Plasmodium berghei

Plasmodium berghei is a single-celled parasite causing rodent malaria. It is in the Plasmodium subgenus Vinckeia. Originally, isolated from thicket rats in Central Africa, P. berghei is one of four Plasmodium species that have been described in African murine rodents, the others being P. chabaudi, P. vinckei, and P. yoelii. Due to its ability to infect rodents and relative ease of genetic engineering, P. berghei is a popular model organism for the study of human malaria. Like all malaria parasites of mammals, including the four human malaria parasites, P. berghei is transmitted by Anopheles mosquitoes and it infects the liver after being injected into the bloodstream by a bite of an infected female mosquito. After a short period (a few days) of development and multiplication, these parasites leave the liver and invade erythrocytes (red blood cells). The multiplication of the parasite in the blood causes the pathology such as anaemia and damage of essential organs of the host such as lungs, liver, spleen. P. berghei infections may also affect the brain and can be the cause of cerebral complications in laboratory mice (cerebral murine malaria, CMM). These symptoms are to a certain degree comparable to symptoms of cerebral malaria in patients infected with the human malaria parasite Plasmodium falciparum. Although sexuality is necessary in vivo in P. berghei as normal for most sexual organisms, it is a stark competitive disadvantage in vitro. Sinha et al., 2014 implement both mechanical passaging and competitive assay to demonstrate the advantage of loss of gametocyte production: During mechanical passage successive generations are found to naturally trend toward lower gametocytaemia; and nonsexuals outcompete sexuals rapidly when placed together in vitro. Endothelin 1 has an uncertain role in producing cerebral murine malaria. Martins et al., 2016 find blockade of endothelin-1 prevents CMM and its symptoms and supplementation helps to produce it. Subramaniam et al., 2015 find mice increase production of BTNL2 during infection and so it is probably protective.