BIOS385 CLASS NOTES; JBM-SPRING 2016. Book: Foundations of Parasitology 9 th Edition lamarck.unl.edu/parasitology-unl/ 13/I/2016 Lamarck: first person to develop a full theory of evolution (before Darwin*) inheritance of characters -was wrong Alfred Russel Wallace: was scooped by Darwin -sent Darwin message that proposed Natural Selection -Zoogeographic region: -Holarctic: Nearctic (New World), Palearctic (Old World: Europa and Asia) -Neotropic; Ethiopian or Afrotropical, Oceania, Oriental (Malagasy, Indo-Malaysian) Ross: figured out life cycle of malaria Parasitism: an intimate symbiotic association parasite lives closely with host and causes the host some degree/level of harm Symbiosis: living together (2 different species) Phoresis: symbiosis in which one organism is carried around by its host phoretic transfer -Ex: Bot flies Mutualism: symbiosis where both partners benefit -Ex: Termites, ruminants Commensalism: symbiosis where one organism benefits but does not benefit/harm their host Ectoparasite: outside of host infests host Endoparasite: inside of host infects host Obligatory parasite: must parasitize host in order to survive -cannot live without host Facultative parasite: can be free-living or can parasitize -Ex: Neglaria falleri amoeba that kills people if they are inhaled (dirty water in TX) Accidental parasitism: parasites transferring to wrong host -Ex: animal consumes an infected host; cross-contamination Temporary parasite: micro-predator Hyper-parasite: parasite that parasitizes another parasite -protozoan of nematode that causes blackhead in chickens and turkeys (Histomonus meleagris) Bot Fly: cutaneous parasite ; endo-ecto parasite Parasitoid: intermediate between parasite/predator; only kills one host (single event) -Ex: Hymenopterans (wasp lays egg in arthropod)
Definitive host: where sexual reproduction occurs Intermediate host: where asexual reproduction occurs -amplification stage of life cycle Paratenic host: transport host -no development occurs but maintains infection -Ex: copepods Reservoir host: parasite population maintained in a population of animals Zoonosis: disease of wild animals that can be transferred to humans 15/I/2016 Ticks: Hypostome exposed Mites: Hypostome not exposed Example of zoonosis: Echinococcus spp. Fox Vole Fox (or Fox Human--asexual reproduction) -West Nile Virus in wild bird populations Epidemiology Vector: transfers infection/disease (parasite); transfers parasites between/among hosts -no amplification of parasite within the vector direct transfer -Ex: ticks, mosquitos, water, Stomoxys spp. (face flies of cows) Direct life cycle: use only one host to complete life cycle -monozenous: using a single host Indirect life cycle: use more than one host to complete life cycle -heterozenous: using more than one host (all trematodes) Sylvatic life cycle: in sylvatic areas without/not among people; lifecycle in natural settings Domestic life cycle: in domestic areas that include people/people s influence Parasitology: study of parasites and parasitism Good book: Bjorn Kurten, Dance of the Tiger and Single Tusk -interactions of Homo sapiens and Homo neandertalensis Trichenilla spiralis-nemas that end up encysting in tongue/abdomen and kills humans Taxonomy: the science of scientific naming of biological entities -established by Linnaeus (1758, Sistema naturae)
Binomial nomenclature: method of naming -Kingdom; Phylum; Class; Order; Family; Genus; Species Systematics: science of understanding evolutionary relationships between/among organisms over time G. G. Thompson: Splendid Isolation Alexander Von Humboldt (1848): thought that the continents once fit together Alfred Wagoner (1913): proposed continental drift -Pangea (1 st continent) Laurasia (North); Gondwanaland (South) Top of Everest: limestone with fossils on top 20/I/2016 Investigating parasitology: Guiding principles: 1.) Must use phylogenetic trees (not sufficient*) 2.) We must be responsible for well-formulated questions as scientists 3.) We are responsible for the quality of data used 4.) Formulate new questions to further scientific investigation Parasitology: when people first discovered symptoms of parasitic infection -Ex: Eskimos would eat bot fly larvae from the backs of caribou (had names) -Ex: New Guinea-had common names for birds -Binomial nomenclature was necessary Alexander Von Humboldt: spontaneous generation (discounted by Louis Pasteur) 4,700 years ago: Chinese knew that nematodes were transferred by eating rotting meat Ecological classification: FW fish vs. SW fish Teleological