Dr. David H. Ley
Professor, Poultry Health Management
Diplomate, American College of Veterinary Microbiologists
Diplomate, American College of Poultry Veterinarians
- BS - Biological Sciences, University of California, Irvine, 1971
- MA - Microbiology, University of California, Davis, 1976
- DVM - University of California, Davis, 1982
- PhD - Microbiology, University of California, Davis, 1982
Areas of Research/Study
- Poultry diseases
- Avian mycoplasmosis
- Identification and control of emerging avian diseases
- Enteric and respiratory avian disease pathogenesis
- Interaction of management and disease
Mycoplasma species are important respiratory tract and systemic pathogens of commercial poultry causing substantial economic losses worldwide due to increased mortality, downgrading and condemnations of carcasses, reduced egg production and hatchability, and decreased feed efficiency. Strategies to reduce the adverse impact of mycoplasmosis in commercial poultry include
- surveillance, control, and eradication programs
- use of antimicrobials, and
Research in my laboratory is focused on improving the health of commercial poultry by developing new knowledge that will contribute to the elimination or reduction of losses due to mycoplasmosis. Specific objectives are to 1) develop and evaluate rapid diagnostic capabilities for the identification of Mycoplasma species and strains causing diseases, 2) to delineate the epidemiology of avian mycoplasmosis by developing and using strain-specific molecular markers and gene sequencing, and 3) to study the dynamics of Mycoplasma gallisepticum conjunctivitis in songbirds from emergence to endemicity.
Emergency Preparedness: Training, Certifications, Affiliations
- Hazardous Materials Awareness Class, North Carolina Division of Emergency Management, 11Mar06.
- Veterinary Response Corps Certificate of Training, North Carolina Department of Agriculture & Consumer Services, Emergency Programs Division, 11Mar06.
- Incident Command System (ICS) 100 Training, USDA, 3May06.
- Incident Command System (ICS) 200 Training, USDA, 18May06.
- National Incident Management System (NIMS) an Introduction IS-700 Independent Study Course, Emergency Management Institute, National Emergency Training Center, 24May06.
- American College of Veterinary Microbiologists, Biosecurity Task Force, 19May06.
- North Carolina Veterinary Response Corps, North Carolina Department of Agriculture & Consumer Services, 30Aug06.
- National Turkey Federation Avian Influenza Scientific Advisory Board, Nov06.
- Depopulation Strike Team Training, North Carolina Department of Agriculture & Consumer Services, Emergency Programs Division. Raleigh, NC, 30 Mar 2007
- Poultry FAD Awareness for Industry Veterinarians, USDA-APHIS. Nashville, TN, 17-19 Apr 2007.
- Registered with USAID DAI STOP AI (http://www.dai.com/work/project_detail.php?pid=163) Expert Resource Network.
- Registered with USDA International Coordination Group (ICG) for Highly Pathogenic Avian Influenza (http://www.usaha.org/news/bulletin/AgSpecialistSOW.pdf).
- Registered with Bird Flu Control (http://www.bfc-birdflucontrol.com/index.html) as Technical Expert.
- Avian Influenza Workshop and Depopulation Strike Team Training, NCDA&CS Emergency Programs Division. Raleigh, NC, 15 April 2008.
- Flu DETECT, Certificate of Training for Synbiotics Avian Influenza Virus Type A Antigen Test Kit. Raleigh, NC, 15 April 2008.
- IATA training for the Shipping of Infectious Substances & Dry Ice, Saf-T-Pac Inc., Edmonton AB, tested as per 49 CFR 172.70. Date of exam 18 April 208, date of expiry 18 April 2010.
- UN Basic Security in the Field – Staff Safety, Health, and Welfare. United Nations Department of Safety and Security. 4 June 2008.
- UN Advanced Security in the Field. United Nations Department of Safety and Security. 6 June 2008.
- Respirator mask fit-test (quantitative, according to USDA-APHIS specifications), completed 8 July 2008.
Appointments and Honors
- Phibro Animal Health Excellence in Poultry Research Award, 2012.
- Professor, Department of Population Health & Pathobiology, College of Veterinary Medicine, North Carolina State University; 1997-present.
- Visiting Research Fellow, University of Melbourne (Australia), Department of Veterinary Science; 6/93-4/94.
