Canine Sporotrichosis Research Articles

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

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

Spatial Distribution of Canine Sporotrichosis in Rio de Janeiro, Brazil (1998-2018) and Its Correlation with Socioeconomic Conditions.

Canine sporotrichosis is a poorly described global disease and a spatial approach has not yet been used to assess the disease in dogs. Therefore, this study aimed to describe the occurrence of canine sporotrichosis in the state of Rio de Janeiro, Brazil, from 1998 to 2018 and its correlation with socioeconomic characteristics using exploratory spatial data analysis. A total of 295 cases of canine sporotrichosis were identified and 249 were georeferenced. There was a higher concentration of cases in the municipality of Rio de Janeiro, as well as along the border of the city and the adjacent municipalities in the great metropolitan area. The cases occurred in areas where most of the dwellings are houses. Moreover, no focus of disease density was found in the southern part of Rio de Janeiro city over the period studied, possibly due to better socioeconomic conditions. Areas with a high concentration of canine sporotrichosis cases coincided with regions that possessed a low proportion of households without paving, suggesting that the disease is not necessarily linked to extreme poverty. The mapping of areas with a greater density of cases is fundamental to formulate targeted and strategic plans in order to implement effective public health prevention and control measures.

Sporotrichosis in dogs: epidemiological and clinical-therapeutic profile and the emergence of itraconazole-resistant isolates.

Sporotrichosis is a neglected and emerging mycosis caused by the traumatic implantation of Sporothrix propagules into the (sub)cutaneous tissues of humans and animals. We evaluated canine sporotrichosis's clinical-therapeutic, epidemiological profile, and in vitro susceptibility of isolates to itraconazole. The variables were evaluated by a chi-square test. A total of 69 dogs were infected with Sporothrix spp., and the molecular identification revealed an overwhelming occurrence of S. brasiliensis as the etiological agent. The epidemiological profile was male (56.5%), adults (4.9±1.92 years old; 69.6%), and mongrels (53.6%). The clinical signs were 76.8%, ulcers, draining tracts, and nodules were predominant, mainly in the nasal region (82.2%). Dogs were diagnosed late with an evolution time of up to 3 months (34.8%). According to the prior therapeutic information, 52.2% received empirical therapy, 79.2% antibiotics, and had a 0.29 significantly greater chance of presenting lesion evolution time ˃ 3 months (P<.05; Odds Ratio [OR] 1/0.29). Additionally, 25 S. brasiliensis isolates recovered between 2006-2012 (n=15; Minimal inhibitory concentration (MIC): 0.06-2μg/ml) and 2013-2018 (n=10; MIC: 2→16μg/ml) were tested against itraconazole (ITZ). These findings highlighted the resistance to ITZ in clinical cases due to S. brasiliensis occurring after 2013, showing the temporal evolution of ITZ-resistance. We warn of the importance of accurate and early diagnosis in Sporothrix-affected areas, and we report the emergence of ITZ-resistant isolates in Southern Brazil.

Canine Sporotricosis: Clinic, Epidemiology, Diagnosis and Treatment

Sporotrichosis is an infectious disease caused by fungi belonging to the genus Sporotrix. In dogs the disease is uncommon, and the infection occurs through lesions caused by vegetation that is contaminated with fungi or when in contact with contaminated cats, by scratching, biting or exudates from the lesions. Thus, the objectives of the present study were to describe the epidemiological, clinical, laboratory and therapeutic aspects of canine sporotrichosis.

Canine sporotrichosis: polyphasic taxonomy and antifungal susceptibility profiles of Sporothrix species in an endemic area in Brazil.

