Laerte Ferreiro

Laerte Ferreiro
Federal University of Mato Grosso | UFMT · Departamento de Patologia Clínica Veterinária

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114
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Publications

Publications (114)
Article
Background: Dermatophytes, fungi of universal distribution, invade semi or fully keratinized structures, such as skin, fur/hair and nails. In companion animals (cats, dogs, or small mammals like rabbits, guinea pigs, and chinchillas) as well as in large animals (mainly in horses and cattle). Frequently are responsible for skin diseases including al...
Article
The classical dermatophytes diagnosis is based on mycological culture and microscopy observation both human and animal hair, skin and nail samples. The aim of this work was to develop the new in-house real-time PCR with pan-dematophyte reaction for detection and identification of the main dermatophytes directly from hair samples, providing a simple...
Article
Background: Dermatophytes, fungi of universal distribution, invade semi or fully keratinized structures, such as skin, fur/hair and nails. The various species of dermatophytes are classified into three genera anamorphic: Microsporum, Trichophyton and Epidermophyton. The genus Epidermophyton includes only E. floccosum, that rarely affects animals. T...
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Trichophyton verrucosum is the most commonly dermatophyte involved in cattle ringworm. This work reported a case of bovine dermatophytosis due to Trichophyton verrucosum detected from the clinical sample by SYBR-Green real-time PCR. The strategy was based on the DNA extraction directly from the infected hair followed by real‐time PCR and melting‐po...
Article
Sporotrichosis is a disease caused by thermally dimorphic fungi belonging to the Sporothrix schenckii complex. We report the occurrence of multiple cases of sporotrichosis in cats in Porto Alegre (RS), Brazil, from 2015 to 2019. A set of 21 fungal isolates were collected and the partial sequence of calmodulin (CAL) gene compared. All isolates were...
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A ten year-old Holstein cow had an intermittent bloody diarrhea, evolving to anorexia and recumbency, followed by death. Mycotic segmental enteritis was diagnosed based on the pathological and immunohistochemical findings. Rhizopus microsporus was identified as the causal agent through fungal culture and PCR analysis. Intestinal mucormycosis is poo...
Article
This report describes a case of tracheobronchitis caused by Aspergillus fumigatus in a cow. A 4-year-old Jersey cow was submitted for necropsy examination. Grossly, the mucosa of the trachea and bronchi was diffusely reddened and was covered by a moderate amount of yellow, caseous material, sometimes with small foci of grey ‘cotton-like’ appearance...
Article
This study examined the effect of minocycline alone and in combination with immunotherapy against pythiosis. Twenty rabbits, aged three months old and subcutaneously inoculated with Pythium insidiosum zoospores were divided into four groups (n = 5): treated with minocycline (10 mg/kg/day twice daily), treated with immunotherapy (34 mg subcutaneousl...
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Susceptibility testing is essential to inform the correct management of Aspergillus infections. In this study we present antifungal susceptibility profile of A. fumigatus isolates recovered from lungs of birds with and without aspergillosis. Fifty three isolates were tested for their antifungal susceptibility to voriconazole (VRC), itraconazole (IT...
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Background: Malassezia species are commensal skin organisms of warm-blooded vertebrates that can act as opportunistic pathogens. Malassezia pachydermatis is of importance in both veterinary and human medicine. Recognised initially as causes of infection of the skin, they are now known to be superficial commensals as well as potential causes of infe...
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Deep fungal infections of the orbit and nasal passages causing rhinitis and ulcerative keratomycosis are uncommonly reported in cats. Hyalohyphomycetes and phaeohyphomycetes have rarely been associated with this disorder. Sino-orbital fungal diseases are emerging and more invasive than sino-nasal fungal diseases with poor response to therapy and a...
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This report describes the clinical, pathological, and molecular aspects of a pneumonia by Cryptococcus neoformans in a goat in the Southern region of Brazil. A goat with a history of prolonged transportation presented dyspnea, nasal discharge and cough, and was subjected to necropsy, histopathology, and mycological evaluation. Grossly, cranio-ventr...
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Skin lesions in feline sporotrichosis usually present a high fungal burden, making cats an important source of infection. This study evaluated the fungal burden and isolation in skin lesions of feline sporotrichosis during treatment with itraconazole (ITZ), combined with or without potassium iodide (KI). Treatment-naïve cats with culture-confirmed...
