Primary Conjunctival Sporotrichosis

Ocular lesions in cats diagnosed with systemic sporotrichosis

OBJECTIVES

To describe the most common ocular lesions and demonstrate the frequency of ophthalmic involvement in a group of cats with systemic sporotrichosis.

ANIMALS STUDIED

Two hundred seventy-four cats diagnosed with systemic sporotrichosis. The inclusion criteria included previous positive cytopathological examination, histopathological examination, or fungal culture.

PROCEDURES

In a prospective case-control study, 274 cats diagnosed with systemic sporotrichosis underwent ophthalmic evaluation and received treatment for systemic sporotrichosis. Of these animals, 63 had ocular abnormalities which were recorded, and conjunctivitis was scored from 0 to 5. Diagnostic techniques utilized included fungal culture, as well as cytopathological (10 eyes; 10 cats), and histopathological examination of the palpebral conjunctiva and eyes (2 eyes).

RESULTS

Cytopathological and histopathological examination of the conjunctiva, as well as fungal culture, proved to be important tests for the detection of Sporothrix sp. Five cats without the evidence of ophthalmic abnormalities also had a positive fungal culture. The identified ocular lesions in animals with systemic sporotrichosis included increased serous discharge (79 eyes; 53 cats), blepharoconjunctivitis (33 eyes; 25 cats), conjunctivitis (39 eyes, 20 cats), blepharitis (9 eyes; 8 cats), uveitis (5 eyes; 3 cats), and Florida keratopathy-like lesions (2 eyes; 1 cat).

CONCLUSION

Sporotrichosis should be considered a differential diagnosis for conjunctivitis and blepharoconjunctivitis, especially in endemic areas. Fungal culture and cytopathology of ocular discharge and histopathological examinations of the conjunctiva are important for the diagnosis of ophthalmic sporotrichosis, although not all cats underwent laboratory testing in this study. Ocular discharge could be a source of contagion transmission.

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.

Ocular Manifestations of Sporotrichosis in a Hyperendemic Region in Brazil: Description of a Series of 120 Cases

PURPOSE

To describe 120 cases of ocular sporotrichosis.

METHODS

Review of medical records of patients with culture-proven (from eye specimen) ocular sporotrichosis, in Rio de Janeiro, from 2007 to 2017.

RESULTS

Women were more affected (61.7%) and median age was 24 years. The isolated ocular form was more frequent (75.8%). Fixed cutaneous sporotrichosis was the most commonly associated form (48.3%). Hypersensitivity reactions were observed in 10% of patients. Ocular involvement was unilateral in 98.3% of the cases, and the most frequent clinical presentation was granulomatous conjunctivitis (86.7%), followed by eyelid lesion (25%). Dacryocystitis represented 7.5% of the cases, predominantly in children (55.6%). Itraconazole was the first choice treatment (95.8%). Sequelae were observed in 23 patients (22.5%), and surgical treatment was required for most of them.

CONCLUSION

Ocular sporotrichosis can be considered a characteristic form of the zoonotic transmission, with high morbidity. Delay in initiating specific treatment is likely to increase the risk of progression to more severe forms of the disease, and development of ocular sequelae.

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.

Ocular Sporotrichosis

Sporotrichosis is a subacute or chronic mycosis predominant in tropical and subtropical regions. It is an infection of subcutaneous tissue caused by Sporothrix fungus species, but occasionally resulting in an extracutaneous condition, including osteoarticular, pulmonary, nervous central system, and ocular disease. Cases of ocular sporotrichosis are rare, but reports have been increasing in recent decades. Ocular infections usually occur in hyperendemic areas of sporotrichosis. For its classification, anatomic criteria are used. The clinical presentation is the infection in the ocular adnexal and intraocular infection. Ocular adnexa infections include palpebral, conjunctivitis, and infections of the lacrimal sac. Intraocular infection includes exogenous or endogenous endophthalmitis. Most infections in the ocular adnexal have been reported in Brazil, China and Peru, and intraocular infections are limited to the USA and Brazil. Diagnosis is performed from Sporothrix isolation in the mycological examination from ocular or skin samples. Both sporotrichosis in the ocular adnexa and intraocular infection can mimic several infectious and non-infectious medical conditions. Ocular adnexa infections are treated with potassium iodide and itraconazole. The intraocular infection is treated with amphotericin B. This review describes the clinical findings and epidemiological, diagnosis, and treatment of ocular sporotrichosis.

