Intriguingly, however, the scientists found that SAP05 attaches to a very specific piece of the cell disposal machinery to accomplish this goal.
Parasite in city save data full#
They also benefit from the plant staying alive and full of tasty juices as long as possible, the better to facilitate insects feeding on it. Parasites benefit from the plant being sterile, so they can focus its energy toward making the microbe’s offspring. “You can imagine that this situation is not a perfect situation for the parasite,” Dr. Before long they would drop their leaves and wither away. If host plants were to mature normally, they would grow flowers and produce seeds, putting all of their energy toward making the next generation of plants. That makes sense, from the parasite’s perspective. As a result, the plants appear frozen in time, unable to progress. Once it latches onto them, it causes them to be broken down by the plant’s own garbage disposal machinery. It turns out that SAP05 binds to two groups of plant proteins that control the expression of genes used in development. But in the new paper, they explain how SAP05 seems to drive some of the more surprising effects, like the life-span extension. The team sequenced the parasite’s genome some time ago and has pinpointed a handful of proteins that it may use to zombify its victims. SAP05 is not the first substance made by this phytoplasma that the scientists have linked to the symptoms it causes. When the insects ingest the parasite, they spread it to new hosts, and the whole “Night of the Living Dead-meets-Dracula” cycle repeats. It becomes something like a mix between a vampire that never ages and a zombie host whose body serves the needs of its parasite, namely, tempting sap-sucking insects to feast on the plant’s bodily fluids as long as possible. The plant’s neighbors grow old, reproduce and die, but the phytoplasma’s eerily youthful host persists. “It looks like it stays in a juvenile phase,” said Saskia Hogenhout, a scientist at the John Innes Centre in England, who studies the life cycle of the parasite, which is called Aster Yellows phytoplasma. Most peculiarly of all, it lives longer than its uninfected brethren, in a state of perpetual adolescence. Its leaves take on odd shapes, its stems form a bushy structure called a witches’ broom and it may grow flowers that do not produce seed. Universal screening, with treatment of persons with positive stool examinations, would save lives but is less cost effective than presumptive treatment.A mustard plant infected with a certain parasite grows strangely, its development warped by tiny invaders. Presumptive administration of albendazole to all immigrants at risk for parasitosis would save lives and money. As compared with watchful waiting, screening would cost $159,236 per DALY averted. Cost effectiveness was expressed both in terms of the cost of treatment per disability-adjusted life-year (DALY) averted (one DALY is defined as the loss of one year of healthy life to disease) and in terms of the cost per hospitalization averted.Īs compared with watchful waiting, presumptive treatment of all immigrants at risk for parasitosis would avert at least 870 DALYs, prevent at least 33 deaths and 374 hospitalizations, and save at least $4.2 million per year. Those at risk were defined as immigrants to the United States from Asia, the Middle East, sub-Saharan Africa, Eastern Europe, and Latin America and the Caribbean. We compared the costs and benefits of no preventive intervention (watchful waiting) with those of universal screening or presumptive treatment with 400 mg of albendazole per day for five days. In the United States there is now disagreement about whether to screen all immigrants for parasites, treat all immigrants presumptively, or do nothing unless they have symptoms. International trials have shown albendazole to be safe and effective in eradicating many parasites. Albendazole is a new, broad-spectrum antiparasitic drug, which was approved recently by the Food and Drug Administration. At entry persons with parasitic infections may be asymptomatic, and stool examinations are not a sensitive method of screening for parasitosis. Currently, more than 600,000 immigrants enter the United States each year from countries where intestinal parasites are endemic.
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