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Malassezia pachydermatis is considered an opportunistic pathogen of the outer ear duct in dogs and cats. This yeast can also be found in the skin, rectum, anal sacks and vagina. Eighty-two samples of this yeast isolated from dogs with the symptoms of external otitis from the Porto Alegre region were tested for their susceptibility to antifungal age...
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The yeast Malassezia pachydermatis is a common commensal and occasional opportunistic pathogen of theskin microbiota of animals and humans. In this study, the susceptibility of M. pachydermatis isolates to fluconazole (FLC), itraconazole (ITZ), ketoconazole (KTZ), clotrimazole (CLZ), and miconazole (MCZ) alone and in combination with terbinafine (T...
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RESUMO: As enfermidades fúngicas são diagnósticos diferenciais de diversas morbidades de caráter infeccioso, degenerativo ou proliferativo neoplásico, principalmente em gatos, que é a espécie mais suscetível a estas. Este trabalho descreve os achados anatomopatológicos de doenças fúngicas em gatos no período de janeiro de 2005 a dezembro de 2015 pe...
Article
The aim of this study was to evaluate the purine levels in serum and brains of mice experimentally infected by Cryptococcus neoformans. Twenty-four mice were divided into the following groups: a control group (n = 12; Group A) and an infection group with animals that were infected (n = 12; Group B) with a 0.3-mL intraperitoneal injection containing...
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Cryptococcus gattii is often associated with pulmonary and systemic infections in humans and animals. In this research we report a case of nasopharyngeal cryptococoma caused by C. gatti in an equine. A 10-year-old mare presented a mass obstructing the oropharynx. Macroscopically the mass was asymmetric, and was attached to the ethmoidal sinuses and...
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Background: Sporotrichosis is a deep cutaneous mycosis caused by the Sporothrix species complex, dimorphic fungi of which at least five are of clinical importance: S. brasiliensis, S. globosa, S. luriei, S. mexicana, and S. schenckii sensu stricto. The disease affects humans and animals, especially cats, which can manifest a wide spectrum of clinic...
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Background: Dermatophytes are infectious agents responsible for dermatophytosis, an important worldwide zoonosis. Cats are considered potential hosts and reservoir of these fungi, especially Microsporum canis. The prevalence in cats without dermatopathies varies according to the region, climate and animal husbandry. The aim of this study was to est...
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Background: Pseudomycetomas are deep cutaneous to subcutaneous lesions caused by Microsporum canis mainly described in Persian cats, with few reports of intra-abdominal location. This report describes the clinical signs and lesions of intra-abdominal pseudomycetomas caused by M. canis in two Persian cats. Case report: Two Persian cats with a his...
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Prototheca zopfii is an alga that can cause disease in animals and humans. Here, we reported a case of systemic protothecosis in a 2-year-old female Boxer. The animal exhibited tetraparesis and vertical nystagmus. It died two weeks after the onset of clinical signs and was necropsied. At gross examination, whitish areas were identified in the heart...
Article
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Background: Sporotrichosis is a deep cutaneous mycosis caused by the Sporothrix species complex, dimorphic fungi of which at least five are of clinical importance: S. brasiliensis, S. globosa, S. luriei, S. mexicana, and S. schenckii sensu stricto. The disease affects humans and animals, especially cats, which can manifest a wide spectrum of clinic...
Article
The present study was carried out to assess the participation of purines in the activation and modulation of inflammatory response of rats experimentally infected by Cryptococcus neoformans. Thus, 24 Wistar rats were divided into two groups of 12 animals each: Group A - uninfected control group and Group B - infected by C. neoformans. Blood was col...
Article
Human patients with diabetes mellitus are at increased risk of fungal infections. Diabetes mellitus has also been implicated as a predisposing factor in the establishment of fungal lung infections in cats. Two diabetic cats of different origins presented with severe acute respiratory conditions that resulted in their death. At necropsy examination...
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Aspergillosis is one of the main causes of mortality in birds. The pulmonary system is most frequently affected, with lesions observed in the air sacs and lungs of a wide variety of bird species. The aim of this study was to confirm by molecular methods the identification and the genetic diversity of Aspergillus fumigatus isolates of lung's samples...
