title: An investigation into the growth and antigenic properties of adenoviruses detected by electron microscopy in the stools of children in Glasgow
Creators: name: Kidd, Alistair H.
Publisher: name: University of Glasgow
Year: 1980
Subjects: subject: Virology.

description: Adenovirus particles which cannot be cultured have been found in the stools of children by various workers. To determine the extent of this problem, stools from children in Glasgow, sent to the Regional Virus Laboratory for electron microscopic examination over a 2-year period (1976-197.) and found to contain adenovirus particles, were put in culture. One third of 148 specimens containing adenovirus (from 28 of 69 children) failed to cause cytopathic effects in primary human amnion and secondary human embryo kidney (HEK) cell cultures. Variations in culture method such as rolling tubes or adsorption periods did not improve the adenovirus isolation frequency. There was no common factor apparent, concerning the patients or their stools, which night explain the non-growth of adenoviruses. Attempts to 'reactivate' non-growing adenoviruses by culture attempts in human cells in the presence of either adeno associated virus (AAV), human adenovirus (type 8) or a canine adenovirus (ICHV) were unsuccessful. AAV type 1 did not multiply in the presence of non-growing adenovirus particles. An immunofluorescence test using group-specific guinea pig antiserum revealed that with some stool extracts a small number of KB cells become infected and produce adenovirus structural antigens. Fluorescence was limited to single cells, indicating that, at 3 days after inoculation, spread of any new infectious virus to adjacent cells did not occur. Attempts to detect an inhibitory substance to adenovirus replication, which might explain the lack of cytopathic effects, were unsuccessful. Bovine cells, canine cells and various continuous human cell lines were tried for the detection of non-growing adenoviruses, and some success was achieved using Intestine 407 and Chang Conjunctiva cells maintained in Leibovitz' L15 medium. Two agents from different children caused cytopathic effects over 8 passages in Chang cells. Apart from these agents, the extent of the cytopathic effects declined in most cases with serial passage, but this decline was not so rapid if the cultures were incubated at 33°C. Antisera prepared in rabbits against one strain of non-growing adenovirus showed group-specific reactivity by immunofluorescence and complement fixation tests to adenoviruses of mammalian origin. These sera at low dilution (l:20) did not neutralise the serotypes of adenovirus commonly isolated from stools, but neutralised all but one of the 'fastidious' (F) strains from 21 children. Strains from 9 of these children were neutralised by one antiserum at a dilution of 1:640 or greater. Three fastidious strains (from different children) were not neutralised by standard antisera to adenovirus types 1 to 33. It is suggested that they are a previously undiscovered serotype. Cultures of fetal human intestinal segments also appear to be capable of supporting the growth of these agents. A limited study to screen the stools of children for fastidious adenoviruses by neutralisation indicated that F adenoviruses of the same or related serotypes may be very common. That some adenoviruses in stools produce neither group-specific antigens detactable by immunofluorescence in KB cells nor cytopathic effects in Chang cells remains to be explained. The significance of these results is discussed and related to the recent work of others.