Sporotrichosis, a mycosis caused by pathogenic species of the genus Sporothrix, affects diverse species of mammals. Until 2007, Sporothrix schenckii was considered the unique etiologic agent of sporotrichosis. Canine sporotrichosis is a poorly reported disease, and the majority of cases are from Rio de Janeiro, Brazil. There are scarce studies on the characterization of canine isolates of Sporothrix schenckii complex, as well as few antifungal susceptibility data available. The aim of this study was to characterize the clinical isolates of Sporothrix from dogs from Brazil at species level and evaluate their antifungal susceptibility profile. Polyphasic taxonomy was used to characterization at species level (morphological, phenotypical characteristics, and molecular identification). Antifungal susceptibility profiles (amphotericin B, itraconazole, ketoconazole, posaconazole, and terbinafine) were determined using the Clinical and Laboratory Standards Institute broth microdilution method (M38-A2). According to phenotypic identification and molecular analysis, 46 isolates included in this study were identified as S. brasiliensis and one as S. schenckii. Amphotericin B presented the highest minimum inhibitory concentration values, and the other drugs showed effective in vitro antifungal activity. This is the first report of S. schenckii in dogs from Brazil, since S. brasiliensis is the only species that has been described in canine isolates from Rio de Janeiro to date. Nevertheless, no differences were observed in the antifungal susceptibility profiles between the S. brasiliensis and S. schenckii isolates, and it is important to continuously study new canine clinical isolates from Rio de Janeiro, Brazil.

Sporotrichosis Outburst after Cancer Chemotherapy in a Dog

Background: Sporotrichosis is a dermatozoonosis that affects mammals in general, with the domestic feline (Felis catus) being the most epidemiologically important species. However, diagnosis of this disease in dogs is important considering the proximity with people and with other communicants. The epidemiology of sporotrichosis is already known in some states of Brazil, especially in the southeast region, but to the best of our knowledge there are no reports of sporotrichosis in non-human species in the state of Espírito Santo. This paper aimed at describing the first case of canine sporotrichosis in Espírito Santo, Brazil.Case: A 10 year-old Bull Terrier male dog was presented with nodular non-ulcerated lesions on the head and nodular ulcerated lesion on the nasal planum. The dog had a previous diagnosis of a low-grade mast cell tumour and palpebral melanoma. Mast cell tumour was treated with scrotum ablation (and orchiectomy) and bilateral inguinal lymph node removal, followed by chemotherapy with twelve intravenous infusion of vinblastine, along with prednisolone. Cutaneous lesions in the head and nasal planum appeared two months after finishing chemotherapy. At further anamnesis, the pet´s responsible reported that the dog had the habit of hunting cats that entered the residence, which raised the hypothesis of sporotrichosis. An undiagnostic cytology was performed, followed by a fungal culture, positive for Sporothrix schenckii. Treatment was then initiated with itraconazol (Oficial generic drug), at a dose of 10mg/kg/SID, until clinical remission, obtained after 60 days, maintaining it for 60 more days. Patient showed completed recovery, with no further complatints after a follow-up of more than 220 days.Discussion: Sporotrichosis is considered a rare disease in dogs, with isolated cases in the literature. The dog of the present report was diagnosed with sporotrichosis two months after the end of a chemotherapy treatment for a mast cell tumour. Therefore, it is suggested that the patient in this study was infected during an immunosuppressive phase. The same can occur with other immunosuppressive treatments, such as glucocorticoid, also included in the chemotherapy treatment of this patient, calcineurin inhibitors (cyclosporine) and mercaptopurine derivatives (azathioprine). Cytology is usually unconclusive for such lesions in dogs, once only a few yeast might be present. Nevertheless, the definitive diagnosis was obtained through fungal microculture. Treatment with itraconazol was successful but dogs might also present favorable responses to ioidine. Itraconazole is a fungistatic drug, fungicidal only in high doses. For this reason, if the fungistatic dose is not administered for sufficient time, recurrences may occur. In the last three years, Espirito Santo has become a new epidemiological scenario for sporotrichosis, and it is placed in the route of transmission, closely to Rio de Janeiro. Cats are the most affected animals and are commonly responsible for transmission to other species, including humans. The increase in cases of canine sporotrichosis requires its inclusion in the differential diagnosis of nodular-ulcerative lesions, along with cutaneous neoplasias and immune-mediated diseases.

Sporotrichosis in Southern Brazil, towards an epidemic?

