Pulmonary sporotrichosis: case series and systematic analysis of literature on clinico-radiological patterns and management outcomes

Extracutaneous sporotrichosis

SUMMARYSporotrichosis is a subacute-to-chronic infection endemic to tropical and subtropical regions. It usually involves subcutaneous tissue but can occasionally cause extracutaneous infections, especially in hyperendemic areas. Extracutaneous infections are classified based on the anatomic location of the lesion and the route of infection (primary or multifocal). The clinical forms are as follows: (i) pulmonary (primary or multifocal); (ii) osteoarticular (primary or multifocal); (iii) ocular (ocular adnexal lesions including eyelid lesions, conjunctivitis and dacryocystitis, and intraocular infections); (iv) central nervous system; and (v) mucosal (primary or disseminated). Multifocal clinical presentations are observed mainly in immunocompromised individuals. The diagnosis must be confirmed in the laboratory by mycological examination of the clinical samples. Itraconazole and amphotericin B are the most commonly used antifungal agents for treating pulmonary, osteoarticular, ocular, and mucosal forms. Treatment may include surgical excision of the initial lesions in pulmonary and osteoarticular forms. The treatment of neurological involvement is far from optimal and is associated with a high mortality rate despite long treatment periods.

Sporothrix and Sporotrichosis: A South African Perspective on a Growing Global Health Threat

Sporotrichosis is a disease that arises from a fungal infection caused by members of the Ascomycete genus Sporothrix. The disease has a unique history in South Africa, due to an association with gold mines, where large numbers of mine workers were infected in the 1930s and 1940s. This was likely driven by hot humid conditions and timber supports used in these mine shafts. Furthermore, the disease is the most common subcutaneous fungal infection amongst the general population in South Africa, and the large number of immunocompromised individuals increases the public health risk in the country. Sporothrix is a genus in the Ophiostomatales, a fungal order primarily associated with environmental habitats. Unsurprisingly, sporotrichosis therefore has a documented history of sapronotic transmission from contaminated plant material. This review provides insights into the understanding of sporotrichosis and Sporothrix species, with a particular emphasis on the South African situation. We highlight knowledge gaps, particularly regarding the ecological factors influencing the occurrence and distribution of these species, which in turn affect the patterns of sporotrichosis. We also emphasise a need for ongoing proactive research and surveillance to prevent future outbreaks of sporotrichosis, an emerging disease with growing health implications worldwide.

Multifocal Sporotrichosis Associated with Armadillo Hunting in Midwest Brazil: An In-Depth Case Study and Comprehensive Literature Analysis

Sporotrichosis is a globally distributed subcutaneous mycosis caused by dimorphic Sporothrix species commonly found in soil, mosses, and decaying plant matter. The lymphocutaneous manifestation, historically associated with occupational activities and sapronotic transmission, has recently been observed to also occur through animal contact, particularly notable in Brazil. We describe a rare case of lymphocutaneous sporotrichosis with simultaneous pulmonary complications resulting from the scratching of a southern three-banded armadillo, Tolypeutes matacus, primarily inhabiting the arid forests of South America's central region. Speciation using multiplex quantitative polymerase chain reaction (qPCR) established the etiological agent as S. schenckii s. str., while amplified fragment length polymorphism (AFLP) analysis unveiled a novel genotype circulating in the Midwest of Brazil. The patient received treatment with itraconazole (200 mg/day) for two months, leading to substantial clinical improvement of cutaneous and pulmonary symptoms. This case highlights the critical role of animal-mediated transmission in sporotrichosis epidemiology, particularly within regions with diverse armadillo species. The unusual epidemiology and genetic characteristics of this case emphasize the need for enhanced awareness and diagnostic vigilance in atypical sporotrichosis presentations.

