Marli Ueda

The effect of concanavalin A on the replication of rotavirus (SA-11) in cell culture

ABSTRACT Rotavirus (RV) strain SA-11 was studied with respect to its infectivity in MA-104 cell cultures and the effect of concanavalin A (ConA). Receptors for ConA at the surface of MA-104 cell were determined by fluorescence assay and specifically inhibited by D-mannose. The kinetics of virus growth was carried out by plaque assay. Electron microscopy and po lyacrylamide gel electrophoresis were used for monitoring the experiments. It was concluded that RV replication was not affected consistently by ConA, however it interfered with the development of cytopathic effect (CPE) without altering virus yields. Key words: Rotavirus, Concanavalin A, Cell culture ∗ Author for correspondence INTRODUCTION Rotaviruses (RV) are agents of acute diarrhea in mammals and birds (Kapikian & Chanock, 1996; Burke & Desselberger, 1996). Virion genome is formed by eleven segments of double -stranded RNA nvolved by a concentric triplei -layered protein shell (Kapikian & Chanock, 1996). The outer layer is constituted by VP4 and VP7 proteins being the former associated to hemagglutinin activity (some strains of RV), attachment andidentification of viral and cell receptorsvirulence (Bridger et al., 1998; Kirkwood et al., 1998). The latter, a glycoprotein, seems to be involved in cell penetration either by promoting the stability of VP4 or enhancing its activity (Prasad & Estes, 1997). VP4 is synthesized in free ribosomes while VP7 in ribosomes associated to the endoplasmic reticulum where it isglycosylated. The number of sites and locations of VP7 glycosylation depend upon the strain of RV albeit the glycans are all of high-mannose type (Both et al

Preliminar characterization of a new virus isolated from the spinal fluid of patients with meningitis in Säo Paulo, Brazil

De dezembro de 1982 a marco de 1983 um total de 138 pacientes com idade de 4 meses a 57 anos foram atendidos em diferentes hospitais de Sao Paulo com sintomas de meningite asseptica. Um agente transmissivel foi isolado de 35 das 53 amostras de liquor. A replicacao desse novo virus ou de um grupo de virus relacionados antigenicamente com caracteristicas semelhantes foi detectada atraves do efeito citopatico produzido em cultura de celulas de MDCK. O agente isolado demonstrou ter um diâmetro em torno de 40 nm quando examinado ao microscopio eletronico atraves da coloracao negativa. Nenhuma atividade hemaglutinante foi detectada em pH 7,2 com hemacias humanas de cobaias ou de galinha e em pH 6,0 - 7,2 com hemacias de ganso. Esse agente nao se mostrou patogenico ao camundongo recem-nascido e adulto, era sensivel ao cloroformio e nao foi inibido pelo BuDR, o que indica conter o genoma RNA.

Influenza virus A(H3N2) strain isolated from cerebrospinal fluid from a patient presenting myelopathy post infectious

BACKGROUND Neurological involvement during influenza infection has been described during epidemics and is often consistent with serious sequelae or death. OBJECTIVE To investigate the etiologic agent involved in myelopathy post influenza-like syndrome. STUDY DESIGN This investigation focuses on virus isolation from the cerebrospinal fluid (CSF) collected from a 19-year-old male student presenting with clinical diagnosis of myelopathy post influenza-like syndrome. To achieve this goal, different cell cultures and molecular methodologies were carried out. RESULTS Influenza virus A(H3N2) strain was isolated in MDCK cell culture; virus particles were observed under electron microscopy. Phylogenetics analyses showed that the Brazilian influenza A(H3N2) strains were closely related to the A/Perth/16/2009-like. CONCLUSION This study demonstrates that influenza virus A(H3N2) strain was the cause of illness of the students. According to the Brazilian influenza virus sentinel surveillance data A/Perth/16/2009-LIKE (H3N2) strain has predominated during the 2010 influenza virus season in Brasília-DF.

Severe acute respiratory syndrome—a global concern—influenza virus isolated from suspected cases in Brazil from April to June 2003

Abstract Severe acute respiratory syndrome (SARS) is a condition associated with substantial morbidity and mortality. Coronavirus has been associated with this severe emerging disease, with a pattern suggesting droplet or contact transmission. From April to June 2003, Institute Adolfo Lutz received 16 respiratory secretions from hospitalized patients with recent history of travel to an area with local transmission of SARS. Rapid antigen detection for influenza A and B, parainfluenza types 1, 2 and 3, respiratory syncytial virus and adenovirus; electron microscopy, polymerase chain reaction (PCR), reverse transcription PCR (RT–PCR) and serologic assay were performed. Virus isolation attempts were performed in Hep-2, Vero, MDCK, NCI-H292, MRC-5, LLC-MK2 and FRhK-4. Influenza virus of type A/Panama/2007/99 (H3N2) and A/New Caledonia/20/99 (H1N2) were identified.