- Associate Professor, Department of Food Animal & Equine Medicine, College of Veterinary Medicine, North Carolina State University; 1989-1997.
- Assistant Professor, Department of Food Animal & Equine Medicine, College of Veterinary Medicine, North Carolina State University; 1984-1989.
- NCSU-CVM Class of 2004 Faculty Teaching Award; 2003.
- NC State University Alumni Outstanding Research Award Nominee: 2000-2001.
- Recipient of a congratulatory resolution from the National Poultry Improvement Plan; 2000.
- Best Poster, AVMA/AAAP Annual Meeting; 1996.
- Best Poster, AVMA/AAAP Annual Meeting; 1995.
- Phi Zeta Honor Society of Veterinary Medicine: Member Elect; 1989
- United States Department of Agriculture Animal Health Science Research Advisory Board Nominee; 1986.
- Ley DH, Berkhoff JE and JM McLaren. Mycoplasma gallisepticum isolated from house finches (Carpodacus mexicanus) with conjunctivitis. Avian Dis. 40:480-483. 1996.
- Ley DH, JM McLaren, AM Miles, HJ Barnes, S Heins Miller and G Franz. Transmissibility of live Mycoplasma gallisepticum vaccine strains ts-11 and 6/85 from vaccinated layer pullets to sentinel poultry. Avian Dis. 41:186-193. 1997.
- Noormohammadi AH, PF Markham, KG Whithear, ID Walker, VA Gurevich, DH Ley, and GF Browning. Mycoplasma synoviae has two distinct phase-variable major membrane antigens, one of which is a putative hemagglutinin. Infection and Immunity 65:2542-2547. 1997.
- Ley DH, JE Berkhoff and S Levisohn. Molecular epidemiological investigations of Mycoplasma gallisepticum (MG) conjunctivitis in songbirds by random amplified polymorphic DNA (RAPD) analyses. Emerging Infectious Diseases, 3:375-380. 1997.
- Ley DH, Geary SJ, Berkhoff JE, McLaren JM and Levisohn S. Mycoplasma sturni from blue jays and northern mockingbirds with conjunctivitis in Florida. Journal of Wildlife Diseases, 34:403-406. 1998.
- Hartup BK, Kollias GV, Ley DH. Mycoplasmal conjunctivitis in songbirds from New York. Journal of Wildlife Diseases, 36:257-264. 2000.
- Mikaelian I, Ley DH, Claveau R, Lemieux M, Berube J-P. Mycoplasmosis in evening and pine grosbeaks with conjunctivitis in Quebec. J Wildl Dis 37:826-830. 2001.
- Hartup BK, Bickal JM, Dhondt AA, Ley DH, Kollias GV. Dynamics of conjunctivitis and Mycoplasma gallisepticum infections in house finches. The Auk 118(2):327-333. 2001.
- Pakpinyo S, Ley DH, Barnes HJ, Vaillancourt JP, Guy JS. Prevalence of enteropathogenic Escherichia coli in naturally occurring cases of poult enteritis-mortality syndrome. Avian Diseases, 46:360-369. 2002.
- Pakpinyo S, Ley DH, Barnes HJ, Vaillancourt JP, Guy JS. Enhancement of enteropathogenic Escherichia coli pathogenicity in young turkeys by concurrent turkey coronavirus infection. Avian Diseases, 47:396-405. 2003.
- Pillai, SR, Mays HL, Jr., Ley DH, Luttrell P, Panangala VS, Farmer KL, Roberts SR. Molecular variability of house finch Mycoplasma gallisepticum isolates as revealed by sequencing and restriction fragment length polymorphism analysis of the pvpA gene. Avian Diseases, 47:640-648. 2003.
- Kollias GV, Sydenstricker KV, Kollias HW, Ley DH, Hosseini PR, Connolly V, Dhondt AA. Experimental infection of house finches with Mycoplasma gallisepticum. Journal of Wildlife Diseases, 40:79-86. 2004.
- Hartup BK, Stott-Messick B, Guzy M, Ley DH. Health survey of house finches (Carpodacus mexicanus) from Wisconsin. Avian Diseases, 48:84-90. 2004.