The spread of cat-transmitted sporotrichosis due to Sporothrix brasiliensis in Brazil towards the Northeast region

BACKGROUND

Sporotrichosis is a worldwide subcutaneous mycosis caused by Sporothrix spp. In the past, this infection was associated with armadillo hunting, horticulturists, miners, and gardeners, being considered an implantation mycosis acquired by plant debris injury. Nevertheless, since the late nineties, it has been considered a zoonotic disease in Brazil. Here we report a case series of 121 patients with cat-transmitted sporotrichosis seen in Northeast Brazil.

METHODOLOGY/PRINCIPAL FINDINGS

Patient's demographic, clinical data, and length of treatment were recorded. In addition, a mycological examination and further PCR confirmation of species identification were performed. One hundred and twenty two patients were diagnosed with subcutaneous sporotrichosis from October 2016 to December 2019, while PCR revealed that 71 of them were due to S. brasiliensis. The majority of the individuals were female (n = 86; 70.5%). Patient's age ranged from 5 to 87 years old. The clinical forms found were lymphocutaneous (58.2%) and fixed cutaneous (39.4%). Interestingly, 115 patients reported previous contact with cats diagnosed with sporotrichosis. Patients were successfully treated with itraconazole and potassium iodide.

CONCLUSIONS/SIGNIFICANCE

Our study adds important contributions for the investigation of the spread of cat-transmitted subcutaneous sporotrichosis in Brazil, specifically towards the Northeast region of a continental-size country. It will also help clinicians to be aware of the existence and importance to accurately diagnose sporotrichosis and treat patients with this infectious disease in the lowest income region of Brazil.

Characterization of animal sporotrichosis in a highly urbanized area

An epidemiological characterization of animal sporotrichosis was carried out between 2017 and 2018, in a highly urbanized area in Brazil, including outcomes and the spatial distribution of the cases according to the health vulnerability index (HVI) of the study territory. One hundred and sixty-five cats and four dogs suspected of sporotrichosis were identified by a surveillance and control program previously implemented in the study area. One hundred and five of these animals (62.1 %) were considered positive for Sporothrix spp., of which 103 were cats and two were dogs. Cases predominated among male cats (53.4 %), although gender did not present a statistically significant association (p > 0.05) with sporotrichosis cases. Considering the positive cats, 55.4 % were not neutered and free access to the street was reported as a habit for 86.4 % of them. Roaming free in the streets increased the chance of infection by 2.54 times. We observed a high frequency of euthanasia or death (48.8 %) among 86 infected cats available to be included in the follow-up stage of the study, even when they were treated (46.5 %) and a low cure rate (31 %). The disease spread, unrelated to the HVI in the territory. Data produced suggested that avoiding access to the street seems to have greater importance to sporotrichosis control in cats than neutering and reinforces the importance of health education, especially in relation to responsible feline ownership. The free offer of diagnosis and treatment also should be taken into consideration as important measures to control the disease.

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.

Ocular Sporotrichosis

Purpose

To present 10 cases of Parinaud oculoglandular syndrome caused by sporotrichosis.

Observations

We report 10 cases of Parinaud oculoglandular syndrome after contact with domestic cats diagnosed with sporotrichosis. They all showed ocular hyperemia associated with unilateral tarsal conjunctival granulomas. After histopathological study and culture of the scrapings and conjunctival secretions, six patients were positive for Sporothrix schenkii and four had a presumed diagnosis of Parinaud oculoglandular syndrome due to sporotrichosis. Treatment with 200 mg/day of oral itraconazole was started, and all patients had a favorable therapeutic response.

Conclusion and importance

These case reports are essential for characterizing a rare etiology of Parinaud oculoglandular syndrome.

Ocular and cutaneous sporotrichosis

Purpose

Sporotrichosis is the most common subcutaneous mycosis in the world and it is presented usually in the lymphocutaneous form. When the eye is involved, it typically includes the conjunctival and periorbital tissues or even the intraocular tissues.

Observations

We present a case of a 13-year-old girl complaining about nodules in the left malar region and in both the outer nasal corner and the lower eyelid of the left eye, which had appeared one month earlier.

