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Biomedical subjects

S M Goyal

Publications and source records attributed to S M Goyal.

At least 91 records · Page 5Linked to original sources

Antibodies to avian infectious bronchitis virus in Pakistani chickens.

Using the hemagglutination inhibition test, sera from 20 diseased and 3 apparently healthy chicken flocks in Pakistan were examined for antibodies to four types of avian infectious bronchitis virus (AIBV). These flocks were not vaccinated against AIBV. Of the 900 serum samples from diseased flocks, 78 (8.7%) had antibodies to the Massachusetts (M41) type, 23 (2.6%) to the Arkansas type and 20 (2.2%) to the Connecticut type of AIBV. None had antibodies to the JMK type. None of the sera (n = 100) from apparently healthy layers was positive to any of the four AIBV types tested. Some of the birds with antibody titers exhibited no signs of illness except that they laid pale colored eggs or had a history of poor hatchability. These results indicate that at least three AIBV types are circulating in chicken flocks in Pakistan.

Animals↗

Comparison of stationary and roller cultures for the isolation of herpesviruses affecting livestock.

The effect of rotating cultures on the isolation and cultivation of pseudorabies, infectious bovine rhinotracheitis and equine rhinopneumonitis viruses was studied. Serial ten-fold dilutions of laboratory strains of these viruses and field strains of pseudorabies virus were inoculated in two each of roller and stationary tubes of appropriate cell cultures. All tubes were examined daily for the appearance of cytopathic effects. Roller cultures were found to slightly enhance the speed and extent of cytopathic effect produced by these viruses. We conclude that it may be worthwhile to utilize roller cultures for isolation of animal viruses, especially for the recovery of low-titered virus, as is often the case with clinical specimens.

Animals↗

Comparison of five cell lines for the propagation of bovine viral diarrhea and infectious bovine rhinotracheitis viruses.

A comparative study was carried out to determine the susceptibility of 5 different cell types to bovine viral diarrhea (BVD) and infectious bovine rhinotracheitis (IBR) viruses. The cell systems used were swine testicle (ST), mink lung (ML), bovine turbinate (BT), porcine kidney (PK15) and equine dermal (ED) cells. For BVD virus, the titers obtained on day 8 post-infection were 10(1.13), 10(3.25), 10(4.13), 10(0.00) and 10(0.00), in ST, ML, BT, PK15 and ED cells, respectively. For the IBR virus, the titers obtained were 10(2.63), 10(8.5), 10(8.38), 10(3.00), and 10(4.63) in ST, ML, BT, PK15 and ED cells, respectively. This indicates, therefore, that BT and ML cells are optimal for the propagation of both BVD and IBR viruses and that ST, PK15, and ED cells are not very sensitive to these viruses.

Animals↗

Antibodies against canine parvovirus in wolves of Minnesota: a serologic study from 1975 through 1985.

Serum samples (n = 137) from 47 wild wolves (Canis lupus; 21 pups and 26 adults) were evaluated from 1975 to 1985 for antibodies against canine parvovirus, using the hemagglutination inhibition (HI) test. In addition, several blood samples (n = 35) from 14 of these wolves (6 pups and 8 adults) were evaluated simultaneously for erythrocyte and leukocyte counts, and for hemoglobin and blood urea nitrogen concentrations. Sixty-nine (50%) of the serum samples (35 wolves) had HI titers of greater than or equal to 256, whereas 68 (50%) of the samples (16 wolves) had HI titers of less than or equal to 128. Significant differences in the geometric mean titers were not found between pups and adults or between males and females. Of the 47 wolves evaluated, 12 (25%) developed a greater than or equal to fourfold increase in antibody titers during the 11-year period, with 2 wolves developing serologic conversions in 1976. The data indicate that canine parvovirus may have begun infecting wolves before or at the same time that it began infecting the dog population in the United States.

Age Factors↗

Adsorption of viruses to charge-modified silica.