- Hong Y, Garcia M, Levisohn S, Savelkoul P, Leiting V, Lysnyansky I, Ley DH, Kleven SH. Differentiation of Mycoplasma gallisepticum strains using amplified fragment length polymorphism and other DNA-based typing methods. Avian Diseases 49:43-49. 2005.
- Dhondt AA, Altizer S, Cooch EG, Davis AK, Dobson A, Driscoll MJL, Hartup BK, Hawley DM, Hochachka WM, Hosseini PR, Jennelle CS, Kollias GV, Ley DH, Swarthout ECH, Sydenstricker KV. Dynamics of a novel pathogen in an avian host: Mycoplasmal conjunctivitis in house finches. Acta Tropica Vol. 94, No. 1, pp 77-93. 2005.
- Sydenstricker KV, Dhondt AA, Ley DH, Kollias GV. Re-exposure of captive house finches that recovered from Mycoplasma gallisepticum infection. Journal of Wildlife Diseases 41:326-333. 2005.
- Cherry JJ, Ley DH, Altizer S. Genotypic analyses of Mycoplasma gallisepticum isolates from songbirds by random amplification of polymorphic DNA and amplified-fragment length polymorphism. Journal of Wildlife Diseases. In press 2005.
- Ley DH, Sheaffer DS, Dhondt AA. Further western spread of Mycoplasma gallisepticum infection of house finches. Journal of Wildlife Diseases 42:429-431, 2006.
- Cherry JJ, Ley DH, Altizer S. Genotypic analyses of Mycoplasma gallisepticum isolates from songbirds by random amplification of polymorphic DNA and amplified-fragment length polymorphism. Journal of Wildlife Diseases 42:421-428, 2006.
- Dhondt AA, Badyaev AV, Dobson AP, Hawley DM, Driscoll MJL, Hochachka WM, Ley DH. Dynamics of mycoplasmal conjunctivitis in the native and introduced range of the host. EcoHealth 3, 95–102, 2006.
- Sanei B, Barnes HJ, Vaillancourt J-P, Ley DH. Experimental infection of chickens and turkeys with Mycoplasma gallisepticum reference strain S6 and North Carolina field isolate RAPD type B. Avian Diseases 51:106-111, 2007.
- Osorio C, Fletcher OJ, Abdul-Aziz T, Gonder E, Tilley B, Ley DH. Pneumonia of turkey breeder hens associated with Mycoplasma synoviae. Avian Diseases 51:791-796, 2007.
- Dhondt KV, Dhondt AA, Ley DH. Effects of route of inoculation on Mycoplasma gallisepticum infection in captive house finches. Avian Pathology 36(3):205-8, 2007.
- Ley DH, Marusak RA, Vivas EJ, Barnes HJ, Fletcher OJ. Mycoplasma iowae associated with chondrodystrophy in commercial turkeys. Avian Pathology 39(2):87-93. 2010.
- Tulman ER, Liao X, Szczepanek SM, Ley DH, Kutish GF, Geary SJ. Extensive variation in surface lipoprotein gene content and genomic changes associated with virulence during evolution of a novel North American house finch epizootic strain of Mycoplasma gallisepticum . Microbiology 158(8), 2073-88. 2012.
- Hawley DM, Osnas EE, Dobson AP, Hochachka WM, Ley DH, Dhondt AA. Parallel patterns of increased virulence in a recently emerged wildlife pathogen. PLoS Biol 11(5): e1001570. doi:10.1371/journal.pbio.1001570. 2013.
- Hochachka WM, Dhondt AA, Dobson AP, Hawley DM, Ley DH, Osnas EE. Multiple host transfers, but only one successful lineage in a continent-spanning emergent pathogen. Proceedings of the Royal Society B: Biological Sciences 280: 20131068. http://dx.doi.org/10.1098/rspb.2013.1068. 2013.
- Ley DH, HW Yoder, Jr. Mycoplasma gallisepticum infection. In: Diseases of Poultry, 10th ed, BW Calnek, HJ Barnes, CW Beard, LR McDougald, YM Saif, eds. Ames, Iowa: Iowa State University Press, pp. 194-207. 1997.
- Ley DH. Mycoplasma gallisepticum infection. In: Diseases of Poultry, 11th ed, BW Calnek, HJ Barnes, CW Beard, LR McDougald, YM Saif, eds. Ames, Iowa: Iowa State University Press, pp. 722-744. 2003.