Abstract Detail

Exploring the environmental side of the disease triangle in animal pathogens

Cornelison, Christopher T [1].

Bacterially-mediated contact-independent antagonism of fungal diseases of bats and honeybees.

Continued declines of North American bats and the European honey bee, Apis mellifera, are attributed to pathogenic insults in the form of filamentous fungi.  The recently identified causative agent of White Nose Syndrome (WNS), Pseudogymnoascus destructans, has been responsible for the mortality of 7 million North American bats since its emergence in 2006. Chalkbrood disease of A. mellifera larvae is caused by Ascosphaera apis and is alleged to contribute to global honey bee declines associated with Colony Collapse Disorder (CCD). In an effort to identify potential biological and chemical control agents for WNS and Chalkbrood disease 6 previously-described bacterially-produced volatile organic compounds (VOCs) and multiply induced Rhodococcus rhodochrous DAP96253 were screened for contact-independent anti-fungal activity. Fungal spores and mycelial plugs of both pathogens were exposed to the VOCs and induced Rhodococcus in a closed air space at a range of temperatures and evaluated for inhibition of spore germination and radial growth. Subsequently, in situ application methods for induced Rhodococcus such as fixed cell catalyst and fermentation cell paste in non-growth conditions were screened with positive results. Additionally, Rhodococcus was assayed for ex vivo activity via exposure to bat tissue ex-plants inoculated with P. destructans conidia.  Pure VOCs and VOC formulations as well as induced Rhodococcus had significant inhibitory activity against both pathogens at all temperatures. As an indicator of applicability, dermal and oral toxicity of Rhodococcus VOCs were screened with adult A.mellifera and three North American bat species. Cumulatively these results represent a significant step in the development of novel, bacterially-mediated contact-independent, controls of two agriculturally significant fungal pathogens.

1 - Georgia State University, Applied and Environmental Microbiology, 24 Peachtree Center Ave, Atlanta, GA, 30303, USA

Keywords:
disease
Colony Collapse Disorder
Pseudogymnoascus destructans
White-nose Syndrome
Rhodococcus rhodochrous
volatile organic compounds
biological control.

Presentation Type: Symposium or Colloquium Presentation
Session: SY2
Location: Room 103 AB/Kellogg Hotel and Conference Center
Date: Monday, June 9th, 2014
Time: 3:30 PM
Number: SY2002
Abstract ID:119
Candidate for Awards:None