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The present study investigated the in vitro and the in vivo interactions among azithromycin, clarithromycin, minocycline and tigecycline against P. insidiosum. In vitro antimicrobial activities were determined by the broth microdilution method in accordance with the CLSI document M38-A2 and antibiotic interactions were assayed using the checkerboar...
Article
The aim of this study was to assess the role of the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) as biomarkers of inflammation and tissue injury on rats experimentally infected by Cryptococcus neoformans. For this purpose, 20 male rats were divided into two groups: 10 animals representing the uninfected control group (Group A) and 1...
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Background: Histoplasma capsulatum and Pneumocystis spp. may cause a host infection through the respiratory airway, mainly affecting the pulmonary tissue. These fungal pathogens affect a wide range of mammalian species, including humans and bats. The co-infection of bats with both organisms above has never been studied in Brazil. The aim of the pre...
Article
This study evaluated the in vitro and in vivo activity of micafungin alone and in combination with the iron chelator deferasirox against Pythium insidiosum. Micafungin showed a poor in vitro activity when it was used alone, but synergistic interactions were observed for 88.2% of the strains when the drug was combined with deferasirox. Smaller lesio...
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Background: The contamination of milk by fungi, often represented by potentially pathogenic species, may pose a risk for consumers, when the product is consumed in natura or even in the processed form. Also, it should be considered detrimental effects in the processing of milk derivative products. In relationship to other milk producing animal spec...
Article
We describe the in vitro activities of the combinations of carvacrol and thymol with antibiotics (azithromycin, clarithromycin, minocycline and tigecycline) and antifungal agents (amphotericin B, caspofungin, itraconazole and terbinafine) against 23 isolates of the oomycete Pythium insidiosum. The assays were based on the M38-A2 technique and check...
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Micotoxinas representam um vasto grupo de contaminantes químicos naturais originados a partir do metabolismo secundário de fungos filamentosos patogênicos. Elas são produzidas, principalmente, pelos gêneros Fusarium, Alternaria, Aspergillus e Penicillium, os quais podem contaminar grãos e cereais, como trigo, milho e soja. Conforme sua natureza e n...
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The contamination of consumer food and animal feed with toxigenic fungi has resulted in economic losses worldwide in animal industries. Mycotoxins are highly biologically reactive secondary metabolites and can inhibit protein synthesis and cell multiplication. Considering the cytotoxicity of mycotoxins, this experiment was performed to determine th...
Article
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We describe here the in vitro activities of azithromycin, clarithromycin, minocycline, or tigecycline alone and in combination with amphotericin B, itraconazole, terbinafine, voriconazole, anidulafungin, caspofungin, or micafungin against 30 isolates of the oomycete Pythium insidiosum. The assays were based on the CLSI M38-A2 technique and the chec...
Article
Background: Dermatophytoses are one of the most frequent skin diseases of pets and livestock in the world. Contagion among animal communities, difficulty in implementing control measures, and the eventual transmission of ringworm to people explain its great importance. Microsporum canis causes a zoonosis that has increased in several countries, out...
Article
Abstract 1. The protective effect of a natural Brazilian calcium montmorillonite (CaMont) against aflatoxins was studied in broiler chickens. 2. A total of 1056 d-old Cobb male broilers were housed in experimental pens (22 chickens per pen) for 42 d. Three levels of CaMont (0, 2.5 and 5 g/kg) and two levels of aflatoxins (0 and 3 mg/kg) were assaye...
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Geotrichum spp. are ubiquitous, saprotrophic fungi found in soil, organic matter, and silage, as a contaminant in food products and in the digestive tracts of mammals. The current study reports a case of Geotrichum candidum infection with dermatitis in an aborted bovine fetus with skin and lung lesions. A 6-month-old aborted male Holstein Friesian...
Article
Dermatophytosis caused by Microsporum canis is a heterogeneous disease with variable clinical manifestations. M. canis is a zoophilic dermatophyte and the most frequent fungi isolated from dogs, cats and children in Brazil. The aim of this study was to investigate the genetic variability of M. canis isolates from different animal species using two...
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Molecular techniques have revealed a high prevalence of Pneumocystis colonization in wild mammals. Accurate quantification of Pneumocystis sp. is essential for the correct interpretation of many research experiments investigating this organism. The objectives of this study were to detect the presence of Pneumocystis sp. in bats by qPCR, and to dist...