Conclusions

and significance: Sporotrichosis is a hyperendemic disease in Brazil and its diagnosis is based on clinical aspects, epidemiological history, and culture. Ophthalmologists and other professionals should be aware of this condition.

Moreira L, F. Barczewski B, X. de Matos L, B. V. de Oliveira J, F. Pimentel MI, Almeida-Paes R, G. Oliveira M, C. A. Pinto T, Lima N, de O. Matos M, de M. e Costa LG, Santos C, Marques Evangelista Oliveira M. Identification by MALDI-TOF MS of Sporothrix brasiliensis Isolated from a Subconjunctival Infiltrative Lesion in an Immunocompetent Patient

Sporotrichosis is a globally distributed subcutaneous fungal infection caused by dimorphic fungi belonging to the Sporothrix species complex that affects the skin of limbs predominantly, but not exclusively. A rare case of ocular sporotrichosis in an immunocompetent Brazilian patient from the countryside of Rio de Janeiro State is reported. A 68-year-old woman presented with a subconjunctival infiltrative lesion in the right eye with pre-auricular lymphadenopathy of onset 4 months ago that evolved to suppurative nodular lesions on the eyelids. Conjunctival secretion was evaluated by histopathological examination and inoculated on Sabouraud Dextrose Agar (SDA). Histopathology showed oval bodies within giant cells and other mononucleated histiocytes. Fungus grown on SDA was identified as Sporothrix sp. by morphological observations. The isolated strain was finally identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) associated with an in-house database enriched with reference Sporothrix complex spectra. The strain presented a MALDI spectrum with the ion peaks of the molecular mass profile of S. brasiliensis. The patient was adequately treated with amphotericin B subsequently replaced by itraconazole. Due to scars left by the suppurative process, the patient presented poor final visual acuity. The present work presents an overview of ocular sporotrichosis and discusses the diagnostic difficulty that can lead to visual sequelae in these cases.

Ocular Sporotrichosis: 26 Cases with Bulbar Involvement in a Hyperendemic Area of Zoonotic Transmission

PURPOSE

To describe 26 cases of bulbar conjunctival sporotrichosis.

METHODS

Review of clinical records of patients with bulbar conjunctivitis due to culture-proven Sporothrix spp. infection, in Rio de Janeiro, from 2007 to 2017.

RESULTS

Twenty-six patients were identified. Median age was 25 years. Adults were more affected (53.8%), followed by adolescents (26.9%). There was a predominance of women (73.1%). Twenty-four patients (96%) reported contact with cats with sporotrichosis. Twenty-one patients (80.8%) presented a primary ocular sporotrichosis. Five patients presented associated eyelid lesions, and 21 (80.8%) tarsal conjunctivitis. Parinaud oculoglandular syndrome was observed in 17 (81%) patients. Eight patients (36.4%) reported the use of steroid drops before diagnosis was made. All patients but one were treated with oral itraconazole. Twenty-three patients (88.5%) were completely cured and three (11.5%) were lost to follow-up. Eight patients (34.8%) developed ocular sequelae.

CONCLUSION

Bulbar conjunctivitis is an important clinical presentation of ocular sporotrichosis. It can lead to ocular sequelae. Sporotrichosis should be considered in the differential diagnosis of ophthalmic external diseases, especially in patients with cat contact history.

A Case of Acute Granulomatous Conjunctivitis Caused by Cat-transmitted Sporothrix schenckii

In human, sporotrichosis infection commonly manifests as skin lesions through direct inoculation. It is rarely associated with ocular manifestation via a zoonotic transmission. We describe a young lady who presented with acute left eye granulomatous conjunctivitis who had a history of exposure to her sick cat diagnosed with sporotrichosis infection. Sporothrix schenckii was isolated from the culture of the excised conjunctival tissue. The patient recovered fully after six months of oral anti-fungal treatment. Clinicians should be aware of this new zoonotic infection transmitted by infected felines as it is reversible with timely diagnosis and initiation of anti-fungal therapy.

