Pathogenic Protozoa: Blood and Tissue Parasites Flashcards
Four pathogenic amoebae
- Acanthamoeba spp
- Balamuthia mandrillaris
- Naegieria flowleri
- Sapphinia diploidea
List one pathogenic flagellates
Trichomonas vaginalis
List three pathogenic Apicomplexa
- Babesia spp
- Plasmodium spp
- Toxoplasma gondii
List two pathogenic trypanosomatids
- Leishmania spp
- Trypanosoma spp
Which species are known as “thorny or spiny amoeba”?
Acanthamoeba spp
Free living (out in nature) ____, many species cause human disease
- Amoebae
- Acanthamoeba spp
Acnathamoeba spp
- Incidence of ____
Acanthamoebiasis
Acanthamoeba spp is infection of what?
Cornea (keratitis)
Acanthamoeba spp
- Epidemiology and transmission
Variety of environmental habitats - Contact lens case - Soil - Fresh, brackish salt water - Sewage, swimming, medicinal pool - Plants - Human throats, nostrils Enter through inhalation, the eye, or ulcerated/broken skin
Acanthamoeba spp
- Infectious form
Both cysts and trophs
List two common infections of Acanthamoeba spp
- Eye tissue = keratitis
- Brain tissue = granulomatis amoebic encephalitis (GAE)
In encephalitis (GAE), most cases have been found in what kind of people?
Immunocompromised people
In encephalitis (GAE), ____ enters through break in skin or upper respiratory tract, migrate to CNS, causes neuronal damage and death
Trophs
Describe two types of diagnosis of Acanthamoeba spp through microscope from tissue (such as eye, brain, lesion materal)
??
Acanthamoeba spp
- Geographic distribution
Worldwide
Balamuthia mandrillaris is ____ amoeba
Free living but not much is known about is habitat
Balamuthia mandrillaris
- Geographic distribution
Temperate regions of globe
Balamuthia mandrillaris
- Causes what disease?
GAE
Balamuthia mandrillaris
- Incidence of ____
Balamuthiasis
Balamuthia mandrillaris
- Transmission through ____
Skin wounds or inhaling DST
Balamuthia mandrillaris
- Infectious forms
Both cysts and trophs are found in tissue (just like Acanthamoebae)
What type of people are at risk for Balamuthia mandrillaris GAE?
Cases in both immunosuppressed and immunocompetent people
Balamuthia mandrillaris
- Diagnosis
Characteristic of cysts
- Double-walled in tissue
- Troph → bulls eye nucleus
How can we distinguish Balamuthia mandrillaris from Acanthamoba since they have identical diagnosis.
Distinguish using PCR and immunofluorescence (IFA)
Where would you find Neagleria flowerleri ameobae
Free-living amoeba;
- They prefer warm water so lakes, ponds, swimming pools, air conditioner cooling towers, tap water, etc
Neagleri floweri
- Geographic distribution
Presumably worldwide
Neagleria flowerli
- Cuases ____
Primary ameobic meningoencephalitis (PAM)
Neagleria flowerli
- Infectious form
Troph
Neagleria flowleri
- Diagnosis through microscope
- Characteristic trophs in brain and CSF
- NO CYST forms in hosts
Neagleria flowleri
- Symptoms
- Acute onset of frontal headache, fever, nausea, and vomiting (phase 1)
- Stiff neck, seizures, altered mental status, coma, and death (phase 2)
- From exposure to death: 1-12 days
Which pathogenic flagellates is sexually transmitted protozoan?