classification: edible vs. inedible; domestic vs. wild; etc. *No rule set in naming above family level of classification Phylum: Protozoa/Protista/Proctista: - one cell does it all -Ex: Termite protists produce cellulase to breakdown cellulose Class: Kinetoplastida -Hosts/Parasites: Intermediate host; definitive host; reservoir host; vectors Family: Trypanosomatidae -two groups of trypanosomes: (ecological classification) 1.) Salivarian: develop in the anterior end of arthropod host and are transmitted to vertebrate host via bite; African forms of Trypanosoma spp. (mostly Old World) 2.) Stercorarian: develop in the posterior end of arthropod host and are transmitted via a fecal deposit if infective stages; South American forms of Trypanosoma spp. (mostly New World)
(Pg. 66) Tsetse flies (Glossina spp.) occur in Central Africa aka Fly belt -Trypanosomiasis aka African Sleeping Sickness -Bruce: worked on problem of African Sleeping Sickness with Koch (Koch--first person to figure out phathenogenicity of bacteria parasites Typhoid fever*) -Bruce set up rigorous methods to figure out the transfer of trypanosomes from flies to animals and then to domestic animals then humans (Trypanosoma brucei) Moved horses/cows at night to fly-infested areas because flies don t bite at night -Nagana: domestic animals that are infected with trypanosomes (Nagana= Zuli word for useless/no good ) -Bruce ruled out that plants/feed were the cause; found out that/made correlation that flies were transferring trypanosomes; found them in the blood of domestic animals (Nagana); killed domestic animals -Tsetse flies (Glossina spp.): to control these flies cut down all plants/trees to eliminate Tsetse flies; created a wasteland Based on making $ by grazing cattle and exploiting the land; killed every large mammal in an entire 250mi 2 area to control/eliminate all reservoir hosts 22/I/2016 Tsetse flies (Glossina spp.): Nagana of animals; white man helped spread the Tsetse flies via colonization of Africa Two types (sub-species) of trypanosomes in Africa: 1.) Trypanosoma brucei gambiense -most common in West and Central Africa; causes sleeping sickness -Chronic form (Kills you within a few years) 2.) Trypanosoma brucei rhodesiense -most common in East and Central Africa -Acute form (Kills you within a few months) -Reservoir hosts: large mammals Other species: 3.) Trypanosoma brucei brucei (causes Nagana) 4.) Trypanosoma congolense (causes Nagana) 5.) Trypanosoma vivax (causes Nagana) 6.) Trypanosoma evansi -widespread; moved around by people; transmitted via horseflies (Tabanidae); affects domestic animals Nagana 7.) Trypanosoma equinum (South American; affects horses) 8.) Trypanosoma equiperdum (Venereal disease in horses Dourine) *V.A.T. (Variable Antigen Types) of trypanosomes in rats (T. lewisi) Pg. 68-69 *Morphology: Pg. 63-64
25/I/2016 Class: Kinetoplastida Parasites and vectors -Trypanosoma livingstoni: a new species from African bats; supports the bat seeding hypothesis for the origin of Trypanosoma cruzi in South America *Trypanosoma cruzi: Carlos Chagas (Pg. 72) How to diagnose Chagas? 1.) Xenodiagnosis: let different species of Triatoma spp. grown in cultured/sterile conditions feed on you, wait ~10 days, squish bugs, look for trypanosomes effective way to diagnose trypanosomiasis 2.) ELISA 3.) PCR CENTROP: Belgians, Santa Cruz de la Sierra W.H.O.-- $200 million into Rolling Back Chagas Reservoir hosts: mammals; bats, mice and rats (endemic), Xinarthrans (sloths, armadillos, ant-eaters), Marsupials, Carnivores Peridomestic (infectious disease) life cycle: [dogs, bats, rats] humans -occurs around human habitations (houses; human associated) - Vinchugas (Bolivian term) aka Triatoma spp. bugs; live in the thatched roof of houses Sylvatic cycle: in the woods; where there are no people (wild lands) General: Trypanosomes -occur in fish, reptiles, birds, mammals, amphibians -have no intermediate host, only vector because there is no asexual/sexual form in life cycle -splenomegaly (enlarged spleen) -megacolon (archaeoparasitological evidence) -how to treat? 1.) Chronic form: can treat over time; still kills host 2.) Acute form: kills host quickly DON T EAT BUGS 27/I/2016 Triatoma spp. + Trypanosoma spp. life cycle - Chagoma : selling that occurs on face; connective tissue swelling (amastigotes released in blood) Phylum: Protozoa Class: Kinetoplastida -two major types of transmission routes for Leishmania spp. (Pg. 80)* 1.) Blood transfusion 2.) Sand fly: vector -Old World: Phlebotomus sp. -New World: Lutzomia sp.
