Читать книгу Principles of Virology - Jane Flint, S. Jane Flint - Страница 23

 Viruses are the most abundant entities in the biosphere. The biomass on our planet of bacterial viruses alone exceeds that of all of Earth’s elephants by more than 1,000-fold. There are more than 1030 particles of bacterial viruses in the world’s oceans, enough to extend out into space for 200 million light-years if arranged head to tail (http://www.virology.ws/2009/03/20/the-abundant-and-diverse-viruses-of-the-seas/; http://www.phagehunter.org/2008/09/how-far-do-those-phages-stretch.html).

 Whales are commonly infected with a member of the virus family Caliciviridae that causes rashes, blisters, intestinal problems, and diarrhea, and that can also infect humans. Infected whales excrete more than 1013 calicivirus particles daily.

 The average human body contains approximately 1013 cells, but almost an equal number of bacteria, and as many as 100-fold more virus particles.

 With about 1016 human immunodeficiency virus type 1 (HIV-1) genomes on the planet today, it is highly probable that somewhere there exist HIV-1 genomes that are resistant to every one of the antiviral drugs that we have now or are likely to have in the future.

Viruses reside in Earth’s vast oceans and everywhere else on our planet. Courtesy of NASA’s Earth Observatory, Suomi NPP satellite image courtesy of NASA/GSFC.

Figure 1.1 The human virome. Our knowledge of the diversity of viruses that can be present in or on a normal human (including some potential pathogens) has increased greatly with the development of high-throughput sequencing techniques and new bioinformatic tools. Current estimates of the numbers of distinct viral families with DNA or RNA genomes in various sites are in parentheses; the > symbol signifies the presence of additional viruses not yet assigned to known families. The numbers may increase as diagnostic tools improve and new viral families are identified. Data from Popgeorgiev N et al. 2013. Intervirology 56:395-412; see also http://www.virology.ws/2017/03/23/the-viruses-in-your-blood/.