Suyene Oltramari de Souza

In vitro and in vivo antimicrobial activities of minocycline in combination with azithromycin, clarithromycin or tigecycline against Pythium insidiosum

ABSTRACT The present study investigated the in vitro and the in vivo interactions among azithromycin, clarithromycin, minocycline, and tigecycline against Pythium insidiosum. In vitro antimicrobial activities were determined by the broth microdilution method in accordance with CLSI document M38-A2, and the antibiotic interactions were assayed using the checkerboard MIC format. In vivo efficacy was determined using a rabbit infection model. The geometric mean MICs of azithromycin, clarithromycin, minocycline, and tigecycline against P. insidiosum were, respectively, 1.91, 1.38, 0.91, and 0.79 μg/ml. By checkerboard testing, all combinations resulted in in vitro synergistic interactions (>60%). Antagonism was not observed. The in vivo studies showed that azithromycin (20 mg/kg/day twice daily) alone or in combination with minocycline (10 mg/kg/day twice daily) significantly decreased the fungal burden. This study demonstrates that azithromycin possesses potent curative efficacy against subcutaneous pythiosis in the rabbit model.

Natural Infection of Wild Canids (Cerdocyon thous and Lycalopex gymnocercus) with the Intraendothelial Piroplasm Rangelia vitalii in Southern Brazil

Abstract Rangelia vitalii is a piroplasm that infects canines, causing lesions typical of a hemolytic disorder. Two wild canids, a crab-eating fox (Cerdocyon thous) and a Pampas fox (Lycalopex gymnocercus), were presented for necropsy in Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. On gross examination, both animals had pale mucosae and moderate tick infestation (Amblyomma aureolatum). There was severe splenomegaly, and the liver had a diffusely orange-reddish lobular pattern. The mesenteric lymph nodes were brownish and slightly enlarged. Structures compatible with R. vitalii were observed in the cytoplasm of endothelial cells in the liver, stomach, heart, kidney, lungs, lymph nodes, and bladder. The agent was characterized by PCR and genetic sequencing of liver samples and ticks. We show that parasitism with R. vitalii follows an epidemiologic cycle in which wild canids act as reservoirs.

Decreased expression of cardiac troponin C is associated with cardiac lesions in Amorimia exotropica poisoned cattle

The plants which cause sudden death of cattle in Brazil occupy a leading position for losses in the cattle industry. Amorimia exotropica is one of the plants pertaining to this group. Diagnostic findings in these cases may be inconclusive; further knowledge is necessary. This paper identifies cardiac lesions through anti-cardiac troponin C (cTnC) immunehistochemistry performed in tissues from cattle poisoned after consumption of A.exotropica in southern Brazil. Heart fragments from nine A. exotropica-poisoned cattle were studied immunohistochemically using anti-human cTnC as the primary antibody. In the hearts from all of the poisoned cattle, there was a sharp decrease in the cTnC expression level in the cytoplasm of groups of cardiomyocytes. A significant decrease in anti-cTnC immunoreactivity occurred particularly in degenerated or necrotic cardiomyocytes. Occasional groups of cells showed complete loss of immunolabeling. In the remaining intact cardiomyocytes from poisoned cattle and in cardiomyocytes from six cattle that died from other causes there was intense cytoplasmic staining.

OSTEOMYELITIS CAUSED BY SALMONELLA ENTERICA SEROVAR DERBY IN BOA CONSTRICTOR

Abstract:  After demonstrating chronic weight loss, prostration, and muscle flaccidness, a captive-bred 9-mo-old boa constrictor (Boa constrictor constrictor) died and was submitted for necropsy. Along the spinal column there were multiple, yellowish white, macroscopic nodules of 1–5 mm in diameter in the ventral side of the vertebral body and in the intervertebral spaces. Severe multifocal necrotizing osteomyelitis associated with granulomatous inflammation was the main histologic finding in the vertebral column. In the liver, there was discrete but similar granulomatous changes. Positive anti-Salmonella immunostaining was observed in the spinal column and in the liver. Salmonella enterica serovar Derby was isolated from fragments of the spinal column. These bacteria are important cause of disease in captive reptiles.