-lots of genetic diversity (more than expected) -can be treated with antimonial compounds applied on lesions or injected intravenously or intramuscularly secondary infections can be treated with antibiotics -Immuno-privileged sites: inside a cell; inside eyeball Old World: (vector: Phlebotomus sp. sand fly Palearctic, Ethiopian) -Leishmania tropica and L. major cause cutaneous leishmaniasis ulcers in skin -heals in 2-12 months -low numerical density in skin/body -Distribution: West Central Africa, Middle East, South West Asia, India -Diagnosis: find L-D bodies (L. donovani bodies) from a smear of the legion stained in geimsa New World: (vector: Lutzomia sp. sand fly Neotropical/Nearctic) -Leishmania braziliensis causes muco-cutaneous leishmaniasis -Sylvatic -Distribution: from Central Mexico hasta Argentina (East slopes of Andes) -L. mexicana -Distribution: Texas, Dominican Republic, Mexico, Central America -Cutaneous lesion -L-D Bodies, ELISA (detections) -ulcer appears after a few weeks and may take long period of time to heal 29/I/2016 Leishmania donovani: Old and New World in tropical areas (poverty-stricken areas) -diagnosis: ELISA or immunofluorescent antribody (I.F.A.) - transmission dynamics of leishmaniasis in the Sudan (article) Amoebas and Flagellates -Flagellates: two types 1.) Blood and Tissue 2.) Intestinal and Genital Amoebas: -Entamoeba histolytica Morphology and Diagnosis -cysts have 4 nuclei* -trophozoites: feeding/active stage of organism; clean cytoplasm (not foamy ) -find cysts and trophozoites in loose stool -find only cysts in hard stool -Small intestine: trophozoite encysts (more water) -in-between SI and LI: find uni-nucleated/bi-nucleated cysts (immature cysts) -Large intestine: mature cysts with 4 nuclei (less water) -Cysts: are susceptible to heat and hard freezes -are spherical, can stay in environment for up to one month with adequate moisture
-Trophozoites: consume mucosa and starches of intestinal tract (active stage); damage gut (epithelial lining; gut produces more mucosa) -Problems: Pathology damage; Symptoms body s signals/reactions from the pathology Entamoeba histolytica: has surface enzymes that digest/hydrolyze host epithelial lining/cells -causes flask-shaped ulcers in epithelial lining -Pathology: -Primary: intestinal lesions, mostly in descending colon -Secondary: infections of liver, lungs, spleen, pericardial lining, genitals, skin, eyes -goes through hepatic portal vein from gut to liver and then dispersed throughout body -Incubation period is ~4-5 days (time from initial infection to first symptoms) -Symptoms: -dysentery; diarrhea with blood -rectal tenesmus: feels like you have to poop ; watery stool -10% of world s population is infected; only 3% have symptoms -lots of carriers without symptoms (asymptomatic) -dangerous because it is infectious for one month -Distribution: world-wide - wherever there s poop and people; it s possible - <1% in Canada and USA - >40% in tropical areas -Flagel: three rounds of tetracycline -Prognosis: 90% chance of recovery; can cause permanent chronic bowel problems -Vectors: contaminated food, water, medical treatment; fertilizing with night soil -Eccentric nuclei (not in center) 1/II/2016 Triatoma spp. vectors for Trypanosoma cruzi and T. lewisi (Stercorarians; blood flagellates) -not equal vectors: vector competence -more exposure than infection=higher vector competence -differ in size of bloodmeal -Triatoma infestans: largest bloodmeal (higher level of vector competence) -Triatoma sordida: smallest bloodmeal (lower level of vector competence) -Hemimetabolous life cycle: no change in morphology from larva adult (egg N 1 N 5 adult) -Holometabolous life cycle: adults look different from larva (caterpillar butterfly) Genus: Iodamoeba -Iodamoeba buetschlii: only species that infects humans, other primates, and pigs -not as pathogenic as Entamoeba histolytica -sign of water contamination -has a large glycogen vacuole Order: Diplomonadida (Pg. 88) Family: Hexamitidae -endo-commensual (not pathogenic)