Rio Grande do Sul (RS) is the second highest state with respect to sporotrichosis incidence in Brazil, with most cases occurring in the southern region. Given the importance of epidemiologic monitoring in hyperendemic areas, this study evaluated the spatial, geographical and annual sporotrichosis incidence over a period of 7years in the southern region of RS, as well as the disease evolution over the last two decades. Data were collected from the Mycology Laboratory of the Federal University of Rio Grande (FAMED-FURG) and from the Centre for Zoonosis Control (CZC) of the Prefeitura Municipal of Pelotas city. All feline cases of sporotrichosis diagnosed between 2010 and 2016 were included and analysed. In addition, cases of human and canine sporotrichosis were accounted for. Over the 7-year period (2010-2016), 372 feline, 34 canine and 83 human cases of sporotrichosis were diagnosed, being the mean number of cases/year 18.33 in the first 3years of the study and 116.33 in the last 3years. Cases were distributed among 34 and 28 neighbourhoods in Rio Grande and Pelotas city, respectively. Socioeconomic features reinforced the result that the disease is already spreading across a major part of the southern region. In addition, the study demonstrated the intensification and expansion of the high endemicity areas. Therefore, given that the number of feline sporotrichosis cases in southern RS reached alarming proportions, we suggested that this region will promptly face an epidemic of sporotrichosis if no preventive or control measures are undertaken.

Comparison of the Sensitivity of Three Methods for the Early Diagnosis of Sporotrichosis in Cats

Sporotrichosis is caused by species of fungi within the Sporothrix schenckii complex that infect man and animals. In Rio de Janeiro, Brazil, an epidemic has been observed since 1998, with most of the cases being related to transmission from infected cats. Although the definitive diagnosis of feline sporotrichosis is made by fungal culture, cytopathological and histopathological examinations are used routinely, because the long culture period may delay treatment onset. However, alternative methods are desirable in cases of low fungal burden. Immunohistochemistry (IHC) has been described as a sensitive method for diagnosing human and canine sporotrichosis, but there are no reports of its application to cats. The aim of this study was to analyse the sensitivity of cytopathological examination (Quick Panoptic method), histopathology (Grocott silver stain) and anti-Sporothrix IHC by blinded comparisons, using fungal culture as the reference standard. Samples were collected from 184 cats with sporotrichosis that exhibited skin ulcers. The sensitivities of Grocott silver stain, cytopathological examination and IHC were 91.3%, 87.0% and 88.6%, respectively. Grocott silver stain showed the best performance. IHC showed high sensitivity, as did cytopathological examinationand these may be considered as alternative methodologies. When the three methods were combined, the diagnosis was established in 180 (97.8%) out of 184 cases. Taken together, these findings indicate the need to implement these methods as routine tools for the early diagnosis of sporotrichosis in cats, notably when fungal culture is not available.

Canine sporotrichosis: report of 15 advanced cases

ABSTRACT: Sporotrichosis is a chronic, granulomatous and usually lymphocutaneous infection of animals and humans, caused by a dimorphic fungus, Sporothrix schenckii complex. The disease in dogs is considered rare, however, in the last years a crescent registration of cases was observed in Brazil, especially in the city of Rio de Janeiro. Fifteen dogs with ulcerated cutaneous lesions were seen at the Dermatology Service in the Small Animal’s Hospital at Universidade Federal Rural do Rio de Janeiro, between January 2014 and October 2015. Most lesions were located on the head, mainly the nose. Lesions were even seen on the chest, disseminated on the body and on the limbs. Three dogs (20%) exhibited the cutaneous-lymphatic form, with lesions initially on the distal aspect of one leg and ascending via lymphatics up the leg to the trunk and head. It was not ruled out the disseminated form in at least 3 dogs (20%). They had consistent signs of generalized or disseminated disease exhibiting respiratory symptoms (nasal discharge, sneezing, stertorous breathing), anorexia and weight loss. Draining tracts and cellulitis were very common. Some had large areas of skin necrosis with exposure of muscle and bone. Definitive diagnosis was obtained by cytological examination of exudates, histological examination, and/or isolation of S. schenckii complex by fungal culture. Because of the severity of the lesions that mimic other disorders like neoplasms or autoimmune skin diseases, and due to the difficulties of getting an accurate diagnosis, this study describes 15 advanced cases of canine sporotrichosis.