Inflammation and epigenetics of sporotrichosis disease

Sporotrichosis, a fungal disease, is caused by exposure to soil that harbors Sporothrix schenckii or through inhalation of fungal spores. Skin is the most frequently exposed organ making sporotrichosis a primarily dermal disease. Many described reports in the literature suggest a connection of sporotrichosis with cutaneous squamous cell carcinoma with some connection between initial sporotrichosis diagnosis and treatment followed by development of cutaneous squamous cell carcinoma at the very site. Conversely, there is also evidence for sporotrichosis subsequent to skin cancer diagnosis, even after cancer chemotherapy, which points towards weakening of immune response by cancer chemotherapy leading to attack and infection by Sporothrix schenckii. We also propose and focus on inflammation as the connection between sporotrichosis, cancer and even the metastatic spread of cancer. Inflammation-associated IL-6, IFN-γ, natural killer cells and M2-macrophages possibly mechanistically link sporotrichosis with cancer, particularly cutaneous squamous cell carcinoma. These inflammation related factors/cells are regulated epigenetically raising the possibility of epigenetic regulation of sporotrichosis, which has not been described yet in the available literature. Clinical management of inflammation may thus be effective strategy not just against sporotrichosis but also the related onset of cutaneous squamous cell carcinoma and possibly its metastasis to lymph nodes.

Clinical factors associated with systemic sporotrichosis in Brazil

BACKGROUND

Systemic sporotrichosis occurs when organs, other than subcutaneous tissues and lymph nodes, are infected. Interestingly, systemic sporotrichosis in apparently immunocompetent individuals is increasing in Brazil, but data on clinical manifestations and risk factors are scarce. Most of the existing data on such condition relate to people living with HIV. We aimed to study the risk factors associated with systemic sporotrichosis among HIV-negative and HIV-positive patients.

METHODS

We performed a retrospective cross-sectional study with 80 patients from Brazil, diagnosed between 2014 and 2021. The association between disease classification, clinical presentation and risk factors were analysed by logistic regression.

RESULTS

Of the 80 patients, 29 (36.3%) presented with systemic sporotrichosis. All HIV-positive patients developed the systemic form, with increased mortality (p = .002). Alcohol ingestion (p = .009) and diabetes (p = .010) were associated with systemic disease. Alcohol ingestion seemed to favour pulmonary infection (p = .013) and, diabetes favoured osteoarticular (p = .009) and ocular involvement (p = .033). The occurrence of fever (p = .001) and weight loss (p = .006) were significantly associated with systemic sporotrichosis, while meningeal involvement (p = .001) increased mortality risk. Nine (11.3%) patients died from sporotrichosis. The presence of fungal structures in the mycological examination of the patients' lesions were associated with the systemic form (p = .017) and death (p = .002).

CONCLUSION

Our study points to the factors that drive systemic sporotrichosis other than HIV, such as alcohol ingestion and diabetes. Considering the high number of patients presenting severe sporotrichosis, the recognising these factors may contribute to timely diagnosis and proper treatment.

Sporotrichosis co-infection with human immunodeficiency virus/acquired immunodeficiency syndrome

Sporotrichosis is a subcutaneous mycosis caused by a dimorphic fungus belonging to the genus Sporothrix. This fungal infection can affect both humans and domestic animals, and in recent years, an increase in the geographic spread and prevalence of sporotrichosis has been observed globally. This systematic review aimed to examine the clinical-epidemiological and therapeutic aspects related to sporotrichosis co-infection with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). An extensive electronic search was conducted on databases including PubMed, Web of Science, Lilacs, Medline, Embase, Scopus and SciELO was performed to identify clinical cases of people living with HIV (PLWH) with sporotrichosis published until May 2023. As a result, we found that most co-infected patients were male, representing 71.76% (94/131) of cases. The most prevalent age group was 41-50 years, with a mean age of 36.98 years. The countries with the highest number of cases were Brazil (75.57%, 99/131) and the United States (16.03%, 21/131). The most frequent clinical presentation was systemic dissemination, accounting for 69.47% (91/131) of the cases, followed by cutaneous dissemination with 13% (17/131). The mean CD4+ cell count was 154.07 cells/μL, and most patients used amphotericin B with at least one azole, which represented 47.33% (62/131) of cases, followed by azole monotherapy in 17.56% (23/131) of cases. As for the outcome, 51.15% (67/131) of the patients remained alive, and 37.4% (49/131) died. Therefore, it was concluded that sporotrichosis in PLWH is a disease with a high prevalence in Brazil and may be associated with systemic clinical manifestations requiring longer periods of systemic antifungal therapy.