Ocular sporotrichosis: A frequently misdiagnosed cause of granulomatous conjunctivitis in epidemic areas

Purpose

Sporotrichosis is a subcutaneous mycosis caused by Sporothrix sp., a dimorphic fungus. Although the cutaneous form is the most frequent form, the ocular presentation has been increasingly diagnosed in epidemic areas. We describe three cases of ocular sporotrichosis with the involvement of the ocular adnexa due to autoinoculation without trauma with successful antifungal treatment.

Observations

Patient 1: A 68-year-old woman presented with granulomatous conjunctivitis of the right eye with an ulcerated nodule on the right temporal region for 5 months. Patient 2: A 46-year-old woman with conjunctival hyperemia of the left eye with associated periorbital edema and erythema for the past 4 months was referred to the Dermatology Department due to an ulcerated nodule on the left malar region. Patient 3: A 14-year-old boy presented to the emergency department with inferior palpebral edema with a 5-day evolution. Specimens were obtained from the lesions of the three patients, and the cultures were positive for Sporothrix sp. The three cases were diagnosed as ocular sporotrichosis and were successfully treated with itraconazole (200–400 mg/d). Two of the three patients developed sequelae such as conjunctival fibrosis and symblepharon.

Conclusions and importance

We emphasize the importance of the ophthalmologist being familiar with the diagnosis and management of this rare and frequently misdiagnosed form of sporotrichosis.

Disseminated cutaneous sporotrichosis associated with ocular lesion in an immunocompetent patient

A 59-year-old female patient, previously healthy, immunocompetent, presented left bulbar conjunctiva lesions and nodular-ulcerated lesions on the arms and cervical region, besides left cervical and retroauricular lymphadenopathy. She had previous contact with domestic cats that excoriated her face. The diagnosis was conclusive of disseminated sporotrichosis through clinical and epidemiological history and cultures of skin and ocular secretions. It evolved with good response to oral antifungal therapy.

Acute dacryocystitis: another clinical manifestation of sporotrichosis

Sporotrichosis associated with exposure to domestic cats is hyperendemic in Rio de Janeiro, Brazil. A review of the clinical records at our institute revealed four patients with clinical signs of dacryocystitis and a positive conjunctival culture for Sporothrix who were diagnosed with Sporothrix dacryocystitis. Three patients were children (< 13 years of age) and one patient was an adult. Two patients reported contact with a cat that had sporotrichosis. Dacryocystitis was associated with nodular, ulcerated lesions on the face of one patient and with granulomatous conjunctivitis in two patients; however, this condition manifested as an isolated disease in another patient. All of the patients were cured of the fungal infections, but three patients had chronic dacryocystitis and one patient developed a cutaneous fistula. Sporotrichosis is usually a benign disease, but may cause severe complications when the eye and the adnexa are affected. Physicians, especially ophthalmologists in endemic areas, should be aware of the ophthalmological manifestations and complications of sporotrichosis.

Sporotrichosis in the Ocular Adnexa: 21 Cases in an Endemic Area in Peru and Review of the Literature

PURPOSE

To describe the clinical and epidemiologic characteristics of sporotrichosis in ocular adnexa and give an insight into factors associated with this condition.

DESIGN

Retrospective case series and literature review.

METHODS

We retrospectively reviewed all cases of sporotrichosis in ocular adnexa between 2004 and 2014 in the Santa Teresa Clinic of Abancay, Peru and reviewed all case reports of sporotrichosis in ocular adnexa in the literature.

RESULTS

We reviewed records of 21 patients with sporotrichosis in ocular adnexa; 12 (57.1%) of them were male and their median age surrounded 9 years. In our series, 19 patients had lesions in the eyelids and 2 in the eyebrows. The lymphocutaneous form occurred in 62% of them. Ten patients (47.6%) were cured with potassium iodide. Among 65 patients with sporotrichosis in ocular adnexa (our 21 patients and 44 from the literature), the average age was 9 years, and 78% were ≤15 years of age; 54% were male. The lesions were more frequent on the eyelids (n = 53 [82%]), followed by the lacrimal gland (n = 5), conjunctiva (n = 4), and eyebrows (n = 3). The lymphocutaneous clinical form (54%) was the most frequent. Fifty patients were cured: 31 of them with potassium iodide, 16 with itraconazole, and 3 with a combination including potassium iodide, itraconazole, and fluconazole. Twenty-nine patients (44.6%) resided in a hyperendemic region, and 5 patients reported contact with cats that had sporotrichosis.

