Final Flashcards
Which parasites are blood flagellates and what are their area of preference?
-T. cruzi (heart)
-T. brucei(CNS)
-Leishmania(liver/spleen, skin, bone marrow)
Which parasites are organ flagellates?
-Giardia(intestine)
Trichomonas( reproductive track)
which parasites are apicomplexans?
-Toxo(CNS)
-Crypto(intestine)
-Plasmodium(Blood/liver)
Platyhelminthes(flatworms)
-Trematodes(have no segments)
Include: schisto and fasciola
-cestodes(have segments)
Include: tapeworms
Nematodes (roundworms)
-ascarids
include: lumbricoides
-Hookworms
what species causes Giardia giardiasis?
G. lamblia
what disease is caused by G. lamblia?
-Causes a diarrheal disease known as beaver fever
-Giardiasis
what two forms does Giardia have?
-cysts and trophozoites
-cysts are the infective stage
-trophozoites destroyed in GI tract
What are some characteristics of Giardia?
-intestinal flagellate protozoan
-trophozoites:
-has 4 flagellas
-has 2 diploid nuclei
-Cyst form contains two trophozoites
-anaerobic
-no mitochondria
-has hydrogenosomes for metabolism
what is the life cycle of Giardia?
-cysts ingested along with feces contaminated food and water
-trophozoites emerge in small intestine
-trophozoites subside on surface of vili
-trophozoites replicate via binary fission
-trophozoites encyst in small intestine
-cysts pass with feces
what is the treatment for giardiasis?
metronidazole and tinidazole
How does metronidazole work?
inhibits anaerobic metabolism
What are the symptoms present for giardiasis?
-foul smelling with flatulence
-diarrhea
-stomach cramping
-weight loss
-bloating
-malabsorption
how can Giardia be diagnosed?
-with a stool sample to check for presence of trophozoites or cysts
- PCR for presence of parasite DNA
-Antigen Test (ELISA)
Trichomonas vaginalis characteristics
-sexually transmitted
-trophozoite form but no cysts
-has hydrogenosomes for metabolism
-aerotolerant microaerophilic
-women tend to be symptomatic
-men tend to be asymptomatic
-carry TVV virus which increases the risk of cervical cancer
what is the treatment for trichomonas vaginalis?
-metronidazole and tinidazole for regular strains
-resistant strain treated with paromomycin and tinidazole `
How do neutrophils kill Tv?
By chomping on it
what kind of immune response do protozoans have?
Mostly TH1
what is the incubation time for T. vaginalis?
between 5-28 days
What are symptoms for women with T. Vaginalis?
- purulent discharge
- vulvar and cervical discharge (strawberry cervix)
-dyspareunia—-> pain during intercourse
-dysuria—-> pain during urination
-abdominal pain
-vaginal itching
What are symptoms of males with T. Vaginalis?
-urethritis
-prostatitis
-epididymitis
How can T. Vaginalis be diagnosed?
-microscopy: wet sample required
-IFA
-Antigen test
- no PCR
What is a similarity and a difference between Giardia and T. Vaginalis?
-They both produce hydrogenosomes for metabolism
- Giardia has two forms cyst and Trophozoites meanwhile T. Vaginalis only has the form of Trophozoites but doesn’t form cysts
what are characteristics of nematodes?
-they are not segmented
-have an anterior mouth
-have a full digestive tract
-have a body cavity (pseudocoelom)
- longitudinal muscles which allows for a thrashing/whiplike movement
-dioecious (two separate sexes)
What are characteristics of cestodes?
-have segments
-have no body cavity (acoelomate)
-have an anterior holdfast organ called a scolex
-take up nutrients through teguments
flattened to facilitate tissue perfusion
-are hermaphroditic
which are cestodes of human importance?
-T. saginata
-T. solium
-E. granulosus
-cysticercosis
What are characteristics or trematodes?
-dont have body cavity
- flattened leaf or oval shape
-dorsoventrally flattened
-have oral and ventral suckers
-blind sac like gut
-most are hermaphroditic except for S. Mansoni
-are visceral flukes
-Include: fasciola and schistosome
guardia trophozoites are
genetically diploid
the clinical progression of giardiasis can be influenced by
-the nutritional state of the patient
-the resident microbiota found in the intestine of the patient
-the strain of the parasite infecting the patient
the most frequent presentation in Male patients infected with T. vaginalis is
-prostatitis
if you analyze the intestinal biopsy of a patient with giardiasis, you expect
-flattening of the intestinal microvilli and reduced absorptive area
Giardia lamblia trophozoites are the infective form of the parasite
Fale; cysts
Trichomonas vaginalis can produce cysts in patients with repeated infections
False; they do not produce cysts
What is the life cycle of digenean trematodes?
- metacercaria develops into adults in definitive host
- adults release eggs which turn into miracidium
- miracidium penetrates intermediate host(snail)
- miracidium turn into sporocysts
- sporocysts develop into rediae
- cercaria emerge from snail
- fully developed encysted cercavia is infective to definitive host
what are the three types of schistosomes?
