Promising use of nanotechnology in Pythium insidiosum: a systematic review / Utilização promissora de nanotecnologia em Pythium insidiosum: uma revisão sistemática

ABSTRACT: The aquatic oomycete Pythium insidiosum is an emerging pathogen highly relevant in human and veterinary medicine and an etiologic agent of pythiosis, a disease of worldwide distribution mainly affecting horses, dogs, and humans, presenting cutaneous, subcutaneous, ocular, gastrointestinal, and systemic forms. The available therapeutic methods to treat this disease and its forms are not entirely effective, thus highlighting the need to investigate the forms of treatments with better efficacy, such as compounds from different pharmacological classes, compounds of natural origin, and new technological alternatives, including nanotechnology. Therefore, this study evaluated scientific publications regarding the use of nanotechnology in P. insidiosum treatment. For this, a systematic literature review, was carried out on articles published from 2010 to 2022 on the LILACS, MEDLINE, Google Scholar, PubMed, and SciELO databases using the descriptors 'Pythium insidiosum,' 'pythiosis,' 'nanotechnology,' 'nanoparticles,' 'nanoemulsion,' and 'treatment.' We reported 162 articles for the researched theme; although, only four studies were included because they met the criteria established herein. A meta-analysis was used for the statistical analysis of the data obtained in vitro studies, and we reported the use of nanotechnology can be a promising alternative in developing antimicrobial compounds with anti-P. insidiosum activity. Nevertheless, additional research is needed to verify the potential use of this technology in clinical therapy against P. insidiosum infections.

RESUMO: O oomiceto aquático Pythium insidiosum é um patógeno emergente de relevância em medicina humana e veterinária. É o agente etiológico da pitiose, uma enfermidade de distribuição mundial, que acomete principalmente em equinos, caninos e seres humanos, podendo apresentar-se nas formas cutâneas, subcutâneas, oculares, gastrointestinais e sistêmicas. Considerando que os métodos terapêuticos disponíveis para o tratamento da doença não são completamente efetivos, há uma necessidade de investigar formas de tratamentos com melhor eficácia, como os compostos de diferentes classes farmacológicas, compostos de origem natural, bem como, novas alternativas tecnológicas, incluindo a nanotecnologia. Deste modo, este trabalho objetivou avaliar publicações científicas referentes a utilização de nanotecnologia em P. insidiosum. Para isso, realizou-se uma revisão sistemática da literatura, buscando artigos no período de 2010 a 2022, nas bases de dados LILACS, MEDLINE, Google Scholar, PubMed e SciELO, utilizando-se os descritores Pythium insidiosum, pitiose, nanotecnologia, nanopartículas, nanoemulsão e tratamento. Encontrou-se 162 artigos com familiaridade a temática pesquisada; no entanto, apenas quatro estudos foram incluídos, pois atendiam os critérios estabelecidos na pesquisa. Para análise estatística dos dados obtidos nos estudos in vitro, utilizou-se meta-análise. Demonstrou-se o promissor uso de nanotecnologia como alternativa no desenvolvimento de compostos antimicrobianos com atividade anti-P. insidiosum. Entretanto, constata-se que estudos adicionais se fazem necessários para verificar o potencial uso desta tecnologia na terapêutica clínica contra infecções por P. insidiosum.

Pitiose cutânea em equino no sertão do Ceará / Skin pythiosis in horse in the backwoods of the Ceará State

A pitiose é uma infecção invasiva ulcerativa piogranulomatosa causada pelo oomiceto Pythium insidiosum, parasita de plantas aquáticas em águas estagnadas. Apesar de não serem raros os relatos de pitiose nas espécies domésticas, a espécie equina é a mais afetada. A enfermidade pode ser adquirida através da colonização de lesões traumáticas e do folículo piloso. Em casos dessa infecção, pode-se encontrar hifas recobertas por células necróticas, formando massas branco-amareladas semelhantes a corais, denominadas de kunkers. As lesões são localizadas prioritariamente nas extremidades distais dos membros e na porção ventral da parede tóraco-abdominal. O diagnóstico da pitiose está relacionado a um prognóstico reservado dependendo do grau de comprometimento anatômico que a enfermidade se encontra. Diante do exposto, este trabalho teve como objetivo relatar um caso de pitiose cutânea em um equino, fêmea da raça Mangalarga Machador. O animal apresentava lesões ulcerativas no membro torácico esquerdo e no membro pélvico esquerdo. O tratamento escolhido foi o cirúrgico e imunoterápico, com intuito de remover todo o tecido lesionado e, posteriormente, coletar material para realização do exame histopatológico. O equino foi submetido a um protocolo pós-operatório com a terapia antitetânica por via intramuscular. A antibioticoterapia sistêmica foi realizada com penicilina benzatina, anti-inflamatório esteroidal, dexametasona foi realizada uma vez ao dia, durante cinco dias. Posteriormente, optou-se pelo uso do anti-inflamatório não esteroidal maxicam uma vez ao dia, durante cinco dias. O animal recebeu quatro doses do imunoterápico PITIUM-VAC por via subcutânea, com intervalo de 14 dias entre uma e outra aplicação, apresentando uma resposta satisfatória ao tratamento.