CONCLUSIONS

Sporotrichosis in ocular adnexa is associated with children ≤15 years of age, and in 82% of these cases the disease is limited to the eyelids.

Update of phylogenetic and genetic diversity of Sporothrix schenckii sensu lato

Sporothrix schenckii sensu lato causes subcutaneous mycosis. In this article we analysed its phylogeny and genetic diversity using calmodulin DNA sequences deposited in GenBank database. Population genetics indices were calculated, plus phylogenetic and haplotype network trees were built. Five clades with high values of posterior probability, 47 haplotypes and high diversity in the complex were found. Analysis of partial calmodulin sequences alignment revealed conserved and polymorphic regions that could be used as reference for taxonomic identification. The use of population genetics analysis allowed understanding the phylogenetic proximity of S. schenckii s. str. and S. brasiliensis; scarce genetic flow among them with low migration index and high ancestry coefficient was found. Similarly, S. globosa, S. mexicana and S. pallida sequences showed highly differentiated species with no genetic exchange. The phylogenetic tree suggests that S. mexicana shared a common ancestor with S. pallida; while S. globosa and S. brasiliensis are more related to S. schenckii s. str. and showed less haplotype diversity and restrictions in geographic distribution. In the haplotype network tree S. schenckii s. str. species displayed worldwide distribution without dispersion centres; while S. brasiliensis and S. globosa, exhibited Brazil and Euro-Asia as dispersion centres, respectively. Our data suggest that S. schenckii complex has been submitted to a divergent evolution process, probably due to the pressure of the environment and of the host. In contrast, S. brasiliensis could have been submitted to purifying selection or expansion process.

Phylogeography and evolutionary patterns in Sporothrix spanning more than 14 000 human and animal case reports

Pathology to vertebrate hosts has emerged repeatedly in the order Ophiostomatales. Occasional infections have been observed in Sporothrix mexicana at a low level of virulence, while the main pathogenic species cluster in a derived clade around S. schenckii s.str. In this paper, phylogeny and epidemiology of the members of this clade were investigated for 99 clinical and 36 environmental strains using four genetic loci, viz. rDNA ITS and partial CAL, TEF1, and TEF3; data are compared with amplified fragment length polymorphism (AFLP) genotyping. The four main species of the pathogenic clade were recognised. The species proved to show high degrees of endemicity, which enabled interpretation of literature data where live material or genetic information is lacking. The clade of four species comprised nine subclusters, which often had limited geographic distribution and were separate from each other in all partitions, suggesting low degrees of interbreeding between populations. In contrast, S. globosa exhibited consistent global distribution of identical AFLP types, suggesting another type of dispersal. Sporothrix brasiliensis is known to be involved in an expanding zoonosis and transmitted by cats, whereas S. globosa infections originated from putrid plant material, causing a sapronosis. Sporothrix schenckii s.str., the most variable species within the clade, also had a plant origin, with ecological similarities to that of S. globosa. A hypothesis was put forward that highly specific conditions in the plant material are required to promote the growth of Sporothrix. Fermented, self-heated plant debris may stimulate the thermodependent yeast-like invasive form of the fungus, which facilitates repeated infection of mammals.

Sporotrichosis: an overview and therapeutic options

Sporotrichosis is a chronic granulomatous mycotic infection caused by Sporothrix schenckii, a common saprophyte of soil, decaying wood, hay, and sphagnum moss, that is endemic in tropical/subtropical areas. The recent phylogenetic studies have delineated the geographic distribution of multiple distinct Sporothrix species causing sporotrichosis. It characteristically involves the skin and subcutaneous tissue following traumatic inoculation of the pathogen. After a variable incubation period, progressively enlarging papulo-nodule at the inoculation site develops that may ulcerate (fixed cutaneous sporotrichosis) or multiple nodules appear proximally along lymphatics (lymphocutaneous sporotrichosis). Osteoarticular sporotrichosis or primary pulmonary sporotrichosis are rare and occur from direct inoculation or inhalation of conidia, respectively. Disseminated cutaneous sporotrichosis or involvement of multiple visceral organs, particularly the central nervous system, occurs most commonly in persons with immunosuppression. Saturated solution of potassium iodide remains a first line treatment choice for uncomplicated cutaneous sporotrichosis in resource poor countries but itraconazole is currently used/recommended for the treatment of all forms of sporotrichosis. Terbinafine has been observed to be effective in the treatment of cutaneous sporotrichosis. Amphotericin B is used initially for the treatment of severe, systemic disease, during pregnancy and in immunosuppressed patients until recovery, then followed by itraconazole for the rest of the therapy.