Trichomonas vaginalis
This is the most common pathogenic protozoan in industrialized countries
Trichomonas vaginalis
Trichomonas vaginalis
- Incidence of ____
- Trichomoniasis
- Very common, more prevalent among people w/ multiple sex partners
Trichomonas vaginalis
- Epidemiology and transmission
- Resides in lower GU tract of females, urethra, and prostate of males
- Sexual intercourse is primary means of transmission
Trichomonas vaginalis
- Life cycle
Trophozoites are the only known form; it replicates on surfaces of tissue
Trichomonas vaginalis
- Symptoms in males
Usually asymptomatic, but can develop uretheritis, epididymitis and/or prostatitis
Trichomonas vaginalis
- Symptoms in females
- Frothy, yellow/green, foul smelling vaginal discharge
- Itching and burning especially during sex
- Vaginitis, urethritis, and cervicitis (strawberry cervix)
Trichomonas vaginalis
- Diagnosis through molecular tests
- DNA probe (e.g., BD Affrim VPIII microbial ID test)
- Nucleic acid amplification test (e.g., Gen-probe APTIMA)
Trichomonas vaginalis
- Diagnosis through microscopy
- Demonstrate motile trophs in vaginal secretion or urine
- Demonstrate trophs in stained smears
Babesia species
- List four specimens which are known human pathogens
- Theileria (Babesia) microti
- Babesia divergens
- B. ducani
- Babesia spp MO-1
Most common Babesia species which is found in the Northeast USA, Nantucket Island
Theileria (Babesia) microti
Babesia species
- Distribution
Worldwide
- Babesia divergens (mainly Europe)
- B. ducani (western USA)
- Bbesia spp MO-1 (Midwestern USA)
Babesia spp
- Incidence of ____
Babesiosis (US)
- Most cases in New England, Minnesota, and Wisconsin
Babesia spp
- Epidemiology
- Tick bites (deer tick and brown dog tick) transmit the parasite to human or mouse hosts
Babesia spp
- Host in natures
Use white footed mice and ticks as hosts
Babesia spp
- Transmission
- Transmission has also occurred through blood txns!!!! (2 cases in IN-both recipients died)
- Vertical transmission (going from mom to baby) has also occurred
Babesia spp
- Infectious form
Merozoite form (maltese cross)
Babesia spp
- Symptoms
- Most are asymptomatic
- Having no spleen makes a person more prone to severe or fatal disease
Babesia spp
- Diagnosis through microscope
- Examination of a Giemsa or Wright-Giemsa stained blood smear
- Presence of ring form and characteristic merozoite in and outside of red cells (multiple rings and merozoites per cell)
Babesia spp
- Two other methods used in diagnosis
- IFA: for detection of Abs to Babesia spp
- Molecular method: real-time PCR for species which can speciate the organisms
How can we distinguish Babesia spp from Plasmodium spp?
- Clinical and travel histories
- Babesia produces racket-shaped merozoites
- Rings and merozoite are only seen in babesiosis
- Extracellular parasites seen in babesiosis
Plasmodium spp
- Causative agents of _____
Malaria
Plasmodium spp
- ____ borne protozoa
Mosquito
List five different species fo Plasmodium that are known to cause malaria in humans
- P. falciparum
- P. malariae
- P. ovale
- P. vivax
- P. knowlesi (first four most common)
Plasmodium spp
- Distribution
Tropical and subtropical regions - mostly in Africa
Plasmodium spp
- Complete life cycle requires two hosts: ____ and ____
Mosquitos; humans
Plasmodium spp
- What type of mosquitoes are found?
Anopheles spp
Plasmodium falciparum
- Epidemiology and incidence
- Widespread, globally
- Predominant cause
Plasmodium malariae
- Epidemiology and incidence
- Widespread, globally
- Less frequently seen causes
Plasmodium ovale
- Epidemiology and incidence
Predominantely in sub-Saharan Africa, other areas also
Plasmodium vivax
- Epidemiology and incidence
- Wider range than P. ovale, and their niches overlap
- Second most predominant cause
Plasmodium knowlesi
- Epidemiology and incidence
Southeast Asia; very rare cause
Plasmodium spp
- Two types of cycles
- Exo-erthryocytic (occurs in liver)
- Erythrocytic
Plasmodium spp
- Important notes above P. ovale and P. vivax in life cycle
They both can stay dormant in liver → disease can relapse weeks or years later
- RMR: w/ P. ovale and P. vivax (“it’s not OVer!!)