Pythiosis is an invasive ulcerative pyogranulomatous infection caused by the Oomycete Pythium insidiosum, a parasite of aquatic plants in standing water. Although reports of pythiosis in domestic species are not uncommon, equine species are the most affected. The disease can be acquired through the colonization of traumatic lesions and hair follicles. Hyphae covered by necrotic cells, forming yellowish-white coral-like masses called "kunkers" can be found. The lesions are located primarily on the distal extremities of the limbs and on the ventral portion of the thoracoabdominal wall. The diagnosis of pythiosis is linked to a poor prognosis, depending on the degree of anatomical involvement of the disease. Thus, this work aimed to report a case of cutaneous pythiosis in a female Mangalarga Machador equine. The animal presented ulcerative lesions on the left thoracic limb and the left pelvic limb. The chosen treatment was surgery and immunotherapy to remove all the injured tissue and, later, collect the material for histopathological examination. The horse was submitted to a post-operative protocol with intramuscular anti-tetanus therapy. Systemic antibiotic therapy with benzathine penicillin, steroidal anti-inflammatory, dexamethasone was performed once a day for five days. Subsequently, it was decided to use the non-steroidal anti-inflammatory maxicam once a day for five days. The animal received four doses of the immunotherapy PITIUM-VAC subcutaneously, with an interval of 14 days between applications, presenting a satisfactory response to the treatment.

Metastatic calcification and granulomatous grastroenteritis associated to Pythium insidiosum in a dog

Pythiosis is a granulomatous process of which the oomycete Pythium insidiosum is its etiological agent. It can affect animals and humans alike and its infection occurs when free zoospores in the water get in contact with the target tissues and encyst. The disease often occurs in tropical places with abundance of water and aquatic plants that host the fungus. Dogs infection is predominantly gastric with granuloma formations in the stomach and intestine with progressive signs of vomiting, weight loss and diarrhea. In this case report, we described clinical, surgical, necroscopic and histopathological findings of a one year and two months old, male boxer that presented clinical signs of anorexia and persistent vomiting. It was noticed on ultrasound examination an increase in stomach and intestine thickness. Laparotomy confirmed a mass affecting the gastric wall which, an incision biopsy, showed an abundant fibrous tissue associated with granulomatous reaction that was surrounded by tubuliform structures. Due to clinical complications, euthanasia was performed and in necroscopic examination a markedly increased stomach and duodenum was observed. An; histological examination of this areas it was observed that they contained granulation tissue with giant cells and epithelioids macrophages around necrosed areas associated with lymphocytes infiltrate. Also, it was possible to observe tubuliform structures by the Grocott-Gomori’s Methenamine Silver (GMS) stain, this finding is compatible with the agent Pythium insidiosum. Therefore, this presumptive identification was confirmed by PCR analysis which amplicon had 97.83% similarity with current available genomic sequence of P. insidiosum.

Metastatic calcification and granulomatous grastroenteritis associated to Pythium insidiosum in a dog

Pythiosis is a granulomatous process of which the oomycete Pythium insidiosum is its etiological agent. It can affect animals and humans alike and its infection occurs when free zoospores in the water get in contact with the target tissues and encyst. The disease often occurs in tropical places with abundance of water and aquatic plants that host the fungus. Dogs infection is predominantly gastric with granuloma formations in the stomach and intestine with progressive signs of vomiting, weight loss and diarrhea. In this case report, we described clinical, surgical, necroscopic and histopathological findings of a one year and two months old, male boxer that presented clinical signs of anorexia and persistent vomiting. It was noticed on ultrasound examination an increase in stomach and intestine thickness. Laparotomy confirmed a mass affecting the gastric wall which, an incision biopsy, showed an abundant fibrous tissue associated with granulomatous reaction that was surrounded by tubuliform structures. Due to clinical complications, euthanasia was performed and in necroscopic examination a markedly increased stomach and duodenum was observed. An; histological examination of this areas it was observed that they contained granulation tissue with giant cells and epithelioids macrophages around necrosed areas associated with lymphocytes infiltrate. Also, it was possible to observe tubuliform structures by the Grocott-Gomoris Methenamine Silver (GMS) stain, this finding is compatible with the agent Pythium insidiosum. Therefore, this presumptive identification was confirmed by PCR analysis which amplicon had 97.83% similarity with current available genomic sequence of P. insidiosum.(AU)

Segmental enteritis associated with Pythium insidiosum infection in a horse

Background: Pythiosis is an infectious disease caused by the oomycete Pythium insidiosum, with higher occurrence in wetlands and hot climate regions. This microorganism develops its cycle in aquatic plants, and most cases happen because of the contact of animals or people with water containing the motile zoospores (infectious form). Horses are the principal species affected and develop principally cutaneous and subcutaneous lesions, but the gastrointestinal tract is seldom affected. Humans develop various forms of pythiosis, such as a vascular form. The objectives of the current study are to describe an unusual case of intestinal pythiosis, its clinical signs, aspects of pathogenesis, and diagnosis. Case: A 13-year-old Crioula mare, from Santa Maria, RS, Brazil, presented with reduced food and water intake, apathy, restlessness, rolling, nasal reflux, firm abdomen upon palpation, and tachypnea during 2 days. The horses of this farm were fed native pasture and horse feed, and they had access to a nearby pond. Two days following the start of the clinical signs, the horse died and was necropsied on the farm. During necropsy, there was around 400 mL of reddish effusion in the abdominal cavity (modified transudate). A 15 cm segment of jejunum was firm upon palpation and had a severe transmural thickening. The wall of the affected area was up to 3 cm in thickness and firm, with small yellowish and irregular masses that stood out and looked friable, interpreted as kunkers. Microscopically, the yellowish masses (kunkers) were characterized by dense accumulations of intact and degenerate eosinophils (eosinophilic necrosis). Within these kunkers, and also on their periphery, there were multiple negatively stained hyphal profiles. Hyphae were also seen on the wall of small arteries inside the kunkers. These hyphae had nearly parallel walls and were occasionally...

