Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VIRUS CULTIVATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

Comparison of glass wool and glass powder methods for concentration of viruses from treated waste waters.

Enumeration of cultivable virus particle in sewage requires the samples to be concentrated. Two adsorption-elution methods, the glass wool cartridge method and the glass powder fluid layer method were compared. Firstly, it was demonstrated that virus could be readily recovered from the head, first 25 ml, of eluate of glass wool rather than from a reconcentration of the entire eluate, either by organic flocculation: 83% of positivity vs 44% respectively or double precipitation by PEG: 85% of positivity vs 61% respectively. Concentration on glass wool allowed the rescue of a greater number of positive samples (33/35) than on glass powder (16/35) as well as a higher mean titer of indigenous viruses, respectively 19 MPNCU/l vs 6 MPNCU/l (F1(34) = 36.02, P < 0.0001). Enteroviruses were the most frequently isolated viruses: found in 34/35 samples by either method, in 32/35 samples by glass wool, and in 14/35 samples by glass powder. Of the 12 enterovirus types identified by either method, a majority was Echovirus 6 (10 samples), Echovirus 11 (7 samples), Coxsackievirus B5 (4 samples) and also Coxsackievirus A7, A16, A21, B1, B6, Echovirus 1, 4, 12 and 19. Adenovirus types 1 and 5 were isolated from 4 samples by either method.

Adsorption↗

Characterization of a virion protein kinase as a virus-specified enzyme.

Antibodies which completely inhibited the enzymatic activity of the protein kinase associated with virions of frog virus were obtained by immunization of rabbits with the purified enzyme. This inhibition provided a specific probe for the frog virus protein kinase, since this antiserum had no inhibitory effect on a variety of other protein kinases, including the activity of uninfected cells, or the protein kinase associated with vesicular stomatitis virus or vaccinia virus cultivated in the same cell line as frog virus. The frog virus protein kinase was characterized as a virus-specified protein on the basis of the following observations: (a) the virion protein kinase was antigenically distinct from essentially all of the protein kinase expressed in uninfected cells; (b) following infection by frog virus more than a 15-fold increase was detected in the specific activity of intracellular protein kinase and most of this activity was antigenically related to the virion enzyme; (c) when frog virus was grown in cells derived from widely different species, the antigenic and biochemical specificities of the virion protein kinase remained identical; and (d) screening of cells infected with different temperature-sensitive mutants of frog virus indicated that certain viral mutants failed to synthesize this protein kinase when cultivated at the nonpermissive temperature.

Adenosine Triphosphate↗

Animal-derived antigenic variants of foot-and-mouth disease virus type A12 have low affinity for cells in culture.

We recently have shown that binding of foot-and-mouth disease virus (FMDV) to cells in culture requires an arginine-glycine-aspartic acid (RGD) sequence in the G-H loop of the capsid protein VP1 (P. W. Mason, E. Rieder, and B. Baxt, Proc. Natl. Acad. Sci. USA 91:1932-1936, 1994). In this report, we show that FMDV type A12 viruses found in infected bovine tongue tissue (BTT) differ from their tissue culture-grown derivatives at amino acid residues near the RGD. Viruses genetically engineered to contain VP1 sequences found in animal tissue (BTT viruses) were antigenically different from their tissue culture derivatives and bound to BHK cells more poorly than did the tissue culture-adapted viruses. Passage of the genetically engineered BTT viruses in BHK cells resulted in the rapid selection of variants with cell-binding properties, antigenic characteristics, and sequences typical of tissue culture-adapted viruses. These data indicate that residues near the RGD are critical for cell binding and that interpretations of antigenic variation of FMDV can be affected by virus cultivation in vitro.

Amino Acid Sequence↗

Genetic variability among Group A and B respiratory syncytial virus isolates from a large referral hospital in New Delhi, India.

Respiratory syncytial virus (RSV) is an important childhood pathogen of acute lower respiratory infections in developed and developing countries. The molecular epidemiology of RSV in India is largely unknown. The present study was undertaken to standardize and evaluate reverse transcription-PCR (RT-PCR) for the rapid and simultaneous detection of RSV groups A and B in clinical samples and to study intragroup genetic variability. RT-PCR was evaluated by comparing the results of seminested RT-PCR with centrifugation-enhanced cultures on 200 nasopharyngeal aspirates from children with acute lower respiratory infections. RSV was isolated in 34 nasopharyngeal aspirates by centrifugation-enhanced cultures and identified in 45 samples by RT-PCR. In 15 samples RSV was identified by seminested RT-PCR alone and in four by centrifugation-enhanced cultures alone. Of the 45 samples positive for RSV by nested PCR, 15 belonged to group A, 29 to group B, and one sample suggested a mixed infection. Group B RSV predominated in both years of the 2-year study. Genetic variability within RSV groups was studied by restriction fragment analysis of 35 PCR products. Among both group A and group B RSV, two different composite patterns were observed. Thus, RSV was found to be a major pathogen of acute lower respiratory tract infections in India, as it was detected in 24.5% of children by RT-PCR. RT-PCR provides a sensitive method for detection and typing of RSV group A and B viruses in clinical samples as well as a means to study intragroup variations. However, a higher sensitivity of detection of RSV in clinical samples can be obtained by its combination with additional techniques, such as virus cultivation.

Cell Line↗