Treatment Abandonment in Feline Sporotrichosis - Study of 147 Cases

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.

Responsible ownership and health education can reduce the time of sporotrichosis treatment in domestic cats

Sporotrichosis is a widespread fungal infection that affects skin and subcutaneous tissues in humans and animals. In cats, it is displayed as nodules, ulcers and lesions on the nasal and respiratory mucosa. Antifungal treatment of cats is crucial but many cases are difficult, thus resulting in discontinue of the treatment, with disastrous consequences for the animal, encouraging contamination of the environment, other animals and people. The effects of responsible ownership education and health education for owners of cats with feline sporotrichosis as well as the interval between veterinary consultations on treatment outcomes for three groups of owners and their pet cats were evaluated in this study. The responsible ownership education and health education strategies consisted in videos in easy and accessible language for people with any level of education and were presented during consultations for two of the three groups included. The time between appointments was two weeks for two of the groups, and four weeks for one of the groups. The median of treatment time for the group without educational activities was 138 days, while for the other two groups it was 77.5 days and 86 days. It was found a significative reduction in the treatment time in the groups exposed to Responsible ownership education videos. There was no contamination of those responsible for home treatment, and the interval between monthly appointments did not impact on cure or death rates compared to the interval between fortnightly appointments. All these results can be applied to feline sporotrichoses treatment protocols increasing the owners treatment adherence and reducing either, the treatment discontinuation and the treatment costs and helps to control zoonotic sporotrichosis. The importance of attractive and comprehensible educational strategies as part of the feline sporotrichosis treatment protocol for the promotion of one health was highlighted.

S. Freitas D, M. de Macedo P, A. Pereira S, D. F. Gremião I, Coelho FC. Mathematical model of the dynamics of transmission and control of sporotrichosis in domestic cats

Sporotrichosis is a subcutaneous mycosis with a global distribution, also known as "rose gardener's disease". Brazil is experiencing a rapid spread of the zoonotic transmission of of Sporothrix brasiliensis, the main etiological agent of this disease in this country, affecting domestic felines. Cost-effective interventions need to be developed to control this emergent public health problem. To allow for the comparison of alternative control strategies, we propose in this paper, a mathematical model representing the transmission of S. brasiliensis among cats, stratified by age and sex. Analytical properties of the model are derived and simulations show possible strategies for reducing the endemic levels of the disease in the cat population, with a positive impact on human health. The scenarios included mass treatment of infected cats and mass implementation of contact reduction practices, such as neutering. The results indicate that mass treatment can reduce substantially the disease prevalence, and this effect is potentialized when combined with neutering or other contact-reduction interventions. On the other hand, contact-reduction methods alone are not sufficient to reduce prevalence.

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.

Advances and challenges in the management of feline sporotrichosis

The domestic cat is the most susceptible host to Sporothrix infection, developing severe clinical forms. Few effective antifungal agents are available for treating feline sporotrichosis, and cases of treatment failure are common. Treatment success depends on cat health status, therapy-related factors, as well as social/economic issues, but it is mainly contingent upon the host-fungus interaction. The owner's adherence is critical and should be reinforced throughout the treatment to increase the chances of a successful outcome. The antifungal agents described for feline sporotrichosis are most often used in monotherapy regimens. Due to cases in which the treatment with itraconazole failed, the use of antifungal agents in combination should be considered to achieve synergy. The combination of itraconazole and potassium iodide represents an important option for the treatment of naïve cats presenting multiple cutaneous lesions, nasal mucosal lesions and/or respiratory signs, as well as for refractory cases. However, the therapeutic options for unsuccessfully treated cases are scarce. Therefore new options are needed, even more taking into account that there are many in vitro potential molecules not available for use in cats yet. More studies are necessary to correlate in vitro antifungal susceptibility tests results and the outcome of cats treated due to sporotrichosis. This review will briefly discuss both the antifungal drugs and treatment protocols used in cats with sporotrichosis, as well as the determinants of treatment failure.

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.

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.

