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P Payment

Publications and source records attributed to P Payment.

At least 55 records · Page 3Linked to original sources
PubMed1986

Elimination of human enteric viruses during conventional waste water treatment by activated sludge.

The present study was undertaken to determine if viruses were selectively eliminated during waste water treatment. Human enteric viruses were detected at all steps of treatment in a conventional activated sludge waste water treatment plant. Liquid overlays and large volume sampling with multiple passages on BGM cells permitted the detection of poliovirus (serotypes 1, 2, and 3), coxsackievirus B (serotypes 1, 2, 3, 4, and 5), and echovirus (serotypes 3, 14, and 22), as well as reoviruses. The mean virus concentration was 95.1 most probable number of infectious units per litre (mpniu/L) in raw sewage, 23.3 in settled water, 1.4 in effluent after activated sludge treatment, and 40.3 mpniu/L in sludge samples. All samples of raw sewage and settled water, 79% of effluent water, and 94% of sludge samples contained viruses. The mean reduction was 75% after settling and 98% after activated sludge treatment. Poliovirus type 3 was rarely isolated after the activated sludge treatment, but was still detected in about one-third of the sludge samples. Reoviruses and coxsackieviruses were detected at similar rates from all samples and appear to be more resistant to the activated sludge treatment than poliovirus type 3. Poliovirus types 1 and 2 were present in almost every sample of raw sewage and settled water and still found in about half of the effluent and sludge samples, indicating a level of resistance similar to that of reoviruses and coxsackieviruses.

Cell Line↗
PubMed1985

E1 glycoprotein of rubella virus carries an epitope that binds a neutralizing antibody.

We identified by immunoprecipitation and Western blot analysis, using a monoclonal antibody that neutralizes rubella virus, that E1 glycoprotein carries an epitope linked with neutralization. Glycosidase treatment of virus does not prevent blotting of this monoclonal antibody with the E1 glycoprotein, dissociating this epitope from the hemagglutination epitope which is linked with the oligosaccharide side chains. We also investigated by Western blot analysis human serum reactivity toward E1 glycoprotein and the two other structural proteins of rubella virus, E2 and C: all positive sera detected E1 and C, irrespective of their titers, indicating the importance of glycoprotein E1 in immunity. Frequent lack of reactivity against E2 might suggest that this glycoprotein is either less exposed or less immunogenic.

Antibodies, Monoclonal↗
PubMed1985

Relative resistance to chlorine of poliovirus and coxsackievirus isolates from environmental sources and drinking water.

Several poliovirus and coxsackievirus isolates from environmental sources were compared with laboratory strains to determine their rate of inactivation by chlorine. All viruses were tested for up to 1,000 min in the presence of an initial free residual chlorine level of ca. 0.4 mg/liter. Coxsackievirus B5 (CB-5) isolates were found to be more resistant to chlorine than coxsackievirus B4 (CB-4), followed by poliovirus 1, 2, and 3 in order of decreasing resistance to chlorine. Environmental isolates of CB-5 were more resistant than the laboratory strain tested, and for two strains 12 and 22% of the input virus was still infectious after 100 min in the presence of free residual chlorine. Although CB-4 isolates were less resistant to chlorine than CB-5 isolates, after 1,000 min of contact 0.01% of the input virus was still infectious. Except for CB-5 isolates, isolates from environmental sources did not appear to be more resistant to chlorine than laboratory strains. Viruses isolated at different phases during the preparation of drinking water were not more resistant to chlorine and must thus have been protected by other mechanisms.

Chlorine↗
PubMed1985

Elimination of viruses and indicator bacteria at each step of treatment during preparation of drinking water at seven water treatment plants.

Seven drinking water treatment plants were sampled twice a month for 12 months to evaluate the removal of indicator bacteria and cytopathogenic enteric viruses. Samples were obtained at each level of treatment: raw water, postchlorination, postsedimentation, postfiltration, postozonation, and finished (tap) water. Raw water quality was usually poor, with total coliform counts exceeding 105 to 106 CFU/liter and the average virus count in raw water of 3.3 most probable number of cytopathogenic units (MPNCU)/liter; several samples contained more than 100 MPNCU/liter. All plants distributed finished water that was essentially free of indicator bacteria as judged by analysis of 1 liter for total coliforms, fecal coliforms, fecal streptococci, coagulase-positive staphylococci, and Pseudomonas aeruginosa. The total plate counts at 20 and 35 degrees C were also evaluated as a measure of the total microbial population and were usually very low. Viruses were detected in 7% (11 of 155) of the finished water samples (1,000 liters) at an average density of 0.0006 MPNCU/liter the highest virus density measured being 0.2 MPNCU/liter. The average cumulative virus reduction was 95.15% after sedimentation and 99.97% after filtration and did not significantly decrease after ozonation or final chlorination. The viruses isolated from treated waters were all enteroviruses: poliovirus types 1, 2, and 3, coxsackievirus types B3, B4, and B5, echovirus type 7, and untyped picornaviruses.