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.

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.

Pulmonary Sporotrichosis Caused by Sporothrix brasiliensis: A 22-Year, Single-Center, Retrospective Cohort Study

Pulmonary sporotrichosis is a rare condition. It can present as a primary pulmonary disease, resulting from direct Sporothrix species (spp). conidia inhalation, or as part of multifocal sporotrichosis with multiple organ involvement, mainly in immunocompromised patients. This study aimed to describe the sociodemographic and epidemiological characteristics and clinical course of patients with positive cultures for Sporothrix spp. from pulmonary specimens (sputum and/or bronchoalveolar lavage) at a reference center in an area hyperendemic for zoonotic sporotrichosis. The clinical records of these patients were reviewed. Fourteen patients were included, and Sporothrix brasiliensis was identified in all cases. Disseminated sporotrichosis was the clinical presentation in 92.9% of cases, and primary pulmonary sporotrichosis accounted for 7.1%. Comorbidities included human immunodeficiency virus infection (78.6%), alcoholism (71.4%), and chronic obstructive pulmonary disease (14.3%). Treatment with amphotericin B followed by itraconazole was the preferred regimen and was prescribed in 92.9% of cases. Sporotrichosis-related death occurred in 42.9% while 35.7% of patients were cured. In five cases there was a probable contamination from upper airway lesions. Despite the significant increase in sporotrichosis cases, pulmonary sporotrichosis remains rare. The treatment of disseminated sporotrichosis is typically difficult. Prompt diagnosis and identification of all affected organs are crucial for better prognosis.

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.

Sporotrichosis: hyperendemic by zoonotic transmission, with atypical presentations, hypersensitivity reactions and greater severity

In recent decades, an alarming increase in the number of sporotrichosis cases has been reported in southern and southeastern Brazil, especially in the state of Rio de Janeiro, has been considered a long-term hyperendemic condition associated with feline transmission. According to phenotypic classifications, the Sporothrix species recovered from cats were classified as S. brasiliensis in 96.5% of the studied cases. This finding has also been demonstrated in humans, which confirms the zoonotic transmission associated with this predominant species in Brazil. The zoonotic transmission of the fungus and its important virulence in the context of the hyperendemic situation in Rio de Janeiro have changed the approach to the disease, which in its classic form was restricted to certain professional groups and very specific regions in the Brazilian territory, into a public health challenge of scientific interest. Its atypical manifestations and hypersensitivity reactions are increasingly frequent, constituting a new sporotrichosis aspect, which deserves attention from the medical community, as well as from other health professionals.

Sporotrichosis in Mexico

Sporotrichosis is an endemic mycosis caused by the species of the Sporothrix genus, and it is considered one of the most frequent subcutaneous mycoses in Mexico. This mycosis has become a relevant fungal infection in the last two decades. Today, much is known of its epidemiology and distribution, and its taxonomy has undergone revisions. New clinical species have been identified and classified through molecular tools, and they now include Sporothrix schenckii sensu stricto, Sporothrix brasiliensis, Sporothrix globosa, and Sporothrix luriei. In this article, we present a systematic review of sporotrichosis in Mexico that analyzes its epidemiology, geographic distribution, and diagnosis. The results show that the most common clinical presentation of sporotrichosis in Mexico is the lymphocutaneous form, with a higher incidence in the 0-15 age range, mainly in males, and for which trauma with plants is the most frequent source of infection. In Mexico, the laboratory diagnosis of sporotrichosis is mainly carried out using conventional methods, but in recent years, several researchers have used molecular methods to identify the Sporothrix species. The treatment of choice depends mainly on the clinical form of the disease, the host's immunological status, and the species of Sporothrix involved. Despite the significance of this mycosis in Mexico, public information about sporotrichosis is scarce, and it is not considered reportable according to Mexico's epidemiological national system, the "Sistema Nacional de Vigilancia Epidemiológica." Due to the lack of data in Mexico regarding the epidemiology of this disease, we present a systematic review of sporotrichosis in Mexico, between 1914 and 2019, that analyzes its epidemiology, geographic distribution, and diagnosis.