Spatial association between sporotrichosis in cats and in human during a Brazilian epidemics

Sporotrichosis is a subcutaneous granulomatous disease caused by the fungus Sporothrix spp. In Brazil, S. brasiliensis is reported in regions of outbreaks and epidemics in the zoonotic form of the disease where cats play an important role in the transmission of the disease to humans. Therefore, it is important to assess how the presence of infected cats impacts the risk for sporotrichosis in humans. The objective of this study was to analyze the spatial association of sporotrichosis in cats and in humans from Belo Horizonte, a Brazilian city where an epidemics of sporotrichosis occurs since the first human case register in 2015, through an inhomogeneous Poisson process model. Feline and human cases of sporotrichosis recorded between January 2016 and June 2019 were georeferenced by address and spatial point patterns were generated. Feline case intensity and human demographic density were calculated using a kernel smoothed estimate. The distance to the nearest feline case was also compute. Model parameters were estimated by Maximum Likelihood Estimate. The model validation was performed by the evaluation of partial residual, leverage and influence measure. There were 343 cases of cats and 135 human cases of sporotrichosis. The average incidence of human sporotrichosis in the period was 1.343 per 100 thousand inhabitants, which is relatively low in relation to the population, but higher than that observed in other regions in zoonotic outbreak of the disease. The southern region of the municipality has a higher intensity of feline cases. According to the fitted model, the risk for human sporotrichosis is greater when at distances very close to a feline case, with a virtually stable effect for distances greater than 1 km. Regarding the intensity of feline cases there is a gradual increase in risk as the intensity of cases increases. From the leverage analysis it was observed that the model was particularly sensitive to the occurrence of human cases in the south and east regions, places with extreme values ​​of covariates. Poisson point process model seems to be a reasonable approach in spatial epidemiology when multiple sources of infection are involved, and there is a low incidence of the disease as long as it is reasonable to assume independence between cases. Interventions for disease prevention and control in humans are suggested to encompass disease control in cats and the search for feline cases, focused on diagnosis and control, close to reported human cases.

Use of the Health Belief Model to identify factors associated with owner adherence to elimination diet trial recommendations in dogs

OBJECTIVE

To use the Health Belief Model to identify factors associated with owner adherence to elimination diet trial (EDT) recommendations by veterinarians for dogs with suspected cutaneous adverse food reactions (CAFRs).

SAMPLE

192 owners of dogs prescribed an EDT between April 1, 2012, and April 1, 2017.

PROCEDURES

Owners of dogs prescribed an EDT to diagnose CAFRs were identified through review of medical records from a single veterinary dermatology specialty practice. Identified owners were invited to participate in an anonymous online survey that was developed on the basis of the Health Belief Model. Multivariable logistic regression was used to evaluate associations between potential predictor variables and 100% adherence to EDT recommendations.

RESULTS

665 owners were invited to participate, and 192 (28.9%) completed the survey. Of the 192 respondents, 77 (40.1%) reported 100% adherence to EDT recommendations, and 115 (59.9%) reported < 100% adherence. Results indicated that the odds of owners reporting 100% adherence to EDT recommendations were significantly decreased by owner perception of barriers (adjusted OR [OR_a] = 0.86) and were significantly increased by owner knowledge regarding diets and CAFRs in dogs (OR_a = 1.30) and by self-efficacy or confidence in performing an EDT as directed (ORa = 1.18).

CONCLUSIONS AND CLINICAL RELEVANCE

Findings indicated that most prescribed EDTs were not followed strictly. Interventions to help owners reduce perceived barriers, increase self-efficacy, and improve related knowledge could improve adherence to EDT recommendations and, thereby, increase the diagnostic utility of EDTs.

Feline sporotrichosis: a case series of itraconazole-resistant Sporothrix brasiliensis infection

The treatment of feline sporotrichosis is a challenge for veterinary clinicians since refractory cases may occur, due either to patient and/or to pharmacological management errors or due to the development of antifungal resistance. Thus, we aimed to describe the therapeutic history of feline cases infected by itraconazole-resistant Sporothrix brasiliensis in an endemic region of Southern Brazil. Medical records of cats attended at the Veterinary Clinic Hospital (Pelotas/RS, Brazil) between 2016 and 2017 were reviewed. Twelve cases of infection by S. brasiliensis with that showed high minimum inhibitory concentration (MIC) values (≥ 4 μg/mL) to itraconazole by M38-A2 of CLSI were selected. At the hospital consultation, disseminated (cats 1-l0, 12) and localized (cat 11) skin lesions remained in the cats, even after treatment with fluconazole, ketoconazole (02/12), and itraconazole (ITZ, 09/12) performed before this study. High doses (25-100 mg/kg/day) of ITZ for up to 4 months (03/12, cats 2, 6, 12) or over 12 months (05/12, cats 1, 5, 7, 8, 11) did not provide a clinical cure, except for the association of ITZ plus potassium iodide (01/12, cat 12) for 3 months, which proved useful in infections with itraconazole-resistant S. brasiliensis. However, the combined issues of abandonment of therapy by owners for financial reasons, difficulties surrounding therapy administration (03/12, cats 6, 11, 12), and the inappropriate choice of medication (01/12, cat 6), together reflect the reality of this endemic region, which greatly compromises clinical healing. This study highlighted the occurrence of refractory cases by itraconazole-resistant S. brasiliensis in cats from Southern Brazil, as well as the abandonment of treatment and therapeutic errors. We warn of the need for antifungal susceptibility tests to adapt therapeutic protocols in feline sporotrichosis.