-divides by binary fission -morphology and life cycle stages (Pg. 89) -Genus: Giardia -Giardia duodenalis: most common flagellate of the human G.I. tract -start to encyst when they are starved of cholesterol -causes malabsorption/villi blockage of G.I. tract Trichomonas vaginalis (Pg. 94-95) -cosmopolitan (where people are) -personal hygiene plays a large role in transmission -vaginitis (inflammation) -males: discolored discharge; in urethra, seminal vesicles, prostate -females: strawberry cervix (disintegration of vaginal lining) 3.5-4.5pH in vagina; T. vaginalis raises ph to 5.5+ (better environment for a bloom) -can cause spontaneous abortions/still births; female morbidity (inflamed cervix won t dilate) -vectors: soiled linens/washcloths; sexually transmitted -reproduction: binary fission 3/II/2016 Apicomplexans: Gregarines (with thermite plasmid=apical complex) -Cyclosporidium parvum: infects/harms bovines (vacas); causes diarrhea -Milwaukee WI: 403,000 cases off crypto out of 1.6 million in 1995 epidemic (almost 1/3 of population) -Toxoplasma gondii: obligate intracellular protozoan parasite -anything warm blooded and mammal can be a possible host -congenital/cervical transmission (from mama to unborn child) can cause hydrocephalus from toxoplasmosis -infective stage has an apical complex with micromeres -manipulation hypothesis: less adverse to felids (definitive hosts of parasite) Malaria: -Family: Apicomplexa -Genus: Plasmodium -P. vivax (needs immature erythrocytes) -Hypnozotic (hide out in liver): 1.) P. falciparum (worst one to get) 2.) P. ovale 3.) P. malariae -causes cyclic fever with splenomegaly -get fever with malaria when erythrocytes burst -Hypnozoites: hide out/stay in liver and are responsible for recurring symptoms/fevers only: Plasmodium falciparum and P. malariae *Anopholes spp. mosquitos are vectors Sporozoites merozoites early/late trophozoites schizonts infect erythrocytes asexual reproduction 5/II/2016
(Malaria continued) Anopholes spp. (mosquitos; definitive host) -females bite (Pg. 145)* Sickle-cell anemia: immune to malaria (Plasmodium falciparum) -erythrocytes poor in transporting O 2 -shortened life-span -heterozygous humans maintain the trait (can reach reproductive stage) -Duffy blood-type: high resistance to malaria Mason and Ross: won the Nobel Prize working with Culex sp. -they proposed that Plasmodium spp. were the causative agent in malaria Ades egypti: yellow fever mosquito; nests in tree holes/bromeliads/tires/cans etc. 8/II/2016 Histomonas meleagridis: -Venereal disease of nematodes affects their hosts; Order: Galliformes (turkeys and chickens) -flagellated; protistan/protozoan -distribution: world wide within all galliforms (cosmopolitan) -causes blackhead in turkeys* Phylum: Microsporidia Family: Nosemidae (Apidae honey bees) -Encephalitozoan cuniculi vertebrates -E. bienuesi birds/mammals Myxozoa: probably related to Cnidarians (Pg. 180 life cycle) Family: Myxobolidae -morphologically similar to a nematocyst; functions like a nematocyst where it punctures and injects DNA into host cell -Myxobolus spp. -Host: Salmonidae; causes whirling disease Phylum: Mesozoa (parasites of marine invertebrates: Mollusca and Echinoderms) Degenerate organisms?? -Class: Dicyemida; parasitize cephalopods (kidneys) -Class: Orthonectida; parasitize echinoderms, mollusks -Orthogenesis: assumes evolution -orthogenetic evolution, Teleological (ultimate goal driven 4 phylogenetic hypotheses Speciation: species give rise to species 10/II/2016 Primary literature: published anuk puk -Ex: Parasites and Vectors (journal) Eucestoda: true cestodes Bilateria: all organisms that are bilaterally symmetrical
Ancestral vs. derived characters primitive vs. advanced Phylum: Platyhelminthes (platy=flat; helminthes=worm) 1.) Dorsoventrally flattened 2.) Usually with limited digestive system (cestodes) 3.) Size range: <1mm to >60m (whale flat worms) 4.) Bilaterally symmetrical 5.) Ciliated epithelial tissue (at least in larvae) 6.) Cephalized (ladder-type nervous system) 7.) Osmoregulatory system aka excretory system -Protonephridia=flame cells Phylum: Platyhelminthes (dorsoventrally flattened) Class: Trematoda -posterior adhesive organ (Acetabulum or ventral sucker) -Adults: have an anterior sucker followed by a pharynx -No anus but have a branched cecae -Subclass: Aspidobothria (have posterior sucker with compartments) -Subclass: Digenea (almost as diverse as nematodes) -more than one host necessary to complete lifecycle (2+) -first larval stage: miracidium (ciliated, has eyespots) one miracidium can produce 50,000+ circariae -second larval stage: sporocyst (daughter sporocyst produce rediae which produce circariae) 15/II/2016 Trematode egg production * Fasciola hepatica life cycle (Pg. 257) -Humans can get it from chewing reeds (Lake Titicaca) Yungasicola travassosi life cycle * Alaria Americana life cycle (Pg. 237) Ectolesaphil (?) eggs: yolk comes from external source (vitelline gland)