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At least 19 recordsLinked to original sources
PubMed1977

Picornaviruses: rapid differentiation and identification by immune electronmicroscopy and immunodiffusion.

Immune electronmicroscopy (IEM) was used to identify human picornaviruses rapidly and to differentiate enteroviruses from rhinoviruses. Human sera, diluted 10- to 50-fold beyond the neutralisation endpoints for homologous virus, readily agglutinated C-type antigens of seven human picornaviruses. Human sera did not react by IEM with a control animal picornavirus. By IEM after acid treatment, differentiation of a human enterovirus from a human rhinovirus was possible. There was an excellent correlation between the results of IEM and immunodiffusion (ID) tests for the presence of antibody to human picornavirus group antigens. By ID, only one of 21 human sera reacted with one of six animal picornaviruses. Immune electronmicroscopy appears to be a sensitive and simple techinque for the detection of picornavirus C-type antigens, and may be useful for identifying viruses belonging to groups comprising many serotypes and sharing a common group antigen.

Adult↗
PubMed2026

Redox cycling of viral RNA polymerase controls picornavirus replication.

Picornaviruses, including foot-and-mouth disease virus (FMDV), enterovirus 71 (EV71) and encephalomyocarditis virus (EMCV), are important pathogens that cause fever, herpes, and myocarditis in humans and animals. The interplay between picornaviruses and their hosts remains enigmatic. Here we perform porcine genome-wide CRISPR/Cas9 screens and identify methionine sulfoxide reductase B3 (MSRB3) as an essential factor for FMDV. MSRB3 deficiency inhibits FMDV replication. Mechanistically, MSRB3 eliminates methionine oxidation of FMDV 3D polymerase and stabilizes its expression. Further studies show that radical SAM domain-containing protein 1 (RSAD1) catalyzes methionine oxidation of FMDV 3D polymerase and promotes its aggregation and subsequent degradation through the autophagy-lysosome pathway. Importantly, RSAD1-MSRB3-mediated redox modification also affects the stability of 3D polymerases of EV71 and EMCV, and regulates their infectivity and pathogenesis both in vitro and in vivo. Collectively, this study corroborates that RSAD1-MSRB3-mediated redox cycling of 3D polymerase plays a conserved function in modulating picornavirus infection, providing insights into viral pathogenesis and broad-spectrum antiviral development.

Animals↗
PubMed1975

An epidemic of picornavirus and adenovirus conjunctivitis.

A pandemic of acute haemorrhagic conjunctivitis occurred in south-east Asia during 1970 and 1971, and became epidemic in Lucknow in May 1971. From the conjunctival swabs adenovirus-like agents were isolated in monkey kidney tissue culture; one was typed as adenovirus 2. In paired sera rising antibody titres were found against an adeno-like agent isolated and the picornavirus (EC2/71) isolated in Singapore. The epidemics in south-east Asia were caused by a picornavirus while in Lucknow both adenovirus and picornavirus appeared to be implicated.

Acute Disease↗
PubMed1975

The importance of picornavirus infections in respiratory disease of man and other mammals.

Picornaviruses may be divided, by physicochemical properties, into enteroviruses, cardioviruses, caliciviruses, rhinoviruses and foot-and-mouth diseases viruses. Although the respiratory tract may be the primary site of entry and multiplication for enteroviruses, cardioviruses and FMD viruses, few agents in these groups cause respiratory disease. A notable exception is coxsackievirus A21 which is an important cause of upper respiratory tract diseases in military recruits. The picornaviruses which most frequently cause respiratory illness are rhinoviruses and caliciviruses. There are over one hundred rhinovirus serotypes which infect man and they have been isolated from up to 50 percent of cases of mild respiratory illness, from 1-2 percent of healthy adults and from 5-10 percent of healthy children. About 10 percent of rhinovirus infections in adults are symptomless. The two bovine serotypes of rhinovirus and the two equine serotypes frequently infect cattle and horses respectively but seldom cause disease. Numerous calicivirus serotypes have been found in 17 percent of cats with respiratory disease and in 19 percent of clinically normal cats. However, experimental inoculation with caliciviruses has confirmed their causative role in respiratory disease of cats. The high rate of virus isolation from normal cats is probably due to their ability to carry virus in an infectious form for up to two years after initial infection and illness.

