Question

Becky is a 53-year-old woman living in Seattle, Washington, with her husband Tim and their dog Tipper. Even though they both have full-time jobs, Becky and Tim try to get out every weekend and do something active—kayaking, hiking, or cycling. While Becky loves the physical activities, her favorite is the two-week vacation that she and Tim take every year. They rent a house on the Washington coast and spend their time gathering crabs, harvesting clams, and relaxing. On the last weekend of their vacation, Becky and Tim always host a big dinner party featuring fresh crabs and clams. This year the dinner party is a huge success— everyone has a great time, and the Dungeness crabs are particularly delicious. The morning after the party, Becky wakes up and doesn’t feel very well—her stomach is upset, and she feels a little bit nauseated. Tim jokes that it’s probably because she drank too much wine at the party; he’s sure that she’ll feel better in a few hours. But as the morning goes on, Becky starts to feel worse, and then she starts vomiting. She decides to lie down and rest for a while. A few hours later, Tim goes to check on Becky. She says that she has a headache and is dizzy; the vomiting hasn’t stopped. Tim grows concerned as Becky talks because she isn’t making sense, and she seems to be confused. Worried that something is seriously wrong with Becky, Tim takes her to the emergency room (ER).
At the ER, Becky’s physical exam is normal. The mental assessment confirms confusion and disorientation. The doctor orders blood and urine lab analysis and admits Becky to the hospital. The blood and urine cultures come back negative for any microbes. Becky’s confusion gets worse, and she begins experiencing weakness in her arms and legs. Even though Becky and Tim told the doctor she hadn’t suffered any head injuries, the doctor orders computed tomography (CT) of her head. The CT scan, also known as a CAT scan, consists of a series of X-ray images taken from multiple angles and then combined by a computer to provide cross-sectional and three-dimensional views. The results come back normal. Urgently seeking a diagnosis, the doctor sits down with Becky and Tim to go over the preceding days again—where had they gone, what had they done, what had they eaten? Becky is having a hard time remembering anything from the last few days. As Tim recounts their meals, the doctor asks where they got their crab and clams and how much they ate. Tim said he had only a bite of crab, but Becky ate a lot. The doctor suspects that Becky was poisoned by the crabs and orders a lab test for a toxin. The results of the test come back positive. Becky has amnesic shellfish poisoning (ASP) from the contaminated crab. Although there is no antidote for the toxin, in nonsevere cases such as Becky’s, the toxin will eventually pass from the system. Becky receives supportive care in the hospital for three weeks; by the time she is discharged, she has made a complete recovery.

questions

Why did Becky's doctor provide only supportive care? Why weren't antimicrobials part of her treatment?

Becky's illness was caused by a diatom from the Pseudo-nitzchia genus. How are diatoms different from other eukaryotic cells? Do they have any features found in prokayotes?

Answer 1

Answer:

Becky’s doctor provided only supportive care because the toxin that poisoned her, the demoic acid, has no known antidotes; which happen to be the only cure for toxins.

Antimicrobial were not part of Becky's treatment because Becky was infected by a toxin and not a microbial infection.

Diatoms are not different from eukaryotic cells or eukaryotes. they are Eukaryotes, which are different from prokaryotes. However both the eukaryotes (diatoms) and the prokaryotes possess cytoplasm, plasma membrane and ribosomes.

Explanation:

Demoic acid is a marine bio-toxin that results in Amnesic Shellfish poisoning (ASP). This biotoxin is produced by diatoms of the species Nitzschia navis-varingica of the genus Pseudo-Nitzschia. This intoxication can result in symptoms ranging from gastrointestinal upset (vomiting, nausea, diarrhea, abdominal cramps, hemorrhagic gastritis) to neurological disturbances (including headaches, diziness, disorientation, vision disturbances, loss of short term memory, motor weakness, abnormal heart rhythm, unstable blood pressure, etc.). In more severe cases, it could lead to permanent short term memory loss, brain damage, coma, and death. Due to the lack of antidotes for this toxin, it is advised that medical attention be sought as soon as possible, where the patient can be closely monitored and cared for.

There's a difference between toxins and microbial infections. while Microbial infections are caused by harmful microorganisms infecting the body tissue and cells, toxins are harmful substances produced by microorganisms. Hence, the approach for treatment for both cases are different.

Diatoms are eukaryotic cells or eukaryotes, which are organisms that have a membrane enclosing in their nucleus, hence they have  a true nucleus and organelles bound by a membrane, supporting functions in compartments. Prokayotic cells or prokayotes, on the other hand, which are typically smaller, do not possess a protective membrane around their nucleus or any organelles enclosed by the membrane. Regardless of their differences, they still both share similarities. After all, they both are cells. So they have the basic features of cells. These similarities include the possession of a cytoplasm, ribosomes, plasma membrane.