Subcutaneous Mycoses in Travelers

Purpose of Review

The increase in international travel in recent decades has contributed to the risk of acquiring diseases considered endemic to a region or country and the change in the epidemiology of these diseases. Endemic mycoses that may be acquired by travelers in the short or long term are endemic subcutaneous mycoses such as sporotrichosis and lobomycosis, while endemic systemic mycoses are a group of serious diseases including histoplasmosis and coccidioidomycosis. Herein, we review the current knowledge and highlight the most important aspects of these fungal infections in travelers.

Recent Findings

The most relevant advances in the study of these mycoses involve the epidemiological distribution; human mycoses can be fatal and there are few antifungal drugs available, increasing drug resistance, and a risk of emerging fungal diseases associated with climate change, as well as the increasing virulence, and the diagnostic strategies that may be limited in many countries.

Summary

Although endemic mycoses are relatively rare, they should be considered as potentially travel-related illnesses. A recent or late trip to an endemic country may guide the clinical suspicion, an early diagnosis, and the institution of effective therapy.

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.

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.

Advances in Fungal Peptide Vaccines

Vaccination is one of the greatest public health achievements in the past century, protecting and improving the quality of life of the population worldwide. However, a safe and effective vaccine for therapeutic or prophylactic treatment of fungal infections is not yet available. The lack of a vaccine for fungi is a problem of increasing importance as the incidence of diverse species, including Paracoccidioides, Aspergillus, Candida, Sporothrix, and Coccidioides, has increased in recent decades and new drug-resistant pathogenic fungi are emerging. In fact, our antifungal armamentarium too frequently fails to effectively control or cure mycoses, leading to high rates of mortality and morbidity. With this in mind, many groups are working towards identifying effective and safe vaccines for fungal pathogens, with a particular focus of generating vaccines that will work in individuals with compromised immunity who bear the major burden of infections from these microbes. In this review, we detail advances in the development of vaccines for pathogenic fungi, and highlight new methodologies using immunoproteomic techniques and bioinformatic tools that have led to new vaccine formulations, like peptide-based vaccines.

Fatal pulmonary sporotrichosis caused by Sporothrix brasiliensis in Northeast Brazil

Background

A relevant case of pulmonary sporotrichosis due to Sporothrix brasiliensis is reported in a 50-year-old immunocompetent woman who had no history of skin trauma, but was in close contact with several stray cats at her nap time. The patient was hospitalized after 7 months of illness. The survey was conducted for pulmonary tuberculosis, an endemic disease in Brazil. She presented multiple central pulmonary nodules images, with central cavitation.

Methodology/Principal findings

The patient bronchoalveolar lavage was cultured and Sporothrix sp. growth was obtained. Then, the isolate (LMMM1097) was accurately identified to the species level by using species-specific polymerase chain reaction (PCR). Molecular diagnosis revealed that the emerging species Sporothrix brasiliensis was the agent of primary pulmonary sporotrichosis and the patient was treated with Amphotericin B lipid complex, but presented severe clinical symptoms and the fatal outcome was observed at day 25 after hospitalization.

Conclusions/Significance

Our report adds important contributions to the clinical-epidemiological features of sporotrichosis, showing the geographic expansion of the agent within different regions of Brazil and a rare clinical manifestation (primary pulmonary sporotrichosis) caused by the emerging agent S. brasiliensis in an immunocompetent female patient.

Sporotrichosis is a fungal infection caused by different species belonging to the genus Sporothrix. In the past, the disease was usually associated with armadillo hunting and horticulturists, acquired after traumatic inoculation. Nevertheless, from 1997 to 2011, 4,188 human cases of sporotrichosis associated with feline transmissions were recorded in Rio de Janeiro, Brazil. Since then, the disease became an epidemic that is currently spreading within different regions of the country. Nevertheless, pulmonary sporotrichosis, specifically after conidial inhalation (without traumatic inoculation) is still a rare entity. In the present study, a female patient had the habit to have a nap at her workplace in a small room full of stray cats, daily. Tuberculosis was investigated, but the laboratory tests were negative. Then, pulmonary aspergillosis was suspected and Amphotericin B was initiated. A culture of the bronchoalveolar lavage was performed, which evidenced Sporothrix sp. growth. The final species identification was Sporothrix brasilensis, as demonstrated by PCR. However, the patient evolved to death. This finding reinforces the idea of exploring different possibilities of etiological agents involved in pulmonary infections, specific in areas of the globe where zoonotic sporotrichosis transmitted by cats have been reported.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

