Entamoeba histolytica is defined as a eukaryotic microorganism because the genetic material in the nucleus is contained in a specific membrane. This type of microbe has been referred to as a protozoan parasite. This is because the parasite needs to have a host to survive. Entamoeba histolytica is the known cause of many horrible diseases in humans including Malaria and Dysentery. Humans are sometimes the host to this type microorganism causing infection and, without proper treatment, death to the host.
Protozoan parasites have extremely complex lifecycles and can change quickly depending on various variables. The life cycle changes differ depending on the host. Protozoan parasites can infect both cold blooded and warm-blooded animals. Scientists do not yet know some of the life cycle changes that are undergone by these parasites. The variables that cause the different morphological stages within the parasite include host temperature, the site, and immune responses.
There are five basic life cycle stages. The first is the reproductive stage. Next is the environment phase. Additionally there is also the asexual stage and human infection stage. Finally, there is the completion of the life cycle or death stage.
During the reproductive stage, the oocysts are introduced into the natural environment usually through the feces of an infected host. This can occur anywhere from five to ten days after the primary infection of the host.
Next, the parasite goes through an infectious stage. Once the oocysts contain spores they are dangerous to any possible host. The spores are infectious and can cause disease. The spores continue to contaminate everything in its path including soil, water and various plants. It only takes on average three to five days for the spores to develop.
Many of these parasites take an intermediate host such as a rodent, a bird, or various other animals. What happens is, when the animal ingests the spores either by drinking contaminated water or numerous other situations, they become infected. Within a week of the ingestion the oocysts morph in to tachyzoites. The tachyozites then attack the nervous system and muscle tissue. This is the point where they transform into bradyzoites. Human infection comes when infected animals are consumed. It is also important to note that humans can also become infected through drinking contaminated water. One of the interesting things is that once the human is infected the parasite becomes dormant until immune system is in a weakened state. The final stage is the completion of the cycle when the human passes on the contaminates.
There is still so much that scientists do not know about this parasite. It is unknown if the parasites die inside the host or if they continually morph through their stages. Scientists have determined that the parasite can live in the open environment for over a year without a host.
References:
http://www.enotes.com/microbiology-encyclopedia/entamoeba-histolytica
http://en.wikipedia.org/wiki/Eukaryote
http://www.dpd.cdc.gov/dpdx/HTML/Toxoplasmosis.htm