Subcutaneous fungal infections

Subcutaneous mycoses are common in tropical and subtropical regions of the world. These infections have multiple features in common, including similar epidemiology, mode of transmission, indolent chronic presentation with low potential for dissemination in immunocompetent hosts, and pyogranulomatous lesions on histopathology. Herein, we provide up-to-date epidemiologic, clinical, diagnostic, and therapeutic data for three important subcutaneous mycoses: chromoblastomycosis, mycetoma, and sporotrichosis.

Sporothrix schenckii and Sporotrichosis

Sporotrichosis, which is caused by the dimorphic fungus Sporothrix schenckii, is currently distributed throughout the world, especially in tropical and subtropical zones. Infection generally occurs by traumatic inoculation of soil, plants, and organic matter contaminated with the fungus. Certain leisure and occupational activities, such as floriculture, agriculture, mining, and wood exploitation, are traditionally associated with the mycosis. Zoonotic transmission has been described in isolated cases or in small outbreaks. Since the end of the 1990s there has been an epidemic of sporotrichosis associated with transmission by cats in Rio de Janeiro, Brazil. More than 2,000 human cases and 3,000 animal cases have been reported. In humans, the lesions are usually restricted to the skin, subcutaneous cellular tissue, and adjacent lymphatic vessels. In cats, the disease can evolve with severe clinical manifestations and frequent systemic involvement. The gold standard for sporotrichosis diagnosis is culture. However, serological, histopathological, and molecular approaches have been recently adopted as auxiliary tools for the diagnosis of this mycotic infection. The first-choice treatment for both humans and cats is itraconazole.

Sporothrix schenckii complex and sporotrichosis, an emerging health problem

Sporothrix schenckii, now named the S. schenckii species complex, has largely been known as the etiological agent of sporotrichosis, which is an acute or chronic subcutaneous mycosis of humans and other mammals. Gene sequencing has revealed the following species in the S. schenckii complex: Sporothrix albicans, Sporothrix brasiliensis, Sporothrix globosa, Sporothrix luriei, Sporothrix mexicana and S. schenckii. The increasing number of reports of Sporothrix infection in immunocompromised patients, mainly the HIV-infected population, suggests sporotrichosis as an emerging global health problem concomitant with the AIDS pandemic. Molecular studies have demonstrated a high level of intraspecific variability. Components of the S. schenckii cell wall that act as adhesins and immunogenic inducers, such as a 70-kDa glycoprotein, are apparently specific to this fungus. The main glycan peptidorhamnomannan cell wall component is the only O-linked glycan structure known in S. schenckii. It contains an α-mannobiose core followed by one α-glucuronic acid unit, which may be mono- or di-rhamnosylated. The oligomeric structure of glucosamine-6-P synthase has led to a significant advance in the development of antifungals targeted to the enzyme’s catalytic domain in S. schenckii.

Molecular epidemiology and antifungal susceptibility patterns of Sporothrix schenckii isolates from a cat-transmitted epidemic of sporotrichosis in Rio de Janeiro, Brazil

Since 1998 a cat-transmitted epidemic of sporotrichosis has been observed in Rio de Janeiro (RJ), Brazil. Besides the lymphocutaneous and fixed forms, other presentations, such as disseminated cutaneous and mucosal involvement, as well as for the first time, erythema nodosum and erythema multiforme have been reported associated with sporotrichosis. This study investigates the phenotypes and genotypes of Sporothrix schenckii isolates recovered from different clinical forms of the disease noted as part of this epidemic. A total of 88 isolates recovered from 59 cases associated with the epidemic and 29 controls (from cases in other Brazilian regions and Spain) were included in this study. In vitro susceptibility testing was conducted as part of the phenotypic analysis, while the genotypic analysis involved a DNA fingerprinting method with primer M13 and ribosomal DNA sequencing of the internal transcribed spacer (ITS). MIC values of amphotericin B, itraconazole, posaconazole, ravuconazole, and terbinafine were found to be significantly lower (P<0.01) for isolates associated with the epidemic than for control strains. No differences in MIC values were observed related to clinical forms of the infection. Fingerprinting analysis showed that RJ epidemic strains were genetically related. Although nine subtypes were found, they were not associated with specific clinical forms. Similar results were obtained with the ITS sequence analysis. These data suggest that the strains isolated from the epidemic cases of sporotrichosis in RJ all originated from a common source.

