Susan Perkins | |
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| Website | https://www.susanperkins.net/  |
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| Fields | Biology, microbiology, genomics, parasite |
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Susan L. Perkins is an American microbiologist and the Martin and Michele Cohen Dean of Science at The City College of New York (CCNY). Her expertise includes the pathology and genetics of malaria parasites and other haemosporidians infecting myriad non-primate species. [1]
Perkins obtained her BA degree in Biology (minor in Chemistry), at the State University of New York at Potsdam in 1993, and graduated with her PhD in biology at the University of Vermont in 2000. [1] [2] In 2018 Perkins was appointed President of the American Society of Parasitologists, having been vice-president since 2016. [1] [3] She served as professor of microbial genomics and curator at the American Museum of Natural History (AMNH) for 15 years before joining CCNY as dean of science in 2020. [1]
Perkins and colleague Rob DeSalle co-curated an exhibition at AMNH in 2015 entitled "The Secret World inside You". [4]
In February 2018 Perkins developed a database of PhD students, postdocs and other junior researchers for consideration as peer reviewers in ecology and evolution studies, given a lack of early-career scientists being selected for the in-demand labor. [5]
Since early in her career, Perkins has been building phylogenetic relationships of the Plasmodium malaria parasites in order to investigate the evolutionary history of the disease-causing organisms. [6] [7] This includes one of the first studies to identify the close relationship between rodent and primate malarias, the former often used in experimental research and the latter including the major human species P. falciparum . [8] Perkins' research has further expanded this analysis to include diverse species of Plasmodium from across the genus, covering less studied parasites infecting hosts such as bats and lizards. [1] By sequencing a subset of genes from the widest array of Plasmodium spp. samples at the time, Perkins' and her team found that the group is more diverse than previously thought, and that using a single generic name (that is, Plasmodium) probably isn't suitable for all the disparate lineages. [9] [10] Many of the traits seen as significant for the parasites, such as the ability to reproduce asexually in the blood cells of hosts, actually originated independently multiple times. [10]
Detailed sampling of malaria parasites in bats showed that the strains they carry are similar to those that infect other mammals, and are highly prevalent in the sampled population (about 40% of bats were infected). This suggests that bats have extreme tolerance to the infection, a feature that has been observed for other diseases and makes them potent reservoirs for cross-species (zoonotic) infection. [11] [12] The lower pathogenicity in bats may be associated with how these parasites reproduce more in the liver compared to species infecting humans. [13] Furthermore, the predicted phylogenetic trajectories suggest that the parasites jumped between different host species multiple times, including between bats and rodents. [13] [14]
Perkins' investigations into malaria species infecting lizards has revealed mechanisms of infection as well as host resistance. Perkins showed in 2000 that the malaria parasite species Plasmodium azurophilum identified in Caribbean Anolis lizards is actually two separate species; one that infects red blood cells and one that uniquely infects white blood cells. [15] Green-blooded skinks in New Guinea have characteristically green-colored blood due to high levels of biliverdin bile, which would be toxic in other species but the skinks have adapted to. This may be because it could function as anti-malarial protection, similar to the protective effect of bilirubin against human malaria, which would explain why 'green blood' may have evolved independently four times among surveyed reptiles. [16] [17] [18]
The Apicomplexa are a large phylum of mainly parasitic alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex structure. The organelle is an adaptation that the apicomplexan applies in penetration of a host cell.
Malaria is a mosquito-borne infectious disease that affects humans and other vertebrates. Human malaria causes symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. Symptoms usually begin 10 to 15 days after being bitten by an infected mosquito. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria.
Plasmodium is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of Plasmodium species involve development in a blood-feeding insect host which then injects parasites into a vertebrate host during a blood meal. Parasites grow within a vertebrate body tissue before entering the bloodstream to infect red blood cells. The ensuing destruction of host red blood cells can result in malaria. During this infection, some parasites are picked up by a blood-feeding insect, continuing the life cycle.
Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of Plasmodium that causes malaria in humans. The parasite is transmitted through the bite of a female Anopheles mosquito and causes the disease's most dangerous form, falciparum malaria. It is responsible for around 50% of all malaria cases. P. falciparum is therefore regarded as the deadliest parasite in humans. It is also associated with the development of blood cancer and is classified as a Group 2A (probable) carcinogen.
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria. Although it is less virulent than Plasmodium falciparum, the deadliest of the five human malaria parasites, P. vivax malaria infections can lead to severe disease and death, often due to splenomegaly. P. vivax is carried by the female Anopheles mosquito; the males do not bite.
Plasmodium ovale is a species of parasitic protozoon that causes tertian malaria in humans. It is one of several species of Plasmodium parasites that infect humans, including Plasmodium falciparum and Plasmodium vivax which are responsible for most cases of malaria in the world. P. ovale is rare compared to these two parasites, and substantially less dangerous than P. falciparum.
