Hepatitis B virus and hepatitis delta virus genotypes in outbreaks of fulminant hepatitis (Labrea black fever) in the western Brazilian Amazon region.

The genotypes of hepatitis B (HBV) and delta (HDV) viruses circulating among fulminant hepatitis cases from the western Amazon Basin of Brazil were characterized in this study. HBV and HDV isolates were obtained from liver samples from 14 patients who developed fulminant hepatitis and died during 1978-1989. HBV DNA and HDV RNA were detected in all samples. Phylogenetic analyses of HDV sequences showed that they all clustered with previously characterized sequences of HDV genotype 3 (HDV-3). HBV genotypes F, A and D were found in 50.0, 28.6 and 21.4 % of cases, respectively. These results confirm the predominance of HDV-3 in South America and its association with the severe form of hepatitis, and the finding of the co-infection of HDV-3 with different genotypes of HBV suggests that the association between HDV-3 and HBV-F is not necessarily causally related to a more severe clinical course of infection.

Ultrastructural study of poxvirus causing myxomatosis in rabbits, in São Paulo and Santa Catarina, Brazil / Estudio ultraestructural del poxvirus causal de mixomatosis en conejos, en São Paulo y Santa Catarina, Brasil

The myxomatosis is a contagious worldwide disease caused by poxvirus which infects domestic and wild rabbits. In the present study we present two distinct outbreaks of myxomatosis when raising rabbits, one for commercial purpose of production of meat and skins and, another one for the commercialization of ornamental rabbits. The observed signs were ocular, auricular, nasal, testis lesions and many times scattered throughout the body of the animals. The lesions were characterized by formation of nodules that by palpation disclosed gummy or gelatinous aspect. At the transmission electron microscopy, all the skin and crust samples were analyzed by negative staining technique. A great number of particles with morphology similar to the poxvirus, some enveloped in a brick-shaped and irregular disposition of tubules on the external membrane, measuring 300x240 nm on the average were visualized. Ultra thin sections revealed the presence of intracytoplasmic inclusion bodies surrounded by membrane containing oval particles, measuring 270 x 130 nm, containing nucleus or an internal biconcave (dumbbell-shaped) core. Immature particles (empty), surrounded by membrane were also observed. In addition, intracytoplasmic electron dense inclusion bodies containing viral particles budding of dense amorphous material and intranuclear fibrillar or "digital" inclusions showing a regular striation and arranged in groups were found in the middle of granular material. The nuclei were deformed with densely condensed chromatin forming amorphous and electron dense inclusion bodies. In the immunocytochemistry technique, the antigen-antibody reaction was strongly marked by the particles of colloidal gold, emphasizing the viral particles. The techniques used in this study were important in the diagnosis of the affected animals.

La mixomatosis es una enfermedad contagiosa de distribución mundial, causada por poxvirus que infecta conejos domésticos y salvajes. En este estudio presentamos dos distintos surtos por mixomatosis que ocurrieron en producciones de conejos, una para fines comerciales de producción de carne y pieles y otra para el comercio de conejos domésticos. Las señales observadas fueron afecciones oculares, nasales, testiculares y, a veces, también distribuida por todo el cuerpo de los animales. Estas se caracterizaban por formación de nódulos que a la palpación tenían un aspecto gelatinoso o gomoso. En la microscopía electrónica de transmisión, por la técnica de contrastación negativa, se pudo observar en todas las muestras examinadas de piel y de costras, un gran número de partículas típicas de poxvirus, con envoltura y forma de ladrillo, mostrando disposición irregular de los túbulos sobre la membrana externa, midiendo 300 x 240 nm en el promedio. Cortes ultrafinos de fragmentos de piel y de costras revelaron la presencia de cuerpos de inclusión intracitoplasmáticas, envueltos por membrana y conteniendo partículas ovales, midiendo 270 x 130 nm, conteniendo núcleo o centro interno bicóncavo (forma de mancuernas). Partículas inmaduras (vacías) envueltas por membrana fueron observadas. También fueron analizados cuerpos de inclusión intracitoplasmáticos, electrodensos, conteniendo partículas virales brotando del material denso y amorfo. Fueron observadas inclusiones intranucleares fibrilares o "digitales" mostrando una estriación periódica y disposición en grupos en medio del material granular. Los núcleos estaban deformados con cromatina densamente condensada formando cuerpos de inclusiones electrodensas y amorfas. En la técnica de imunocitoquímica la reacción antígeno-anticuerpo fue intensamente marcada por las partículas de oro coloidal realzando fuertemente las partículas virales.

Comparison of aztreonam plus clindamycin with tobramycin plus clindamycin in the treatment of intra-abdominal infections.

The activity of aztreonam (a beta-lactam antibiotic with specific activity against gram-negative bacteria) was evaluated and compared with that of tobramycin in hospitalized patients with severe intra-abdominal infections due to gram-negative pathogens, either alone or in association with other bacteria. Of a total study population of 156 patients, 76 were assigned to treatment with aztreonam + clindamycin, and the remaining 80 were treated with tobramycin + clindamycin. Patients underwent a variety of surgical procedures involving the peritoneal cavity. The final clinical evaluation revealed similar percentages of satisfactory results: 86.8% for the patients in the aztreonam-treated group and 86.2% for the tobramycin-treated patients. Among the patients who had a poor therapeutic result, gram-negative bacteria, either alone or associated with gram-positive pathogens, were considered responsible for 50% of the infections in the aztreonam group; the percentage increased to 82% among those treated with tobramycin. The incidence of side effects and laboratory alterations was not significant and was similar in both groups. The results of this study suggest that aztreonam may be an effective and safe drug for the treatment of bacterial infections due to gram-negative pathogens.

Aztreonam plus clindamycin vs. tobramycin plus clindamycin for the treatment of intraabdominal infections.

Sixty-six patients with acute intraabdominal infections due to gram-negative aerobic organisms were treated with aztreonam plus clindamycin or with tobramycin plus clindamycin in a multicenter, comparative, randomized study. The patients had undergone a variety of surgical procedures; most of them had peritonitis. Thirty-three of the 36 patients in the aztreonam group and 26 of the 30 patients in the tobramycin group had satisfactory clinical responses. Only one gram-negative aerobic pathogen, a strain of Pseudomonas aeruginosa, persisted after treatment; the patient involved was in the tobramycin group. The incidences of adverse reactions, superinfections, and abnormal laboratory values were low in each treatment group. The difference between the efficacies of the two regimens was not statistically significant. This study suggests that aztreonam may be a useful alternative to the aminoglycosides in the treatment of gram-negative intraabdominal infections.