Article
Background: Pythium insidiosum is an oomycete classified in the kingdom Stramenopila. P. insidiosum hyphae are not able to initiate infection without the secretion of hydrolytic enzymes, which are considered an important factor in microbial virulence. Aims: To evaluate the extracellular enzymatic activity of 14 Brazilian P. insidiosum isolates a...
Article
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This study evaluated the in vitro activity of aminoglycoside antibiotics and tigecycline against Pythium insidiosum. The susceptibility tests were carried out using the broth microdilution method in accordance with the CLSI document M38-A2. MIC values for gentamicin, neomycin, paromomycin, and streptomycin ranged from 32 to 64 mg/liter, and the min...
Article
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Background: Pneumocystis constitutes a highly diversifi ed biological group, with numerous species, which are strongly host-specifi c and well adapted to live inside the lungs of a diverse range of mammals. The detection of DNA from Pneumocystis in clinical specimens by PCR assays is leading to important advances in pneumonia caused by Pneumocystis...
Article
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Background: Pneumocystis constitutes a highly diversified biological group, with numerous species, which are strongly host-specific and well adapted to live inside the lungs of a diverse range of mammals. The detection of DNA from Pneumocystis in clinical specimens by PCR assays is leading to important advances in pneumonia caused by Pneumocystis a...
Article
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Background: Aspergillosis is the most common mycosis in birds, which are considered potential host also susceptible to the infection by Aspergillus spp. The clinical signs of the disease are often related to the respiratory tract, although other organs or systems may be affected. Signs are generally either not specific or may be directly related to...
Article
The present study investigated the in vitro inhibitory activity of terbinafine, itraconazole, caspofungin, fluvastatin and ibuprofen against 15 isolates of Pythium insidiosum in double and triple combinations and determined in vivo correlations using rabbits with experimental pythiosis. The minimal inhibitory concentration (MIC) was determined in a...
Article
Full-text available
The yeast Malassezia pachydermatis is part of the normal cutaneous microflora of most homoeothermic vertebrates. However, under certain conditions as high humidity, seborrheic skin, corticotherapy and immunodeficiency, it can become pathogenic and cause dermatopathies. The pathogenic role of the genus Malassezia seems to be related to physical, che...
Article
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The Pneumocystis genus is comprised of pathogens dwelling in the lungs of terrestrial, aerial, and aquatic mammals. Occasionally they induce severe pneumonitis, particularly in hosts with severe impairment of the immune system and progressively may fill pulmonary alveolar cavities causing respiratory failure. Molecular genetic studies revealed that...
Article
Full-text available
The yeast Malassezia pachydermatis is part of the normal cutaneous microflora of most homoeothermic vertebrates. However, under certain conditions as high humidity, seborrheic skin, corticotherapy and immunodeficiency, it can become pathogenic and cause dermatopathies. The pathogenic role of the genus Malassezia seems to be related to physical, che...
Article
Skin carriage and quantification of Malassezia yeasts were evaluated in 180 healthy dogs (group 1) and 117 dogs with clinical signs (pruritus, erythema, lichenification/seborrhoea, excoriations and alopecia) that could be related to Malassezia dermatitis (group 2) in Brazil. The lesions in the group 2 dogs were evaluated using CADESI-03 scores. Sam...
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Background: Wild boar population is present worldwide. Contact between wild boars and domestic pigs may occur occa-sionally, and several diseases, as well as the occurrence of opportunistic infections are observed in both species. Mycotic rhinitis and pneumonia were reported before in pig herds, mainly associated with immunosuppression caused by vi...
Article
Background: Sinonasal aspergillosis (SNA) is the second most common cause of nasal discharge in dogs. The diagnosis is confirmed through anamnesis, physical and complementary exams. Aspergillus fumigatus is the species most frequently isolated from dogs with fungal involvement of the upper respiratory tract. Canine SNA is a disease with worldwide d...
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Three lipid-dependent Malassezia isolates (here named 114A, 114B and 114C) recovered from a dog with skin lesions were phenotypically and genotypically characterized. All presented ovoid cells and buds formed on a narrow base. Most of the results from physiological tests were consistent with those of Malassezia furfur. The phylogenetic analysis of...
Article
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Little detailed information is available on the association of Malassezia pachydermatis genotypes and the extent of skin damage that they cause. In the present study, isolates of M. pachydermatis, recovered from the skin of healthy dogs and dogs with dermatitis in Brazil, were characterized on the basis of partial sequencing of the large subunit (L...