Segmental enteritis associated with Pythium insidiosum infection in a horse

Background: Pythiosis is an infectious disease caused by the oomycete Pythium insidiosum, with higher occurrence in wetlands and hot climate regions. This microorganism develops its cycle in aquatic plants, and most cases happen because of the contact of animals or people with water containing the motile zoospores (infectious form). Horses are the principal species affected and develop principally cutaneous and subcutaneous lesions, but the gastrointestinal tract is seldom affected. Humans develop various forms of pythiosis, such as a vascular form. The objectives of the current study are to describe an unusual case of intestinal pythiosis, its clinical signs, aspects of pathogenesis, and diagnosis. Case: A 13-year-old Crioula mare, from Santa Maria, RS, Brazil, presented with reduced food and water intake, apathy, restlessness, rolling, nasal reflux, firm abdomen upon palpation, and tachypnea during 2 days. The horses of this farm were fed native pasture and horse feed, and they had access to a nearby pond. Two days following the start of the clinical signs, the horse died and was necropsied on the farm. During necropsy, there was around 400 mL of reddish effusion in the abdominal cavity (modified transudate). A 15 cm segment of jejunum was firm upon palpation and had a severe transmural thickening. The wall of the affected area was up to 3 cm in thickness and firm, with small yellowish and irregular masses that stood out and looked friable, interpreted as kunkers. Microscopically, the yellowish masses (kunkers) were characterized by dense accumulations of intact and degenerate eosinophils (eosinophilic necrosis). Within these kunkers, and also on their periphery, there were multiple negatively stained hyphal profiles. Hyphae were also seen on the wall of small arteries inside the kunkers. These hyphae had nearly parallel walls and were occasionally...(AU)

Pythiosis in cattle in Northeastern Brazil / Pitiose em bovinos no Nordeste do Brasil

The epidemiological, clinical and pathological aspects of cutaneous pythiosis occurring in cattle from three farms in the Northeastern of Brazil are described. A biopsy of the lesions of one bovine from each farm was performed. In two cases, the affected cattle had contact with water accumulated in dams during the dry season in the semiarid region. Another case occurred in the coastal tropical region in cattle grazing around irrigation channels. Clinically, lesions were observed mainly on the skin of the thoracic and/or pelvic limbs, characterized by flat and irregular ulcerated areas or nodules of varying sizes, some with fistulous tracts penetrating deep into the subcutaneous tissue. In one case the regional lymph nodes were affected. Histologically, in all cases, pyogranulomatous dermatitis associated with negative hyphae images, in hematoxylin-eosin stained sections, were observed. In sections stained by Grocott methenamine silver, the hyphae measured 2-8μm and had irregular ramifications and rare septations. Immunohistochemistry technique demonstrated strong immunolabeling for Pythium insidiosum. Pythiosis should be included in the differential diagnosis of dermatopathies in cattle in the Northeastern of Brazil.(AU)

Descrevem-se os aspectos epidemiológicos, clínicos e patológicos da pitiose cutânea em bovinos de três propriedades do Nordeste do Brasil. Uma biópsia das lesões de um bovino de cada propriedade foi realizada. Em dois casos, os bovinos afetados tiveram acesso à água acumulada em açudes durante a estação seca da região semiárida. O outro bovino acometido estava a pastoreio próximo a canais de irrigação na região litorânea. Clinicamente, as lesões foram observadas principalmente na pele dos membros torácicos e/ou pélvicos e caracterizavam-se por áreas planas e irregulares de ulceração ou nódulos de tamanhos variados, alguns com trajetos fistulosos penetrando profundamente no tecido subcutâneo. Em um caso, os linfonodos regionais foram afetados. Histologicamente, em todos os casos, observou-se dermatite piogranulomatosa associada a imagens negativas de hifas, em secções corados por hematoxilina e eosina. Em seções coradas por metenamina de prata de Grocott, as hifas mediam 2-8μm e possuíam ramificações irregulares com raras septações. A imuno-histoquímica demonstrou forte imunomarcação para Pythium insidiosum. A pitiose deve ser incluída como diagnóstico diferencial de dermatopatias de bovinos no Nordeste do Brasil.(AU)

Cranioesophageal pythiosis in a horse

Background: Pythiosis is a chronic inflammatory disease that is caused by oomycete Pythium insidiosum. This illness affects several species including humans and horses. Equine is the most affected species, having no predisposition for breed, gender, or age. It is usually shown in cutaneous and subcutaneous forms, and the lesions, which grow quickly and are hard to treat, are located mainly in the extremities. The diagnosis is made via epidemiology, clinical signs, and macroscopic and microscopic aspects of the lesion. This study describes a case of cranioesophageal pythiosis in a horse, examining the epidemiological, clinical and pathological characteristics. Case: A 12-year-old male quarter horse, weighing 515 kg was taken to the Veterinary Hospital at the University Center of Espírito Santo (UNESC). The horse had an increase in volume in the cranioesophageal region, coughing, difficulty breathing, and a runny nose. On clinical examination, the horse showed an enlargement in the submandibular and retropharyngeal lymph nodes, subcutaneous edema in the larynx region, and a temperature of 38.2ºC. According to the owner, cough was recurrent and had lasted about 12 months even after treatment with different kinds of antimicrobials. On radiographic exam, there was a marked decrease in the tracheal lumen and increased soft tissue radiopacity in the region adjacent to the narrowing. The animal was taken to surgery to remove the mass, but he died because of complications during surgery. The animal’s owner did not allow necropsy, but a fragment of the mass in the cranioesophageal was removed and sent for histological examination. The fragment was fixed in 10% formalin and processed using routine histological analysis. Macroscopically, the mass was light yellowish and ulcerated, and it measured 7.0 × 5.0 × 5.0 cm. In the middle of the ulcerated areas, there were yellow and...

