Award Date

8-1-2015

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Biological Science

First Committee Member

Helen J. Wing

Second Committee Member

Andrew Andres

Third Committee Member

Eduardo A. Robleto

Fourth Committee Member

Ernesto Abel-Santos

Number of Pages

106

Abstract

American Foulbrood Disease (AFB) is the most detrimental bacterial disease that affects honeybee larvae (Apis mellifera) worldwide. The etiological agent of AFB is the Gram-positive, spore-forming bacterial pathogen, Paenibacillus larvae. Treatment with antibiotics, specifically oxytetracycline, has led to the development of antibiotic resistance in P. larvae. Therefore, there is a pressing need for an alternative treatment method. The overall goal of this project was to test naturally occurring, active antimicrobial peptides (AMPs), which are produced in the adult honeybee, against vegetative P. larvae. These active AMPs could potentially be used as a prophylactic treatment to prevent P. larvae infection of honeybee larvae. The use of AMPs is a superior approach to preventing/treating AFB than common practices, such as antibiotics, due to the unlikeliness of developing AMP-resistant bacteria and the prevention of burning and destroying hives. My research first focuses on adapting and creating two in vitro methods in order to test the antimicrobial activity of honeybee AMPs against vegetative P. larvae. Once methods were established, a total of five AMPs were tested against P. larvae either individually or in certain combinations. I found that four of the five AMPs were capable of inhibiting P. larvae growth; however, only two AMPs met my threshold requirements and were deemed suitable candidates for AFB prophylaxis. Furthermore, based on statistical significance, none of the AMP combinations tested inhibited the growth of P. larvae more than the single active AMP. Overall, my research demonstrates that honeybee AMPs do inhibit the growth of P. larvae in vitro and have the potential to be used in use in treatments and /or prophylaxis strategies for AFB.

Keywords

American Foulbrood; antimicrobial compounds; honeybee

Disciplines

Microbiology

Language

English


Included in

Microbiology Commons

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