Antifungal activity of silver salts of Keggin-type heteropolyacids against Sporothrix spp

Sporotrichosis is a chronic and subacute mycosis causing epidemiological outbreaks involving sick cats and humans in southeastern Brazil. The systemic disease prevails in cats, and in humans, the symptoms are restricted to skin in immunocompetent individuals. Under these conditions, the prolonged treatment of animals and cases of recurrence justify the discovery of new treatments for sporotrichosis. This work addresses the antifungal activity of silver salts of Keggin-type heteropolyacid salts (Ag-HPA salts) such as Ag₃[PW₁₂O₄₀], Ag₆[SiW₁₀V₂O₄₀], Ag₄[SiW₁₂O₄₀] and Ag₃[PMo₁₂O₄₀] and interactions with the antifungal drugs itraconazole (ITC), terbinafine (TBF) and amphotericin B (AMB) on the yeast and mycelia forms of Sporothrix spp. Sporothrix spp. yeast cells were susceptible to Ag-HPA salts at minimum inhibitory concentration (MIC) values ranging from 8 to 128 μg/mL. Interactions between Ag₃[PW₁₂O₄₀] and Ag₃[PMo₁₂O₄₀] with itraconazole and amphotericin B resulted in higher antifungal activity with a reduction in growth and melanization. Treated cells showed changes in cell membrane integrity, vacuolization, cytoplasm disorder, and membrane detachment. Promising antifungal activity for treating sporotrichosis was observed for the Ag-HPA salts Ag₃[PMo₁₂O₄₀] and Ag₃[PW₁₂O₄₀], which have a low cost, high yield and activity at low concentrations. However, further evaluation of in vivo tests is still required.

Coinfection of domestic felines by distinct Sporothrix brasiliensis in the Brazilian sporotrichosis hyperendemic area

Microbial interactions may impact patient's diagnosis, prognosis and treatment. Sporotrichosis is a hyperendemic neglected zoonosis in Brazil, caused by Sporothrix brasiliensis. Four pairs of clinical isolates of Sporothrix were recovered from four diseased cats (CIM01-CIM04, two isolates per animal) raising the possibility of coinfection in a sporotrichosis hyperendemic area, Brazil. Each isolate of the pair had distinct pigmentation in mycological culture, and was designated as "Light" or "Dark", for low and high pigmentation, respectively. Dark isolates reacted strongly with monoclonal antibodies to melanin (p ≤ 0.05) by both ELISA and FACS quantitation, and displayed a ring pattern with some regions exhibiting higher punctuated labeling at cell wall by immunofluorescence. In turn, Light isolates reacted less intensely, with few and discrete punctuated labeling at the cell wall. PCR identified all isolates as S. brasiliensis, MAT1-2 idiomorph. Sequencing of β-tubulin and calmodulin genes followed by phylogenetic analysis placed all eight isolates within the same cluster as others from the Brazilian hyperendemic area. The ability of these strains to stimulate cytokine production by human PBMCs (Peripheral blood mononuclear cells) was also analyzed. CIM01 and CIM03 Light and Dark isolates showed similar cytokine profiles to the control strain, while CIM02 and CIM04 behaved differently (p < 0.001), suggesting that differences in the surface of the isolates can influence host-fungus interaction. MICs for amphotericin B, terbinafine, caspofungin, micafungin, itraconazole, fluconazole, and voriconazole were obtained (CLSI M38-A2/M27-A3). Pairwise comparisons showed distinct MICs between Sporothrix Light and Dark isolates, higher than at least two-fold dilutions, to at least one of the antifungals tested. Isolates from the same pair displayed discrepancies in relation to fungistatic or fungicidal drug activity, notably after itraconazole exposure. Since S. brasiliensis Light and Dark isolates show disparate phenotypic parameters it is quite possible that coinfection represents a common occurrence in the hyperendemic area, with potential clinical implications on feline sporotrichosis dynamics. Alternatively, future studies will address if this specie may have, as reported for other fungi, broad phenotypic plasticity.

