Hello, welcome to Flavonoide: our Pharmacy, Young Health and Science channel. Did you thought there was no more parasitology class, did you? But it almost didn't!
There are a lot of people asking for pharmacology video classes and I tell you there will be, calm down. But how could I leave parasitology incomplete? Guys, I can't, it's not my nature.
So are we going to do some more parasitology classes? Let's go! And no people, there's no way to remove the cat because I live in a loft, that is, there are no walls here in this house.
Unless I put him in the bathroom then you will hear him scream so, deal with Pastel. So starting. When we say that a person is an amoeba, we usually mean that he is a bit of a lazy person, not funny, you know?
A person of no importance. BUT, this is not the amoeba that we are going to talk about today. This damn thing is very important because it is the second leading cause of deaths from parasitological disease, second only to: malaria, which we have seen here.
Just to give you an idea, it is estimated that 10% of the world population has either Entamoeba histolytica or Entamoeba dispar. They are two morphologically identical species, but the only one that is capable of causing disease, because it is the only one that has PATHOGENICITY FACTORS is histolytica. Calm that we will see this better later on.
Between 40,000 and 110,000 people die each year worldwide from amebiasis. In Brazil, there are cases registered in all regions, but the highest prevalence is in the Amazon region. If we compare, there are countries that suffer much more from amoebiasis than we do For example, Mexico, some countries in Asia and Africa.
In Brazil, we have more asymptomatic cases than symptomatic ones, that is, there are people infected but who do not manifest the symptoms. When they manifest symptoms, it tends to be milder than when compared to these other countries. However, specifically, looking only at the Amazon region, it has a higher prevalence and it also has more severe cases.
Remembering that as well as several other parasitological infections that we have seen here, this disease is not mandatory to report, so we work with estimates, okay? So let's go to AMEBIASIS <3. There are several species of Entamoebas.
There are several that can infect humans, but two are the most commonly found (in exams): that is Entamoeba histolytica and dispar. As I speak in every holy video and I explain it in the video of introduction to parasitology. What defines a person having a symptom or not are the factors related to the triad: microorganism, which in our case is a parasite, host and the environment.
So you have in this triad each tip influencing your infection. Entamoeba dispar, which was what I said, despite being morphologically identical to histolytica, it does not have pathogenic factors. So in this triad it does not prove an imbalance in that sense.
That is why people infected by it, regardless of their health condition, will not present a disease, will not present the symptom. As for histolytica, which has pathogenic factors, it can cause an imbalance and consequently not only generate asymptomatic people, but also generate the disease. So I hope that after all these videos, it became very clear that having an infection is different from having the disease, it is different from you having symptoms.
That is why in many conditions we have many, many asymptomatic people, but they remain reservoirs for microorganisms, don't forget that. So as the dispar will not cause disease, we will focus only on histolytica in this video, okay? Oh, and a very important thing: that I almost missed it, pay attention.
Do you know when we talk about E. coli? when we talk about the bacteria?
Escherichia coli? So, there is Entamoeba coli, and if you abbreviate, it becomes E. coli too.
So, be careful not to confuse these two completely different things. Entamoeba histolytica basically comes in two forms: the cyst and the trophozoite. There are intermediate forms, but your teacher will probably focus on just those two.
n addition to having repeated a thousand times that the dispar is morphologically identical to histolytica, which is a big problem in the diagnosis and we will see that, there are other rarer Entamoebas, but they can infect humans. So, it is a big confusion at the time of diagnosis, seriously, everything is very similar. But looking only at histolytica, what do we see?
We see a cell with four nuclei there. As the dye fixes very well in chromatin you will be able to see the nuclear membrane and the kiosome that is inside the nucleus very well pigmented And sometimes you can see a little stick-shaped thing that is the chromatoid body. The trophozoite is shaped like nothing.
Seriously, it's like a very irregular thing, there's no way I can tell you the specific shape. Do you know Amoeba? The play dough (popular in Brazil, like slime)?
When you play on the wall is that weird thing? So, it's like that. What will you see in the trophozoite?
You will be able to differentiate the ectoplasm from the endoplasm, because the ectoplasm will be very light and the endoplasm will be darker. Because in the endoplasm you will have granules, vacuoles, nuclei. Oops!
but calm down! I said wrong, because it's not more than one nuclei, it's only one nucleus. In the trophozoite you will have only one nucleus.
Usually, right? because sometimes these animals are very crazy, but anyway, it's usually just a nucleus. And you can also see the kiosoma inside there.
Have you, my student who knows everything about parasitology, already realized that there is a cyst? form of resistance! So you can get a sense of the transmission, right?
As in Giardia, in amebiasis you have fecal-oral transmission. So people get contaminated with contaminated water and contaminated food. Oh, and a detail: in addition to eating contaminated food and contaminated water, it can happen that a fly or a cockroach passes over there in the poop, right?
take some cysts in the paws and then land on yout food, you are there at the table with your family, with a lot of people (I miss my family), and then a little fly comes and lands there and you "oh, excuse me little fly". And it is much more rare, but sexual transmission is possible: oral-anal. And in infections where you have a lot of asymptomatic people, these people are the big problem because they do not manifest symptoms so they continue to manipulate food, work in restaurants and you easily spread the cysts of this parasite around the environment to other people.
Remember that the Entamoeba cyst can stay up to 20 days in the environment and an infected person who is not treated can expel, excrete the cysts in the feces for years. So it is easily spread. The life cycle of Entamoeba histolytica is monoxenic, that is, it manages to do its entire cycle in just one host, in this case, us, right?
It all starts when an uninfected person eats food or water contaminated with the parasite's cysts. These ingested cysts will then pass through the stomach, will not be affected by gastric acid, they will not care for that. They will get in the small intestine or even in the beginning of the large intestine and then these cysts will start to get out of the cyst.
What a difficult word (in portuguese). And from within the cyst, the trophozoite will emerge and will start to multiply by binary division. If the cyst has four nuclei, it can give rise to four trophozoites.
The trophozoites will pass there to the large intestine and make their home and colonize everything. These trophozoites will adhere to the intestinal wall and stay there, just eating debris, bacteria, just getting stronger. Until, due to factors that we do not know exactly what they are, these trophozoites return to cyst form.
They secrete the cystic wall again and the cyst will be eliminated in the feces. But also remember: an individual who has diarrhea, everything is coming out, so you can also find trophozoites in individuals with diarrhea or pasty stools. But in the environment, only the cyst, which is the form of resistance, survives because there is a cystic wall and everything is well protected, and then, as I said, it can stay in the environment for weeks.
A very peculiar thing can happen, we also don’t know exactly what the factors are for this, but trophozoites can become hematophagous and start to invade the intestinal submucosa, form ulcers and multiply within these ulcers. So it becomes very easy for this parasite to end up in the bloodstream. Once in the bloodstream, it can reach several other organs, right?
First the liver because it is the first stop and then others: lung, kidney, brain, skin. We call this Extraintestinal Amebiasis. It is no longer limited to the intestine alone.
So our first part is this, doubts here and let's go to part 2? Oh, and don't forget to follow us on Flavonoide's Instagram and we have a mental map of this class ready for you in the Flavonoide store, okay? The link will be in the description.
Kiss, bye bye.
