Date of Award
Spring 2021
Document Type
Honors Thesis
Department/Major
Biology
First Advisor
Dr. Benjamin Hause
Second Advisor
Mr. Jonathan Mahlberg
Third Advisor
Dr. Victor Huber
Keywords
Deformed Wing Virus (DWV), Colony Collapse Disorder (CCD), Immunoglobulin Y (IgY), honeybees, Apis mellifera, Paenibacillus larvae (P. larvae)
Subject Categories
Apiculture | Bacteriology | Immunology of Infectious Disease | Immunotherapy | Parasitology | Pathogenic Microbiology | Poultry or Avian Science | Virology
Abstract
Honeybees (Apis mellifera) are widely recognized as a vital part of the global ecosystem and the world's food supply due to their pivotal role in the pollination of both natural and agricultural flora. Colony Collapse Disorder (CCD) is an emerging phenomenon characterized by a colony's worker bees deserting the hive and leaving the queen behind. This usually results in colony failure. CCD is a multifactorial issue, with many environmental stressors and pathogens playing a role. Deformed Wing Virus (DWV) has been identified as a leading cause in this phenomenon. Paenibacillus larvae (P. larvae) is another lethal pathogen that is responsible for American Foulbrood Disease and can also ultimately lead to colony collapse. Honeybees have ineffective innate immunity against these pathogens and lack an adaptive immune system altogether.
In the research being presented, novel passive antibody therapy was used to treat DWV and P. larvae. To develop this therapeutic, white leghorn hens, which are known to confer passive immunity to the yolks of their eggs in the form of Immunoglobulin Y (IgY), were vaccinated against one of these antigens. The egg yolks were harvested, diluted, and purified to produce concentrated IgY specific to either DWV or P. larvae. This purified IgY was added to the larval diet and orally administered to 1st instar larvae in a challenge study to test its ability to protect against either DWV or P. larvae challenge. Experimental results revealed that among larvae challenged with DWV, mortality dropped from 79% to just 29% when a 1:100 dilution of DWV-specific IgY was administered. Likewise, larvae challenged with P. larvae saw mortality drop from 100% to only 17% when treated with a 1:100 dilution of P. larvae-specific IgY. The mortality trends in both models were supported by corresponding molecular data in the form of either RT-PCR or CFU/mL data. These results suggest that pathogen-specific IgY may provide honeybee larvae with approximately 50% protection against lethal DWV disease and 80% protection against lethal P. larvae disease – figures that would significantly reduce CCD. This technology could have a profound impact on the future of beekeeping – an industry that is key to avoiding a global food sustainability crisis.
Recommended Citation
Nordseth, Tanner, "Effectiveness of Pathogen-Specific Passive Antibodies to Mitigate Infectious Diseases in Apis Mellifera" (2021). Honors Thesis. 128.
https://red.library.usd.edu/honors-thesis/128
Included in
Apiculture Commons, Bacteriology Commons, Immunology of Infectious Disease Commons, Immunotherapy Commons, Parasitology Commons, Pathogenic Microbiology Commons, Poultry or Avian Science Commons, Virology Commons