Adult↗
PubMed1978

Intranuclear crystal formation in picornavirus-infected cells.

Cells infected with echovirus or poliovirus were incubated at a suboptimal temperature (28 degrees C). When the cells were examined by electron microscopy, not only were crystalline arrays of mature virus particles observed in the cytoplasm but crystals composed of immature virus-like particles were also evident in the less electron-dense central region of the nucleus. Immunofluorescent and autoradiographic studies revealed the presence of viral proteins and RNA in the nucleus. These findings strongly suggest that the intranuclear crystals are composed of incomplete virus particles and that crystal formation at such a low temperature may be a remarkable feature common to picornaviruses. Possible mechanisms for the intranuclear synthesis of viral constituents are discussed.

Antigens, Viral↗
PubMed1975

Chromatographic studies on picornavirus capsid polypeptides.

The polypeptides of encephalomyocarditis, Mouse-Elberfeld and type 5 rhinoviruses behave similarly when chromatographed on calcium phosphate (brushite), each being eluted by a linear phosphate buffer gradient containing sodium dodecyl sulphate in three major peaks, CI, C2 and C3. Analysis of the peaks by polyacrylamide gel electrophoresis suggests that the major capsid polypeptides of these three picornaviruses elute in the order: delta (peak CI), gamma with (peak C2) and alpha (peak C3).

Animals↗
PubMed1975

Replication of picornaviruses. I. Evidence from in vitro RNA synthesis that poly(A) of the poliovirus genome is genetically coded.

A crude replication complex has been isolated from poliovirus-infected HeLa cells and used for synthesis of poliovirus replicative intermediate (RI) RNA, replicative form (RF) RNA, and single-stranded (SS) RNA in vitro. All three classes of virus-specific RNA synthesized in vitro are shown to contain poly(A). Poly(A) of RF and of SS RNA [RF-poly(A) and SS-poly(A)] has a chain length (50 to 70 nucleotides) that is shorter than that of poly(A) of in vivo-synthesized RNAs. Poly(A) of RI [RI-poly(A),] however, is at least 200 nucleotides long and, therefore, larger than poly(A) of RI isolated from HeLa cells 4 h after infection. The crude membrane-bound replication complex contains a terminal adenylate transferase activity that is stimulated by Mn2+ and the addition of an (Ap)2AOH primer. This transferase activity is found also in extracts of mock-infected cells. Partial purificaiton of the replication complex in a stepwise sucrose gradient, in which the viral replicase is associated with the smooth cytoplasmic membrane fraction, does not remove the terminal transferase. However, when the partially purified replication complex is treated with deoxycholate and sedimented through a sucrose gradient, a soluble replication complex can be isolated that is free from terminal adenylate transferase. This soluble replication complex was found to synthesize viral RNA-linked poly(A) longer in chain length than that synthesized by the crude replication complex. Taking into account the 5'-terminal poly(U) in poliovirus minus strands, our data suggest that polyadenylation of poliovirus RNA occurs by transcription and not by end addition. When compared to other viral systems, poliovirus and, probably, all picornaviruses appear to be unique in that the poly(A) of their genome is genetically coded.

Adenosine Monophosphate↗
PubMed1977

RNA synthesized in calicivirus-infected cells is atypical of picornaviruses.