Cranioesophageal pythiosis in a horse

Background: Pythiosis is a chronic inflammatory disease that is caused by oomycete Pythium insidiosum. This illness affects several species including humans and horses. Equine is the most affected species, having no predisposition for breed, gender, or age. It is usually shown in cutaneous and subcutaneous forms, and the lesions, which grow quickly and are hard to treat, are located mainly in the extremities. The diagnosis is made via epidemiology, clinical signs, and macroscopic and microscopic aspects of the lesion. This study describes a case of cranioesophageal pythiosis in a horse, examining the epidemiological, clinical and pathological characteristics. Case: A 12-year-old male quarter horse, weighing 515 kg was taken to the Veterinary Hospital at the University Center of Espírito Santo (UNESC). The horse had an increase in volume in the cranioesophageal region, coughing, difficulty breathing, and a runny nose. On clinical examination, the horse showed an enlargement in the submandibular and retropharyngeal lymph nodes, subcutaneous edema in the larynx region, and a temperature of 38.2ºC. According to the owner, cough was recurrent and had lasted about 12 months even after treatment with different kinds of antimicrobials. On radiographic exam, there was a marked decrease in the tracheal lumen and increased soft tissue radiopacity in the region adjacent to the narrowing. The animal was taken to surgery to remove the mass, but he died because of complications during surgery. The animals owner did not allow necropsy, but a fragment of the mass in the cranioesophageal was removed and sent for histological examination. The fragment was fixed in 10% formalin and processed using routine histological analysis. Macroscopically, the mass was light yellowish and ulcerated, and it measured 7.0 × 5.0 × 5.0 cm. In the middle of the ulcerated areas, there were yellow and...(AU)

Pythiosis in cattle in Northeastern Brazil / Pitiose em bovinos no Nordeste do Brasil

The epidemiological, clinical and pathological aspects of cutaneous pythiosis occurring in cattle from three farms in the Northeastern of Brazil are described. A biopsy of the lesions of one bovine from each farm was performed. In two cases, the affected cattle had contact with water accumulated in dams during the dry season in the semiarid region. Another case occurred in the coastal tropical region in cattle grazing around irrigation channels. Clinically, lesions were observed mainly on the skin of the thoracic and/or pelvic limbs, characterized by flat and irregular ulcerated areas or nodules of varying sizes, some with fistulous tracts penetrating deep into the subcutaneous tissue. In one case the regional lymph nodes were affected. Histologically, in all cases, pyogranulomatous dermatitis associated with negative hyphae images, in hematoxylin-eosin stained sections, were observed. In sections stained by Grocott methenamine silver, the hyphae measured 2-8μm and had irregular ramifications and rare septations. Immunohistochemistry technique demonstrated strong immunolabeling for Pythium insidiosum. Pythiosis should be included in the differential diagnosis of dermatopathies in cattle in the Northeastern of Brazil.(AU)

Descrevem-se os aspectos epidemiológicos, clínicos e patológicos da pitiose cutânea em bovinos de três propriedades do Nordeste do Brasil. Uma biópsia das lesões de um bovino de cada propriedade foi realizada. Em dois casos, os bovinos afetados tiveram acesso à água acumulada em açudes durante a estação seca da região semiárida. O outro bovino acometido estava a pastoreio próximo a canais de irrigação na região litorânea. Clinicamente, as lesões foram observadas principalmente na pele dos membros torácicos e/ou pélvicos e caracterizavam-se por áreas planas e irregulares de ulceração ou nódulos de tamanhos variados, alguns com trajetos fistulosos penetrando profundamente no tecido subcutâneo. Em um caso, os linfonodos regionais foram afetados. Histologicamente, em todos os casos, observou-se dermatite piogranulomatosa associada a imagens negativas de hifas, em secções corados por hematoxilina e eosina. Em seções coradas por metenamina de prata de Grocott, as hifas mediam 2-8μm e possuíam ramificações irregulares com raras septações. A imuno-histoquímica demonstrou forte imunomarcação para Pythium insidiosum. A pitiose deve ser incluída como diagnóstico diferencial de dermatopatias de bovinos no Nordeste do Brasil.(AU)

Mastite por Pythium insidiosum em éguas / Mastitis by Pythium insidiosum in mares

Background: Pythiosis is a chronic inflammatory disease caused by the oomycete Pythium insidiosum. This disease hasbeen reported in several species, but most cases occur in horses. In this species, the cutaneous form is more prevalent,with occasional involvement of adjacent lymph nodes and bone tissue. The involvement of the mammary glands was notproperly characterized. Therefore, the aim of this study is to describe cases of pythiosis with the involvement of the mammary glands in mares.Case: A retrospective study of all biopsy samples and necropsy examinations of horses, performed at the Animal PathologyLaboratory of the Federal University of Campina Grande from January 2000 to December 2018, was carried out. During thestudy period, 142 cases of cutaneous pythiosis were identified. Of these, in three the lesions extended to the mammary glands.Mares with 3-, 7- and 12-year-old, mongrel, from the backlands of the Paraiba were affected. On physical examination, themares presented swollen mammary glands and multifocal wounds, which discharge serosanguinolent secretion. Clinicalevolution ranged from 15 to 30 days. The animals had been medicated, but the wounds did not heal and mastectomies wereperformed. Macroscopically, the mammary glands were enlarged and with multifocal areas of ulceration measuring 1 to 3.5cm in diameter. At the cut surface, they exhibited fistulous tracts containing kunkers. In the histopathological evaluation,was observed diffuse and marked inflammatory infiltrate of eosinophils extending through the deep dermis and interlobularmammary stroma; and multifocal areas, sometimes focally extensive, of eosinophilic necrosis with intralesional negativeimages of hyphae. In histological sections stained by periodic acid-Schiff, the walls of the hyphae were weakly stained inblue; but when impregnated by Grocott methenamine silver, they were strongly marked in black...(AU)

Mastite por Pythium insidiosum em éguas / Mastitis by Pythium insidiosum in mares