Immunization with recombinant enolase of Sporothrix spp. (rSsEno) confers effective protection against sporotrichosis in mice

In recent years, research has focused on the immunoreactive components of the Sporothrix schenckii cell wall that can be relevant targets for preventive and therapeutic vaccines against sporotrichosis, an emergent worldwide mycosis. In a previous study, we identified a 47-kDa enolase as an immunodominant antigen in mice vaccinated with an adjuvanted mixture of S. schenckii cell wall proteins. Here, we sought to assess the protective potential of a Sporothrix spp. recombinant enolase (rSsEno) formulated with or without the adjuvant Montanide Pet-GelA (PGA) against the S. brasiliensis infection in mice. Mice that were immunized with rSsEno plus PGA showed increased antibody titters against rSsEno and increased median survival time when challenged with S. brasiliensis as compared with mice that had not been immunized or that were immunized with rSsEno alone. Immunization with rSsEno plus PGA induced a predominantly T-helper 1 cytokine pattern after in vitro stimulation of splenic cells with rSsEno: elevated levels of IFN-γ and IL-2, as well as of other cytokines involved in host defense against sporotrichosis, such as TNF-alpha, IL-6, and IL-4. Furthermore, we show for the first time the presence of enolase in the cell wall of both S. schenckii and S. brasiliensis. As a whole, our results suggest that enolase could be used as a potential antigenic target for vaccinal purposes against sporotrichosis.

Endemic pulmonary fungal diseases in immunocompetent patients: an emphasis on thoracic imaging

INTRODUCTION

Systemic endemic mycoses are prevalent in specific geographical areas of the world and are responsible for high rates of morbidity and mortality in these populations, and in immigrants and travelers returning from endemic regions. The most common fungal infections that can affect the lungs of immunocompetent patients include histoplasmosis, coccidioidomycosis, paracoccidioidomycosis, blastomycosis, sporotrichosis, aspergillosis, and cryptococcosis. Diagnosis and management of these diseases remain challenging, especially in non-endemic areas due to the lack of experience. Therefore, recognition of the various radiologic manifestations of pulmonary fungal infections associated with patients' clinical and epidemiologic history is imperative for narrowing the differential diagnosis. Areas covered: This review discusses the clinical and radiological findings of the main endemic fungal diseases affecting the lungs in immunocompetent patients. Specific topics discussed are their etiology, epidemiology, pathogenesis, clinical manifestations, methods of diagnosis, pathology and main imaging findings, especially in computed tomography. Expert commentary: Imaging plays an important role in the diagnosis and management of pulmonary fungal infection and may reveal useful signs. Although definitive diagnosis cannot be made based on imaging features alone, the use of a combination of epidemiologic, clinical and imaging findings may permit the formulation of an adequate differential diagnosis.

Sporotrichosis In Immunocompromised Hosts

Sporotrichosis is a global implantation or subcutaneous mycosis caused by several members of the genus Sporothrix, a thermo-dimorphic fungus. This disease may also depict an endemic profile, especially in tropical to subtropical zones around the world. Interestingly, sporotrichosis is an anthropozoonotic disease that may be transmitted to humans by plants or by animals, especially cats. It may be associated with rather isolated or clustered cases but also with outbreaks in different periods and geographic regions. Usually, sporotrichosis affects immunocompetent hosts, presenting a chronic to subacute evolution course. Less frequently, sporotrichosis may be acquired by inhalation, leading to disseminated clinical forms. Both modes of infection may occur in immunocompromised patients, especially associated with human immunodeficiency virus (HIV) infection, but also diabetes mellitus, chronic alcoholism, steroids, anti-TNF treatment, hematologic cancer and transplanted patients. Similar to other endemic mycoses caused by dimorphic fungi, sporotrichosis in immunocompromised hosts may be associated with rather more severe clinical courses, larger fungal burden and longer periods of systemic antifungal therapy. A prolonged outbreak of cat-transmitted sporotrichosis is in progress in Brazil and potentially crossing the border to neighboring countries. This huge outbreak involves thousands of human and cats, including immunocompromised subjects affected by HIV and FIV (feline immunodeficiency virus), respectively. We reviewed the main epidemiologic, clinical, diagnostic and therapeutic aspects of sporotrichosis in immunocompromised hosts.

