Isolation of Measles Virus

Abstract

SIR,-Workers interested in the isolation of measles virus from patients may like to hear, before the present epidemic closes, of some investigations now in progress. A main object of the work has been to use for culture tissues which are readily available everywhere and thus to obviate the use of human or monkey kidney cultures, which, it may be recalled, were employed by Enders and Peebles' in their original investigations on the isolation and cytopathogenicity of measles virus.In the present investigation cultures of human chorion and human amnion' were inoculated with nose and throat swabs taken from measles patients on the first or second day of the rash. The swabs were inoculated, within 20 minutes of taking them, direct into the nutrient fluid (medium 199+ 20% ox serum) of the cultures. Fluid changes were made shortly before inoculation, on the day following, and thereafter at 3-4-day intervals. Culture tubes were incubated in the stationary position throughout. Cytopathic changes followed the inoculation in all of five chorion cultures and eight of nine amnion cultures.In both types of culture the lesions were usually first detectable on the 3rd or 4th day after inoculation. Development of cytopathic changes differed in the two tissues. In the chorion cultures they were diffusely distributed; little necrosis occurred and, on staining, large numbers of nuclei containing eosinophilic inclusions in various stages of development were seen. These were present in many individual cells as well as in the multinucleate syncytia which developed, more particularly, in the marginal areas. In the amnion cultures, on the other hand, the affected areas were discrete, large, and round, and could in fact be seen as " plaques " with the naked eye or hand-lens. They varied in number in individual cultures from one to about twenty. Vacuolation was conspicuous. With continued incubation the lesions increased in size but apparently not in number; the margins of the syncytia became more sharply defined and necrosis developed early. On staining, large eosinophilic inclusions were seen in the nuclei of the multinucleate cells of the affected areas.The relative merits of the two tissues for serial propagation of virus following isolation in them has not yet been assessed. The widespread invasion of the cultured chorion suggested that this might prove the better tissue, and the few experiments which have as yet been undertaken supported this view. The chorion had an advantage in that it was hardier in withstanding any deleterious influences during placental delivery and subsequent collection; it proved a uniformly reliable tissue with which to prepare cultures. On the other hand, an advantage in isolation in amnion lay in the ease with which the discrete plaque-like lesions could be detected in the living unstained cultures; in the chorion the full extent of the cytopathic changes was only revealed by staining. The results suggest that both these tissues, in culture, may find a place in the clinical and epidemiological investigatio...

Multiplication of measles virus in cell cultures.

“…Thus, the findings of Ruckle (111) and Bech (9), who employed both human amnion and renal cell cultures, showed that, although the virus could be occasionally isolated in human amnion cell cultures, this occurred less frequently than in renal cell cultures. Wright (146) reported successful isolation in human amnion and chorion cultures, but gave no quantitative information. Zhdanov and his associates also isolated measles virus in human amnion cultures (149).…”