Background: Pythiosis is a chronic inflammatory disease caused by the oomycete Pythium insidiosum. This disease hasbeen reported in several species, but most cases occur in horses. In this species, the cutaneous form is more prevalent,with occasional involvement of adjacent lymph nodes and bone tissue. The involvement of the mammary glands was notproperly characterized. Therefore, the aim of this study is to describe cases of pythiosis with the involvement of the mammary glands in mares.Case: A retrospective study of all biopsy samples and necropsy examinations of horses, performed at the Animal PathologyLaboratory of the Federal University of Campina Grande from January 2000 to December 2018, was carried out. During thestudy period, 142 cases of cutaneous pythiosis were identified. Of these, in three the lesions extended to the mammary glands.Mares with 3-, 7- and 12-year-old, mongrel, from the backlands of the Paraiba were affected. On physical examination, themares presented swollen mammary glands and multifocal wounds, which discharge serosanguinolent secretion. Clinicalevolution ranged from 15 to 30 days. The animals had been medicated, but the wounds did not heal and mastectomies wereperformed. Macroscopically, the mammary glands were enlarged and with multifocal areas of ulceration measuring 1 to 3.5cm in diameter. At the cut surface, they exhibited fistulous tracts containing kunkers. In the histopathological evaluation,was observed diffuse and marked inflammatory infiltrate of eosinophils extending through the deep dermis and interlobularmammary stroma; and multifocal areas, sometimes focally extensive, of eosinophilic necrosis with intralesional negativeimages of hyphae. In histological sections stained by periodic acid-Schiff, the walls of the hyphae were weakly stained inblue; but when impregnated by Grocott methenamine silver, they were strongly marked in black...

Culture medium and inoculation methodology for the study of soft root rot caused by Phytopythium sp / Meio de cultura e metodologia de inoculação para o estudo da podridão mole de raízes causada por Phytopythium sp

Cassava (Manihot esculenta Crantz) is an important crop in Brazil and Pará is the major producer of roots. High temperature and humidity of tropical regions favor the development of various diseases, among them the cassava root rot. The objective of this study was to evaluate the effect of luminosity and culture medium on the mycelial growth and sporulation of Phytopythium sp. associated with different methods of inoculation on cassava roots. In vitro tests for pathogen growth were established in a 2 x 6 factorial design (luminosity x culture medium) with five replicates and the means were compared by t test (P0.05). The culture medium containing sweet cassava root produced greater mycelial development and higher pathogen sporulation and it was the most suitable medium for pathogen culture. The culture under absence of light generated better mycelial growth than culture under 12 hour of light. Regarding the type of inoculation, the response was better when deeper injuries were induced.(AU)

A mandioca (Manihot esculenta Crantz) é uma importante cultura para o Brasil, onde o Pará é o principal produtor de raízes. Regiões tropicais com alta umidade e temperatura favorecem o desenvolvimento de diversas doenças, como as podridões de raiz. O presente estudo tem como objetivo avaliar o efeito da luminosidade e de meios de cultura no crescimento micelial e na esporulação de Phytopythium sp. e analisar métodos de inoculação do patógeno em raízes de mandioca destacadas. Os ensaios in vitro foram instalados em esquema fatorial 2x6 (luminosidade x meio de cultura), com cinco repetições e as médias comparadas pelo teste t (p0,05). O meio de cultura contendo raiz de mandioca mansa proporcionou maior desenvolvimento micelial e maior esporulação do patógeno e é o mais adequado para o cultivo do patógeno. O cultivo sob ausência de luz gerou melhor crescimento micelial do que o cultivo sob 12 horas de luz. Quanto ao tipo de inoculação, a resposta foi melhor nas raízes que obtiveram ferimentos mais profundos.(AU)

Equine pythiosis in the eastern wetlands of Uruguay

ABSTRACT: Equine pythiosis is an ulcerative and granulomatous disease of the skin, caused by the oomycete Pythium insidiosum (Pythiaceae). The objective of this study was to describe seven cases of equine pythiosis that occurred from 2012 to 2017 in the eastern region of Uruguay. Six of the seven cases occurred in the eastern wetland ecosystems of the Merin basin, and the remaining case occurred in the wetland fluvial plains of the Tacuarembó River. Lesions consisted of a large, rapidly growing ulcerated tumor with abundant granulation tissue, serosanguineous secretion, and fistulous tracts containing large concretions or kunkers. The animals presented intense pruritus, claudication and loss of body condition, with death or euthanasia in extremis in six cases. The main histological lesions consisted of an eosinophilic and pyogranulomatous inflammatory process, with numerous foci of eosinophilic necrosis (kunkers), collagenolysis, and a Splendore-Hoeppli reaction. In all cases, silver coloration (Grocott) showed intralesional hyphae compatible with P. insidiosum, which was confirmed by immunohistochemistry in three cases. A horse in the terminal phase of the disease was treated with triamcinolone acetonide (50mg IM every 15 days), and fully recovered after 1 year. It is concluded that equine pythiosis is prevalent in the wetland ecosystems of eastern Uruguay and that treatment with triamcinolone is auspicious.

