Friday, January 13, 2017

A tale of Histomonas meleagridis

Today in Poultrytopia is just like any other day in this lovely country. There are many states that make Poultrytopia with the two largest being Chickensota and Turkeyia. For many years these were safe states. Both states have a central infrastructure that includes important buildings one of those being called the cecum that is involved in processing much of the plant material in the state and the liver which has many important roles. If the cecum is at all compromised, many of its workers will spill out into the rest of the state. These workers are very dumb and all they know how to do is break down all sorts of material. Many of these workers are different species of bacteria. If they get out of the cecum they will seek to break down other buildings that are important to the infrastructure and ultimately lead to the downfall of the state. If the liver shuts down, the entire state will quickly die because many essential roles are no longer being carried out. Luckily this is very hard to do since the cecum and liver it is made up of very special bricks called cells that very few intruders can breach.
The police force in Poultrytopia is very effective and has many lines of defense. Unfortunately one branch of the police force called the Federal Bureau of Innate Immunity or FBI for short will generically target suspected intruders. They have been known to make mistakes and this causes much displeasure on many different Poultrytopia social media platforms. Anyway, my point is Poultrytopia is generally a very safe place even if the occasional bad seed gets past the border.
So on this bright and sunny day in Chickensota, a seemingly innocent tourist was admitted entry to the state. This tourist’s name is Heterakis gallinarum but he likes to go by the nickname Nematode. For as long as he can remember he has always wanted to visit the different cecums in the different states of Poultrytopia. He had visited the cecum in smaller states such as Grousefornia and Pheasantington. On these visits he was overly excited and didn’t know the rules of the cecum and got lost during the guided tour. He ended up causing some minor issues but luckily didn’t cause any serious damage to either of the smaller states. It’s when nematode enters the cecum with He was determined to redeem himself by behaving on a tour of the cecum in Chickensota and maybe someday visit Turkeyia once he saved up enough money and nothing goes wrong on this trip. Unfortunately for Nematode he wouldn’t be so lucky.
Figure 1: Nematode after taking up the trophozoites. Credit: BNU China    
While he was traveling he had noticed a few Histomonas meleagridis babies that were scared on the side of the highway. The Histomonas meleagridis babies are also known as trophozoites and are very delicate when they are in this state and can’t survive long in the outside world. Nematode has always been a bit of a softy so he decided to wrap the trophozoites in his own Nematode eggs so they will be able to live for up to two years. Nematode was going to leave the eggs behind because he knows it’s against the law to bring baby trophozoites into any state in Poultrytopia. This is due to the fact that the babies can reproduce very quickly through a process called binary fission. Many years ago there was an outbreak that caused many of the states to die. Nematode decided that he would put the eggs with the trophozoites in his backpack and once he reaches the border he’d give the eggs to border patrol and they would be able to find them a place to live. So Nematode gets to the border and see that the FBI is profiling everyone and taking out anything that looks like a threat. Nematode is very scared for the eggs and for himself. He decides to hide the eggs in his backpack and hope the FBI doesn’t notice. Nema isn’t the smartest guy and accidentally gets taken up by the mouth of the state while it is harvesting nutrients from the outside environment. Now that he’s past most of the danger he decides to head to the cecum, the place he is most excited to see. But he must still be careful because the FBI has many different modes of action that help protect various parts of the state.
In the cecum he decides he loves it so much he’s going to hang out awhile and make some more eggs. Many of these eggs leave the cecum and are eventually deposited outside of the state. Many of the eggs that are deposited have the potential to be taken up by other states. While Nematode was hanging out and having the time of his life in the cecum, he forget he left the eggs with the trophozoites alone in the cecum! The trophozoites made their way out of the eggs and much like a puppy, wanted to eat everything.
They started my chewing on all of the cells the make up the lining of the cecum. They were eating so much the they had to divide into more trophozoites so they wouldn’t get too full. As they kept eating they kept dividing. Eventually there got to be so many that they made it out of the cecum and decided that the liver looks especially delicious and decided to continue their feast there. As they left the cecum some of the bacterial workers of the cecum found their way out as well and they too started to damage many of the internal organs. As they munch away on the liver a few of the trophozoites still in the cecum find their way into some of the eggs that Nematode made since they wanted to take a nap after eating. As they’re napping the eggs get sent out of the cecum and out of Chickensota. Before Turkeyia has time to hear about the disaster in Chickensota, the eggs with the sleeping trophozoites are taken up by Turkeyia. Pretty soon trophozoites are in both states and causing all sorts of damage! As the trophozoites spread through the states and they cause lesions in the different vital buildings. These lesions cause many of the buildings to fail. Back in Chickensota, Nematode is freaking out because he has, once again, messed up the cecum but this time in a very big way. He’s also very sad because he will never be able to see the Turkeyia cecum because the trophozoites spread from Chickensota and killed the state. He decided to flee the country and find a cecum in some distant land that he won’t mess up so badly it causes the downfall of every state. Hopefully our pal Nematode will be able to live his life happily ever after in a cozy cecum for the rest of his days.

1.    Mcdougald, L. R. (2005). Blackhead Disease (Histomoniasis) in Poultry: A Critical Review. Avian Diseases, 49(4), 462-476.
2.    Mcdougald, L. R. (1998). Intestinal protozoa important to poultry. Poultry Science, 77(8), 1156-1158.
3. Beckstead, R. B. (2014, July). Overview of Histomoniasis in Poultry.

No comments:

Post a Comment