PMB: p Flashcards
Are Parisites prokaryotes or Eukaryotes?
What are the classifications of eukaryotes?
Eukaryotes
- Protozoa (unicellular)
- Metazoa (multicellular)
Where are Protozoa found?
What classes of protozoa is there?
Aquatic enviroments - doesnt have to be water, could be digestive tract of herbevores
- Ciliates
- Flagellate
- Sporozoa
- Amoebae
How do protozoa reproduce?
Reproduction is complicated. They can under go asexual or sexual reproduction
Diviision can occur by fission. bussing, shizogony.
Shizogony is basically multiple fissions - the nucleus under goes multiple divisions and each is used to form a new cell
What are special about some ciliates?
The biology of protozoa can be rather complicated. The temptation is to regard them as simple organisms as they are unicellular. However reproduction can be sexual or asexual; division can be by fission, budding or schizogony (multiple fission). In addition, some ciliates have two different kinds of nuclei; a diploid sexual nucleus (micronucleus) containing all the genetic material needed by the cell and polyploid asexual nucleus (macronucleus) containing multiple copies of subsets of the genetic material. In addition, some ciliates have more than one micronucleus present.
Are Protozoa harmful?
- Most protozoa are non-virulent (non-harmful).
- In some species protozoa are benefical e.g. in the digestive systems of some herbivores, help to digest fibre
- Some speices of protozoa can be harfmul. The severity of infection depends on intial dose of protozoa and route of entery. Small doses of some protozoa aloow the bos immune system to respond
What are potential routes of infection for protozoa?
- Skin acts as barrier to infection
- Oral ingestion provides an entery route
- Cuts in the skin provide an entery route
- Insects bites are also another way to penetrate tthe skin barrier
What is required for infection?
What are the problems?
- Physical contact is required for infectino. Either directly - via protozoa or indirectly - via a vector.
- Protozoa conditions are often chronic:
- Last several months
- Complications arise due to further reinfections
What is the most common type of protozoa infection?
- STIs e.g. trichominas vaginals
- Where do infections tend to occur in females?
- What are symptoms for males and females?
- In the cervical of the vagina or urethra region
- Symptoms include but vary of an individual basis (feamle):
- Pain when urinating/ during sexual activity
- More frequently urinating
- Vaginal Itching/ burnign
- bleeding/ spotting
- Vaginal isharge which is frothy
- Not all females show symptoms
- Many males show no symptoms (asymptomatic)
What is the general treatment for STIs?
Metronidazole - a generic inhibitor of DNA replicatino
Give an example of a protozoa which causes GI infections
How does this infect a person?
- Cryptosporidium parvum
- Via the faceal-oral route. An infected person excreted the pathogen which ends up in the water source and contaminates it. The water source is untreated and causes infection to a suspetible person
What are the symptoms of Cryptosporidium parvum?
How do people recover?
- Severe diaohrrea for 2-7 days
- NAusea, vomitting, dehydration
- MOst people recover with little more needed than rehydration
- What is an example of another GI protozoa?
- How transmitted
- What does it do?
- Incubation period
- Symptoms
- Giardia Lamblia
- This can be trnasmitted from contaminated water or food
- It has a specific mode of action and attaches to the duodenum and causes localised inflammation of the duodenum
- Has an incubation period of 1 - 4 weeks
- Symptoms: water diaohhrea and adombinal cramps
Entamoeba histolytica is a protozo:
- What does it cause?
- Mechanism?
- Symptoms
- Amoebic dysentery
- Infescts the lumon of the tract - generally the bowel. Leads to ulceration of the mucosal tissue of the epithelial parts of the tract
- Severe Cramps, colitis, bloody diarrhoea