The purpose of this study was to provide a clearer understanding of virus adsorption, focusing specifically on the role of electrostatic interactions between virus particles and adsorbent surfaces. The adsorption of poliovirus 1, reovirus types 1 and 3, and coliphages MS-2 and T2 to colloidal silica synthetically modified to carry either positive or negative surface charge was evaluated. Adsorption experiments were performed by combining virus and silica in 0.1-ionic-strength buffers of pH 4.0, 6.4, and 8.5. Samples agitated for specified adsorption periods were centrifuged to pellet adsorbent particles plus adsorbed virus, and the supernatants were assayed for unadsorbed virus. All viruses adsorbed exclusively to negatively charged silica at pH values below their isoelectric points, i.e., under conditions favoring a positive surface charge on the virions. Conversely, all viruses adsorbed exclusively to positively charged silica at pH values above their isoelectric points, i.e., where virus surface charge is negative. Viruses in near-isoelectric state adsorbed to all types of silica, albeit to a lesser degree.

Adsorption↗

Isolation of enteroviruses from water, suspended solids, and sediments from Galveston Bay: survival of poliovirus and rotavirus adsorbed to sediments.

The distribution and quantitation of enteroviruses among water, suspended solids, and compact sediments in a polluted estuary are described. Samples were collected sequentially from water, suspended solids, fluffy sediments (uppermost layer of bottom sediments), and compact sediment. A total of 103 samples were examined of which 27 (26%) were positive for virus. Polioviruses were recovered most often, followed by coxsackie B viruses and echoviruses 7 and 29. Virus was found most often attached to suspended solids: 72% of these samples were positive, whereas only 14% of water samples without solids yielded virus. Fluffy sediments yielded virus in 47% of the samples, whereas only 5% of compact bottom-sediment samples were positive. When associated with solids, poliovirus and rotavirus retained their infectious quality for 19 days. The same viruses remained infectious for only 9 days when freely suspended in seawater. Collection of suspended solids at ambient water pH appears to be very useful for the detection of virus; it has advantages over collecting and processing large volumes of water, with accompanying pH adjustment and salt addition for processing.

Animals↗

Round robin investigation of methods for recovering human enteric viruses from sludge.

To select a tentative standard method for detection of viruses in sludge the American Society for Testing and Materials D19:24:04:04 Subcommittee Task Group initiated round robin comparative testing of two procedures that, after initial screening of several methodologies, were found to meet the basic criteria considered essential by the task group. Eight task group member laboratories agreed to perform round robin testing of the two candidate methods, namely, The Environmental Protection Agency or low pH-AlCl3 method and the Glass or sonication-extraction method. Five different types of sludge were tested. For each particular type of sludge, a single laboratory was designated to collect the sludge in a single sampling, make samples, and ship it to the participating laboratories. In most cases, participating laboratories completed all the tests within 48 h of sample arrival. To establish the reproducibility of the methods, each laboratory tested each sludge sample in triplicate for the two candidate virus methods. Each processed sludge sample was quantitatively assayed for viruses by the procedures of each individual round robin laboratory. To attain a more uniform standard of comparison, a sample of each processed sample from all laboratories was reassayed with one cell line and passage number by a single laboratory (Environmental Protection Agency Environmental Monitoring and Support Laboratory, Cincinnati, Ohio). When the data were statistically analyzed, the Environmental Protection Agency method was found to yield slightly higher virus recoveries for all sludge types, except the dewatered sludge. The precisions of both methods were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗

Human pathogenic viruses at sewage sludge disposal sites in the Middle Atlantic region.

Human enteric viruses were detected in samples of water, crabs, and bottom sediments obtained from two sewage sludge disposal sites in the Atlantic Ocean. Viruses were isolated from sediments 17 months after the cessation of sludge dumping. These findings indicate that, under natural conditions, viruses can survive for a long period of time in the marine environment and that they may present potential public health problems to humans using these resources for food and recreation. The isolation of viruses in the absence of fecal indicator bacteria reinforces previous observations on the inadequacy of these bacteria for predicting the virological quality of water and shellfish.

Enterobacteriaceae↗

Drug-resistant bacteria in Continental Shelf sediments.

Fecal indicator bacteria were isolated from water and sediment samples obtained from a sewage sludge disposal site in the Middle Atlantic. Some were found to be resistant to several antimicrobial agents. Isolation of these microbes 30 months after cessation of sludge dumping indicates their survivability in the environment.