Chemical and cytotoxic analyses of three varieties of Brazilian propolis (green propolis, jataí propolis and brown propolis) and its anti-Sporothrix brasiliensis in vitro activity

ABSTRACT In this study, we described the antifungal activity of three Brazilian propolis extracts: brown, green and from jataí bees against Sporothrix brasiliensis. The extracts were obtained from ethanolic extraction and their chemical composition was determined by high-performance liquid chromatography coupled to mass spectrometry. The cellular toxicity was measured in MDBK (Madin-Darby Bovine Kidney) cells and quantified by the MTT assay (3- (4,5 dimethylthiazol-2yl -2,5-diphenyl-2H bromine tetrazolato). For antifungal activity, the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined by broth microdilution. The results showed that cell toxicity was not observed at lower concentrations (0.097 to 0.39μg/ml) for all extracts in comparison to cell control. Among the chemical compounds identified, caffeic acid, p-coumaric acid, chlorogenic acid, ferulic acid and rutin were quantified. In antifungal activity, green and jataí did not exhibit activity against the isolates (MIC and MFC greater than 0.78mg/ml). However, all isolates of S. brasiliensis were sensitive to brown propolis (MIC of 0.09 to 0.78mg/ml), including the standard strain (P<0.001). Among the Brazilian propolis studied, the brown propolis showed activity against the S. brasiliensis isolates and more studies should be undertaken in order to evaluate its promising use in the treatment of sporotrichosis.

Chemical and cytotoxic analyses of brown Brazilian propolis (Apis mellifera) and its in vitro activity against itraconazole-resistant Sporothrix brasiliensis

This study aimed to evaluate the chemical composition and cytotoxic activity of brown Brazilian propolis and its in vitro activity against itraconazole-resistant Sporothrix brasiliensis from animal sporotrichosis. Propolis was acquired commercially and prepared as a hydroalcoholic extract. Chemical analysis was evaluated by liquid chromatography coupled to mass spectrometry of ultra-efficiency. The cell viability was evaluated by MTT test in MDBK cells of 50 to 0.09 μg/mL. For antifungal tests, twenty isolates of Sporothrix brasiliensis from dogs (n = 11) and cats (n = 9) with sporotrichosis were tested to itraconazole (16-0.0313 μg/mL) and to propolis (3.125-0.09 mg/mL) by broth microdilution technique (CLSI M38-A2), adapted to natural products. The results were expressed in minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). Itraconazole showed activity between MIC values of 0.25 to greater than 16 μg/mL, and 88.9% (08/09) and 72.7% (08/11) of S. brasiliensis from cats and dogs, respectively, were considered itraconazole-resistant. All Sporothrix brasiliensis were sensitive to brown propolis between MIC values of 0.19-1.56 mg/mL, including the itraconazole-resistant isolates, whereas the MFC values of propolis were from 0.78 to greater than 3.125 mg/mL. Propolis maintained a medium to high cell viability between concentration of 0.78 to 0.09 μg/mL, and p-coumaric acid was the major compound. Brown Brazilian propolis is a promising antifungal candidate against sporotrichosis and more studies need to be undertaken to evaluate its safe use to understand its efficacy.

Cytotoxicity and anti-Sporothrix brasiliensis activity of the Origanum majorana Linn. oil

The study aimed to evaluate the anti-Sporothrix sp. activity of the essential oil of Origanum majorana Linn. (marjoram), its chemical analysis, and its cytotoxic activity. A total of 18 fungal isolates of Sporothrix brasiliensis (n: 17) from humans, dogs and cats, and a standard strain of Sporothrix schenckii (n: 1) were tested using the broth microdilution technique (Clinical and Laboratory Standard Institute – CLSI M27-A3) and the results were expressed in minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). The MIC₅₀ and MIC₉₀ of itraconazole against S. brasiliensis were 2 μg/mL and 8 μg/mL, respectively, and the MFC₅₀ and MFC₉₀ were 2 μg/mL and >16 μg/mL, respectively, with three S. brasiliensis isolates resistant to antifungal. S. schenckii was sensitive at MIC of 1 μg/mL and MFC of 8 μg/mL. For the oil of O. majorana L., all isolates were susceptible to MIC of ≤2.25–9 mg/mL and MFC of ≤2.25–18 mg/mL. The MIC₅₀ and MIC₉₀ were ≤2.25 mg/mL and 4.5 mg/mL, respectively, and the MFC_50/90 values were twice more than the MIC. Twenty-two compounds were identified by gas chromatography with a flame ionization detector (CG-FID) and 1,8-cineole and 4-terpineol were the majority. Through the colorimetric (MTT) assay, the toxicity was observed in 70–80% of VERO cells between 0.078 and 5 mg/mL. For the first time, the study demonstrated the satisfactory in vitro anti-Sporothrix sp. activity of marjoram oil and further studies are needed to ensure its safe and effective use.