Article
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Pythium insidiosum is a zoosporic organism which causes pythiosis in humans and animals. This study aimed to report the paradoxical growth of Brazilian P. insidiosum strains when submitted to in vitro susceptibility tests with caspofungin. The growth at concentrations above the minimal inhibitory concentration (MIC) ranged from 16 to 128 μg/ml and...
Article
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Phaeohyphomycosis include cutaneous, subcutaneous, and systemic diseases that affect humans and animals. The diseases are usually associated with immunocompromised hosts and are caused by fungi whose wall cell contains melanin (dematiaceous). This communication describes clinical, histopathological, and microbiological aspects observed in a case of...
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Background: Researches have been developed to observe the normal microbiota of different animal species. This subject is of major importance for the control of potential infection risks. Fungi can be found in various substrates, foodstuffs (cereals, meat, milk, vegetables) and also in the skin, mucosae, respiratory and gastrointestinal tracts of an...
Article
Background: Dermatophytoses are cosmopolitan contagious mycoses of the skin and concern a wide range of mammals, including man, and more rarely birds. These mycoses are rarely diagnosed in New World Primates. The most frequent tinea of the subhuman Primates is microsporosis due to Microsporum canis or trichophytosis by Trichophyton mentagrophytes a...
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Descrevem-se dois surtos de uma doença neurológica que afetou rebanhos bovinos leiteiros que consumiam bagaço de malte contaminado por Aspergillus clavatus no município de Viamão, estado do Rio Grande do Sul. A morbidade em ambos os surtos foi em torno de 30% e a letalidade, 50% e 100%. A evolução clínica da doença variou de 5 a 64 dias. Dentre os...
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This paper describes the experimental reproduction of a neurological condition in sheep by the administration of a beer by-product contaminated with Aspergillus clavatus. Samples of this by-product, in which pure cultures of A. clavatus grew, originated from two farms where outbreaks of A. clavatus poisoning in cattle had occurred. The onset of sym...
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Two outbreaks of a neurological disease affecting herds of dairy cattle that were fed moldy beer residues contaminated with Aspergillus clavatus in the county of Viamão, Rio Grande do Sul, Brazil, are described. The morbidity of both outbreaks was 30% and the lethality 50% and 100%. The clinical course varied from 5 to 64 days. Only one of the anim...
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A ocorrência de casos esporádicos de mastite causados por microrganismos de origem ambiental pode ser considerada como emergente e as leveduras, os fungos leveduriformes e os filamentosos são alguns dos principais agentes envolvidos. Em relação à mastite micótica, as leveduras são freqüentemente causas de infecções da glândula mamária em animais pr...
Article
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A ocorrência de casos esporádicos de mastite causados por microrganismos de origem ambiental pode ser considerada como emergente e as leveduras, os fungos leveduriformes e os filamentosos são alguns dos principais agentes envolvidos. Em relação à mastite micótica, as leveduras são freqüentemente causas de infecções da glândula mamária em animais pr...
Conference Paper
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The choice of a culture media to proceed a mycological analysis of food is extremely important to guarantee the reliability of the analysis. The medium should allow an excellent recovery of fungal species present in the food at the same time that it is necessary to avoid bacterial development. Thus the real microbial ecology will be reflected in th...
Article
Objective. - This work compares the virulence between pigmented (P) and albino (A) filamentous forms of S. schenckii through experimental skin sporotrichosis. Material and methods. - Two original wild pigmented isolates (1 and 2) cultivated in yeast extract peptone dextrose (YEPD), were exposed to 300 erg/mm(2) of UV radiation in order to produce m...
Article
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Mastitis is one of the most serious problems in the dairy cattle farms. The great majority of the cases are caused by bacteria, but lately there have been an increasing number of reports about cases of mycotic etiology. The objective of this work was to characterize the yeasts and yeast-like fungi associated with milk of cows with mastitis. Milk sa...
Article
La pythiose est une maladie émergente très difficile à traiter due au développement de l’oomycète Pythium insidiosum. Le but de cette étude est d’évaluer l’efficacité de deux traitements différents de la pythiose expérimentale chez le lapin. Trois groupes de cinq lapins sont inoculés par la voie sous-cutanée avec une suspension de zoospores de P. i...