RESUMEN
A collaborative virological survey of drinking water was initiated in three major Canadian urban areas, Montreal, Ottawa, and Toronto. In each selected area, three water purification plants were sampled monthly for up to 18 months. The total population served by all nine plants was about 1 500 000. Samples of raw (100 L) and treated (1000 L) water were examined by virus concentration procedures based on adsorption-elution. Sample concentrates were assayed for cytopathic viruses on BS-C-1 cells and the results were expressed as the most probable number of cytopathic units (MPNCU). Viruses were detected in 57% (0-15.35 MPNCU/L) of the raw water samples from Montreal, 37% (0-46.0 MPNCU/L) in Ottawa, and 33% (0-4.91 MPNCU/L) in Toronto. The majority of isolates were reoviruses, but picornaviruses were also found. All finished waters (177 samples) met bacteriological, turbidity, and residual chlorine standards and were free of detectable viruses.
Asunto(s)
Virus/aislamiento & purificación , Microbiología del Agua , Abastecimiento de Agua/normas , CanadáRESUMEN
Twenty-six strains of faecal adenovirus from three continents (two from Europe, 16 from South Africa, and eight from Canada) were typed as Ad40 by restriction enzyme analysis of the DNA using Sma I. The DNA of the strains was further compared by digestion with six other enzymes, namely Bam HI, Eco RI, Bgl I, Xho I, Sst I, and Hind III. At least two different restriction profiles were found to exist for each enzyme. Nineteen of the 26 strains studied had the same combination of profiles for all the enzymes, within the limits of resolution of the technique. This genome type was detected from all three continents and included the Finnish reference strain Hovi-X. The other seven strains were genome variants, representing five other genome types. Three genome types were detected only in South African specimens, whereas one genome type was detected in single specimens from both South Africa and Canada. Strain Dugan from Holland, indistinguishable from other Ad40 strains in neutralization tests using polyclonal antibody preparations [de Jong et al, 1983], deviated from the common Hovi-X-like genome on digestion of the DNA with any of the enzymes except Sma I.
Asunto(s)
Adenovirus Humanos/genética , Genes Virales , Infecciones por Adenoviridae/microbiología , Adenovirus Humanos/aislamiento & purificación , Enzimas de Restricción del ADN , ADN Viral/análisis , Diarrea Infantil/microbiología , Heces/microbiología , Humanos , Cultivo de VirusRESUMEN
Highly purified Nebraska calf diarrhea virus (NCDV) was prepared by cesium chloride density gradient centrifugation. The effect of temperature, pH, different concentrations of formaldehyde, chloroform, ether, ethyl alcohol, and methyl alcohol on NCDV hemagglutinin and virus morphology was studied. NCDV hemagglutinin was inactivated by temperature, pH 2.0, chloroform, ethyl alcohol, and methyl alcohol.
Asunto(s)
Hemaglutininas Virales/análisis , Virus ARN/inmunología , Rotavirus/inmunología , Alcoholes/farmacología , Centrifugación por Gradiente de Densidad , Formaldehído/farmacología , Concentración de Iones de Hidrógeno , Nebraska , Rotavirus/ultraestructura , Solventes/farmacología , TemperaturaRESUMEN
The sensitivity of conventional systems was compared with the sensitivity of the newer system of combined cultures for the isolation of influenza viruses. Both systems were comparable. It was found, that certain isolates were obtained only by conventional systems, and conversly, others by combined cultures only. These results showed that the joint usage of both the conventional and newer systems resulted in a significantly higher isolation rate.