Bacteria↗
PubMed1985

Immunoperoxidase method with human immune serum globulin for broad-spectrum detection of cultivable human enteric viruses: application to enumeration of cultivable viruses in environmental samples.

The detection and enumeration of most cultivable human enteric viruses from water is possible if samples are first inoculated onto a suitable cell line such as MA-104 or BGM. Virus growth is then detected by an indirect immunoperoxidase method with human immune serum globulin as the source of antibody to most enteric viruses. The number of positive cell cultures in the immunoperoxidase assay is used to calculate the virus titer (as a most probable number) in the sample assayed.

Cell Line↗
PubMed1985

Influence of inoculum size, incubation temperature, and cell culture density on virus detection in environmental samples.

The influence of inoculum size and cell culture density on virus titer by cytopathic effect or plaque assay was studied using poliovirus type 1 and BGM (Buffalo green monkey) cells as a model for this evaluation. With a plaque assay system, a linear relationship was observed for an inoculum size of up 1 mL/25 cm2; a marked decrease in the number of plaques was observed when over 1 mL of sample was inoculated on this surface area. Cell culture density also affected virus titer; maximal titers were observed when cells were seeded at 25 000 to 75 000 cells/mL and incubated for 6 days before infection with the virus. Viral density, evaluated as most-probable-number and measured by cytopathic effect under liquid overlay, revealed that the viral titer was similar up to 1 mL inoculum and increased only when over 1 mL was inoculated. Cell density had no significant effect on the viral titer measured by the most-probable-number method and cytopathic effect. Inactivation of inoculum due to an incubation temperature of 37 degrees C for a short period was shown to be minimal for poliovirus type 1, reovirus type 2, coxsackievirus B-5, and the simian rotavirus SA-11. Longer inactivation time led to a 2 logs reduction of the infectious titer of coxsackievirus B-5 (in 48 h) while the other viruses showed a significant reduction in titer only after 96 h.

Animals↗
PubMed1984

Ferric chloride flocculation for nonflocculating beef extract preparations.

The addition of 2.5 mM ferric chloride to 0.5% beef extract solution at pH 3.5 was found to be highly efficient in the recovery of seeded poliovirus type 1 (Sabin) or indigenous viruses from environmental samples. This method was extremely useful to reconcentrate viruses from beef extract solutions that did not flocculate at pH 3.5.

Chlorides↗
PubMed1984

Virological examination of drinking water: a Canadian collaborative study.

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.

Canada↗
PubMed1983

Modified immunoprecipitation procedure for the identification of human respiratory syncytial virus polypeptides.

When analysed by polyacrylamide gel electrophoresis, human respiratory syncytial virus harvested after a one step growth cycle and purified through a continuous sucrose density gradient was shown to be composed of nine structural proteins of 90, 68, 49, 42, 34, 28, 25, 19 an 13 kd. The 90, 49 and 19 kd polypeptides were identified as glycopolypeptides by glucosamine incorporation. A modified immunoprecipitation procedure confirmed the viral specificity of the 49, 42, 28, 25 and 19 kd polypeptides.

Centrifugation, Density Gradient↗
PubMed1983

Microbial investigation of the air in an apartment building.

The microbial and viral flora in the ventilating ducts of an apartment building was evaluated. Several types of sampler (slit sampler, Andersen sampler, large volume air sampler) were used to evaluate the hourly, weekly and seasonal variation of this flora. The mean bacterial concentration was 17.2 e.f.u./m3 with a maximum level at 07.30 h (41.3 c.f.u./m3) and a minimal concentration in the early afternoon (8 c.f.u./m3). The bacterial concentration observed correlated with the relative humidity in the air-ducts although there were no seasonal differences. The bacteria were mainly gram-positive cocci (73.5%) represented by a large number of Micrococcaceae (47.1%); gram-positive bacilli accounted for 14.2% of the isolates, gram-negative bacilli 12.0% and gram-negative cocci 0.3%. The majority of the bacteria-carrying particles were in the respirable range with 80.4% of them being less than 5 microns. The methods used did not result in the isolation of viruses during the winter sampling period.

Air Microbiology↗
PubMed1983

A survey of enteric viruses in domestic sewage.

