Rapid typing of herpes simplex virus strains using the indirect immunoperoxidase method

Identification and typing of herpes simplex virus by enzyme immunoassay with monoclonal antibodies

A double-antibody enzyme immunoassay was developed for the identification and typing of herpes simplex virus (HSV) by employing a polyclonal rabbit capture antiserum together with type-common and type 2-specific monoclonal antibodies as detectors. The test successfully identified 45 type I isolates and 30 type 2 isolates as HSVs. Compared with immunofluorescent staining and restriction endonuclease analysis, enzyme immunoassay correctly typed 45 type 1 and 30 type 2 HSV isolates. Enzyme immunoassay was 100% sensitive for identification of HSV as compared with cell culture and 100% specific for typing as compared with immunofluorescence and restriction endonuclease analysis. Electron microscopy analysis suggested that approximately 10(6) virus particles were required for the identification and typing of HSV by enzyme immunoassay.

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.

Rapid detection and identification of herpes simplex virus in cell culture by a direct immunoperoxidase staining procedure

Cell monolayers were inoculated with 169 fresh and 76 previously frozen clinical specimens and examined for the presence of herpes simplex virus (HSV) by noting the appearance of characteristic cytopathic effect (CPE) and by using direct immunoperoxidase (IP) stain for viral antigen. HSV was detected by IP staining in 40 of 169 (23.7%) monolayers and by CPE in 39 of 169 (23.1%) monolayers inoculated with fresh specimens. All 40 isolates were detected and confirmed by IP staining within 24 h. Although 39 of 40 isolates were detected by CPE, only 9 of 39 (23%) were positive within 24 h. CPE was observed at 2.7 days on the average, but 4 days were required before 90% of the cultures were positive and more than 5 days were required before all HSV isolates were recognized. Similar results were observed for frozen specimens. HSV was detected earlier with IP staining, which demonstrated more extensive infection of cell monolayers inoculated with titrated fresh culture isolates and clinical specimens than did CPE. IP staining reduces the amount of time required for detection and identification of HSV in culture, is readily adaptable for use in the clinical laboratory, and permanent stained preparations can be made.

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

A miniaturised, simplified and rapid method for typing and subtyping herpes simplex virus by restriction enzyme analysis of radioactively labelled DNA is described. This method requires far less label than those described previously, giving advantages in both cost and safety and therefore in its suitability for use in a routine laboratory. It produces results indistinguishable from those obtained by the parent method.

Comparison of biological, biochemical, immunological, and immunochemical techniques for typing herpes simplex virus isolates

In this study, 102 herpes simplex virus isolates were typed by cell culture selection (chicken embryo cells and guinea pig embryo cells [CE/GPE]), (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) sensitivity, plaque reduction neutralization, and indirect immunofluorescence staining techniques. The percentages of agreement between the typing methods were as follows: BVDU sensitivity versus CE/GPE, 99% (99/102); CE/GPE and BVDU sensitivity versus neutralization, 32% (33/102); CE/GPE and BVDU sensitivity versus indirect immunofluorescence staining 17% (17/102). Results were easy to interpret when the CE/GPE and BVDU sensitivity systems were used. In contrast, when type-specific antisera prepared commercially were used, results were often obscure, even contradictory, because of antibody cross-reactions. Therefore, this study suggests that immunological and immunochemical methods that use presently available commercially prepared antisera cannot reliably differentiate herpes simplex virus type 1 from type 2.

Simplified method for typing herpes simplex virus by restriction endonuclease analysis

We have developed a simplified method for unambiguously typing herpes simplex virus. The method depends on the production of cell-associated virus at 34 degrees C and subsequently, on the separation of cellular DNA and viral DNA by Dounce homogenization and the removal of nuclei by centrifugation. Viral nucleic acid was prepared from the cytoplasmic fraction and analyzed after restriction endonuclease cleavage. The method obviates the use of radioactive isotopes, and the viral DNA is effectively free of interfering cellular DNA.

Typing of clinical herpes simplex virus isolates with mouse monoclonal antibodies to herpes simplex virus types 1 and 2: comparison with type-specific rabbit antisera and restriction endonuclease analysis of viral DNA

A total of 122 clinical isolates of herpes simplex virus (HSV) from 107 patients were typed by using an indirect immunoperoxidase technique with commercially available type-specific rabbit antisera, recently developed mouse monoclonal antibodies to HSV types 1 and 2, and restriction endonuclease analysis of viral DNA. With the commercially available type-specific rabbit antisera, 34% of clinical HSV isolates were of indeterminate type; 63% of them were typed as HSV type 1 and 37% as HSV type 2 by using monoclonal antibody and restriction enzyme typing systems. Typing by immunofluorescence assay with the monoclonal antibodies gave identical results to those obtained by restriction enzyme analysis. Simultaneous infection with both HSV types was demonstrated by monoclonal antibody typing in five isolates from three patients. These findings were subsequently confirmed by plaque purification and restriction endonuclease analysis of viral DNA. Monoclonal antibodies were as sensitive as restriction enzyme analysis for the typing of clinical HSV isolates. Because of their simplicity, they are more amenable to use in clinical laboratories than is restriction endonuclease analysis.

