DNA analyses on Amblyomma americanum adults

Since my last blog post, I have been conducting analyses on adult ticks to check for zoonotic pathogens. Specifically, I have been testing for Ehrlichia chaffeensis, which can be transmitted to humans. To conduct the DNA analyses, I first start by identifying the adult ticks and cutting each on in half using a sterile razor blade. Each tick is placed in a sterile tube for DNA extraction. Following a series of elutions, a polymerase chain reaction is carried out to amplify the DNA. After the reaction is complete, gel electrophoresis is completed to determine the presence or absence of Ehrlichia chaffeensis. 

So far, I have completed analyses on the ticks I collected this summer as well as the adult ticks that were collected in the summer of 2017. For those years, the prevalence of the pathogen in adult ticks was about 3.4% and 3.0% respectively, which is significantly higher than the prevalence in the nymph populations for the same years. I intend on completing the same analyses on the previously collected adult ticks from 2016, 2015, and 2013. Prevalence has already been determined for the nymph ticks for the listed years, so I am interested to compare how the adult ticks compare to the nymph populations. Because adult ticks have fed from more potential hosts for the pathogen, I anticipate that adult ticks will show higher prevalence than nymphs each year.

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