Feline sporotrichosis: epidemiological and clinical aspects

Feline sporotrichosis, which is caused by species of the Sporothrix schenckii complex, is endemic to Rio de Janeiro, Brazil. More than 4000 cases of the disease were diagnosed at Fundação Oswaldo Cruz, Brazil, between 1998 and 2012. Sporotrichosis in cats has been reported in several countries, but nowhere has an outbreak of animal sporotrichosis been as large as that seen in Brazil. The clinical manifestations of the disease range from an isolated skin lesion that can progress to multiple skin lesions and even fatal systemic involvement. Nodules and ulcers are the most common types of lesions, and respiratory signs and mucosa involvement are frequent. The definitive diagnosis depends on isolation of the etiologic agent in culture. Cytology, histopathology, and serology are useful tools for preliminary diagnosis. Severe pyogranulomatous inflammatory infiltrate, high fungal load, and extension of lesions to mucosa, cartilage, and bone in the nose of cats are indicative of an agent of high virulence in this endemic region. Itraconazole is the drug of choice, while, in refractory cases, amphotericin B or potassium iodide might be alternative treatments; however, recurrence after discharge may occur. Sporotrichosis persists as a neglected disease in Rio de Janeiro, and the treatment of cats remains a challenging and long-term endeavor.

Feline sporotrichosis due to Sporothrix brasiliensis: an emerging animal infection in São Paulo, Brazil

Background

Sporotrichosis is a mycotic infectious disease that is generally acquired by traumatic inoculation of contaminated materials especially from plant debris or through bites and scratches from diseased animals, such as domestic cats. It affects the skin, lymphatic system, and other organs in the warm-blooded host. Etiological agents are embedded in the plant-associated order Ophiostomatales. With essential differences between possible outbreak sources and ecological niche, host-environment interactions are classic determinants of risk factors for disease acquisition. Sporotrichosis outbreaks with zoonotic transmission, such as those that are ongoing in southern and southeastern Brazil, have highlighted the threat of cross-species pathogen transmission. Sporothrix brasiliensis has emerged as a human threat owing to the intimate contact pattern between diseased cats and humans in endemic areas.

Results

We describe the recent emergence of feline sporotrichosis in the metropolitan region of São Paulo, Brazil, with an overwhelming occurrence of S. brasiliensis as the etiological agent. A phylogenetic and a haplotype approach were used to investigate the origin of this epidemic and the impact of feline transmission on genetic diversity. During the last 3-year period, 163 cases of feline sporotrichosis were reported in São Paulo with proven S. brasiliensis culture. The haplotype diversity of feline S. brasiliensis isolates revealed the expansion of a clonal population with low genetic diversity. Haplotype analysis confirmed that isolates from São Paulo shared the haplotype originated in the long-lasting outbreak of cat-transmitted sporotrichosis in Rio de Janeiro, which differed from the haplotype circulating in the Rio Grande do Sul epidemic.

Conclusions

The fast spread of sporotrichosis in a short period of time highlights the potential for outbreaks and suggests that the mycosis may affect an urban population with a high concentration of susceptible felines. The feline sporotrichosis epidemic shows no signs of slowing, and this epidemiological pattern may require specific public health strategies to control future outbreaks.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-014-0269-5) contains supplementary material, which is available to authorized users.

Phylogenetic analysis reveals a high prevalence of Sporothrix brasiliensis in feline sporotrichosis outbreaks

Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1α) loci in strains originated from Rio de Janeiro (RJ, n = 15), Rio Grande do Sul (RS, n = 10), Paraná (PR, n = 4), São Paulo (SP, n =3) and Minas Gerais (MG, n = 1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil.