NSRecent events New viral illnesses in people often begin as a spillover effect from an infection that affects other species. However, viruses are not the only pathogens that do so. Three potentially deadly diseases caused by unicellular organisms called leishmaniasis, sleeping sickness, Chagas disease, and trypanosoma are probably also in this category. Not only are they spread by insects (sand flies, tsetse flies, and triatoma rubrofas, respectively), but they are also probably derived from insects (although not necessarily the current vector). Most known trypanosoma are insect parasites. It raises the question of how they jumped over the seed wall.The study just published in Bulletin of the Royal Society, Evan Palmer-Young of America’s Ministry of Agriculture suggests that the answer may be “honeybees.”
The starting point for Dr. Palmer Young was an observation made several years ago. Chestnut merifica, Trypanosoma, once thought to be exclusive to honeybees, has appeared in mammals. Marmosets (a type of New World monkey), coati (small raccoon-related flesh), fruit bats, crab-eating dogs, and ocelots are all known to currently host it. Therefore, he wonders if there is anything special about this particular trypanosoma that enables these leap to mammals, and if so, whether adaptation to honeybees might be. I did.
He had two ideas. For one, most insects are feverish (that is, body temperature depends on the ambient temperature), but bees, like mammals, often generate extra heat and benefit from being close to their neighbors in the hive. receive. This keeps your body temperature at mammal-like levels from your mid-thirties to your first half.
Another idea of Dr. Palmer Young was that the intestines of bees are more acidic than most insects (which helps digest nectar and pollen). Indeed, they have a pH that matches the pH of the mammalian gastrointestinal tract. Therefore, he speculated that mammalian heat, and / or acidity, could create a barrier to mammalian trypanosoma infections that bee-adapted parasites could easily overcome.
To test this idea, he and his colleagues C. Merifikae, And also the second honeybee Trypanosoma parasite, Lotmaria passim..For comparison, they studied two strains Crithidia fasciculata, A trypanosoma commonly found in mosquitoes, C. Merifikae..
They cultivate all four trypanosomes in flasks and each sample has a temperature range of 20-41 ° C with constant acidity, or pH 2.1 (very acidic) to pH 11.3 (very acidic). Exposed to the acidity of. Alkaline) At a constant temperature. While doing so, they monitored the rate of increase in parasite populations.
As Dr. Palmer-Young theorized, both honeybee parasites tolerated the temperatures commonly found in urticaria. But they did not tolerate them equally well.Growth rate C. MerifikaeA well-established species of honeybees, peaked at 35.4 ° C.of L. PassimWas not reported in honeybees until 2014 and is believed to have arrived recently, peaking at 33.4 ° C.Both stocks C. fasciculatHowever, a could only handle low temperatures. Their growth rate peaked around 31 ° C. Similarly in acidity experiments, both bee parasites propagate at pH 5.2, the level of acidity in the gastrointestinal tract of honeybees, whereas mosquito parasites are about 7.5 more alkaline to grow well. It became clear that the pH of was required.
Anyway, both the acidity of the bee’s intestines and the temperature of the nest create a barrier to trypanosoma. C. Merifikae Mainly overcame it L. Passim It’s just a matter of dealing with it, and mosquito parasites are intolerable. It’s unclear how this happened.However, what is clear from the spillover effect of mammals C. Merifikae, That means it can lead to parasites that can also breed in mammals.
Whether it was the path that trypanosoma, which causes leishmaniasis, once followed, Chagas disease and sleeping sickness have not yet been seen, as well as how their respective modern vectors fit into the picture. However, Dr. Palmer Young’s findings suggest that monitoring urticaria for diseases that can spread to humans is a worthwhile endeavor. ■■
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This article was published in the Science and Technology section of the printed version under the heading “Troublesome Stab Wounds”.
Sleeping sickness and its relatives may have arrived via the honeycomb
Source link Sleeping sickness and its relatives may have arrived via the honeycomb