Immunopathogenesis of Human Sporotrichosis: What We Already Know

Sporotrichosis is a subacute/chronic mycosis caused by dimorphic fungus of the genus Sporothrix. This mycosis may affect both human and domestic animals and in the last few years, the geographic dispersion and increase of sporotrichosis worldwide has been observed. The occurrence of cases related to scratching/bites of domestic felines have increased, characterizing the disease as predominantly a zoonosis. In humans, sporotrichosis mainly involves the cutaneous tegument of infected patients, but other tissues may also present the infection. The main forms of clinical presentation are lymphocutanous sporotrichosis (LC) and fixed sporotrichosis (F). Although less common, mucosal, cutaneous disseminated, and extracutaneous forms have also been described. Multiple factors from the fungus and host can play a role in driving the clinical evolution of sporotrichosis to benign or severe disease. In this review, we discuss the immunopathological aspects involved in human sporotrichosis. Putting together the two branches of knowledge—host immune response and fungal evading mechanisms—we may perceive new possibilities in understanding the fungus–host interaction in order to be in a position to go further in the control of sporotrichosis.

Refractory sporotrichosis due to Sporothrix brasiliensis in humans appears to be unrelated to in vivo resistance

Sporotrichosis is a subacute to chronic infection caused by members of the Sporothrix schenckii complex. Itraconazole is the first choice antifungal drug for treating this infection, with terbinafine and potassium iodide as alternatives and amphotericin B used in cases of severe infections. Correlation of antifungal susceptibility data with the clinical outcome of the patients is scarce. The aim of this study was to correlate clinical and mycological data in patients with refractory sporotrichosis. In this work, antifungal susceptibilities, determined according to the reference M38-A2 CLSI protocol, of 25 Sporothrix strains, isolated from seven human cases of sporotrichosis with adversities in the treatment, are presented. Tested drugs included itraconazole, ketoconazole, posaconazole, voriconazole, terbinafine, and amphotericin B. Fungi were identified using the T3B PCR fingerprinting. This method identified all strains as Sporothrix brasiliensis and also demonstrated a high degree of similarity between the strains. In general, voriconazole was ineffective against all strains, and elevated minimal inhibitory concentrations (MICs) were observed for amphotericin B. High itraconazole and terbinafine MICs were not observed in S. brasiliensis isolates from patients of this study. Moreover, a significant increase in itraconazole and terbinafine MIC values from strains isolated from the same patient in different periods was not observed. The results suggest that the antifungal susceptibility to terbinafine and itraconazole determined by the reference method does not play an important role in therapeutic failure of sporotrichosis and that acquisition of resistance during prolonged antifungal treatment is not likely to occur in S. brasiliensis.

The Infection Returns: A Case of Pulmonary Sporotrichosis Relapse after Chemotherapy

Background

Pulmonary sporotrichosis is a rare disease caused by a dimorphic fungus, Sporothrix schenckii. It is rarely found in association with malignancy. We present a case of pulmonary sporotrichosis recurrence after chemotherapy.

Case Presentation

A 44-year-old man, treated for pulmonary sporotrichosis in the past, presented with dysphagia and was found to have squamous cell carcinoma of the esophagus. After undergoing chemotherapy, extensive cavitary lesions were observed on thoracic computed tomography scan. A bronchoalveolar lavage revealed the presence of Sporothrix schenckii sensu lato. Despite treatment with itraconazole, he eventually required a left pneumonectomy for progressive destructive cavitary lesions involving the left lung.

