A miniaturised and simplified technique for typing and subtyping herpes simplex virus

Rapid small-scale isolation of SV40 virions and SV40 DNA

A rapid method for the small-scale isolation of SV40 virions and SV40 DNA is presented. CV-1 monkey epithelial cells are transfected with linear SV40 DNA. After the onset of transfection, cells are lysed by several freeze/thaw cycles and virions are isolated using polyethylene glycol (PEG) precipitation of DNase I treated lysates. Viral DNA is released by proteinase K and dithiothreitol treatment of the isolated virions followed by phenol/chloroform extraction and ethanol precipitation. This method yields on average 7.5x10(4) plaque forming units (PFUs) and DNA of adequate purity and concentration to be used for restriction analysis on ethidium bromide agarose gels from a single 35-mm tissue culture dish.

Rapid small-scale isolation of herpes simplex virus DNA

A method has been developed for the rapid isolation of herpes simplex virus DNA analogous to miniprep methods for bacterial plasmid isolation. Infected Vero cells are lysed with three freeze-thaw cycles, and the nuclei are removed by centrifugation. DNA is released from the virions in the supernatant by proteinase K digestion. Then the DNA is extracted with phenol/chloroform and precipitated with ethanol. This method requires only small amounts of infected cells as a source of viral DNA, does not use radioactivity, and routinely produces DNA of sufficient purity to be used for restriction fragment length polymorphism (RFLP) analysis on ethidium-stained gels.

Experimental in vivo generation of intertypic recombinant strains of HSV in the mouse

The primary replication of one strain of HSV was generally unaffected by the simultaneous inoculation of another strain either at the same site or at a different site within the same dermatome. Exceptions to this were the result of the generation of intertypic recombinants which were readily isolated only from sensory ganglia 5 and 6 days after inoculation with a mixture of HSV-1 and HSV-2 and from explant culture of the resultant latently infected ganglia. By restriction enzyme analysis the majority of the recombinant strains from primary infection were characterized as HSV 1; all those from latently infected ganglia were characterized as type 2.

Antiviral drug sensitivity in ocular herpes simplex virus infection

Thirty-nine herpes simplex virus (HSV) isolates were assayed for their sensitivity to 10 different antiviral agents. Of these 39 HSV isolates 10 were cultured from recipient buttons obtained at penetrating keratoplasty in patients with inactive stromal scarring due to recurrent herpetic keratitis, 25 were cultured from patients with conjunctival and ulcerative ocular infections, and the remaining four were laboratory strains with known drug sensitivity patterns, thus providing controls for the experiment. All but one of the 35 clinical isolates of HSV were type 1 and all were sensitive to the 10 antiviral agents. A single type 2 isolate from a young man with recurrent conjunctivitis proved to be resistant to a number of the antiviral agents. Since many of the clinical isolates had been exposed to multiple and protracted antiviral drug treatment, it is suggested that antiviral drug resistance in type 1 HSV ocular infection is not a significant problem.

A rapid and simplified micromethod for subtyping varicella-zoster virus

A simplified and rapid micromethod based on restriction endonuclease analysis of radiolabelled varicella-zoster virus (VZV) DNA is described and applied to strains for comparison. This procedure is cheaper and less time consuming than that requiring viral nucleocapsid purification (macromethod). The micromethod is suitable for routine DNA analysis of VZV isolates, allows differentiation of vaccine strain from wild strains, and provides evidence for variability of wild strains.

Alphaherpesvirus saimiri infection in rabbits. 1. Light and electron microscopy study of cutaneous spinal nerves

A light and electron microscopic study was undertaken to determine pathological changes in cutaneous spinal nerves of rabbits following intradermal inoculation with alphaherpesvirus saimiri (alpha HVS) isolate KM 322. Infected rabbits were killed at 3, 10, 17, 45 days and 2 years after infection. No abnormalities were seen at 3 days postinoculation. In the nerves of the rabbits killed at 10, 17 and 45 days after infection, axonal (Wallerian-type) degeneration was the main pathological feature. Regeneration, manifested by axonal sprouting, was observed in the nerves of the rabbits killed at 45 days post-inoculation. Neural fibrosis and paucity of unmyelinated axons was the final outcome. The severity of the neural damage not only varied according to the progression of the disease but between nerves taken from the same rabbit. This was probably associated with variation in the numbers of virus particles that had reached the dorsal root ganglion of the dermatome served by a particular nerve. Since alpha HVS (isolate KM 322) provides a model system for the study of virus latency in dorsal root ganglia, and consequently for the study of varicellazoster infection in man, these findings give further insight into the pathology of herpetic neuropathy.

Genome isomerism in two alphaherpesviruses: Herpesvirus saimiri-1 (Herpesvirus tamarinus) and avian infectious laryngotracheitis virus. Brief report

Genome isomerism of avian infectious laryngotracheitis virus (ILT) and Herpesvirus saimiri-1 (HVS-1) (formerly H. tamarinus) was investigated using restriction endonuclease analysis and scanning densitometry. ILT DNA was found to have 2 isomers with a molecular weight of 109 X 10(6). HVS-1 DNA was found to have four isomers with a molecular weight of 102 X 10(6).