Identification and typing of herpes simplex viruses with monoclonal antibodies

Monoclonal antibodies which reacted with type-specific antigens of herpes simplex virus type 2 or with antigens shared by herpes simplex virus types 1 and 2 were used in an indirect immunofluorescence assay to type virus isolates and to detect viral antigens in cells obtained from herpetic lesions. Complete concordance was obtained for 42 isolates typed by endonuclease restriction analysis of viral DNA and by indirect immunofluorescence with monoclonal antibodies. Examination of a limited number of ulcerative lesions revealed that indirect immunofluorescence and virus isolation were comparable in detecting herpes simplex virus. The results indicate that monoclonal antibodies can be used to accurately identify and type isolates of herpes simplex virus.

Rapid serological technique for typing herpes simplex viruses

A rapid technique is described which can accurately identify a herpes simplex virus (HSV) isolate as type 1 or type 2. Filter paper disks were used to immobilize viral antigens, which were then identified by means of an (125)I-labeled staphylococcal protein A immunoassay. The assay was performed in a specially designed 96-well filtration device which served as both an incubation chamber and a filter manifold. By using this system and cross-absorbed antisera to HSV types 1 and 2, 69 coded clinical isolates of HSV were correctly and unequivocally typed. HSV was also clearly distinguished from varicella-zoster virus and cytomegalovirus. This assay can be rapidly executed (less than 2 h) and yielded an objective endpoint; it required only minute quantities of typing sera and can be easily performed with the cells from a single infected roller tube culture. Thus, it can be used to type initial clinical isolates of HSV, yielding results within hours after the first appearance of cytopathic effects in the culture used for primary virus isolation. Moreover, it is particularly well suited to the simultaneous analysis of many specimens and is amenable to automation. These characteristics suggest that this (125)I-labeled staphylococcal protein A immunofiltration technique will be applicable to the rapid identification of other herpesviruses, as well as other clinical isolates.

Confirmation of herpes simplex virus type 2 infections in herpes-like genital lesions by a simple complement-fixation test

The presence of complement-fixing antibody to an early herpes simplex virus type 2 (HSV-2) antigen (the AG-4 antigen) was correlated with HSV-2 infection in the sera of patients with genital herpes. Eighty-eight per cent of sera taken two weeks after clinical diagnosis of a primary or recurrent herpes infection in patients, confirmed to have HSV-2 by virus isolation and typing, contained the anti-AG-4 complement-fixing antibody. None of the patients with genital HSV-1 had the antibody, and only 9% of controls or patients with facial HSV-1 infection had positive results for the antibody. This correlation was used to identify genital HSV-2 infections when either no virus sample had been taken or when virus isolations had been unsuccessful. Thus, a simple complement-fixation test can confirm an HSV-2 virus infection without isolation of the virus from the herpetic lesion.

Comparison of viral isolation, direct immunofluorescence, and indirect immunoperoxidase techniques for detection of genital herpes simplex virus infection

Seventy-six consecutive patients presenting to a genital herpes simplex virus (HSV) clinic were enrolled in a study comparing viral isolation (VI), indirect immunoperoxidase (indirect IP), and direct immunofluorescence (direct FA) techniques for the detection of HSV antigen. Of the 76 patients, 61 (80%) demonstrated HSV by VI, compared with 66% by indirect IP and 55% by direct FA (P less than 0.05). Genital lesions from nine patients demonstrated HSV antigen by direct FA or indirect IP but were VI negative; eight of nine patients had subsequent episodes of genital HSV confirmed by VI. During the vesicular-pustular stage of the disease, VI was positive in 90%, indirect IP was positive in 76%, and direct FA was positive in 71% of the lesions, whereas with ulcerative lesions, VI was positive in 72%, indirect IP was positive in 55%, and direct FA was positive in 38%. These commercially available rapid viral diagnostic techniques are specific and useful, if adequate specimens are obtained from early genital lesions.

