary oil is a promising antifungal to treat sporotrichosis, since it protects systemic organs from fungal spread.

Clinical and epidemiological aspects of feline sporotrichosis caused by Sporothrix brasiliensis and in vitro antifungal susceptibility

Sporotrichosis is a subcutaneous mycosis resulting from the traumatic implantation of pathogenic Sporothrix species. In Brazil, zoonotic transmission plays an important role in the epidemiology of the disease, involving especially cats. The objective of this study was to isolate Sporothrix spp. from cats with signs of sporotrichosis, determining the causative species, clinical and epidemiological aspects, and the in vitro susceptibility profile of the isolates against antifungal drugs. From September 2017 to February 2019, 245 samples of lesions were collected from symptomatic cats in São José do Rio Preto, Brazil. Identification of the isolates was performed by morphophysiological parameters and species-specific polymerase chain reaction. The susceptibility profile of the isolates was determined for five drugs (amphotericin B, itraconazole, ketoconazole, potassium iodide and terbinafine), using the broth microdilution method. Clinical and epidemiological aspects were analyzed based on data contained on investigation forms filled by the veterinarians at moment of collection. Sporothrix spp. were isolated in 189 (77.2%) of the samples. Phenotypic and molecular analyses revealed S. brasiliensis as the only causative agent. In vitro susceptibility testing showed lower MIC values for terbinafine (MIC = 0.03-2 μg/ml), ketoconazole (MIC = 0.03-2 μg/ml), and itraconazole (MIC = 0.03-4 μg/ml). Most of the animals were male (73.5%), adults (96.3%), stray (53.5%), and uncastrated (69.8%). Our results show the expansion of the S. brasiliensis epidemic to an area nearly 840 km apart from the epicenter of the long-lasting outbreak of cat-transmitted sporotrichosis in Rio de Janeiro.

Diphenyl diselenide alone and in combination with itraconazole against Sporothrix schenckii s.str. and Sporothrix globosa

We evaluated the in vitro susceptibility of Sporothrix schenckii s.str. and Sporothrix globosa to diphenyl diselenide (PhSe)₂ alone and in association with itraconazole (ITZ). Eight clinical isolates were tested in microdilution and checkerboard assays. (PhSe)₂ alone inhibited all isolates in concentration ≤ 8 µg/mL and was effective in killing one S. schenckii isolate. Inhibitory and fungicidal beneficial effects in its interaction with ITZ were shown against 87.5% (7/8) and 50% (4/8) of the isolates tested, respectively. Our study demonstrates the in vitro antifungal activity of (PhSe)₂ against two pathogenic Sporothrix species, suggesting studies of in vivo applications are warranted.

Antifungal resistance on Sporothrix species: an overview

INTRODUCTION

The treatment of human and animal sporotrichosis is often performed with antifungal agents; however, the emergence of antifungal-resistant strains of Sporothrix species has been reported. We aimed to discuss the ability of Sporothrix species in developing resistance to the conventional antifungals and mechanisms for this.

METHODOLOGY

Published data on databases (PubMed, Science Direct, Google Scholar) were investigated using a combination of keywords from 2008 to 2019 by the StArt tool.

RESULTS

The minimal inhibitory concentrations values based on the Clinical and Laboratory Standards Institute (CLSI) from eight references were classified according to the epidemiological cutoff values in wild-type or non-wild-type strains. In this way, non-wild-type S. schenckii and, mainly, S. brasiliensis isolates were recognized on itraconazole, amphotericin B, terbinafine, and voriconazole, which are strains that deserve more attention toward antifungal control, with a probable risk of mutation to antifungal resistance. Among the few reviewed studied on antifungal resistance, the melanin production capacity (DHN-melanin, L-DOPA melanin, and pyomelanin), the low genetic diversity due to the abnormal number of chromosomes, and the mutation in cytochrome P450 are some of the factors for developing resistance mechanism.

CONCLUSIONS

The emergence of Sporothrix species with in vitro antifungal resistance was evidenced and the possible mechanisms for resistance development may be due to the melanin production capacity, genetic diversity and mutations in cytochrome P450. Further studies should be carried out targeting gene expression for the development of antifungal resistance on Sporothrix species in order to prospect new therapeutic targets for human and veterinary use.

Guideline for the management of feline sporotrichosis caused by Sporothrix brasiliensis and literature revision

We herein present a Brazilian guideline for the management of feline sporotrichosis, a mycosis caused by Sporothrix brasiliensis. This guideline is an effort of a national technical group organized by the Working Group on Sporothrix and Sporotrichosis of the International Society for Human and Animal Mycology (ISHAM). This publication intends to provide information on clinical-epidemiological aspects of this zoonosis, as well as a literature revision. Moreover, it gives some practical information on diagnosis and treatment of feline sporotrichosis. It also contains information that can be helpful for the prevention and control of S. brasiliensis transmission.