RNA labeled with [3H]uridine from Vero cells infected with San Miguel sea lion virus in the presence of actinomycin D was analyzed by glycerol density gradient sedimentation and polyacrylamide gel electrophoresis. The predominant single-stranded RNA (36S, 2.6 x 10(6) molecular weight) was genome size. There was also a prominent 22S, 1.1 x 10(6)-molecular weight, single-stranded component and one or more double-stranded or partially double-stranded classes. Replicative forms, sedimenting at 18S, contained single-stranded RNA corresponding to the larger-molecular-weight class. All classes of intracellular RNA and virion RNA were polyadenylated. These findings and results with pig kidney cells infected with vesicular exanthema of swine virus and feline cells infected with feline calicivirus indicate that caliciviruses exhibit a strategy of replication different from typical picornaviruses and supports removal of the caliciviruses from the family Picornaviridae.

Animals↗
PubMed1978

Effect of cordycepin triphosphate on in vitro RNA synthesis by picornavirus polymerase complexes.

Cordycepin triphosphate inhibited in vitro [3H]GMP incorporation by pricornavirus-specific polymerase complexes isolated from infected HeLa cells. The inhibition of [3H]GMP incorporation could be reversed with ATP added to the reaction mixture along with the inhibitor, but not with GTP so added or with ATP added 10 min after the inhibitor. Products synthesized in vitro in the presence of cordycepin triphosphate lacked full-length single-stranded viral RNA. These results support RNA chain termination by specific competition with ATP as the mechanism of inhibition of picornavirus-specific RNA synthesis by cordycepin triphosphate.

Adenosine Triphosphate↗
PubMed1979

Isolation of picornavirus from feces and semen from an infertile bull.

Virus was isolated from semen and fecal samples from a bull with orchitis, testicular degeneration, aspermatogenesis, and loss of libido. Both isolates were classified as picornavirus, bovine enterovirus serotype I, on the basis of physical, chemical, and serologic characteristics. Veterinary practitioners that may suspect viral infection as a cause of bovine infertility should submit both semen and fecal samples for virus isolation and identification.

Animals↗
PubMedDate not supplied

Pathogenicity for baby chicks of the G-4260 strain of the picornavirus "avian nephritis virus".

The pathogenicity of the G-4260 strain of picornavirus for day-old chicks was studied by intraperitoneal inoculation. No clinical signs were observed. A mild yellowish-tan discoloration of the kidneys was noticed in necropsy 7 to 21 days after inoculation. Mean body weight was significantly lower (P less than 0.01) in inoculated groups than in control groups 7 days after inoculation. In a chronological study on the distribution of the virus in organs, the virus was recovered from various organs, exclusive of the brain and trachea. The virus titer was higher in the kidneys, jejunum, rectum, and bursa of Fabricius than in any other organ. Fluorescent antigens were seen predominantly in the epithelia of the renal tubules.

Animals↗
PubMedDate not supplied

Pathological changes in chicks inoculated with the picornavirus "avian nephritis virus".

One-day-old chicks were inoculated intraperitoneally with a newly isolated picornavirus. The inoculated chicks showed no clinical signs until 28 days postinoculation (PI), but discoloration of the kidneys was recognized from 7 to 21 days PI at autopsy. Histologically, focal lesions were observed in the cortex of the kidneys from 3 to 21 days PI. The lesions were characterized by interstitial lymphocytic infiltration and degeneration of epithelial cells of the proximal convoluted tubules. The degenerated cells contained acidophilic granules in their cytoplasm. Electron-microscope examination of the cytoplasm revealed electron-dense amorphous areas, phagosomal areas with viral particles, and isolated crystal arrays of the virus particles, 23 to 30 nm in size. Granular antigen was also detected by fluorescent-antibody technique in the cells.

Animals↗
PubMedDate not supplied

Characterization of a picornavirus isolated from broiler chicks.

The rectal content of an apparently normal 1-week-old broiler chick yielded an unclassified cytopathogenic virus with cytopathic effects of the round type. It was identified as a picornavirus from the following: ribonucleic acid in the viral core; virus growth in the cytoplasm; a particle about 30 nm in diameter; resistance to ethyl ether, chloroform, trypsin, and acid; relative heat-lability; and partial stabilization to molar magnesium chloride. The virus was stable under freezing and thawing, and sonication. It was distinguished from avian encephalomyelitis virus by the neutralization test.

Animals↗