Plasmodium spp
- Symptoms
- Blackwater fever: intravascular hemolysis, dark urine from hemoglobin; malaria caused by P. falciparum can be very dangerous!!
- Fever, chills, fatigue, muscle aches, joint aches, diarrhea, vomiting, neurologic change
Plasmodium spp
- Types of blood smears used for examination
Examination of a Giemsa or Wright-Giemsa stained blood smears
Plasmodium spp
- Things to look for when examining the stained blood smears
- Presence of ring forms, shizonts, gametocytes
- Chuffner’s dots in P. ovale and P. vivax
- Thin and thick smears should be looked at
Plasmodium spp
- Two other methods for diagnosis
Molecular methods
- PCR
- Ag detection → lateral flow test
Plasmodium spp
- Microscopic exam can be fixed w/ ____
Methanol → RBCs will NOT lyse
Plasmodium spp
- Microscopic exam → why do we not fix slides w/ MeOH?
You need to RBCs to lyse
P. falciparum
- Rings present/absent
- Size of RBCs it infects
- Presence of stippling
- # of merozoites in schizonts
- Shape of gametocytes
- Other forms present
- Rings present/absent: present
- Size of RBCs it infects: normal/same size
- Presence of stippling: None
- # of merozoites in schizonts: None
- Shape of gametocytes: banana
- Other forms present: only rings
P. malariae
- Rings present/absent
- Size of RBCs it infects
- Presence of stippling
- # of merozoites in schizonts
- Shape of gametocytes
- Other forms present
- Rings present/absent: Present
- Size of RBCs it infects: Normal/same size
- Presence of stippling: None
- # of merozoites in schizonts: 6-12
- Shape of gametocytes: Round/oval
- Other forms present: Band forms
P. ovale
- Rings present/absent
- Size of RBCs it infects
- Presence of stippling
- # of merozoites in schizonts
- Shape of gametocytes
- Other forms present
- Rings present/absent: Present
- Size of RBCs it infects: Larger
- Presence of stippling: Present
- # of merozoites in schizonts: 6-14
- Shape of gametocytes: Round/oval
- Other forms present: Fimbriated forms
P. vivax
- Rings present/absent
- Size of RBCs it infects
- Presence of stippling
- # of merozoites in schizonts
- Shape of gametocytes
- Other forms present
- Rings present/absent: Present
- Size of RBCs it infects: Larger
- Presence of stippling: Present
- # of merozoites in schizonts: 12-24
- Shape of gametocytes: Round/oval
- Other forms present: Amoeboid trophs
Plasmodium species
- Diagnosis through microscope
Must distinguish plasmodium spp from Babesia spp
Plasmodium knowelsi and P. falciparum look very similar how can we differentiate?
