[The contribution of the virology laboratory to the diagnosis of neuroinfections].

The authors summarizes the results of a virological examination in 1231 patients with neuroinfections hospitalized in 1973-1984 at the Infectious Diseases Clinic in Plzen. The virological diagnosis contributed towards the elucidation of the aetiology in 62.4% of the patients.

[Occurrence of zoonoses in a natural reservoir in the West Bohemian Region. I. Tick-borne encephalitis--basic epidemiologic characteristics].

In 1960-1987 in the population of the West Bohemian region by means of various serological methods 621 cases of tick-borne encephalitis were diagnose. The disease was not present in the northern districts (Cheb, Sokolov, Karlovy Vary) and in the mountainous zone along the western frontier of the country. In other areas it is ubiquitary with the highest mean morbidity for the entire period - 5.

[A tonsillitis epidemic caused by adenoviruses].

An epidemic of lacunar angina which affected, in relatively close common life, mostly only one of nine military units living in the same area. The failure of penicillin and negative finding of streptococci resulted in a retrospective establishment of the agent, which with all probability was adenovirus type 4. It has become obvious that the typical picture of lacunar or even pseudomembranous angina is not a reliable sign indicating streptococcal etiological even in a mass infection.

Use of hyperimmune mouse ascitic fluids for arbovirus differentiation by indirect immunofluorescence and conventional serology.

The cross-reactivity of 22 arbovirus species (alphaviruses; tick- and mosquito-borne flaviviruses; and selected bunyaviruses) was tested with monovalent immune mouse ascitic fluids by indirect immunofluorescence (IIF) in comparison with classical serological reactions (virus neutralization -- VN; haemagglutination inhibition -- HI; and complement fixation -- CF -- reactions). Known relationships within the virus groups studied were confirmed. As to the differentiation limits, the VN test was followed by IIF.

CV-1 monkey kidney cell line -- a highly susceptible substrate for diagnosis and study of arboviruses.

The CV-1 cell line, derived from Cercopithecus aethiops monkey kidneys, acquired in the course of serial passaging an epitheloid morphology and heteroploid karyotype. As compared with Vero and GMK cell lines, the CV-1 line proved to be more susceptible to a broad spectrum of arboviruses belonging to the families Togaviridae and Bunyaviridae. Most of them reached high titres and were markedly cytopathic in CV-1 cells so that all tests based on the cytopathic effect could be carried out.

Cultivation of Tuleniy virus (strain Murman) in vitro.

In vitro culturability of Murman strain of Tuleniy flavivirus isolated recently in the northern regions of the USSR was studied. Stable PS pig kidney line was found suitable as a primary sensitive cell substrate for the isolation, proliferation and serial propagation of the virus. The pronounced pathogenicity of the virus to PS cells permits the testing of its infective activity comparable with i.

Experiences with the adaptation of crimean hemorrhagic fever virus to the CV-1 monkey cell line.

Of several cell lines tested, the CV-1 monkey cell line proved to be the most suitable system for propagation of Crimean hemorrhagic fever (CHF) virus. Two CHF strains could be adapted to this cell line by serial passaging. The viral progeny from these passages was specifically cytocidal and produced plaques in CV-1 cells, which could be used in serological diagnosis of CHF.

A modified plaque method for arboviruses on plastic panels.

Autoclavable culture media containing an increased (10---15-fold)concentration of succinate buffer permit a comparitively long-term cultivation of cells in free gas exchange with the atmosphere. Based on them, an economical technique of plaque titration of arboviruses on plastic panels with methylcellulose overlay was developed. With seven arboviruses of three different groups and three cell lines (CV-1, PS and PK), the method proved sufficiently sensitive as compared with titrations in mice or tube cell cultures and suitable for plaque reduction tests.