What type of virus is poliovirus?
Polio. Poliovirus is an RNA virus that in 90% of individuals is entirely asymptomatic. In fewer than 1% of cases, however, the virus enters the central nervous system, preferentially infecting and destroying motor neurons, leading to muscle weakness and acute flaccid paralysis.
How does the polio virus reproduce?
Poliovirus infection occurs by the fecal-oral route, when the host ingests the virus, which replicates in the alimentary tract. The virus is then shed in the feces. Most polio infections are asymptomatic. In about 5 percent of cases, the virus replicates in other tissues.
What type of cell does polio infect?
In the event that polio infects CNS cells, it can then replicate in motor neurons in the anteriror horn and the brain stem. The damage caused by this can result in nervous cell and tissue destruction, leading to the symptoms of paralysis in polio victims (17).
What is the life cycle of the polio virus?
The replication cycle of poliovirus is initiated by binding to the cell surface receptor CD155 (1). The virion is taken up via endocytosis, and the viral RNA is released (2). Translation of the viral RNA occurs by an IRES-mediated mechanism (3). The polyprotein is cleaved, yielding mature viral proteins (4).
What is the host of polio?
Poliovirus, a human enterovirus that belongs to the family Picornaviridae, is the causative agent of poliomyelitis. Humans are the only natural hosts of poliovirus.
What’s the difference between a lytic and a lysogenic cell cycle?
In the lysogenic cell cycle, viral DNA or RNA makes a long term relationship with the host cell. Thus, this is also a difference between lytic and lysogenic cycle. Unlike in the lysogenic cycle, viruses produce progeny phases in the lytic cycle. On the other hand, ‘prophage’ can only be seen in the lysogenic cycle.
When does the lytic-lysogeny decision take place?
Lower levels of CII, by contrast, allow CI production and a resulting tripping of the switch to a lysogenic cycle. The actual lytic-lysogeny decision is made quite far into the lambda infection, though, occurring after about 10 min under typical laboratory growth conditions.
How does polio get into the human body?
Poliovirus only infects people. It enters the body through the mouth and spreads through: Contact with the feces (poop) of an infected person. Droplets from a sneeze or cough of an infected person (less common). You can get infected with poliovirus if: You have feces on your hands, and you touch your mouth.
What happens to a virus during a lytic cycle?
The viruses that show lytic cycle, first enter a cell, replicate and then cause the cell to burst releasing new viruses. What happens here is, the virus injects its nucleic acids (DNA or RNA) into the host cell and next that particular gene takes over the metabolic activities of the host cell.