Plasmodium malariae is a parasitic protozoan that causes malaria in humans. It is one of several species of Plasmodium parasites that infect other organisms as pathogens, also including Plasmodium falciparum and Plasmodium vivax, responsible for most malarial infection. Found worldwide, it causes a so-called "benign malaria", not nearly as dangerous as that produced by P. falciparum or P. vivax. The signs include fevers that recur at approximately three-day intervals – a quartan fever or quartan malaria – longer than the two-day (tertian) intervals of the other malarial parasite.
Plasmodium knowlesi is a parasite that causes malaria in humans and other primates. It is found throughout Southeast Asia, and is the most common cause of human malaria in Malaysia. Like other Plasmodium species, P. knowlesi has a life cycle that requires infection of both a mosquito and a warm-blooded host. While the natural warm-blooded hosts of P. knowlesi are likely various Old World monkeys, humans can be infected by P. knowlesi if they are fed upon by infected mosquitoes. P. knowlesi is a eukaryote in the phylum Apicomplexa, genus Plasmodium, and subgenus Plasmodium. It is most closely related to the human parasite Plasmodium vivax as well as other Plasmodium species that infect non-human primates.
Plasmodium berghei is a single-celled parasite causing rodent malaria. It is in the Plasmodium subgenus Vinckeia.
Plasmodium chabaudi is a parasite of the genus Plasmodium subgenus Vinckeia. As in all Plasmodium species, P. chabaudi has both vertebrate and insect hosts. The vertebrate hosts for this parasite are rodents.
Plasmodium azurophilum is a species of the genus Plasmodium. Like all species in this genus it is a parasite of both vertebrates and insects. The vertebrate hosts are anole lizards.
Plasmodium floridense is a parasite of the genus Plasmodium subgenus Lacertaemoba. As in all Plasmodium species, P. floridense has both vertebrate and insect hosts. The vertebrate hosts for this parasite are lizards.
Avian malaria is a parasitic disease of birds, caused by parasite species belonging to the genera Plasmodium and Hemoproteus. The disease is transmitted by a dipteran vector including mosquitoes in the case of Plasmodium parasites and biting midges for Hemoproteus. The range of symptoms and effects of the parasite on its bird hosts is very wide, from asymptomatic cases to drastic population declines due to the disease, as is the case of the Hawaiian honeycreepers. The diversity of parasites is large, as it is estimated that there are approximately as many parasites as there are species of hosts. As research on human malaria parasites became difficult, Dr. Ross studied avian malaria parasites. Co-speciation and host switching events have contributed to the broad range of hosts that these parasites can infect, causing avian malaria to be a widespread global disease, found everywhere except Antarctica.
The history of malaria extends from its prehistoric origin as a zoonotic disease in the primates of Africa through to the 21st century. A widespread and potentially lethal human infectious disease, at its peak malaria infested every continent except Antarctica. Its prevention and treatment have been targeted in science and medicine for hundreds of years. Since the discovery of the Plasmodium parasites which cause it, research attention has focused on their biology as well as that of the mosquitoes which transmit the parasites.
Nycteria is a genus of protozoan parasites that belong to the phylum Apicomplexa. It is composed of vector-borne haemosporidian parasites that infect a wide range of mammals such as primates, rodents and bats. Its vertebrate hosts are bats. First described by Garnham and Heisch in 1953, Nycteria is mostly found in bat species where it feeds off the blood of their hosts and causes disease. Within the host, Nycteria develops into peculiar lobulated schizonts in parenchyma cells of the liver, similarly to the stages of Plasmodium falciparum in the liver. The vector of Nycteria has been hard to acquire and identify. Because of this, the life cycle of Nycteria still remains unknown and understudied. It has been suggested that this vector could be an arthropod other than a mosquito or the vector of most haemosporidian parasites.
Haemoproteus columbae is a species of blood parasite related to Plasmodium and other malaria parasites.
The mainstay of malaria diagnosis has been the microscopic examination of blood, utilizing blood films. Although blood is the sample most frequently used to make a diagnosis, both saliva and urine have been investigated as alternative, less invasive specimens. More recently, modern techniques utilizing antigen tests or polymerase chain reaction have been discovered, though these are not widely implemented in malaria endemic regions. Areas that cannot afford laboratory diagnostic tests often use only a history of subjective fever as the indication to treat for malaria.
Plasmodium cynomolgi is an apicomplexan parasite that infects mosquitoes and Asian Old World monkeys. In recent years, a number of natural infections of humans have also been documented. This species has been used as a model for human Plasmodium vivax because Plasmodium cynomolgi shares the same life cycle and some important biological features with P. vivax.
Irène Landau is a French parasitologist and professor emeritus at the National Museum of Natural History, France (MNHN) and Centre national de la recherche scientifique.
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