Conclusion

This case highlights the importance of considering past fungal infections, albeit cured, in patients initiating immunosuppressive therapy.

Lung Infections

A review of pulmonary infections of all types with diagnostic and morphological features.

Cavitary Pulmonary Sporotrichosis: Case Report and Literature Review

A case of cavitary pulmonary sporotrichosis without mucocutaneous involvement caused by Sporothrix schenckii is reported in a sexagenarian woman with a long smoking history. The patient was hospitalized for septic shock with multiorgan failure from a respiratory focus. The diagnosis was delayed due to the fungal etiological agent was not initially considered in the differential diagnosis. A good clinical and radiological evolution was obtained with the antifungal therapy. Occasional cases of primary pulmonary sporotrichosis have been reported in the literature. Due to its low incidence, this is a less-known and underestimated clinical form. Both clinical suspicion and microbiological studies are needed to reach pulmonary sporotrichosis diagnosis.

Cutaneous Disseminated and Extracutaneous Sporotrichosis: Current Status of a Complex Disease

Sporotrichosis is an implantation or inoculation mycosis caused by species of Sporothrix schenckii complex; its main manifestations are limited to skin; however, cutaneous-disseminated, disseminated (visceral) and extracutaneous variants of sporotrichosis can be associated with immunosuppression, including HIV-AIDS, chronic alcoholism or more virulent strains. The most common extracutaneous form of sporotrichosis includes pulmonary, osteoarticular and meningeal. The laboratory diagnosis requires observing yeast forms and isolating the fungus; the two main causative agents are Sporothrix schenckii (ss) and Sporothrix brasiliensis. Antibody levels and species recognition by Polimerase Chain Reaction using biological samples or cultures are also useful. The treatment of choice for most cases is amphotericin B and subsequent itraconazole for maintenance therapy.

Filamentous Fungi

Filamentous mycoses are often associated with significant morbidity and mortality. Prompt diagnosis and aggressive treatment are essential for good clinical outcomes in immunocompromised patients. The host immune response plays an essential role in determining the course of exposure to potential fungal pathogens. Depending on the effectiveness of immune response and the burden of organism exposure, fungi can either be cleared or infection can occur and progress to a potentially fatal invasive disease. Nonspecific cellular immunity (i.e., neutrophils, natural killer [NK] cells, and macrophages) combined with T-cell responses are the main immunologic mechanisms of protection. The most common potential mold pathogens include certain hyaline hyphomycetes, endemic fungi, the Mucorales , and some dematiaceous fungi. Laboratory diagnostics aimed at detecting and differentiating these organisms are crucial to helping clinicians make informed decisions about treatment. The purpose of this chapter is to provide an overview of the medically important fungal pathogens, as well as to discuss the patient characteristics, antifungal-therapy considerations, and laboratory tests used in current clinical practice for the immunocompromised host.

The Upside of Bias: A Case of Chronic Meningitis Due to Sporothrix Schenckii in an Immunocompetent Host

Chronic meningitis of unknown etiology is a vexing illness for patients and clinicians. Identification of the correct pathogen can be challenging and time consuming, leading to delays in appropriate treatment. Although Sporothrix schenckii is a recognized and treatable cause of chronic meningitis, neurologists and infectious diseases physicians may not regularly evaluate for Sporothrix infection. We describe an immunocompetent patient with chronic meningitis who partially responded to empiric fluconazole. Prompted by a recent culture-confirmed case of meningeal sporotrichosis, we tested for S schenckii antibodies from the cerebrospinal fluid, which were positive. His clinical and functional status improved, and the S schenckii antibody titer decreased with itraconazole therapy. Clinicians should consider S schenckii in the differential diagnosis for chronic meningitis, even in immunocompetent patients, particularly when the clinical picture does not respond to standard empiric therapy.