Sporothrix Brasiliensis: A Review of an Emerging South American Fungal Pathogen, Its Related Disease, Presentation and Spread in Argentina

Sporotrichosis, caused by Sporothrix schenckii and related species, is the most frequent implantation mycosis in Latin America. In Argentina, over the last 8 years, there have been 0.16 new cases per month of feline sporotrichosis in 2011, increasing to 0.75 cases per month in 2019 and involving zoonotic transmission to humans. Molecular identification by polymerase chain reaction (PCR) detected Sporothrix brasiliensis in these feline and zoonotic outbreaks. This study will focus on different feline and human sporotrichosis outbreaks caused by S. brasiliensis in Argentina during 2011–2019. We will address the sources of infection and environmental hotspots, as well as the application of several treatment strategies for improving the pharmacotherapy of the different clinical forms of the disease. Finally, we will provide a detailed summary of the clinical aspects and new advances in host–pathogen interactions, virulence factors and immune response, focusing on state-of-the-art diagnostic tools and potential vaccine candidates.

Zoonotic sporotrichosis in renal transplant recipients from Rio de Janeiro, Brazil

Sporotrichosis is the main subcutaneous mycosis in the world. In the last two decades, zoonotic sporotrichosis transmitted by cats has become hyperendemic in Rio de Janeiro, Brazil. Renal transplant recipients are subject to invasive fungal infection because of the effects of immunosuppressive therapy, but sporotrichosis is rarely reported. The authors conducted a retrospective study describing epidemiological, clinical, and therapeutic data related to adult renal-transplant-recipient patients diagnosed with sporotrichosis. The molecular identification of fungal isolates was performed. Minimal inhibitory concentration (MIC) of amphotericin B (AMB), itraconazole (ITZ), posaconazole (POS), isavuconazole, and terbinafine (TRB) against the strains was determined using the protocol described by the Clinical and Laboratory Standards Institute (CLSI). Six cases were identified from a cohort with 2429 sporotrichosis patients. They were five men and one woman, with a mean age of 44.2 years (range: 34-54 years). Four of them had cutaneous limited forms, and two patients had disseminated forms. The mean time between transplant and the onset of sporotrichosis symptoms was 25.5 (range: 6-36) months. Sporothrix brasiliensis was identified as the causative agent. The isolates were classified as wild type for all antifungal drugs tested. Treatment schemes included AMB (deoxycholate and liposomal), ITZ, and TRB. Five patients evolved to cure, and one died as a result of disseminated disease. Renal transplant recipients may be a vulnerable group for sporotrichosis in endemic countries. The authors highlight the importance of sporotrichosis prevention, early diagnosis, and treatment to prevent disseminated disease and poor prognosis.

Influence of iron on growth and on susceptibility to itraconazole in Sporothrix spp

We evaluated the growth and the susceptibility to oxidative stress of Sporothrix spp., exposed to different iron concentrations in culture medium, and the susceptibility of Sporothrix spp. to itraconazole, alone and in combination with to the iron chelator deferasirox. The results showed that the growth of S. brasiliensis isolates was more affected by iron availability in comparison to S. schenckii, but both fungal species conidia became more prone to oxidative stress when iron was added to culture medium. Conversely, the combination of itraconazole and deferasirox only resulted in synergism against a minority of S. schenckii isolates.

A One Health Approach to Combatting Sporothrix brasiliensis: Narrative Review of an Emerging Zoonotic Fungal Pathogen in South America

Cat-transmitted sporotrichosis caused by Sporothrix brasiliensis has become a major public health concern and presents a distinct divergence from the traditional epidemiology of sporotrichosis. This emerging fungal pathogen spreads readily among cat populations, and human infections occur exclusively via zoonotic transmission. While sporotrichosis is an implantation mycosis that typically manifests as cutaneous lesions in humans and cats, severe extracutaneous manifestations are more common with S. brasiliensis than other Sporothrix species infections. Rapid diagnosis and appropriate treatment regimens are critical for successful clinical resolution of sporotrichosis in both cats and humans. Species-level identification of Sporothrix is possible with molecular diagnostics and necessary for tracking the geographic expansion of S. brasiliensis and better understanding its epidemiology. Combatting cat-transmitted sporotrichosis requires a One Health approach to successfully implement public health control measures.