Immunoglobulins G, M, and A against Sporothrix schenckii exoantigens in patients with sporotrichosis before and during treatment with itraconazole

Sporotrichosis is an important subcutaneous mycosis, with an increasing worldwide incidence. However, few data are available regarding the immunological aspects of Sporothrix schenckii infection, particularly the humoral responses to the fungus. In this study we measured immunoglobulin G (IgG), IgM, and IgA in sera from 41 patients with sporotrichosis before antifungal treatment and from another 35 patients with sporotrichosis during itraconazole treatment by using a recently described S. schenckii exoantigen enzyme-linked immunosorbent assay (ELISA). More than 95% of patients had detectable IgA antibodies, and more than 85% had IgM and IgG antibodies before treatment. The number of patients with IgG antibodies increased to 91% during treatment. Conversely, significantly fewer samples from treated patients were positive for IgM (71%) and IgA (89%). Overall, 78% of patients had detectable levels of all isotypes tested at diagnosis, and this percentage dropped to 62.9% in patients receiving itraconazole. Testing of all three isotypes improved the sensitivity; at least two isotypes were detected in 93% of patients before and 89% after treatment. The reactivity of 94 sera from patients with other diseases and healthy individuals was also tested. Cross-reactivity occurred in 33% of the heterologous sera. Most of them were positive only in one isotype, 8.5% were positive for at least two isotypes, and only one serum (1.1%) was positive for the three isotypes. Antibodies produced during S. schenckii infection are diverse, and we demonstrate that an exoantigen ELISA for the detection of combinations of IgA, IgG, and IgM antibodies is a highly sensitive and specific diagnostic assay for sporotrichosis.

Sporotrichosis

Sporotrichosis is a deep fungal disease caused by a dimorphic fungus, Sporothrix schenckii. It occurs more frequently in the tropical and subtropical areas and is mainly characterized by nodular lesions of cutaneous and subcutaneous tissues and adjacent lymphatics that suppurate and ulcerate. Infection occurs by manipulation of contaminated soil, cats, or some wild animals or by inhalation of spores. Itraconazole is the best drug for treatment of sporotrichosis.

Molecular phylogeny of Sporothrix schenckii

The pathogenic dimorphic fungus Sporothrix schenckii is the agent responsible for sporotrichosis, an important fungal infection with a worldwide distribution. Little is known about the population structure of S. schenckii, although recent molecular and phenotypic data seem to demonstrate that different genetic lineages exist within this species. The aim of this study was to determine, by sequence analysis of three protein coding loci (chitin synthase, beta-tubulin, and calmodulin), whether this variability is due to species divergence or intraspecific diversity in S. schenckii. We included in the analysis 60 isolates (59 of clinical and 1 of environmental origin) of this species from a wide geographical range. DNA sequence data from the three nuclear regions were used in a phylogenetic analysis. The combined analysis of the three loci revealed the presence of three major clades, one grouping all of the European isolates, another with only Brazilian isolates, and the third with isolates from other South American countries and Africa. A total of 14 100% bootstrap-supported nodes were shown, 6 of them representing putative phylogenetic species. Our data also demonstrated that most of these species prevail in different geographical regions.

Sporothrix schenckii and sporotrichosis

For a long time sporotrichosis has been regarded to have a low incidence in Brazil; however, recent studies demonstrate that not only the number of reported cases but also the incidence of more severe or atypical clinical forms of the disease are increasing. Recent data indicate that these more severe forms occur in about 10% of patients with confirmed diagnosis. The less frequent forms, mainly osteoarticular sporotrichosis, might be associated both with patient immunodepression and zoonotic transmission of the disease. The extracutaneous form and the atypical forms are a challenge to a newly developed serological test, introduced as an auxiliary tool for the diagnosis of unusual clinical forms of sporotrichosis.