Development of rotavirus molecular epidemiology: electropherotyping
Early in the era of rotavirology it was realized that the characteristic patterns of bands produced in polyacrylamide gels following electrophoresis of genomic dsRNA were useful for checking the identity of rotavirus isolates. However it was Romilio Espej
- PDF / 697,373 Bytes
- 5 Pages / 595.278 x 793.684 pts Page_size
- 78 Downloads / 203 Views
VIrology
Arch Virol (1996) [Suppl] 12: 87-91
© Springer-Verlag 1996
Development of rota virus molecular epidemiology: electropherotyping I. H. Holmes
Department of Microbiology, University of Melbourne, Parkville, Victoria, Australia
Summary. Early in the era of rota virology it was realized that the characteristic patterns of bands produced in polyacrylamide gels following electrophoresis of genomic dsRNA were useful for checking the identity of rotavirus isolates. However it was Romilio Espejo who first proposed the use of this technique for epidemiology, although most others did not take the suggestion seriously because the technique was then rather specialized and RNA staining methods were not very sensitive. Using samples collected by Ruth Bishop in Melbourne following the original identification of human rotaviruses, Sue Rodger recorded the "electropherotypes" of all samples available to 1979 and painstakingly compared them, side by side (since minor variations in conditions, especially temperature, alter the relative migration distances of dsRNA bands). These efforts produced the first longitudinal, extensive study of human rotavirus strain variation. Since then, technical improvements have greatly increased the sensitivity of the procedures, and electropherotyping has been recognized as a powerful and economical method for epidemiological studies of rotaVIruses.
*
Rotaviruses (family Reoviridae) are very frequently associated with acute diarrheal disease in infants and young animals. Virions consist of a core containing the dsRNA genome, and inner and outer capsids exhibiting icosahedral symmetry. In the early days of rotavirus investigations, it was found that analysis of rotaviral dsRNA by polyacrylamide gel electrophoresis (PAGE) produced characteristic migration patterns of the 11 genome segments. These patterns, which were easy to demonstrate and were reproducible for individual samples, were called "electropherotypes". Because at the time (mid 1970s) cultivation and serotyping of rota viruses was so difficult, it was quickly realized that electropherotyping was very useful for strain identification in the laboratory, although the technique was regarded as rather specialized. Neverthless, in a series of visionary papers, Romilio Espejo [3-6] suggested that it "could become a routine diagnostic procedure". At the time, this appeared very
88
1. H. Holmes
optImIstIc, but as a result of various improvements of the technique, the prophecy has been adequately fulfilled. Initially, the methods employed for RNA extraction were somewhat complex and involved either partial purification of the virus, or of the viral RNA, or both [13,26]. Espejo et al. [3J estimated that to produce a visible pattern using ethidium bromide staining of the RNA bands required a stool sample of 1-2 g, containing about 10 10 rotavirus particles, and many samples were not adequate for this purpose. However, in the early 1980s and using the original methods, it was still possible to carry out the first large scale epidemiologi
Data Loading...
