M31- Protozoa Flashcards
Describe protozoa.
- Single celled eukaryotes (Pro)sta)
- 0.01 mm – 0.05 mm
- Lack a cell wall
- Many free living aerobes
- Rare obligate anaerobes oKen include parasi)c species that inhabit GI tract of animals
- Some parasi)c protozoa that live in blood have evolved use of simplified respira)on system that does not involve mitochondria.
what are characteristics of protozoa?
-Nuclear envelope
>present
-Transcription & Translation >different compartements
-Histone proteins (DNA)
>present
-Cytoskeleton
>present
-Mitochondria
>present or absent
-Chloroplasts
>present
-Cell Wall
>variety, absent in some
-Genetic recombination
>fertilisation and meiosis
-Nutrition
>photosynthesis or heterotroph
-Motility
>Cilia,flagella,ameoboid,contractile fibrils
-Multicellularity
>normally absent
-Nervous system
some forms primitive stimuli system
Name 3 protozoan diseases of man.
- Malaria
- Toxoplasma
- Oral protozoa
Name 3 protozoa of the oral cavity.
- Trichomonas tenax
- Trichomonas vaginalis
- Entamoeba gingivalis
what can T.vaginalis STD cause?
– Adverse pregnancy – Cervical neoplasia – Atypical Pelvic inflammatory disease – Infertility – Urethritis, prostitis, epydidymitis, – Cervical cancer, prostrate cancer – Increased risk of HIV seroconversion
what broad diseases does T.vaginalis and T.tenax cause?
– Broncho-pulmonary infections (P. carinii)
– Associated with lung disease & underlying cancers
What is the treatment for trichomoniasis?
– Metronidazole
– Single 2g oral dose
– 500mg twice daily for 7 days
what is associated with poor oral hygiene?
Trichomonas tenax
how much does Trichomonas tenax occur in periodontal disease?
21%
What can entamoeba gingival do?
Can ingest microbes, leukocytes, & dead organic matter
Describe the disease of entamoeba gingivalis.
– Specific association with progressive periodontal disease in immunocompromised.
– Isolated from pulmonary abscesses
– Reports of acute osteomyolitis of the mandible
how much does entamoeba gingvalis occur in periodontal disease?
26 patients periodontal disease 27-69% carriage, 17 health 0%
what is the infection of EntAmeobosis?
Cysts shed into warm moist environment, swallowed & excyst to trophozoite
what can an amoebic dysentery or colitis cause?
– Fulmina)ng dysentery – Bloody diarrhoea – Abdominal pain – Ameobic lesions (burrowed into intes)nal wall) – Blood stream in severe episodes – Liver abscess
What is the treatment for EntAmeobosis?
Treatment with metronidazole & chloroquinone
What can cause cryptosporidiosis?
• Cryptosporidium sp
• Poor hygiene, faeces,
contamination etc.
What are the symptoms of cryptosporidiosis?
– 3-12 day incubation
– Watery diarrhoea
– Stomach cramps
– High temp & loss of appetite – 12 to 14 days (up to a month)
What is the treatment of cryptosporidiosis?
treatment largely concerns ensuring rehydration
How is malaria transmitted?
mosquito (zoonosis)
what is malaria cause by?
Protozoa:
– Plasmodium falciparum
what is distribution of malaria also that of?
anopheles misquito
where do mosquito live?
Lives in/on stagnant water in hot countries
What gender of mosquito are the vectors and why?
– the male does not feed on blood
– supports the produc)on of eggs
– usually bite between sunset & sunrise
What are the stages of the life cycle of malaria?
- Infected mosquito releases sporozoites
- Sporozoites travel to the liver where they enter hepatocytes & divide for 10 days. (+ 30 minutes)
- Merozoites released
- Merozoites infect erythrocytes
- 48hr development within erythrocyte
- Remodelling of erythrocyte & expression of surface proteins, produce knobs & mauers cleKs
what happens in the first 24 hours of the blood stage?
- 1000s of merozoites generated in liver & released (+ 10 days)
- Blood stage; Asexual reproductive cycle
- Attachment & invasion develop in parsitophprous vacuole (PV).
- > 24 hrs mature stage membrane bound structures appears in cytoplasm & knobbly deformations on membrane
what happens at 48 hrs of the blood stage?
- 48hrs infected red cell ruptures 16-32 merozoites released
- Degradation of haemobglobin & crystals appear in digestive vacuole, 02 carriage reduced onset of fever & chills
What are the initial symptoms of malaria?
- Initial symptoms similar to common flu.
- High temperature/fever occurs in hours from ini)al feeling of being ill.
- Often fever subsides for a few hours & returns (successive waves).
- Temperature fluctua)on oKen accompanied by a number of symptoms
what are temperature fluctuation accompanied by (malaria)?
- Headaches
- Chills
- Diarrhoea
- Muscular Pain
- Lethargy
- Sickness
- Coughing Fits
- Abdominal pains
You should Seek Immediate attention before progression to what? (malaria)
- Delerium, confusion, acting erractically
- Fits & Seizures that can end in coma
- Death; anemia &/or restricted blood flow to the brain
how is malaria prevented? (body or environmental)
Mosquito nets, long sleeve clothes & insect repellents
How is malaria prevented with drugs?
– Atovaquone & Proguanil
– Chloroquine
– Deoxycline
what type of treatment can cure malaria?
prompt and adequate
Name the types of treatment for malaria.
-Ouinine
-Chloroquinine
-Combination therapy:
> Drug resistance so no longer used in isolation
>Multi-drug resistance in SE Asia is a major concern
what is a toxoplasma?
Obligate intracellular parasite
Describe the toxoplasma life cycle.
• Life Cycle oKen involves rodents :
– Oocysts eaten by rat
– Form cysts in rats CNS
– Persist in brain
– generates a_rac)on to cat urine & feline pheromones
– Eaten by cat enters feline intes)ne
– Reproduces sexually (cat only known host for this stage) – Sheds 100,000,000 immature oocysts in faeces
– Oocysts mature in 2 days and become infective
Describe the disease of toxoplasmosis.
– Asymptomatic to severe & fatal (rare)
– Acute disease ;2 week flu like symptoms
– Occasional acute infections in healthy (e.g.eye,encephali)s)
– Immunocompromised
– Primary disease occurring. during pregnancy & reaching developing foetus
What is the treatment of toxoplasmosis?
Pyrimethamine & Sulphadiazine (doesn’t eliminate cystic stage)
what is the developing view of the toxoplasmosis disease?
– Infection has associations with Risk Taking Activities,personality alterations
– Slower reflexes( musclecysts?)
– Psychiatric disorders,depression & schizophrenia
– Can influence your personality and on a wider scale & the entire culture?
Summary slide.
- Protozoa/protista
- Parasitic eukaryotic infections of man
- Oral protozoa & STD, significance/treatment
- Zoonotic diseases
- Plasmodium/Malaria
- Toxoplasma most successful parasite
- Many more parasites not easy to treat