Lymphocyte-derived chemotactic factor synthesis in initial genital herpesvirus infection: correlation with lymphocyte transformation

Lymphocyte transformation and production of lymphocyte-derived chemotactic factor in response to herpes simplex virus antigen were studied in 15 patients with initial genital herpes and 10 controls. The patients underwent frequent genital examinations, viral cultures, and weekly immunological studies for a period of 11 weeks. The production of lymphocyte-derived chemotactic factor was maximal in week 1 of the disease and declined to control levels by week 6. In contrast, lymphocyte transformation was lowest in week 1, reached a maximum by week 4, and declined to control levels by week 11. Production of lymphocyte-derived chemotactic factor in week 1 was significantly lower in nine patients who developed signs or symptoms of systemic herpes infection than in six who had localized disease. In addition, a marked but transient decline in the production of this lymphokine was observed in patients at the time of clinical recurrence. Virus-specific lymphocyte transformation correlated inversely with the duration of genital pain and lesions and did not correlate with the presence of systemic signs or symptoms. These findings indicate that during initial genital herpes infection the dynamics of lymphocyte transformation and those of lymphocyte-derived chemotactic factor production are different, and that the generation of this lymphokine is an early component of the cellular immune response in this disease. Furthermore, adequate produce of lymphocyte-derived chemotactic factor may be important in restricting herpes simplex virus to the genital area and preventing disease recurrence.

Rapid typing of herpes simplex virus isolates by deoxyribonucleic acid:deoxyribonucleic acid hybridization

A method for typing clinical isolates of herpes simplex virus was developed. It utilizes hybridization between unlabeled deoxyribonucleic acid from infected cultures and tritium-labeled virus deoxyribonucleic acid, and it can be completed within a day using a single roller-tube culture of the clinical isolated. The data obtained are inherently quantitative, and the method yields unequivocal identification and typing. Thirty-nine coded clinical isolates were all correctly typed by this method.

Recurrent genital herpes among women: symptomatic v. asymptomatic viral shedding

To investigate whether asymptomatic shedding of herpes simplex virus occurs in women with recurrent genital herpes, six women with documented disease were followed up twice weekly with viral cultures and pelvic examination. During the study period of 1330 patient days and 452 patient visits, 26 episodes of genital herpesvirus infection were recorded. Twenty-three (88%) episodes were accompanied by signs and symptoms. Three (14%) of the culture-positive recurrences were asymptomatic. In one episode an asymptomatic lesion was noted, and in two instances viral shedding from the vulva or cervix occurred in the absence of visible herpetic lesions. Three of the six women had evidence of recurrent cervical herpesvirus infection. No relationships between menstrual cycle and sexual activity and the onset of recurrence were noted.

Type specificity and use of human sera for rapid typing of herpes simplex virus isolates by an indirect peroxidase-labeled antibody technique: a comparison with three other methods

Human sera from patients showing seroconversion following a primary herpes simplex virus type 1 (HSV-1) or HSV type 2 (HSV-2) infection, as well as 19S and 7S fractions obtained from the same sera, have been used for typing 191 HSV isolates by an indirect peroxidase-labeled antibody (PLA) method. Typing has also been performed on all of the isolates using a microneutralization (MN) and the indirect hemagglutination (IHA) inhibition test. Furthermore, 30 isolates have been typed by a plaque method. Results obtained with the PLA method was in complete agreement with those of the other two procedures. The PLA method is rapid and simple, offers easy interpretation and a permanent record of results.

The immunoperoxidase technique for rapid human cytomegalovirus identification

Sixteen cytomegalovirus (CMV) isolates from both ill and healthy patients were identified by the immunoperoxidase technique (IP). CMV detection was accomplished by direct examination of the primary isolate using either direct (DIP) or indirect immunoperoxidase (IIP) techniques. In thirteen of the isolates, confirmation of identification was achieved by indirect immunofluorescence (IFA) and by demonstration of herpes particles by electron microscopy (EM). Further, in four cases of non-CMV alterations in the tissue culture which might be confused with actual infection, the IP test was negative as were the confirmatory tests. The IIP is preferred over the DIP test since the latter shows a certain amount of background stain of uninfected cells. Tissue culture cells showing focal CMV cytopathic effect contained both nuclear and cytoplasmic inclusions stained by IP technique. Nonspecific staining was associated with cytoplasmic inclusion bodies. The IP technique can detect individual cell CMV infection at 24 hours when EM reveals only unenveloped viral particles. It is sensitive, specific, and allows direct identification of infected cells in the primary isolate in as little as 90 minutes. Furthermore, it can be performed in standard isolation tissue culture tubes, whereas IFA requires the transfer of the infected cells onto slides or the routine use of Leighton tubes.