S. mansoni, S. japonicum, S. haematobium
what are the differences between male and female schistosomes?
-male are bigger and have a ventral fold called gynaecophoric canal
-males have 5-9 testes
-females are longer and slender and have a single ovary that varies in position based on the species
What are characteristics of schistosoma?
-they are blood flukes
-they have sexual dimorphism
-male and female stay together
-there are three types
what us the life cycle of schistosoma?
- eggs pass with feces or urine
- eggs hatch and release miracidia in freshwater
- miracidia penetrates snail tissue
- sporocysts develop in the snail
- cercaria emerge from the snail
- cercaria penetrates the skin
- cercaria loses its tail during penetration
- circulation
- migration through the portal blood in the liver where it matures into adult
Schistosoma egg
-different morphologies for each species
-mansoni has a lateral spike
-they are non operculated
-only one third of eggs make it to the exterior
-eggs have to pass through the venue endothelium and transverse tissues to make it to lumen or bladder to escape
-eggs release hydrolytic enzymes to enter organ cavities
-immune response facilitates passing of eggs through blood stream into lumen
Schistosomula
-mechanism of transmission is transdermal
-appear in pulmonary capillaries after third day of penetration
-on the fourth day they start feeding on erythrocytes
-after a week move through the pulmonary vein into the left side of heart and then to systemic circulation
-three weeks after reach hepatic portal veins where they reach maturity and mate
what kind of response is produced against schistosoma?
TH1 and the TH2 as IL-10 levels increase due to presence of adults and females depositing eggs
What causes the the acute or katayama syndrome?
-immune response due migration of schistosomulas, worm maturation, or egg production, antigens produced by eggs
what causes the chronic phase of schistosomiasis?
-caused by granulomatous inflammatory response due to eggs being deposited in different organs or tissues
What are symptoms of intestinal schistosomiasis?
-abdominal pain
-diarrhea
-blood in the stool
- enlargement of spleen and liver
-eosinophilia
-fever
what are symptoms of urogenital schistosomiasis?
-haematuria(blood in urine)
-pain during intercourse
-vaginal bleeding
-nodules in the vulva
-can cause infertility and ectopic pregnancies
How can schistosomiasis be diagnosed?
-stool sample or urine sample for detection of eggs
-kato katz for intestinal
-antigen and antibody detection
What is not a form of transmission for helminths?
- transplacental (mother to child)
How is fascioliasis acquired?
Through the consumption raw vegetables
True or false; fasciola egg is operculated
True
What is the life cycle of fasciola hepatica?
- metacercaria is ingested along with watercress
- metacercaria hatches in the small intestine
- larva penetrates small intestine and enters liver
- adult lives in bile duct and other
5.eggs pass through small intestine and leave with feces - eggs incubate and hatch in freshwater
- miracidium penetrates snail
- cercaria exits snail
- encysted cercaria develops into metacercaria
- metacercaria in watercress
Fascioliasis pathogenesis
-immature worms feed on liver parenchymal meanwhile adults feed on epithelial cells lining bile duct
- juveniles burrow throw liver creating tunnels in which eggs and waste can be deposited
-migration of flukes cause tissue destruction and inflammatory response
what symptoms are present in the acute phase of fascioliasis?
-headache
-fever
-abdominal pain
-upper right quadrant pain
-myalgia(pain in muscle)
-urticaria(itching due to increase in eosinophils)
-enlarged liver due to heavy infection
What symptoms are present in the chronic phase of fascioliasis?
-obstruction of bile ducts and gallbladder damage
How can fascioliasis be diagnosed?
-pcr
-kato katz
-detection of eggs in stool
-detection of eosinophilia
-ultrasound, CT scan, MRI
what do microtriches do?
-they increase surface area for nutrient absorption
What is the characteristic of a cestode egg?
-they have an oncosphere followed by the inner envelope and then embryophore
-has a larva inside that will penetrate intestinal wall of intermediate host
-ocosphere has 4 pairs of hooks
what do the definitive host harbor for cestodes?
the adult worm
What do the intermediate host harbor for cestodes?
-the tissue cyst
how do humans acquire an infection caused by cestode?
fecal-oral contamination with egg
-ingestion of cysts in undercooked meats
What is the life cycle of cestodes?
- egg
- coracidium
3.procercoid
4.plerocercoid - adult cestode
What are symptoms of diphyllobothrium latum?
-weakness
-nausea
-diarrhea
-anemia due to vitamin B12 deficiency caused by parasite absorbing it all
-eosinophilia
What is sparganosis?
disease associated with larval and juvenile of any form of diphyllobothrium tapeworms
-humans cannot be definitive host
-caused by copepods in drinking water or accidentally ingesting egg
-also caused by undercooked amphibians, reptiles, birds, mammals