Zoonotic transmission of canine sporotrichosis in northeastern Brazil

Sporotrichosis is a subcutaneous mycosis, caused by the fungal complex Sporothrix schenckii, and composed of several species of the genus. Although diseased dogs show the minimal risk of infection to humans, such susceptibility is non-null and, therefore, should be considered. In the Northeast of Brazil, such mycosis has been reported in dogs but its role in local public health is still unknown. The objective of this study was to report the occurrence of canine sporotrichosis with transference capacity to humans, pointing a case in a Brazilian northeastern city. An 11-year-old male dachshund dog presenting skin lesions for two months. The dog was autochthonous to the city of Natal. The animal was referred for physical evaluation. Subcutaneous nodules were detected in the nasal and ventral-cervical regions. An incisional biopsy of the lesions was performed, subjecting the samples to histopathology. Itraconazole (10 mg/ kg, orally, every 24 hours) was prescribed. After a few days under physical evaluation, the guardian of the animal noticed alterations in the integument of her left upper limb. A clinical laboratory examination by a dermatologist detected sporotrichosis condition, being the animal caregiver submitted to a specialized therapy. The dermato-histopathology of the canine revealed the presence of Sporothrix spp., thus confirming the diagnosis of sporotrichosis. After the histopathological examination, itraconazole therapy was continued, achieving a complete lesion regression after 120 days. In dogs infected with the S. schenckii complex, transmission to humans should be considered regardless of the affected animal species, once sporotrichosis is an anthropozoonosis.

Evaluation of immunohistochemistry for the diagnosis of sporotrichosis in dogs

The aim of this study was to apply immunohistochemistry (IHC) for the diagnosis of canine sporotrichosis and to compare this method with the Grocott's silver stain (GSS) and periodic acid Schiff (PAS) techniques. Eighty-seven dogs with sporotrichosis (group 1) and 35 with American tegumentary leishmaniosis (ATL) (group 2) were studied. The fungus was detected in group 1 by GSS, PAS and IHC. IHC was also applied to group 2 to evaluate the occurrence of cross-reactions. PAS, GSS and IHC detected yeast cells in 19.5%, 43.7% and 65.5% of the group 1 cases, respectively. The detection of intracellular antigens of Sporothrix schenckii by IHC increased the sensitivity of the histological diagnosis to 80.5%. No positive reaction was observed in ATL lesions. The results suggest that IHC may be indicated for the diagnosis of sporotrichosis because of its higher diagnostic sensitivity.

ESPOROTRICOSE NA ESPÉCIE CANINA: RELATO DE UM CASO NA CIDADE DE MOSSORÓ-RN

Sporotrichosis is a mycosis caused by Sporothrix schenckii and little frequent in canines. The diagnosis confirmation occurs by fungal isolation in culture medium, but this procedure can be difficult on infected dogs. Because it is rare in canines, its definitive diagnosis is difficult to achieve and due to a lack of reports about the disease in the northeast region of Brazil, the present study aimed to describe a canine sporotrichosis case, in the city of Mossoro, RN. A three-year-old female canine presented chronic cutaneous injuries. The animal was lodged at the backyard, in touch with sand, plants and felines. The dermatological examination showed alopecia and cervical subcutaneous nodules. Cytology, scraping, serology for leishmaniasis and fungal culture were requested. The serological result was not reagent and the scraping showed negative. However, cytology evidenced suggestive structures of S. schenckii on macrophages cytoplasm. The fungal isolation confirmed the sporotrichosis diagnosis. The treatment corresponded to itraconazole. The constant inclusion of sporotrichosis for papules differential diagnosis, nodules and/or cutaneous ulcers is basic on canine species. KEY WORDS: Canine, dermatology, sporotrichosis, Mossoro.

Esporotricose canina: relato de caso

Relata-se um caso de esporotricose em um cão da raça Boxer, macho, com seis anos, encaminhado para uma consulta por causa de massa na região nasal e de dispneia. Após o exame físico, o animal foi internado para a realização de citologia, histologia e radiografia. Nos exames citológico e radiográfico, não foram constatadas alterações que justificassem a massa e a dispneia. Na histologia, observou-se a presença de um granuloma contendo dois esporos de Sporothrix schenckii. Foi realizado tratamento com itraconazol 5mg/kg BID por 60 dias. Após esse período, a massa desapareceu e a respiração do animal melhorou, tendo sido recomendada a manutenção da terapia por mais 30 dias, para evitar recidiva.