Characterization of four herpesviruses isolated from owl monkeys and their comparison with Herpesvirus saimiri type 1 (Herpesvirus tamarinus) and herpes simplex virus type 1

Four herpesviruses were previously isolated from four outbreaks of lethal disease in owl monkeys. All four isolates have been shown to be antigenically closely related to each other and to Herpesvirus saimiri 1 (HVS-1) by kinetic neutralizations. The owl monkey strains also share similarities to HVS-1 and to each other with respect to host range, growth cycles and molecular weights of peptides and of DNA fragments generated by restriction endonuclease (R.E.) digestion. R.E. analysis, however, can differentiate strains by the use of certain enzymes. All four isolates share a common G-C ratio percentage with HVS-1 of 67 per cent. On the basis of these findings, we believe that these owl monkey virus isolates are strains of HVS-1.

Herpes simplex virus isolation in chronic stromal keratitis: human and laboratory studies

The corneal discs of 41 patients with scarring reminiscent of herpetic infection were organ cultured for HSV isolation. Of the 41 patients, 34 had a definite history of herpetic keratitis, from 10 of whom (29.4%) HSV was isolated. There were no clinical features which distinguished between these groups; there was however an indication that those from whom HSV was not isolated had been previously treated with substantial amounts of topical acycloguanosine. In three patients of 12 patients when the disc was separated into 7 parts using a punch technique, virus was isolated exclusively from those portions demonstrating clinical scarring. Electron microscopy (EM) demonstrated HSV particles in stromal cells in the cultured corneas of seven patients. In two of the patients no virus was detected prior to culture with EM. In one patient HSV antigen was not found using peroxidase-antiperoxidase (PAP) staining prior to subsequently positive organ culture. Studies were made to determine how HSV accedes to the corneal stroma using a murine model in which keratitis occurs by zosteriform spread of HSV following inoculation of the snout. Preliminary evidence using PAP staining indicates that the virus reaches the stroma at the same time as the epithelium, via the sensory nerves. Evidence of HSV persistence in anterior segments was obtained in the same model, in contrast to which no virus could be isolated following direct inoculation into the cornea. It is speculated that for virus to set up a longterm association with the stromal keratocyte, it must be introduced via the sensory nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Herpesvirus simplex in chronic human stromal keratitis

A method is described for the isolation of Herpesvirus simplex (HSV) from corneal discs of patients suffering from chronic stromal keratitis. The discs were removed during penetrating keratoplasty. Virus was successfully isolated from 2 out of 8 discs maintained in vitro.

Genetic heterogeneity of recent isolates of adenovirus types 3, 4, and 7

Restriction endonuclease analysis was carried out on adenovirus types 3, 4, and 7 (Ad3, Ad4, and Ad7, respectively) isolated during a 16-month epidemic period. Most of the isolates were associated with respiratory or ocular infection or both. Forty-four strains of the subtype Ad7b were identified with SmaI; these strains could be further subdivided into three distinct genome groups, designated Ad7b1, Ad7b2, and Ad7b3, by digestion with PvuII, BglI, and SstII. These Ad7b variants occurred at approximately similar frequencies throughout the epidemic and were associated with similar clinical illnesses. Nine distinct intratypic genome groups were identified among 29 Ad3 strains with HindIII, PstI, and SmaI; adenoviruses similar to subtype Ad3a, formerly reported to be uncommon in Europe, were isolated most frequently (41% of strains), and the previously predominant prototype (Ad3p) was not found. Considerable similarities among the genomes of some strains of Ad3 and Ad7 could be demonstrated, and clinical and epidemiological presentations were very similar. The four strains of Ad4 isolated fell into two distinct patterns, i.e., the previously recognized prototype (Ad4p) and a new subtype designated Ad4b. Both of these subtypes were associated with follicular conjunctivitis. Thus we were unable to produce evidence that particular genome types of Ad3, Ad4, and Ad7 are associated with particular clinical presentations. However, restriction endonuclease analysis should prove useful for epidemiological studies on these viruses.

Simplified restriction endonuclease method for typing and subtyping adenoviruses

Restriction endonuclease digestion of viral DNA labelled in vivo with phosphorus-32 has been used to type and to subtype both conventional and enteric adenoviruses. The method is a modification of that already described for typing and subtyping herpes simplex virus and, like the latter, needs far less material than methods previously described.

Comparison of a commercial ELISA system with restriction endonuclease analysis for typing herpes simplex virus

Isolates of herpes simplex virus which had previously been typed by restriction enzyme analysis were typed again with a commercial ELISA system using polyclonal antibodies. There was complete correlation between the two techniques. Although restriction is more precise and definitive, when typing only is required the simplicity of ELISA makes it the preferred technique.