RESUMO: Pitiose é uma doença granulomatosa e ulcerativa da pele dos equinos causada pelo oomyceto Pythium insidiosum (Pythiaceae). O objetivo deste trabalho foi descrever sete casos de pitiose equina que ocorreram de 2012 a 2017 na região leste do Uruguai. Seis dos sete casos ocorreram no ecossistema de áreas pantanosas da bacia da bacia da Lagoa Mirim Merin e o restante nas planícies fluviais pantanosas do rio Tacuarembó. As lesões se caracterizaram por tumores ulcerados de crescimento rápido com abundante tecido de granulação, secreção serossanguinolenta e presença de tratos fistulosos contendo material coraloide ou kunkers. Os equinos apresentavam prurido intenso, claudicação e perda da condição corporal e seis morreram ou foram eutanasiados in extremis. As principais lesões histológicas consistiam de um processo inflamatório piogranulomatoso com numerosos focos de necrose eosinofílicos (kunkers), colagenólise e reação de Splendori-Hoepli. Em todos os casos a impregnação pela prata (Grocott) revelou a presença de hifas intralesionais compatíveis com P. insidiosum, o que foi confirmado pela imuno-histoquímica em três casos. Um equino em fase terminal da doença foi tratado com triamcinolona acetonida (50mg, IM, a cada 15 dias), recuperando-se completamente após um ano. Conclui-se que a pitiose é uma enfermidade presente em áreas úmidas na região leste do Uruguai e o tratamento com triamcinolona pode ser uma alternativa promissora.

Equine pythiosis in the eastern wetlands of Uruguay / Pitiose equina em áreas úmidas do leste do Uruguai

Equine pythiosis is an ulcerative and granulomatous disease of the skin, caused by the oomycete Pythium insidiosum (Pythiaceae). The objective of this study was to describe seven cases of equine pythiosis that occurred from 2012 to 2017 in the eastern region of Uruguay. Six of the seven cases occurred in the eastern wetland ecosystems of the Merin basin, and the remaining case occurred in the wetland fluvial plains of the Tacuarembó River. Lesions consisted of a large, rapidly growing ulcerated tumor with abundant granulation tissue, serosanguineous secretion, and fistulous tracts containing large concretions or kunkers. The animals presented intense pruritus, claudication and loss of body condition, with death or euthanasia in extremis in six cases. The main histological lesions consisted of an eosinophilic and pyogranulomatous inflammatory process, with numerous foci of eosinophilic necrosis (kunkers), collagenolysis, and a Splendore-Hoeppli reaction. In all cases, silver coloration (Grocott) showed intralesional hyphae compatible with P. insidiosum, which was confirmed by immunohistochemistry in three cases. A horse in the terminal phase of the disease was treated with triamcinolone acetonide (50mg IM every 15 days), and fully recovered after 1 year. It is concluded that equine pythiosis is prevalent in the wetland ecosystems of eastern Uruguay and that treatment with triamcinolone is auspicious.(AU)

Pitiose é uma doença granulomatosa e ulcerativa da pele dos equinos causada pelo oomyceto Pythium insidiosum (Pythiaceae). O objetivo deste trabalho foi descrever sete casos de pitiose equina que ocorreram de 2012 a 2017 na região leste do Uruguai. Seis dos sete casos ocorreram no ecossistema de áreas pantanosas da bacia da bacia da Lagoa Mirim Merin e o restante nas planícies fluviais pantanosas do rio Tacuarembó. As lesões se caracterizaram por tumores ulcerados de crescimento rápido com abundante tecido de granulação, secreção serossanguinolenta e presença de tratos fistulosos contendo material coraloide ou kunkers. Os equinos apresentavam prurido intenso, claudicação e perda da condição corporal e seis morreram ou foram eutanasiados in extremis. As principais lesões histológicas consistiam de um processo inflamatório piogranulomatoso com numerosos focos de necrose eosinofílicos (kunkers), colagenólise e reação de Splendori-Hoepli. Em todos os casos a impregnação pela prata (Grocott) revelou a presença de hifas intralesionais compatíveis com P. insidiosum, o que foi confirmado pela imuno-histoquímica em três casos. Um equino em fase terminal da doença foi tratado com triamcinolona acetonida (50mg, IM, a cada 15 dias), recuperando-se completamente após um ano. Conclui-se que a pitiose é uma enfermidade presente em áreas úmidas na região leste do Uruguai e o tratamento com triamcinolona pode ser uma alternativa promissora.(AU)

Feline subcutaneous pythiosis / Pitiose subcutânea em um felino

Pythiosis in felines is a rare disease associated with the oomycete Pythium insidiosum. The aim of this report was to describe the macroscopic, histopathological, and molecular characteristics of P. insidiosum infection in a 2-year-old cat, with a localized invasive subcutaneous mass. The feline had an increase of volume near the anal region since it was younger. The cat died just after surgery. The necropsy was performed, and samples were collected for histopathological examination. Microscopically, the skin lesion was characterized by necro-eosinophilic dermatitis, panniculitis, and myositis surrounding negatively stained hyphal structures. In the sections stained with GMS, dark brown hyphae were clearly seen inside the affected tissue. They were rarely septate and their walls were almost parallel. Immunohistochemistry using a polyclonal anti-P. insidiosum antibody showed a strongly immunostained hyphae into the lesions. The analysis based on PCR had a positive result for P. insidiosum. Pythiosis should be considered in the differential diagnosis of subcutaneous tissue disorders in felines.(AU)

Pitiose em felinos é uma doença de ocorrência rara associada ao oomiceto Pythium insidiosum. O objetivo deste relato é descrever as características macroscópicas, histopatológicas e moleculares da infecção por P. insidiosum em um gato de dois anos de idade, com uma massa invasiva localizada no subcutâneo. O gato morreu logo após a cirurgia, sendo realizada a necropsia e coleta de amostras para exame histopatológico. Microscopicamente, a lesão cutânea foi caracterizada por dermatite necroeosinofílica, paniculite e miosite envolvendo imagens de hifas negativamente coradas. Nas seções coradas com GMS, hifas marrom-escuras foram claramente vistas dentro do tecido afetado. As hifas raramente eram septadas e suas paredes eram quase paralelas. A imuno-histoquímica, utilizando um anticorpo policlonal anti-P. insidiosum, mostrou hifas fortemente imunomarcadas nas lesões. A análise baseada em PCR teve resultado positivo para P. insidiosum. A pitiose deve ser considerada no diagnóstico diferencial de desordens teciduais subcutâneas em felinos.(AU)