Identification of two potential inhibitors of Sporothrix brasiliensis and Sporothrix schenckii in the Pathogen Box collection

Sporotrichosis is a neglected endemic mycosis with a high incidence in Latin America, mainly in Brazil. Sporothrix schenckii is the most frequent species in Latin America, whereas Sporothrix brasiliensis is the predominant species observed in Brazil and is associated with both human and animal sporotrichosis. Sporotrichosis treatment remains restricted to a few options, itraconazole being the first choice for human and animal therapy. In this work, we screened the molecular library Pathogen Box (Medicines for Malaria Venture [MMV], Switzerland) in search of compounds with anti-Sporothrix activity. Our initial screen of the 400 compounds identified five compounds that inhibited more than 80% of S. brasiliensis and S. schenkii growth. Among those, three compounds (MMV675968, MMV102872, and MMV002817 (known as iodoquinol)) not previously described as antifungals or agrochemicals, were selected for further evaluation. MMV102872 and iodoquinol showed the most promising combination of antifungal activity (lower inhibitory concentration) and fungal selectivity (lower cytotoxicity in LLC-MK2 cells). Scanning electron microscopy and flow cytometry analyses revealed that MMV102872 and iodoquinol induced changes in cell morphology, membrane integrity, and the presence of neutral lipids, impairing fungal survival. Our results indicate that MMV102872 and iodoquinol are promising molecules for use as scaffolds for the development of new antifungal agents.

Benzylidene-carbonyl compounds are active against itraconazole-susceptible and itraconazole-resistant Sporothrix brasiliensis

We evaluated the antifungal activity of benzylidene-carbonyl compounds (LINS03) based on the structure of gibbilimbol from Piper malacophyllum Linn. Five analogues (1-5) were synthetized following a classic aldol condensation between an aromatic aldehyde and a ketone, under basic conditions. These were tested against itraconazole-susceptible (n = 3) and itraconazole-resistant (n = 5) isolates of Sporothrix brasiliensis by M38-A2 guidelines of CLSI. All of them were fungistatic (MIC ranged of 0.11-0.22 mg/mL (1); 0.08-0.17 mg/mL (2); 0.05-0.1 mg/mL (3); 0.04-0.33 mg/mL (4); and 0.04-0.3 mg/mL (5)), highlighting compounds 2 and 3. As fungicidal, compounds 1 and 2 were highlighted (MFC ranged of 0.22-0.89 mg/mL and 0.08-1.35 mg/mL, respectively), compared with the remaining (0.77-> 3.08 mg/mL (3); 0.08-> 2.6 mg/mL (4); and 0.59-> 2.37 mg/mL (5)). The inhibitory activity was related to the benzylidene-carbonyl, whereas the phenol group and the low chain homolog seems to contribute to some extent to the fungicidal effect. Compound 2 highlighted due to the considerable fungistatic and fungicidal activities, including itraconazole-resistant Sporothrix brasiliensis. These findings support the potential usefulness of benzylidene-carbonyl compounds as promising prototypes for the development of antifungal against sporotrichosis by Sporothrix brasiliensis, including against itraconazole-resistant isolates.

Phenotypic and molecular characterisation of Sporothrix globosa of diverse origin from India

Sporotrichosis is one of the neglected tropical diseases causing subcutaneous chronic granulomatous lesion by thermally dimorphic fungi belonging to Sporothrix species. Sporothrix brasiliensis, Sporothrix mexicana and Sporothrix globosa are the common pathogenic species. In Asian countries, S. globosa constitutes nearly 99.3% of all Sporothrix species. We studied 63 cases of sporotrichosis of geographically diverse origin from India and Sporothrix isolates were characterised for its growth in different media, temperatures, ability to assimilate sugars and antifungal susceptibility profile. Molecular characterization was performed by sequencing of the calmodulin (CAL), beta tubulin (BT) and translational elongation factor 1-alpha (TEF-1α) and typing by fluorescent amplified fragment length polymorphism (FAFLP). In patients who presented with fixed (49.2%), lymphocutaneous lesions (23.8%), in 26.9% the details were not known, none had systemic dissemination. All the isolates tested were Sporothrix globosa and that could grow up to 35 °C and unable to grow at and beyond 37 °C. The assimilation of sucrose, ribitol and raffinose helps in identifying S. globosa. Sequences of CAL or BT or TEF-1α can differentiate S. globosa from other species in the complex. FAFLP results exhibited low genetic diversity. No correlation was noted between genotypes and clinical presentation, or geographic distribution. Itraconazole, terbinafine and posaconazole showed good in vitro antifungal activity against S. globosa whereas fluconazole and micafungin had no activity. S. globosa of Indian origin is relatively less pathogenic than other pathogenic Sporothrix species as it does not cause systemic dissemination and in the diagnostic laboratory, incubation of the cultures below 37 °C is essential for effective isolation.