Respiratory Failure due to Possible Donor-Derived Sporothrix schenckii Infection in a Lung Transplant Recipient

Background. De novo and donor-derived invasive fungal infections (IFIs) contribute to morbidity and mortality in solid organ transplant (SOT) recipients. Reporting of donor-derived IFIs (DDIFIs) to the Organ Procurement Transplant Network has been mandated since 2005. Prior to that time no systematic monitoring of DDIFIs occurred in the United States. Case Presentation. We report a case of primary graft dysfunction in a 49-year-old male lung transplant recipient with diffuse patchy bilateral infiltrates likely related to pulmonary Sporothrix schenckii infection. The organism was isolated from a bronchoalveolar lavage on the second day after transplantation. Clinical and radiographic responses occurred after initiation of amphotericin B lipid formulation. Conclusion. We believe that this was likely a donor-derived infection given the early timing of the Sporothrix isolation after transplant in a bilateral single lung transplant recipient. This is the first case report of sporotrichosis in a lung transplant recipient. Our patient responded well to amphotericin induction therapy followed by maintenance therapy with itraconazole. The implications of donor-derived fungal infections and Sporothrix in transplant recipients are reviewed. Early recognition and management of these fungi are essential in improving outcomes.

Optimal clearance of Sporothrix schenckii requires an intact Th17 response in a mouse model of systemic infection

The discovery of Th17 cells, along with many other Th cell subsets in the recent years, has expanded the Th1/Th2 paradigm that had persisted since its proposition by Mosmann in 1986. Defined by the characteristic expression of the transcription factor retinoic-related orphan receptor γt (RORγt) and production of IL-17A (IL-17), Th17 cells are powerful inducers of tissue inflammation with a recognized role against extracellular bacteria and fungi. Despite this, the interest in their study came from the pivotal role they play in the development and maintenance of major chronic inflammatory conditions such as multiple sclerosis, rheumatoid arthritis and Crohn's disease, hence they have been the target of promising new anti-Th17 therapies. Accordingly, the identification of opportunistic pathogens whose clearance relies on the Th17 response is of huge prophylactic importance. As shown here for the first time, this applies to Sporothrix schenckii, a thermo-dimorphic fungus and the causative agent of sporotrichosis. Our results show that both Th17 and Th1/Th17 mixed cells are developed during the S. schenckii systemic mice infection, which also leads to augmented production of IL-17 and IL-22. Also, by using an antibody-mediated IL-23 depletion model, we further demonstrate that optimal fungal clearance, but not survival, depends on an intact Th17 response.

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.

Global epidemiology of sporotrichosis

Sporotrichosis is an endemic mycosis caused by the dimorphic fungus Sporothrix schenckii sensu lato. It has gained importance in recent years due to its worldwide prevalence, recognition of multiple cryptic species within the originally described species, and its distinctive ecology, distribution, and epidemiology across the globe. In this review, we describe the current knowledge of the taxonomy, ecology, prevalence, molecular epidemiology, and outbreaks due to S. schenckii sensu lato. Despite its omnipresence in the environment, this fungus has remarkably diverse modes of infection and distribution patterns across the world. We have delved into the nuances of how sporotrichosis is intimately linked to different forms of human activities, habitats, lifestyles, and environmental and zoonotic interactions. The purpose of this review is to stimulate discussion about the peculiarities of this unique fungal pathogen and increase the awareness of clinicians and microbiologists, especially in regions of high endemicity, to its emergence and evolving presentations and to kindle further research into understanding the unorthodox mechanisms by which this fungus afflicts different human populations.

Sporothrix schenckii complex biology: environment and fungal pathogenicity

Sporothrix schenckii is a complex of various species of fungus found in soils, plants, decaying vegetables and other outdoor environments. It is the aetiological agent of sporotrichosis in humans and several animals. Humans and animals can acquire the disease through traumatic inoculation of the fungus into subcutaneous tissue. Despite the importance of sporotrichosis, it being currently regarded as an emergent disease in several countries, the factors driving its increasing medical importance are still largely unknown. There have only been a few studies addressing the influence of the environment on the virulence of these pathogens. However, recent studies have demonstrated that adverse conditions in its natural habitats can trigger the expression of different virulence factors that confer survival advantages both in animal hosts and in the environment. In this review, we provide updates on the important advances in the understanding of the biology of Spor. schenckii and the modification of its virulence linked to demonstrated or putative environmental factors.