Caracterização histológica e imuno-histoquímica das lesões de tuberculose em bovinos e de linfadenite granulomatosa em suínos

Mycobacterium sp. induz inflamacao granuloma-tosa em diferentes especies animais. Mycobacterium bovis e o complexo Mycobacterium avium sao importantes patogenos de bovinos e suinos e podem causar infeccao em humanos, principalmente imunossuprimidos. Perdas na producao, barreiras comerciais e prejuizos por condenacao de carcacas em abatedouro/frigorifico estao atrelados a ocorrencia dessas infeccoes, com prejuizos economicos significativos. Foi realizado um estudo de casos diagnosticados como tuberculose em bovinos e linfadenite granulomatosa em suinos no Setor de Patologia Veterinaria da Universidade Federal do Rio Grande do Sul (SPV-UFRGS) no periodo de janeiro de 2007 a dezembro de 2011. Dados referentes a raca, ao sexo, a idade e ao historico clinico foram compilados dos livros de registro e analisados. As caracteristicas histologicas das lesoes em linfonodos e pulmoes foram avaliadas em Hematoxilina-Eosina, com predominio de celulas gigantes nas lesoes de tuberculose bovina e de macrofagos epitelioides em suinos. As tecnicas histoquimicas de Ziehl-Neelsen e Tricromico de Masson foram utilizadas para evidenciar, respectivamente, bacilos alcool-acido resistentes e tecido conjuntivo fibroso nas lesoes. A tecnica de imuno-histoquimica foi utilizada em aproximadamente 30% dos casos estudados de cada especie, selecionados aleatoriamente, para a caracterizacao do infiltrado linfocitico. Foram utilizados os anticorpos anti-CD3 para a marcacao de linfocitos T e anti-CD79αcy para a marcacao de linfocitos B. Linfocitos T predominaram nas lesoes em ambas as especies, com diferenca estatisticamente significativa entre as medias dos linfocitos T e linfocitos B. Foi usado o teste t pareado, com t=5,501 (p<0,001) nas lesoes dos bovinos e t=5,826 (p<0,001) para as lesoes de linfadenite dos suinos. Adicionalmente foram marcados macrofagos com o uso do anticorpo anti-CD68 para bovinos e anti-Lisozima para suinos. Alem desses, o anticorpo policlonal anti-Mycobacterium tuberculosis foi utilizado para a deteccao de bacterias do genero Mycobacterium, com imunomarcacao positiva em todos os casos e, nos casos dos suinos, houve marcacao anti-Mycobacterium avium.

Diagnóstico imuno-histoquímico e caracterização anatomopatológica de Mycoplasma gallisepticum em galinhas de subsistência

Avian mycoplasmosis is caused by bacteria from the Mycoplasmataceae family. Mycoplasma gallisepticum (MG) is the most pathogenic and economically significant species affecting poultry. The aim of this study was to use the immunohistochemistry technique (IHC) as a diagnostic method for the MG infection in poultry. In this report we described two outbreaks of mycoplasmosis caused by MG in free-range chickens. Clinical signs were characterized by prostration, decreased appetite, difficult breathing, nasal and ocular discharge. Necropsy findings were serous secretion in conjunctiva (7/10) and seioses (4/10), edema and caseous exudate; air sacs thickened with foam and caseous exudate (6/10); trachea diffusely reddish (4/10); lungs with 0.5 cm whitish spots (2/10); and pericardial sac with fibrin exudate (2/10). Histologically was observed a lymphoplasmacytic hyperplastic acute tracheitis (10/10), seiositis (5/5) and conjunctivitis (3/4); fibrinonecrotic bronchopneumonia (5/10); acute fibrinous pericarditis (2/10); and fibrinonecrotic aerosaculitis (1/1). IHC anti-MG stained in the extracellular surface of ciliated brush border and/or in the top of epithelium of trachea (10/10), bronchi (5/10) and sinuses (4/5). In seven out of ten cases it was possible to detect MG by real-time PCR from tracheal swabs. IHC anti-MG used as a diagnostic method showed good correlation with clinical signs, lesions and real-time PCR results.

Caracterização patológica e imuno-histoquímica das lesões de actinobacilose em bovinos

Actinobacillosis is a not contagious infectious disease, usually chronic, and characterized by pyogranulomatous inflammatory reaction that occurs in cattle and is less common in sheep, pig, and horse. Soft tissues of head, mouth, and regional lymph nodes are affected. In this retrospective study, lesions suggestive of Actinobacillosis from 18 cases of anatomopathologic bovine samples were retrieved from the archives of Setor de Patologia Veterinaria of Universidade Federal do Rio Grande do Sul, from January 1997 to May 2011. The lesions were classified histologically, evaluated by histochemistry, and immunohistochemistry (IHC) in order to standardize inflammatory infiltration. The most frequent histological findings were typical pyogranulomas of actinobacillosis contained radiating eosinophilic clubs surrounded by neutrophils, macrophages, lymphocytes and abundant fibrous connective tissue. Gram-negative coccobacillus bacteria were shown in all lesions by Gram stain. Abundant macrophages were immunopositive for CD68, especially epithelioid cells and multinucleated giant cells. In addition, a positive immunostaining for CD3 (T lymphocyte) was observed in proportion of 1:3 in lymphocyte inflammatory infiltration, while IHC for CD79αcy (B lymphocytes) was obtained in proportion of 2:3. These results indicated that B lymphocytes are the majority of lymphocyte in the inflammatory area.