Equine pythiosis in the eastern wetlands of Uruguay / Pitiose equina em áreas úmidas do leste do Uruguai

Equine pythiosis is an ulcerative and granulomatous disease of the skin, caused by the oomycete Pythium insidiosum (Pythiaceae). The objective of this study was to describe seven cases of equine pythiosis that occurred from 2012 to 2017 in the eastern region of Uruguay. Six of the seven cases occurred in the eastern wetland ecosystems of the Merin basin, and the remaining case occurred in the wetland fluvial plains of the Tacuarembó River. Lesions consisted of a large, rapidly growing ulcerated tumor with abundant granulation tissue, serosanguineous secretion, and fistulous tracts containing large concretions or kunkers. The animals presented intense pruritus, claudication and loss of body condition, with death or euthanasia in extremis in six cases. The main histological lesions consisted of an eosinophilic and pyogranulomatous inflammatory process, with numerous foci of eosinophilic necrosis (kunkers), collagenolysis, and a Splendore-Hoeppli reaction. In all cases, silver coloration (Grocott) showed intralesional hyphae compatible with P. insidiosum, which was confirmed by immunohistochemistry in three cases. A horse in the terminal phase of the disease was treated with triamcinolone acetonide (50mg IM every 15 days), and fully recovered after 1 year. It is concluded that equine pythiosis is prevalent in the wetland ecosystems of eastern Uruguay and that treatment with triamcinolone is auspicious.(AU)

Pitiose é uma doença granulomatosa e ulcerativa da pele dos equinos causada pelo oomyceto Pythium insidiosum (Pythiaceae). O objetivo deste trabalho foi descrever sete casos de pitiose equina que ocorreram de 2012 a 2017 na região leste do Uruguai. Seis dos sete casos ocorreram no ecossistema de áreas pantanosas da bacia da bacia da Lagoa Mirim Merin e o restante nas planícies fluviais pantanosas do rio Tacuarembó. As lesões se caracterizaram por tumores ulcerados de crescimento rápido com abundante tecido de granulação, secreção serossanguinolenta e presença de tratos fistulosos contendo material coraloide ou kunkers. Os equinos apresentavam prurido intenso, claudicação e perda da condição corporal e seis morreram ou foram eutanasiados in extremis. As principais lesões histológicas consistiam de um processo inflamatório piogranulomatoso com numerosos focos de necrose eosinofílicos (kunkers), colagenólise e reação de Splendori-Hoepli. Em todos os casos a impregnação pela prata (Grocott) revelou a presença de hifas intralesionais compatíveis com P. insidiosum, o que foi confirmado pela imuno-histoquímica em três casos. Um equino em fase terminal da doença foi tratado com triamcinolona acetonida (50mg, IM, a cada 15 dias), recuperando-se completamente após um ano. Conclui-se que a pitiose é uma enfermidade presente em áreas úmidas na região leste do Uruguai e o tratamento com triamcinolona pode ser uma alternativa promissora.(AU)

Biological activity of 7beta-acetoxywithanolide D isolated from Acnistus arborescens / Atividade biológica de 7beta-acetoxivitanolido D isolado de Acnistus arborescens

Many oomycete species are plant pathogens and are responsible for causing significant losses in agriculture. Currently, plant pathogen control is carried out by chemical, biological and physical methods. However, due to the development of resistance to these methods by some pathogens, it is imperative that alternative methods are developed. Brazilian biodiversity is well-known for its species richness and is considered a promising source of natural products. Among the vascular plants, the family Solanaceae A. Juss. (Solanaceae) is considered one of the largest, with distributions across all tropical and temperate regions of the world. The Solanaceae family presents a high diversity of species of economic importance as sources of food, medicinal and ornamental properties. Plants of this family are sources of secondary metabolites of various chemical classes that possess potential diverse applications. Therefore, chemical and biological investigations of these compounds are extremely important as they present alternatives for their potential use in the control of plant pathogens. Here, we report for the first time, the biological activity of 7β-acetoxywithanolide D, a compound isolated from Acnistus arborescens, against the oomycete Phytophthora cinnamomi. With these results, we emphasize the importance of such studies on plant secondary metabolites, which may present coadjuvant options in the control of plant pathogens.(AU)

Muitas espécies de oomicetos são fitopatógenos e responsáveis por causar perdas significativas na agricultura. Atualmente, o controle de fitopatógenos é realizado por métodos químicos, biológicos e físicos. No entanto, alguns agentes patogênicos adquirem resistência a esses métodos, por isso é necessário desenvolver constantemente alternativas para controlá-los. A biodiversidade brasileira é conhecida devido à sua riqueza de espécies, sendo considerada uma fonte promissora de produtos naturais. Entre as plantas vasculares, a família Solanaceae A. Juss. (Solanaceae) é considerada uma das maiores, apresentando distribuição em todas as regiões tropicais e temperadas do mundo. A família Solanaceae apresenta alta diversidade de espécies de importância econômica como fonte de alimentos, propriedades medicinais e ornamentais. As plantas desta família são fontes de metabolitos secundários de várias classes químicas com as mais diversas aplicações. Portanto, as investigações químicas e biológicas desses compostos são extremamente importantes e podem se tornar uma alternativa para o controle dos agentes patogênicos das plantas. Aqui, relatamos pela primeira vez a atividade biológica do composto 7β-acetoxivitanolido D isolado de Acnistus arborescens contra o oomiceto Phytophthora cinnamomi. Com este resultado, enfatizamos a importância de estudos com metabolitos secundários de plantas, que podem ser uma opção coadjuvante no controle de fitopatógenos.(AU)