PCR can discriminate the two
This is named after the gundi, a rodent in which it was first described
Toxoplasma gondii
Toxoplasma gondii
- Can infect a wide array of ____ hosts
Warm-blooded
Toxoplasma gondi
- Incidence of ____
Toxoplasmosis (it produces mainly asymptomatic disease)
Toxoplasma gondi
- Epidemiology
Definitive hosts are domestic cats and their relatives. And intermediate hosts include rodents and birds
Toxoplasma gondii
- Transmission
Cat feces; uncooked meat, meat spread (very high prevalence in France
- 85% seropositivity rate
- Steak tartare
- Can cross the placenta
Toxoplasma gondii
- Infectious forms caused by meat consumption
Tissue → cyst
Toxoplasma gondii
- Infectious forms caused by cat poop consumption
Oocysts
Toxoplasma gondii
- Symptoms
- Most cases are asymptomatic
- Flu-like illness
- Immunodeficient patients can develop CNS disease, pneumonitis, systemic disorder
Toxoplasma gondii
- Routine testing for diagnosis (IFA for IgM and IgG)
Serology
Toxoplasma gondii
- Microscopy diagnosis
- Identify tachyzoites in some species
- identify tissue cysts (contain bradyzoites)
Toxoplasma gondii
- Describe tachyzoites (active form of trophozoites seen through microscope)
- Sausage shape forms (tend to round up if phagocytized)
- Have nucleus only (no kinetoplast; no undulating membrane)
Toxoplasma gondii
- Describe bradyzoites (inactive tissue forms seen through microscope)
Many small, round, dot like forms found within tissue cysts; may become active trophs is cyst ruptures
Leishmania spp
- Vector borne disease ______
Sandflies (Lutzomyia and Phlebotomus spp)
Leishmania spp
- Indicdnece of ____
Leishmaniasis
Leishmania spp
- Two forms of epidemology
Visceral and cutaneous
Leishmania spp
- Transmission
By bite of sandflies
Leishmania spp
- Infectious form
????
Replication of organisms w/in the skin around where a sandfly has fed
Cutaneous leishmaniasis
This type of leishmaniasis causes dissemination of organisms to liver, spleen, bone marrow, etc.
Visceral leishmaniasis
Leishmania spp
- Diagnosis
- Microscopy: examination of Giemsa stained smears of BM, tissue, etc
- Will see amastigotes in macrophages and outside of host cells
Leishmania spp
- Send to ____ lab for confirmation
CDC
Two types of disease caused in Trypanosoma spp
- Chagas disease (in the Americas)
- African sleepign sickness (in Africa)
____ transmit Chagas disease parasite
Triatomine beetles (“kissing bugs” or Reduvild bettles)
____ transmits African sleeping sickness parasite
Tsetse flies (Glossina sp)
Trypansoma spp
- Distribution
Parts of Africa, Latin America and even part of the U.S.
Trypansoma spp
- Incidence of ____
Trypanosomiasis
Trypansoma spp
- Epidemiology and two forms of transmission
- African Sleeping sickness: Trypanosoma brucei, T. gambiense, and Trypanosoma brucei rhodesience
- Chagas disease: American trypanosomiasis caused by Trypanosoma cruzi
Trypansoma spp
- Infectious form
Tryphmastigotes
Trypansoma spp
- Infections they cause in African sleeping sickness
Chancre
Trypansoma spp
- Infections they cause in Chagas disease
??
Trypansoma spp
- Symptoms in Chagas disease
If trypomastigotes are introduced into the eye, the patient can develop Ramana’s sign
Trypansoma spp
- Diagnosis through microscopy and two forms that are found
- Examination of giemsa stained smears of blood, CSF and tissue; also histologic sections of muscle (Chagas)
- Trypomastigotes in fluids; Amastigotes in tissue cells
Microscopic characteristic of Trypanosoma cruzi
- Tryptomastigote form
Found in blood; has nucleus and large kinetoplast at tip of tryptomastigote; less wavy, with C or U shape
Microscopic characterisic of Trypanosoma cruzi
- Amastigote form
Found in tissue; small, intacellular forms in macropahges or near disrupted cells. has nucleus and very small rod shaped kinetoplast
Microscopic characteristic of Trypanosoma gambiense/rhodesiense
-Tryptomastigote form
Found in blood, CSF, BM, or Lymph nodes. ; Has nucleus and small kinetoplast at tip; is very wavy, with S or W shape
Three types of form found in Leishmania species during microscopy examination
Amastgote form (found in clinical specimens), Epimastigote (in cultures), and Trypomastigote forms (only in teh sandfly vector, not in humans)
Microscopic characterstics of Leishmania species- Amastgote form
Small forms, intracellular in, has nucleus and very small rod shaped kinetoplast
List the organisms that are vector borne disease
Trypanosoma species, Leishmania species, Babesia species
