Hi everyone ! I hope you are all fine. Today I will introduce you what I did for the previous two months and what will be my work for the next one. As I said in my precedent post, one f the biggest part of the project is to experiment on the bacterial inactivation by bacteriophages. The process is very simple : You have to see how efficient a phage target a bacteria. But before that, it means that you have to find the phages ! Since we are in a coastal city, we are able to search phages directly in the water and not just by them to an other laboratory that already have phages for the targeted bacteria. There are a lot of pathogenic bacteria that involve problems in fish and shellfish farming, but with the increase of the temperatures of the oceans due to the global warming make the bacterial family of Vibrio [1] and Aeromonas [2] very dangerous [3][4]. In fact, according to the Centers for Disease Control and Prevention, Vibrio is known to cause “80,000 illnesses and 100 deaths in the United states every year” [5]. So It was decides that I will work with three different type of Vibrio which are Vibrio parahaemolyticus, Vibrio anguillarum and Vibrio metschnikovii ; and one type of Aeromonas which is Aeromonas hydrophila. The phages isolation is a long process which can take days. In fact, as a lot of things in biology it requires time for the bacteria and phages to multiply. The process is very simple. The first thing you have to do is to take water samples from the see or the river next to the see when the tide is high, or sewer water sample too. After that you take bacteria that you already put to multiply the day before and you mix the water sample (filtrated or not, it depends of what you want), the bacteria and a media very rich in nutrients for the bacteria. After letting incubate overnight, you have to do a spottest. The spottest is a very simple way to see if you have pages in your sample. You take a plate whare you spread a high concentration of your targeted bacteria and you put on the middle some drops of your liquid that you had already centrifuge to separate the phages from the bacteria. If the spottest is negative, you have to start again all the experiment. But if the spottest is positive, congratulations : you have phages ! (See figure bellow) Example of positive spottest Example of negative spottest All you have to do after that is to find the concentration of you stock. I was supposed to do it all my internship, but fortunately I handle this part quietly and after two months and a lot of failure in my search of phages, I finally found and produce a stock of bacteriophages for the Aeromonas hydrophila ! So I will continue to search phages, but I will do in the same time experiments to evaluate the efficiency of the phages I found. But I will do this experiment only next week so I ill explain it and my next post. See you soon ! :) References :
[1] https://en.wikipedia.org/wiki/Vibrio [2] https://en.wikipedia.org/wiki/Aeromonas [3] As ocean temperatures rise, so too will Vibrio outbreaks, Clare Leschin-Hoar [4] Studies on Aeromonas hydrophila in Cultured Oreochromis niloticus at Kafr El Sheikh Governorate, Egypt with Reference to Histopathological Alterations in Some Vital Organs, A.E. Noor El Deen, Sohad, M. Dorgham, Azza H.M. Hassan and A.S. Hakim [5] https://www.cdc.gov/vibrio/
3 Comments
Hanae
8/11/2016 07:11:37 am
Hey there !
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Nicolas
10/11/2016 06:56:08 am
Hi Hanaé !
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Hanaé
7/12/2016 05:50:29 am
haha ok ! great thanks for your answer :) Leave a Reply. |