Caracterização histopatológica e imuno-histoquímica de neoplasmas mesenquimais da genitália em 43 cadelas

The biopsies archives from SPV-UFRGS (2000-2010) were retrieved, and cases of mesenchymal neoplasms of genitalia (uterus, cervix, vagina, and vulva) of 43 bitches were revised. Also Massons trichrome staining (MT) and immunohistochemical characterization were evaluated. The main breeds affected were Cocker, Poodle and German Shepherd, but the greatest number of cases were observed in mixed breed dogs. The average age of the bitches was 10.6 years (3-10 years of age). The anatomical locations of the neoplasms were vagina (44.2%), uterus (27.9%), vulva (23.3%) and cervix (4.6%). Histologically, 46.5% were classified as leiomyoma, 41.9% as fibroleiomyoma, 7.0% as fibroma, and 4.6% as leiomyosarcoma. In MT staining, the fibroma had all neoplastic cells stained blue (collagen), the leiomyomas and leiomyosarcomas had less than 50% of collagen among the muscle neoplastic cells, and the fibroleiomyomas had more than 50% of collagen. Positive immunostaining for vimentin and absence for desmin was observed in fibroma. Leiomyomas were positive for vimentin in more than 50% of the cells, and for desmin (in 75% of the cases in more than 50% of the cells, and in 25% less than 50%). Regarding leiomyossarcomas, one case had immunostaining for vimentin and absence for desmin, and the opposite occurred in the other. Fibroleiomyomas were positive for vimentin in 94.4% (in more than 50% of the cells) and for desmin in 77.8% (64.3% in less than 50% of the cells, and 35.7% in more than 50% of the cells).

Diagnóstico imuno-histoquímico e caracterização anatomopatológica de clamidiose em psitacídeos

Chlamydiosis is caused by Chlamydophila psittaci and is one of the most important avian zoonosis. A retrospective study in psittacines was performed from 1995 to 2012 with immunohistochemistry (IHC) anti-Chlamydia. Hundred eleven cases were evaluated and twelve birds died due to chlamydiosis. The birds were obtained from illegal commerce traffic or captive conditions (zoos, breeding birds, wildlife rehabilitation center and pets). Grossly, there were hepatomegaly (4/12) with yellowish-white areas (3/12), splenomegaly (2/12), splenic rupture (1/12), fibrin deposition in pericardial sac (1/12), fibrinous polyserositis (1/12), and in three cases lesion was not found. Histopathological evaluation revealed mononuclear necrotizing hepatitis (7/12), mononuclear hepatitis (3/12), biliary duct hyperplasia (8/12), histiocytic necrotizing splenitis (9/12), hemosiderosis in liver (9/12) and spleen (9/12), mononuclear aerosaculitis (4/12), fibrin heterophilic pericarditis (2/12), lymphoid necrosis (1/12) and depletion of bursa Fabricius (1/12), fibrinous pneumonia (1/12), mononuclear nephritis (1/12), and renal granulomas (1/12). Basophilic intracytoplasmic inclusions (elementary bodies) were observed in liver (2/12), spleen and kidney (1/12). Positive immunostaining for Chlamydia could be detected in liver (11/12), spleen (7/9), lung (3/9), kidney (2/8), intestines (2/3), air sacs (1/4) and bursa of Fabricius (1/2). It was concluded that IHC can be used as postmortem definitive diagnosis of chlamydiosis in psittacines.

Pathological and molecular findings of avian reoviruses from clinical cases of tenosynovitis in poultry flocks from Brazil

Avian reoviruses (ARVs) can infect a variety of species worldwide. Birds can present stunting syndrome, respiratory and/or enteric diseases, immunosuppression, malabsorption, viral arthritis/tenosynovitis, and even secondary infections by other microorganisms. Flaws in conventional vaccines and the increase in the diagnostic rate of disease in the last 5 yr suggest the emergence of pathogenic ARVs in the poultry flocks worldwide. This study aimed to characterize birds lesions and to detect/genotype ARVs from a severe outbreak of tenosynovitis in broiler poultry flocks from Brazil. Tissue samples of lesions on pelvic limbs of broiler chicken were collected in poultry flocks with a high condemnation rate of carcasses due to lesions and submitted to histological and molecular analysis. Major gross pathological lesions included marked swelling, edema, and hemorrhages. Serous exudate was present between the tendons and hock joint. Histological examination demonstrated necrosis and inflammation of muscle fibers, mixed inflammatory infiltrate was observed in subcutaneous tissue and tendon sheaths. ARVs RNA was detected in 5 samples tested by polymerase chain reaction. These samples were also genotyped and demonstrated the occurrence of strains of the ARVs lineages II and V in the flocks. These results suggest that theses field ARVs, genetically distant from previously characterized strains, are associated to tenosynovitis and present in commercial Brazilian poultry flocks.