0:04 → 0:07
SpeakerQuestion.
0:07 → 0:11
SpeakerMy research question focuses on malaria.
0:11 → 0:26
SpeakerMalaria is a human infectious disease, which in contrast to tuberculosis, ****, or to COVID-19, can only be transmitted from one human to another by a little mosquito.
0:26 → 0:37
SpeakerSo a mosquito can take blood from an infected individual, develop the parasite inside during the period of three weeks, and then it can inject a new form of the parasite into the next human.
0:37 → 0:44
Speaker So the question we ask, what happens in the mosquito during these three weeks and how it supports parasite development?
0:45 → 0:47
SpeakerMethod.
0:48 → 0:54
SpeakerIn the laboratory, we employ a series of methods to understand how mosquitoes transmit malaria.
0:54 → 1:09
SpeakerThat involves population biology studies in the field, where we can trap mosquitoes and bring them to the lab and to analyze using mathematical approaches the composition of the mosquito populations in the wild.
1:09 → 1:15
Speaker And it's interesting because there is more than one single vector in the population.
1:15 → 1:25
SpeakerSo many times and often we can find different vectors located in the same population, and the question is which one of them is involved in malaria transmission.
1:25 → 1:31
SpeakerThen we could look at the genetics of these vectors, and see the differences in the genetical composition.
1:31 → 1:40
SpeakerAnd then we can ask the question, if with this genetic difference using experimental approaches in the labs we could maybe understand better what happens in the field.
1:40 → 1:49
SpeakerThen in the lab, we could use some tools which allow us to inactivate particular genes of interest.
1:49 → 1:59
SpeakerAnd in fact, experimentally mosquitoes with plasmodium parasites, which transmit malaria, and see how that affects parasite development within the mosquito.
1:59 → 2:13
SpeakerIf this gene has an effect, then we can go back to the field and set up a new study and specifically ask the question how different mosquito populations express this particular gene?
2:13 → 2:19
SpeakerAnd would one population be more expressing gene which allows better malaria transmission in the field?
2:19 → 2:32
SpeakerSo, in principle, we use these iterations of population biology studies in the field and laboratory studies in the lab to understand the question, what are the mechanistics of malaria transmission?
2:33 → 2:36
SpeakerFindings.
2:36 → 2:51
SpeakerSo what we found out in the lab was that there is a particular gene which is conserved from bacteria to animals and of course is present in the mosquitoes and which is involved in the immune response regulation of mosquitoes.
2:51 → 3:10
SpeakerThis gene encodes for a protein which can directly bind to pathogens such as bacteria, fungi, and what we found out that it also recognizes the parasite inside the mosquito when they go through the midgut epithelium of these mosquitoes and during the infection.
3:10 → 3:19
SpeakerSo if we eliminate this gene in the mosquito, what we see in the laboratory is that the mosquitoes start to have huge numbers of parasites.
3:19 → 3:30
SpeakerAnd that was very interesting because that was just by eliminating one gene that we can convert mosquitoes from susceptible to highly susceptible.
3:30 → 3:38
SpeakerNow, the question which we asked was whether this gene has different forms in natural populations.
3:38 → 3:50
SpeakerFor that, we went back to Africa and looked at these different forms of this gene in different areas in West, Central, and Eastern Africa.
3:50 → 4:04
SpeakerAnd what we found out that, indeed, different forms exist in these populations, and that we find that in areas with a high transmission, there are really very particular forms of this gene.
4:04 → 4:20
SpeakerSo we next asked the question whether we could go into a single location in Africa with the populations of mosquitoes, which will have differences in this allelic composition of this gene, and compare the transmission capacity of these mosquitoes.
4:20 → 4:38
SpeakerAnd so we found such a location in the village close to Bamako in Africa, and we had a very good collaboration with our Malian colleagues from the University of Bamako, who established a site of collections of mosquitoes during the whole rainy season over two years.
4:38 → 5:00
SpeakerWhy was it important? Because to understand the dynamic of transmission, or what we understand by that number of mosquitoes which would have infected with plasmodium in this area, and to use later on mathematical approaches, we had to have a time series of collections which would have very dense data set.
5:00 → 5:05
SpeakerSo we collected mosquitoes every day over a period of three months.
5:05 → 5:20
SpeakerAfter that, we looked at the parasite presence in these mosquitoes by molecular methods; we looked at the form of the gene, which I was talking previously, which we were connecting to the efficiency of malaria infection in mosquitoes.
5:20 → 5:35
SpeakerAnd what we found out that it is usually considered that the major determinant of malaria abundance in a particular area is the number of mosquitoes present in this particular area.
5:35 → 5:45
SpeakerWhich is true, because if there are no mosquitoes, there will be no malaria transmission, right? But if there are mosquitoes, what's enough to transmit malaria?
5:45 → 5:54
Speaker What our data showed, that it was not really the number of mosquitoes in the area, but the composition of these mosquito populations.
5:54 → 6:05
SpeakerSo if there were more mosquitoes, which will have a gene which would not support parasite development, then the numbers of infected mosquitoes went down.
6:05 → 6:18
Speaker And on the contrary, if there were mosquitoes in the population which will have a susceptible form of this gene, right, which will be very good in transmitting malaria, the number of infected mosquitoes in the population increased.
6:18 → 6:28
SpeakerSo, in other words, what we found out that the more of these refractory mosquitoes in the populations, fewer cases of malaria will be in the area.
6:28 → 6:30
SpeakerRelevance.
6:31 → 6:42
SpeakerSo what was important in this study is the understanding that mosquito populations are complex and they contain species which are good and not so good in malaria transmission.
6:42 → 6:55
SpeakerWhy is this important? It's important first of all for the dramatic decisions of building dams or river management in Africa; and this is, of course, of high importance for the local population.
6:55 → 7:04
Speaker And the obvious question is, if you increase the water body, in this case, you will attract more mosquitoes and increase malaria transmission in the area.
7:04 → 7:08
Speaker However, our study shows that that's not always true.
7:08 → 7:18
Speaker And you could really monitor this and build these dams in the areas where you have vectors which are not good transmitters of malaria.
7:18 → 7:28
Speaker Secondary, this study is important because the understanding that you have to target the particular species if you want to interfere with malaria transmission and not with all mosquitoes.
7:28 → 7:44
SpeakerSo you can use very selective methods of gene drive or genetic engineering and target the species which are really responsible for malaria transmission in the area and leave other mosquito species untouched and fulfilling their ecological functions.
7:44 → 7:56
SpeakerFinally, this is also important for this climate change scenario where mosquito populations with the warming up of planet will probably extend and change their localizations in the world,
7:56 → 8:07
Speaker and to understand how is it dangerous for us as humans to be exposed to these mosquito populations, which could transmit and bring malaria back to Europe.
8:07 → 8:10
SpeakerOutlook.
8:10 → 8:28
SpeakerSo the outlook of this study is highlighting the importance of bringing more mathematical approaches, which are very widely used in economics, to understand the dynamics of mosquito populations in the malaria-endemic areas.
8:28 → 8:40
SpeakerWe also understand better that we need to collect better samples of mosquitoes and to involve more our colleagues from African countries to be engaged into this project,
8:40 → 8:50
Speakerand really to understand what happens in this area of high malaria transmission and how we could prevent malaria transmission by mosquitoes.
8:50 → 9:03
SpeakerOur aspiration is that we can contribute to the arsenal of the tools which will allow us to control malaria and at the best to eradicate this disease from the face of the world.