In this second study (1979-1981) of the viral content of sewage we have demonstrated the presence of poliovirus types 1, 2, and 3 in Laval and Montreal. Several strains of poliovirus types 2 and 3 were nonvaccinal. This is in contrast with our first study (1977-1978) in which only type 1 poliovirus isolates were nonvaccinal. Coxsackievirus types B-3, B-4, and B-5 and echovirus types 1, 7, and 11 were also isolated from sewage. Interestingly, these isolations coincided with reports of isolation of the same strains during the same period by diagnostic laboratories. Our method based on Vero and BSC-1 cell cultures for virus isolation and immune electron microscopy for identification permitted the recovery not only of several strains of enteroviruses but also of some adenoviruses and reoviruses.

Adenoviridae↗
PubMed1982

Rapid identification and serotyping of poliovirus isolates by an immunoassay.

An enzyme-linked immunosorbent assay (ELISA) for the identification and typing of polioviruses is described. Polioviruses could be rapidly detected and typed from cell culture supernatants by a double antibody sandwich technique. The assay is valuable for the rapid screening of a large number of viral isolates from water samples submitted for virological analysis. Several hundred isolates per day can be typed and only the remainder have to be tested by the conventional serum neutralization test.

Antibodies, Viral↗
PubMed1982

Antibody response to rubella virus proteins in different physical forms.

The immunogenicity of different antigens, containing rubella virus hemagglutinating (HA) membrane protein, was studied using live virus, beta-propiolactone-inactivated virus, detergent and lipid-free octamers and virosomes. Whole virus particles, live or inactivated, induced hemagglutination inhibition (HAI) antibodies in rabbits after one subcutaneous injection of 0.16 micrograms of HA protein. Hemagglutinin rosettes or virosomes failed to induce antibodies even at a dose of 120 micrograms. Apparently, the extraction of viral membrane hemagglutinin, for the preparation of a rubella subunit vaccine, led to destruction of the antigenicity responsible for the induction of hemagglutination inhibiting antibodies. These results are discussed in the light of earlier studies on the preparation of a rubella subunit vaccine.

Animals↗
PubMed1981

Comparison of hemagglutination inhibition, serum neutralization and ELISA-PVM tests for the detection of antibodies to pneumonia virus of mice in rat sera.

Recently, the seroneutralization, hemagglutination inhibition, and the ELISA procedures were used to determine the presence of serum antibody to the pneumonia virus of mice in rat sera. This study was initiated to evaluate the reliability of these procedures to detect specific antibodies in our laboratory animal species. The results obtained indicate that: 1) the seroneutralization test is not reliable since numerous false-positive sera were detected; 2) the ELISA is more sensitive than both the seroneutralization and hemagglutination inhibition procedures, and 3) the presence of low hemagglutination inhibition titers should not be considered significant.

Animals↗
PubMed1981

Characterisation of rubella virus hemagglutinin rosettes.

Purified rubella virus treated with Triton X-100 was subjected to centrifugation in a sucrose density gradient containing nonionic detergent beta-D-octylglucoside. The result of this treatment was the formation of hemagglutinating rosettes containing viral glycoproteins VP2 (50,000 mol. wt.) and VP3 (63,000 mol. wt.). The rosettes have a 26 S sedimentation coefficient and a density of 1.2 g/cm3 in sucrose. Electron microscopy revealed 15 nm rosettes with a hollow center. The molecular weight of the rosettes was extrapolated at 850,000.

Centrifugation, Isopycnic↗
PubMed1981

Purification of infectious rubella virus by gel filtration on sepharose 2B compared to gradient centrifugation in sucrose, sodium metrizoate and metrizamide.

Rubella virus was purified by chromatography on Sepharose 2B after concentration by ultrafiltration on hollow fibers and hydroextraction with PEG 20,000. Yields of 40% infectivity and 70% hemagglutinating activity were routinely obtained. Chromatographic purification was compared to ultracentrifugation in sucrose, metrizamide and sodium metrizoate. Yields were lower in sucrose and metrizamide, while sodium metrizoate reduced the infectivity of the virus below detectable levels. These results demonstrate the advantage of Sepharose 2B for the purification of infectious rubella virus.

Centrifugation, Density Gradient↗
PubMed1981

Rubella virosomes: preparation and ultrastructure.

Rubella virosomes were prepared from performed liposomes and detergent solubilized viral hemagglutinin. The liposomes were made from lecithin/dicetyl phosphate (3.5 : 1) films resuspended in NTE buffer and sonicated. Viral hemagglutinin was prepared from purified virus after solubilization with Triton X-100 and centrifugation through a sucrose gradient containing beta-D-octylglucoside. Electron microscopy of the rate zonal purified virosomes, showed virus-like structures of 40 - 80 nm. The virosomes retained the biological activity of the hemagglutinin and had a buoyant density of 1.2 g/cm3.

Centrifugation, Density Gradient↗