Isolation of Saprolegnia aenigmatica oomycetes and protocol for experimental infection of pacu (Piaractus mesopotamicus) / Isolamento do oomiceto Saprolegnia aenigmatica e protocolo de infecção experimental em pacu (Piaractus mesopotamicus)

Successful disease treatment depends on molecular studies under indoor conditions with experimental infection protocols that facilitate understanding the disease and the drug`s efficacy. The internal transcribed spacer (ITS) region was sequenced from three isolates, which were identified as Saprolegnia aenigmatica. Subsequently, healthy fish were immunosuppressed with dexamethasone (1.2 mg kg-1) and descaled to the skin using a sharp scalpel. These individuals were isolated in individual aquariums maintained at 22°C. Individuals in one group were subcutaneously inoculated with 9,000 zoospores (DDZ treatment), a second group was exposed to oomycetes in water with three colonized baits (DDB), a third group was maintained in water without zoospores (DD), and a control group (C) consisted of healthy animals. After 48 and 96 hours, two animals from each group were euthanized for fungal reisolation. The fish from groups DD and C did not show clinical signs, and no oomycetes were isolated. The animals from the DDZ and DDB groups showed cotton-wool-like masses on the skin, and S. aenigmatica was re-isolated. Thus, for infection using zoospores or baits parasitized by S. aenigmatica, an immunosuppressor (dexamethasone) and a sharp scalpel can be used effectively to establish an experimental infection in P. mesopotamicus.

O sucesso do tratamento de uma enfermidade depende do estudo de moléculas em condições de laboratório por meio de protocolos de infecção experimental que viabilizam a compreensão da doença e da eficácia dos fármacos. Pela sequência ITS foram identificadas três cepas de Saprolegnia aenigmatica. Dessa forma, pacus sadios foram submetidos à imunossupressão com dexametasona (1,2 mg kg-1), esfoliados com auxílio de bisturi e distribuídos em aquários a 22ºC. Após este procedimento, um grupo de animais foi inoculado com 9.000 zoósporos/peixe subcutâneo (DEZ), a outro foram adicionadas três iscas colonizadas com o oomiceto na água (DEI), um terceiro grupo foi mantido sem contato com o oomiceto (DE) e um quarto grupo, de animais sadios, representaram o controle (C). Após 48 e 96h deste procedimento, foram eutanaziados animais de cada grupo para reisolamento. Os animais do grupo DE e C não apresentaram sinais clínicos e não foi reisolado o oomiceto. Porém, tanto os animais do grupo DEZ quanto como os animais do grupo DEI apresentaram micélio branco na pele e foi reisolado Saprolegnia aenigmatica. Assim, a infecção com zoósporos ou com iscas colonizadas por S. aenigmatica, com o uso de dexametasona e abrasivo epitelial são formas eficazes de infecção experimental em P. mesopotamicus.

Isolation of Saprolegnia aenigmatica oomycetes and protocol for experimental infection of pacu (Piaractus mesopotamicus) / Isolamento do oomiceto Saprolegnia aenigmatica e protocolo de infecção experimental em pacu (Piaractus mesopotamicus)

Successful disease treatment depends on molecular studies under indoor conditions with experimental infection protocols that facilitate understanding the disease and the drug`s efficacy. The internal transcribed spacer (ITS) region was sequenced from three isolates, which were identified as Saprolegnia aenigmatica. Subsequently, healthy fish were immunosuppressed with dexamethasone (1.2 mg kg-1) and descaled to the skin using a sharp scalpel. These individuals were isolated in individual aquariums maintained at 22°C. Individuals in one group were subcutaneously inoculated with 9,000 zoospores (DDZ treatment), a second group was exposed to oomycetes in water with three colonized baits (DDB), a third group was maintained in water without zoospores (DD), and a control group (C) consisted of healthy animals. After 48 and 96 hours, two animals from each group were euthanized for fungal reisolation. The fish from groups DD and C did not show clinical signs, and no oomycetes were isolated. The animals from the DDZ and DDB groups showed cotton-wool-like masses on the skin, and S. aenigmatica was re-isolated. Thus, for infection using zoospores or baits parasitized by S. aenigmatica, an immunosuppressor (dexamethasone) and a sharp scalpel can be used effectively to establish an experimental infection in P. mesopotamicus.(AU)

O sucesso do tratamento de uma enfermidade depende do estudo de moléculas em condições de laboratório por meio de protocolos de infecção experimental que viabilizam a compreensão da doença e da eficácia dos fármacos. Pela sequência ITS foram identificadas três cepas de Saprolegnia aenigmatica. Dessa forma, pacus sadios foram submetidos à imunossupressão com dexametasona (1,2 mg kg-1), esfoliados com auxílio de bisturi e distribuídos em aquários a 22ºC. Após este procedimento, um grupo de animais foi inoculado com 9.000 zoósporos/peixe subcutâneo (DEZ), a outro foram adicionadas três iscas colonizadas com o oomiceto na água (DEI), um terceiro grupo foi mantido sem contato com o oomiceto (DE) e um quarto grupo, de animais sadios, representaram o controle (C). Após 48 e 96h deste procedimento, foram eutanaziados animais de cada grupo para reisolamento. Os animais do grupo DE e C não apresentaram sinais clínicos e não foi reisolado o oomiceto. Porém, tanto os animais do grupo DEZ quanto como os animais do grupo DEI apresentaram micélio branco na pele e foi reisolado Saprolegnia aenigmatica. Assim, a infecção com zoósporos ou com iscas colonizadas por S. aenigmatica, com o uso de dexametasona e abrasivo epitelial são formas eficazes de infecção experimental em P. mesopotamicus.(AU)