Bacteria↗

Viradel method for detection of rotavirus from seawater.

This report describes the use of a virus adsorption-elution (Viradel) technique for the concentration and detection of rotavirus from seawater. Simian rotavirus SA-11 was used as a model virus because it can be readily propagated and plaqued in vitro. The virus adsorbed optimally to fiberglass epoxy filters when seawater was adjusted to pH 3.5 and aluminum chloride added to a concentration of 1.0 mM. Adsorbed virus was eluted with 6% beef extract at pH 10.5 and was further concentrated to a smaller volume by a modification of the organic flocculation method. Using this method, in conjunction with an indirect immunofluorescence test, rotavirus was detected in sewage-contaminated seawater.

Adsorption↗

Concentration of rotavirus and enteroviruses from blue crabs (Callinectes sapidus).

A simple method for concentration and detection of rotavirus and enteroviruses in the blue crab is described. Virus was separated from tissue homogenates at pH 9.5, concentrated by adsorption to protein precipitates at pH 3.5, and recovered by elution of precipitates at pH 9.2. Test samples of 12 to 15 ml were produced from an initial 100 g of crab tissues. Cat-floc precipitation was used to remove sample toxicity for cell cultures. Recovery effectiveness averaged 52% with poliovirus 1, echovirus 7, and coxsackievirus B5 and 23% with rotavirus SA11.

Animals↗

Occurrence of enteroviruses in community swimming pools.

Municipal swimming pools and wading pools were examined for the presence of human enteric viruses using a portable virus concentrator at the site to concentrate viruses from 100-gallon to 500-gallon samples. Ten of 14 samples contained viruses; three of these were positive for virus in the presence of residual free chlorine. Enteroviruses were isolated from two pools which exceeded the 0.4 ppm free residual chlorine standard. This study appears to be supportive of recent evidence that indicates a higher incidence of enterovirus infection among bathers. All seven wading pool samples contained virus. Coxsackieviruses B3 and B4, poliovirus 1, and echovirus 7 were isolated. Total coliform bacteria were not adequate indicators of the presence of virus, as six of the samples were positive for virus but negative for coliforms. Total plate counts appeared to provide a better indication of the sanitary quality of the pool water, but viruses could still be detected in samples that met currently recommended bacterial levels. It is possible that swimming and wading pools may serve as a means of transmission of enteroviral disease, especially in children, during summer months.

Enterovirus↗

Concentration of bacteriophage lysates by filter chromatography.

High-titered phage stocks are required for carrying out genetic and physicochemical studies on bacteriophages. This study describes a simple method for the concentration of coliphages MS-2 and T2 by charge-modified filters. Phage lysates were first clarified by filtration through serum-coated membrane filters. The clarified lysate was adjusted to pH 6 and passed through a Zeta-plus filter (30 S size). Greater than 99% virus adsorption occurred under these conditions. Adsorbed viruses were successfully eluted by small volumes of 3% beef extract (pH 10) which was subsequently neutralized with 3% beef extract (pH2). A concentration factor as great as 126 could be achieved by this method, with recoveries ranging from 54% to 97% (average = 60%).

Adsorption↗

Concentration of coliphages from large volumes of water and wastewater.

Membrane filter adsorption-elution technology has been extensively used for the concentration and detection of animal viruses from large volumes of water. This study describes the development of positively charged microporous filters (Zeta Plus) for the concentration of coliphages from large volumes of water and wastewater. Four different coliphages were studied: MS-2, phi X174, T2, and T4. Positively charged microporous filters were found to efficiently adsorb these coliphages from tap water, sewage, and lake water at neutral pH. Adsorbed viruses were eluted with a 1:1 mixture of 8% beef extract and 1 M sodium chloride at pH 9. Using this method, coliphages could be concentrated from 17-liter volumes of tap water with recoveries ranging from 34 to 100%. Coliphages occurring naturally in raw and secondarily treated sewage were recovered with average efficiencies of 56.5 and 55.0%, respectively. This method should be useful in isolation of rare phages, the ecology of phages in natural waters, and the evaluation of water quality.

Coliphages↗