Parotozoa Flashcards
Realize that the protozoa can secrete a protective coat and shrink into a round armored form called a ____, which is the infective form when ingested by humans
Once ingested, it will turn back into the motile form called a ___
Cyst
Trophozoite
There are 5 intestinal protozoa, 3 are found in normal individuals are 2 are in patients with defective immune systems
In normal hosts, ___ causes bloody diarrhea
In normal hosts, ___ and ____ cause non bloody diarrhea
In immunosuppressed hosts, ___ and ___ cause severed diarrhea
Entamoeba histolytica
Giardia lamblia and Cyclospora cayetanensis
Cryptosporidium and Isospora belli
Entamoeba histolytica is asymptomatic in 90% of infected people, ESPECIALLY homosexual men
The motile feeding form (trophozoite) often contains a ___ shaped nucleus and ___ are seen in the cytoplasm
^** So if you see a trophozoite with RBCs in the cytoplasm, think this protozoa****
The trophozoite form can form a binucleated (2 nuclei) precyst and this can mature into a tetranucleated cyst that can be eaten to infect humans
E. Histolytica can invade the intestinal mucosa to cause erosions leading to bloody diarrhea and if it penetrates the portal blood circulation, one would see ___ abscesses and then if it spreads through the diaphragm ____ abscesses can also be seen
Bulls eye, RBCs
Liver, Pulmonary (lung)
Giardia lamblia has a cyst and flagellated trophozoite form that looks like a ___ and often obtained by ____ drinking from a “clear” mountain stream
Also mostly asymptomatic, but when ingested it coats the small intestinal wall and prevents intestinal ___ absorption leading to stools packed with fat and a HORRIBLE odor characterized by greasy, frothy diarrhea with abdominal gassy distention and cramps
^** NO BLOOD in diarrhea since it does NOT invade the intestinal cells, just adheres to them
Kite
Fat
____ stains with acid fast and causes watery diarrhea, nausea, and vomiting in normal hosts and is assocaited with raspberries and strawberries
___ also stains with acid fast but causes severe diarrhea in immunocompromised patients and has 8 sporozoites in it’s infective oocyst
Which one is an obligate intracellular parasite?
Which one also has eosinophilia?
Cyclospora cayetanesis
Isospora belli
Isospora belli
Isospora belli
Cryptosporidium is ingested as a round oocyst that contains ___ motile _____ and is an ____ because it’s life cycle occurs in the intestinal epithelial cells
In normal hosts, symptoms are self-limiting but in immunocompromised patients, watery diarrhea, vomiting, and abdominal pain occurs
4, Sporozoites, Obligate intracellular parasite
A patient with yellow-green malodorous, frothy vaginal discharge has been infected with ____
^** There is also often painful vaginal itching (pruritus), and burning on urination
This is a STD and there is no cyst and the trophozoite has ___, along with the other protoza that has a flagellated trophozoite called ____
Trichomonas vaginalis
flagellum, Giardia lamblia
A patient with a fever, headache, stiff neck, nausea, and vomiting would have you thinking some form of meningitis. If they tell you they went SWIMMING about a week ago in a fresh water lake (aka it is ACUTE), it is most likely a ___ infection which causes ACUTE meningoencephalitis and death within a week
^** Penetrates the nasal mucosa, pass through cribriform plate, into brain and CSF
What is found in the brain tissue for infection?
^**There is ONLY a mature amoeba (trophozoite) in the brain tissue and NO cysts/corneal infection
____ occurs in immunocompromised patients that present with CHRONIC granulomatous meningoencephalitis, amoeba AND a cyst is found in CSF of brain tissue, AND ____ infection is seen often due to poor care of contacts
^** Similar to the above protozoa, ____ also causes CHRONIC granulomatous meningoencephalitis, however it differs in the fact that it can infect BOTH immunocompromised hosts AND normal hosts AND it also differs because it can cause granulomatous ___ lesions
Both Acanthamoeba and B. Mandrillaris live in fresh water lakes
So once again, Acanthamoeba can cause chronic granulomatous brain infections and ____ infections whereas B. Mandrillaris causes chronic granulomatous brain infections and ___ infections
Naegleria fowleri
ONLY Amoebas
Acanthamoeba, corneal
Balamuthia Mandrillaris, skin
Cornea, skin
____ is often acquired from cat feces (from a litter box) and can cause either transplacental infection of the fetus in pregnant women or infect immunocompromised patients
Realize that this infection is toxic to the ___ and ____
^** So if you see a contrast enhanced mass in the brain and retinal inflammation, think this
Congenital toxoplasmosis occurs in women never exposed to the protozoa before and can cause choriorentinitis, blindness, seizures, mental retardation, microcephaly, encephalitis, and even stillbirths
Immunocompromised patients can have their brain infected which involves a ___ (looks like a tumor) leading to headache and neurological signs, along with infection in the retina (chorioretinitis) that looks like yellow-white fluffy patches around the red retina
This is an obligate intracellular parasite
** Will occur of CD4 is less than 200 in AIDS patients
Toxoplasma gondii
Brain and Eyes
Mass
Another opportunistic infection seen in AIDS patients with CD4 less than 200 is Pneumocystis carinii (aka P. Jiroveci)
In normal hosts, it lives peacefully in the lungs but in AIDS patients it can multiply and cause ____ characterized by fever, shortness of breath, nonproductive cough, and may or may not have bilateral interstitial infiltrates
