Parasitology 8/25/17. Definitions

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1 Parasitology 8/25/17 Definitions Definitive Host: the host in which the parasite achieves sexual maturity. Sexual recombination occurs in the parasite egg production. Intermediate Host: a host in which a parasite develops to some extent but not to sexual maturity. Asexual reproduction of parasite occurs. No egg production. Ex: One egg could produce thousands of propagules. (Muskrats) Peter Pan (1901) Paratenic (Transport) Host: a host in which the parasite survives without undergoing further development. Transportation device. Stasis: static. No development. Reservoir Host: an animal other than a human or domestic or species of interest which serves as a host for a parasite that can also infect domestic animals or humans. Population of organisms that harbor parasites in the wild that then can transfer the parasite to other organisms (Vampire Bat) Zoonosis: a disease of animals (wild animals) that is transmissible to humans or domestic animals Epidemiology: The study of the distribution, dynamics, and determinants of disease in human and/or animal populations. Vector: the means of transmission of a disease organism from one host to another. Ex:Mechanical wind, water, sputum Direct Life Cycle: (Monoxenous) living within or on a single host during the parasite s life-cycle Indirect Life Cycle: (Heteroxenous) living within or on more than one host during the parasite s life-cycle Sylvatic cycle: one that occurs in nature Domestic cycle: one that is human oriented.

2 Parasitology 8/28/17 Sylvatic: lifecycle in the forest. Has a lifecycle in the wild Domestic cycle: domestic hosts. Potential human hosts o Ex. Cat, dog, human, cow. Parasitology is complex. The History Classification Home Remedies ASP.unl.edu medical parasitology o People identified parasites coming out of themselves o Story from Prof. Gardner Raw warthog meat Bidler dies from eating raw meat you need to cook meat. o Parasites date all the way back to the beginning of mammals Can you eat it? Y/N? edible Can it eat you? Y/N? dangerous Taxonomy: naming of things in categories. Science of naming. o Linnaeus (1758) in Sweden o Binomial Nomenclature Linnaeus tried to base this classification on God s natural system led to evolution theory (good to use at parties for icebreaker or compatibility test) The Nature of Diversity o Dan Brooks o University of Chicago o Phylogeny trees apamorphies, synapamorphies. Host switching. 1. Phylogenetic Trees are necessary but rarely sufficient for explaining evolutionary origins and diversification. 2. We as scientists are always responsible for developing well formulated questions. 3. We as scientists are always responsible for the quality of data at any level in our analysis. 2

3 a. All things that are living right now are at the same level of evolution because none have gone extinct yet. 4. Everything we learn involves more cycles of discovery and evaluation. Human s understanding we are not alone Studies of local faunas (animals) Non-formal explanations of diversity o Tribe in New Guinea had named 137 species. Ornithologist came in with 138 species after studying for a few weeks. o Alaska Brooks Range, Eskimo were migratory/nomadic. Late 1940s to 1950, they stopped migrating because of post office. Only named species they used. Hippocrates B.C. wrote down all species he saw Aristotle 322 B.C. animals may be characterized according to their way of living, behaviors, and body parts. (morphology, ecology). o Recognized birds, fish, whales, insects o Thought spontaneous generation occurred. Chinese 4700 B.C. Parasitology 8/30/17 Chinese knew that spontaneous generation did not occur 4700 B.C. Jeanne-Baptiste LaMarck (1829 death) Came up with the first full blown theory of evolution o Organisms go through time and give rise to other organisms who have changed a little bit o Mechanism was inheritance of acquired characteristics o Now we know that some microbes can do some of that ^ but it is not common Darwin 1860 voyage o Natural selection o Had Mendel s papers, read about genetics, didn t make connection 3

4 o Was a religious person and took a long time to publish paper Monks Mendel. Genes segregate, genetics, gene frequency. o Looked at peas Alfred Russel Wallace Malaysia (Malay Archipelago) o Collected many, many species on expeditions. Ship burned down o Plasmodia Wallace got malaria from mosquito o Came up with evolution by natural selection and sent letter to Darwin Classification by KPCOFGS Kingdom o Phylum Class Order o Family Genus Species o Population biology Speciation Event mutation or natural disaster/event - Phylogenetic species concept is the one that we will use: all of the species we will work with originated from a single species Kingdom Protista (protozoa pre animals) Phylum: Flagellata (Mastigophora) o Plant parasites crithidia Class: Kinetoplastida (those that occur in mammals) flagellum, undulating membrane, kinetoplast Family: Trypanosomatidae (Trypanosomes) [insect vectors] 4

5 o Salivarian (anterior) - transmitted via saliva of the insect host (tsetse flies). Order: Diptera. Genus: Glossina only transmitted by this genus. o Stercorarian (posterior) transmitted via fecal deposition (kissing bugs or true bugs). Order: Hemiptera. Flies have 6 legs. Halteres are there for balance (gyroscopes). One pair of wings. Trypanosomes Middle portion of Africa British colonialists moved people around and spread the disease south and east. Tsetse flies Glossina bites infected mammal (picture of fly biting rhinoceros) Up to 5 mammal species blood can be in the Glossina at a time. o Use barrels of oil on legs to capture the excessive amounts of flies o Mammals are usually wild ruminants o Trypanosomes locate in posterior gut of fly While dividing trypomastigotes (don t have any flagella) o Move to salivary glands o Transmitted into a mammal (potentially human 4 weeks to 4 months until death once infected). Other mammals can be reservoir hosts because they evolved with their parasites. The reservoir hosts are what causes this to continue. o Parasite goes into the blood and multiplies. Gets into lymphatic system and multiplies. Gets into brain and spinal system sleeping sickness die o Bruce they know that flies will attack if they go to this certain area. Took horses in and didn t let flies feed on them they lived. Took horses in and didn t let them eat the grass but did let the flies feed on them they died. Trypanosoma brucei Man vs. Tetse by McKelvy about sleeping sickness in Africa. 5