Microbiology Exam 1 Material

Microbiology Exam 1 Material - Microbiology Exam 1...

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Unformatted text preview: Microbiology Exam 1 Material Parasitology ­ Protozoa Single cell organism (Eurkaryotes), No eggs (reproduce by fission) Can either Incyst or Excyst Transmission: fecal ­oral route, insect vector, direct contact Vector ­ carrier of the disease Fomite: harbors organism Immune Response to Parasites IgA response in intestines Eosinophils provide primary protection after migration Sarcodina (Amoeba) Cysts ­ protective coating around trophozoite; dormant stage Trophozoite ­ active and feeding stage Opportunistic Amoebas Naegleria spp (Naegleria fowleri) “Brain eating amoeba” Causes Meningoencephalitis Get from swimming or splashing in warm bodies of standing water Acanthamoeba Slow chronic infections Causes Corneal ulceration leading to blindness Parasitic Amoeba Entamoeba histolytica Causes Ameobiasis and Amoebic dysentery Ameobiasis is the most cosmopolitan parasitic disease Infects liver Obtain through fecal ­oral route prevent by making sure water is treated Mastigophora: Flagellates Trichomonas vaginalis STD or urogenital disease Can get through Fomites, such as used towels We have no immune response to Never in cyst form, only trophozoite Giardia Lamblia Trophozoite Most common contaminant of U.S. drinking water (cyst is resistant to chlorine) Beavers are main carriers Giardiasis (Beaver Fever) ­ diarrhea, flatulence, anorexia, epigastric tenderness, fatty stools, malabsorption Hemoflagellates ­Trypanosomes live in blood between cells Trypanosoma brucei gambiense Causes Classic African sleeping sickness (febrile attacks, also a long neurological stage of 7 ­8 years) vector: Tsetse fly Trypanosoma brucei rhodesiense more virulent form of Trypanosomiasis (person can die within a year) vector: Tsetse fly Trypanosoma cruzi Causes: Chagas disease (aka American Trypanosomiasis) Vector: Reduviid bug (aka Kissing bug) IgM levels rise Difference between African & American sleeping sickness involves the effects on the heart Leishmania spp. Vector: Sand fly Sporozoa Plasmodium (Malaria) Vector: female mosquitos Sporozoite goes to the liver and gets into the blood Plasmodium vivax (Most common form) Invades reticulocytes (immature RBC’s) Defense: IgG antibodies Can relapse because it hides out in liver Plasmodium ovale (mild form) Targets reticulocytes Plasmodium malariae Targets mature, senescent RBC’s Plasmodium falciparum Severe malaria, aka Blackwater fever due to blood in urine (Hemoglobinuria) Effects all stages of RBC’s Toxoplasma gondii Definitive host ­ sexual replication takes place in, “True spreader” Definitive host is the domestic cat Toxoplasmosis ­ crosses placenta making fetus susceptible Toxoplasmosis severly effects AIDS and immunosuppressed patients Auther Ashe ­ Had AIDS and toxoplasmosis in brain Trematodes (flukes) Hermaphroditic (except for Schitisomes) st nd Miracidim ­ 1 stage, “egg case” leaves human host Cercariae ­2 stage, larva st nd 1 host ­ snail 2 host ­ fish or another intermediate host Cercaria can penetrate directly through skin or enter insect, fish or other intermediate host can also attach to vegetation (bamboo, watercrest, etc) Opisthorchis sinosis Chinese liver fluke, aka liver fluke lives in human biliary track Ingestion of raw fish Fasciolopsis buski Giant intestinal fluke Ingestion of freshwater vegetation Paragonimus westermani Lung fluke Adult flukes are reddish brown, sputum is rusty colored, when coughed up can get misdiagnosed as TB Cycle ­ can get coughed up, swallowed then shed in feces Ingestion of crab and crayfish Schistosomes Blood flukes Distinctly male and female, male carries female through life in his ventral groove Can penetrate skin ­ infection is not due to digestion “male menstruation” Schistosoma mansoni Cover themselves with a blood protein to go undetected but Eosinophils do recognize found in Inferior Mesenteric Vein Intestinal absess & disentary is result of infection Schistosoma japonicum Oriental blood fluke found in Superior Mesenteric Vein Can cause Portal Hypertension Schistosoma haematobium Found in venous plexuses that supply the bladder, prostate and urinary tract Non ­human pathogenic schistosomes Schistosomal dermatitis, “swimmers itch”, caused by penetration of the skin cecaria of the schistosome infect waterfowl (ducks, geese, etc) Cestodes ( Cestoda or Tapeworm) Do not have a digestive system ­ have to live off of ours Scolex ­ attachment organ If any part of the scolex remains the strobila will regrow Taenia solium Pork tapeworm intestinal obstruction can occur after the ingestion of the Cystercerus (aka bladderworm) Cysticercosis is the second stage of Taenia solium get by eating undercooked pork, flash freezing kills the bladderworm Eggs are infective Taenia saginata Beef tape worm get by eating undercooked beef Heavy infestation in areas of poor sanitation causes intestinal infection Echinococcus granulosus minute tapeworm man becomes the intermediate host causes Hydatid disease Adult form lives in canines Hymenolepsis nana Dwarf tapeworm get from mice or grain beetles Can set up a successive life cycle in host’s intestines= egg ­adult ­egg ­adult defense response: IgA Diphyllobothrium latum Broad fish tapeworm, can shed a lot of eggs each day get from improperly cooked fish causes normochromatic macrocytic anemia due to parasite absorbing B12 Nematodes Roundworm Has a complete digestive tract, not dependent on ours sexes are separate covered in a tough protective coating Ascaris lumbriocoides Large intestinal roundworm Due to POOR sanitation parasite can go to the lung and then back to the intestines Mature into adults in the intestines Enterobius vermicularis Pin Worm Common in the US Most commonly found in areas of HIGH sanitation Anal itching (Can spread by children’s fingers) Due to migration of the female Strongyloides stercoralis Threadworm Filariform ­ infectous, penetrates skin Rhabditiform ­ non ­infectous larva can exist outside the body cycle= egg – rhabditiform – filariform  ­ intestinal tract  ­ penetrates intestinal tract  ­ spreads in host Hookworms 2 species are human pathogens Ancylostoma duodenale Old world hookworm Sucks more blood Can cause microcytic hypochromic anemia ­ loss of Fe causing Fe anemia which in turn causes small RBC’s Also causes nutritional deficiencies leading to emaciation, mental retardation and physical retardation Necator americanus New world hookworm Causes “Ground itch” Filariform penetrates skin Southern US Cutaneous larva migrants Others Dog hookworms penetrate skin and causes intense itching at site Trichuris tichiura Whip worm Trichinella spiralis Host ­ swine No eggs are produced ­live birth Tissue phase of cycle is clinically important ­infests muscle Filariae Thread like nematodes Can block lymphatics give birth to microfilariae Wuchereria bancrofti Vector ­ mosquito worms mate and produce microfilariae Causes: Filariasis, Elephantoid fever and Elephatiasis (clogged lymphatics) Loa Loa African Eye worm Vector ­ Mango fly gets in eye and bridge of nose Most irritating when crossing conjunctiva Onchocerca volvulus Causes River blindness Vector: black fly or buffalo gnat occurs by fast flowing rivers Dracunulus medinensis The Guinea worm Not a true filarial removed by turning it on a stick and slowly removing over time ...
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