^*** Realize this is now classified as a fungus, but use to be classified as a protozoan and has a ____ appearance
PCP (Pneumocystis carinni pneumonia) aka interstitial pneumonia
Flying saucer (*****THINK you got to be on PCP to think you see a Flying Saucer)
Intermittent shaking chills, fevers, and soaking sweats is commonly due to ___, which is transmitted via a female anopheles ____ and there are 5 different protozoas that cause the febrile disease
^** Also anemia, hepatomegaly, and splenomegaly can occur
Plasmodium ____ can cause post capillary venules in organs to be plugged up by the sticky RBCs leading to kidney, lung, and brain hemorrhages and blocked blood delivery
Realize that the organism grows in the liver and spreads to human RBCs where they reproduce by filling the RBCs with protozoa and bursting, and the 5 different protozoas that cause Malaria are based on the time intervals that the RBCS burst
Malaria is characterized by episodes of high fever and shaking chills and then the RBCs burst, periods of profuse sweating occurs
____ malaria bursts every 48 hour and includes Plasmodium ___ and ___
^** These two forms can live in a dormant phase in the liver called the ____ and if reactivated cause relapsing malaria
____ malaria bursts every 72 hours and includes Plasmodium ____
Plasmodium ___ bursts every 36-48 hours aka irregularly or can be continuous with less pronounced chills and sweats
Duff a and b antigens provide resistance to plasmodium ___ since it needs those to bind and sickle cell anemia trait provides resistance to plasmodium ____
Trophozoites will have a ___ shape appearance in the RBCs for malaria
Malaria, Mosquito
Falciparum
Tertian Malaria, Vivax and Ovale
Hypnozoite
Quartan Malaria, malariae
Falciparum
Vivax, falciparum
Diamond
Similar to Malaria, Babesia microti can cause anemia (hemolysis), fatigue, and fever and also similar to Malaria, the infection invades RBCs
However it is different because instead of transmission via a mosquito, it is transmitted via a ___ (the same one that spreads lyme disease so a co-infection often occurs)
Also unlike Malaria, it does NOT infect the liver (so no exo-erythrocytic phase, only an erythrocytic phase)
In the erythrocytic phase for Malaria, the trophozoite has a distinct ___ shape and in a Babesia microti infection the trophozoites have a distinct ____ shape
Tick
Diamond, cross (aka X shaped tetrad called the Maltese cross)
Leishmaniasis infections are transmitted via a ____ which carries the flagellated motile form of the disease called a ____ and once in the human it turns into a nonmotile ____ where in infects macrophages and circulates in the blood
Depending on the patients cell-mediated immune responses, determines how bad the infection is (this is similar to how ____ works)
A Leishmanin skin test can be performed similar to how the PPD is done and if patients have normal cell-mediated immunity, a DTH reaction occurs causing a + test and if no immunity, test will be -
These infections range from
1) ____ cutaneous lesions have a single ulcer at the site of the bite called an oriental sore (Leishmanin skin test is ___)
2) ____ cutaneous lesions cause nodules to form at the bite site that do NOT ulcerate and spread throughout the body (especially near the ____) aka this is a CHRONIC infection (Skin test is ___)
3) ____ leishmaniasis has a skin ulcer heal but months/years later ulcers in the nose and mouth arise (mucous membranes)
4) ____ leishmaniasis (aka Kala-azar) occurs in young, malnourished kids with fever, anorexia, weight loss, and abdominal swelling from hepatomegaly and splenomegaly since the infection occurs in the reticuloendothelial cells of the liver and spleen
Sandfly, promastigote, amastigote
Leprosy
1) Simple, +
2) Diffuse, nose, -
3) Mucocutaneous
4) Visceral
African sleeping sickness is due to African ____ that is transmitted via the ____ in its motile (flagellated) form ____
There is a West African Sickness caused by T. Gambiense and a East African Sickness caused by T. rhodesiense
Characterized by a hard, red, painful skin ulcer at site of bite and then it heals followed by fever, headache, lymphnode swelling, and CNS symptoms, etc….
A unique feature of this infection is that the fever is ____ due to the antigenic variation of the ____ proteins
^** Remember, antigenic variation leading to relapsing fever is also seen in the ____ infection
Trypanosome brucei (Rhodesiense or Gambiense), Tsetse fly, Trypomastigote
Relapsing, VSG (Variable surface glycoproteins)
Borrelia recurrentis (a spirochete)
American Trypanosome ____ is very different from the African Sleeping Sickness diseases
It is transmitted via the ____ that has its motile (flagellated) form called a ____ infecting humans and then intracellularly turns into an ____ to multiply
This causes ___ disease characterized by a hard, red area at the site of the bite infection called a ___ (similar to that seen in the African form)
There are three phases for this diseases
1) Acute Chagas disease has the chagoma, fever, malaise, swollen lymph nodes, and the heart (inflammation and tachycardia) and CNS (meningoencephalitis) occurs
2) Once it resolves, the intermediate phase occurs and patients are asymptomatic and remain in this phase for life
3) Sometimes chronic Chagas disease can occur leading to a dilated ____, ____, and ____
^** Called megadisease aka megacolon, megaesophagus, etc…
Kissing bud (aka Reduviid bug), trypomastigote, amastigote
Chagas disease, Chagoma
Heart (cardiomyopathy), colon, esophagus