Epidemic sporotrichosis

Epidemic sporotrichosis is rare and has been related to an environmental source of infection. There were no reports of epizootics before a cat-transmitted epidemic was reported in Rio de Janeiro, Brazil. In the present paper we review the data published on this epidemic. From 1998 to 2004, 759 humans, 64 dogs and 1503 cats were diagnosed with sporotrichosis in the Evandro Chagas Clinical Research Institute. Of them, 85% of dogs and 83.4% of patients were reported to have had contact with cats with sporotrichosis, and 55.8% of the latter reported cat bites or scratches. Unusual manifestations were diagnosed in humans. Canine sporotrichosis presented as a self-limited mycosis. Feline sporotrichosis varied from subclinical infection to severe systemic disease with hematogenous dissemination of Sporothrix schenckii. Sporotrichosis in cats always preceded its occurrence among their owners and their domiciliary canine contacts. The zoonotic potential of cats was demonstrated by the isolation of S. schenckii from skin lesion fragments, and from material collected from their nasal and oral cavities. Thus far it is not known why sporotrichosis takes on the proportion of an emergent zoonosis in Rio de Janeiro. We alert physicians and veterinarians working outside the epidemic area to the diagnostic challenges involved with sporotrichosis.

Cytologic diagnosis of generalized cutaneous sporotrichosis in a hunting hound

A 1-year-old male Foxhound/Walker Hound mix was presented to the small animal internal medicine service at Louisiana State University School of Veterinary Medicine with a 6-week history of progressive, multifocal, ulcerative and draining, well-circumscribed lesions in a generalized distribution. Prior to referral, a presumptive diagnosis was made of sterile pyogranulomatous disease; immunosuppressive therapy was instituted but resulted in clinical deterioration. At presentation, the dog had marked neutropenia (1100 neutrophils/microL), and a mild toxic left shift (400 bands/microL). Cytologic findings in the exudates from a draining skin lesion included high numbers of markedly degenerate neutrophils (about 95% of nucleated cells) as well as low numbers of macrophages, small mature lymphocytes, and eosinophils. Low numbers of intracellular (within neutrophils and macrophages) and extracellular, pleomorphic, cigar-to-ovoid shaped organisms ( approximately 3x9 microm) consistent with Sporothrix were observed. Histopathologic examination of a skin biopsy showed marked, chronic, active, ulcerative, pyogranulomatous dermatitis and panniculitis, with intralesional yeast consistent with Sporothrix sp. The etiologic agent was confirmed as Sporothrix schenckii by macerated tissue fungal culture. The patient was treated with itraconazole, enrofloxacin, and clindamycin, with clinical resolution occurring over a 3-month period. This case is a rare example of the cytologic diagnosis of Sporothrix schenckii in a canine patient. Diagnosis of canine sporotrichosis is often challenging and usually requires tissue culture, as infected dogs typically harbor very few organisms. The patient's prior immunosuppressive therapy likely contributed to higher numbers of organisms in exudates from the cutaneous lesions, facilitating cytologic diagnosis.

Canine sporotrichosis in Rio de Janeiro, Brazil: clinical presentation, laboratory diagnosis and therapeutic response in 44 cases (1998–2003)

A sporotichosis epidemic involving forty-four dogs in the Metropolitan area of Rio de Janeiro is described. Solitary skin lesions were noted in 18 dogs (40.9%), 2-4 such lesions were observed in 17 animals (38.6%), and nine (20.5%) animals had five or more lesions. Twenty-five (56.8%) animals had single ulcerated skin lesions on the nose and nine (20.5%) showed nasal mucosal involvement (three of which also has a skin lesion). Respiratory symptoms were observed in 17 (38.6%) dogs and were found to be the most common extracutaneous signs of infection. Anemia, leukocytosis with neutrophilia, hypoalbuminemia and hyperglobulinemia were the most frequent hematological abnormalities. Histopathological analysis of skin biopsies in most cases revealed granulomatous reactions characterized by histiocytic hyperplasia and neutrophil infiltration. Yeast-like cells were observed in seven (16.7%) of 42 dogs examined histologically. During the study, eight (18.2%) animals were lost to follow-up and three (6.8%) were submitted to euthanasia. Of the remaining 33 dogs, five (15.2%) presented spontaneous regression of the lesions, 26 (78.8%) were cured after treatment, and two (6%) continue to be treated. The present cases indicate that many dogs with sporotrichosis respond well to treatment and in a few dogs, the disease may be self-limiting.