Margaret A. Davis, DVM, MPH, PhD
Education
PhD: Washington State University. 2002
MPH: University of Washington, 1992
DVM: Washington State University, 1985
B.S. Zoology: University of Massachusetts. 1976
Research
My research has focused on the molecular epidemiology of zoonotic
foodborne pathogens including non-Typhoid Salmonella, E. coli
O157:H7 and other STEC, Campylobacter spp. and multi-drug antibmicrobial resistance in
Salmonella and other Gram-negative
bacteria. I am particularly interested in the use of genotyping
methods to study transmission routes of zoonotic pathogens and their
maintenance and dissemination in reservoir species. I am also
interested in exploring the causes of antimicrobial resistance in
bacterial pathogens.
Selected Publications
Broschat SL, Call DR, Davis MA, Meng D, Ahmed R, Besser TE. Improved
identification of epidemiologically related strains of Salmonella
enterica using a fusion algorithm based on PFGE and MLVA. J Clin
Microbiol. 2010 Aug 25. [Epub ahead of print]
Hoelzer K, Soyer Y, Rodriguez-Rivera LD, Cummings KJ, McDonough PL,
Schoonmaker-Bopp DJ, Root TP, Dumas NB, Warnick LD, Gröhn YT,
Wiedmann M, Baker KN, Besser TE, Hancock DD, Davis MA. The
prevalence of multidrug resistance is higher among bovine than human
Salmonella enterica serotype Newport, Typhimurium, and 4,5,12:i:-
isolates in the United States but differs by serotype and geographic
region. Appl Environ Microbiol. 2010 Sep;76(17):5947-59. Epub 2010
Jul 16.
Davis MA, Baker NKN, Orfe LH, Shah D, Besser TE, Call DR. Discovery
of a gene conferring multiple aminoglycoside resistance in
Escherichia coli. Antimicrob Agents Chemother 2010;54(6):2666-9.
Davis MA, Lim JY, Soyer Y, Harbottle H, Chang YF, New D, Orfe LH,
Besser TE, Call DR. Development and validation of a resistance and
virulence gene microarray targeting Escherichia coli and Salmonella
enterica. J Microbiol Methods 2010 Mar 31 [Epub ahead of print].
Adhikari B, Besser TE, Gay JM, Fox LK, Hancock DD, Davis MA.
Multilocus variable number of tandem repeats analysis and plasmid
profiling to study the occurrence of blaCMY-2 within a PFGE defined
clade of Salmonella enterica serovar Typhimurium Appl Environ
Microbiol 2010;76:69-74.
Adhikari B, Besser TE, Gay JM, Fox LK, Davis MA, Cobbold RN, Berge
AC, Hancock
DD. The role of animal movement, including off-farm rearing of
heifers, in the
interherd transmission of multidrug-resistant Salmonella. J Dairy
Sci. 2009
Sep;92(9):4229-38.
Adhikari B, Besser TE, Gay JM, Fox LK, Davis MA, Cobbold RN, Berge
AC,
McClanahan R, Hancock DD. Introduction of new multidrug-resistant
Salmonella
enterica strains into commercial dairy herds. J Dairy Sci. 2009
Sep;92(9):4218-28.
Soyer, Y., A. Moreno Switt, M.A. Davis, J. Maurer, P.L. McDonough,
D. J. Schoonmaker-Bopp, N. B. Dumas, T. Root, L.D. Warnick, Y.T.
Gröhn and M. Wiedmann. 2009.Salmonella 4,5,12:i:-: an emerging
Salmonella serotype that represents multiple distinct clones. J.
Clin. Microbiol 2009 Sep 9. [Epub ahead of print]
Davis MA, Baker, KNK, Call DR, Warnick LD, Soyer Y, Wiedmann M,
Gröhn Y, McDonough PL, Hancock DD, Besser TE. 2009. Multiple locus
variable number of tandem repeats typing method for Salmonella
enterica serovar Newport. J Clin Microbiol 2009;47:1934-8.
Call DR, Davis MA, Sawant AA Antimicrobial resistance in beef and
dairy cattle production. Anim Health Res Rev. 2008 Dec;9(2):159-67.
Epub 2008 Nov 5.
Call DR, Orfe L, Davis MA, Lafrentz S, Kang MS. Impact of
compounding error on strategies for subtyping pathogenic bacteria.
Foodborne Pathog Dis. 2008 Aug;5(4):505-16.
Davis MA, Evermann JF, Petersen CR, VanderSchalie J, Besser TE,
Huckabee J, Daniels JB, Hancock DD, Leslie M, Baer R. Serological
survey for antibodies to Leptospira in dogs and raccoons in
Washington State. Zoonoses Public Health. 2008 Oct;55(8-10):436-42.
Chen CYC, Davis MA, LaPatra SE, Cain KE, Snekvik KR, Call DR. 2008
Genetic diversity of Flavobacterium psychrophilum recovered from
commercially raised rainbow trout, Oncorhynchus mykiss, and spawning
coho salmon, Oncorhynchus kisutch. Journal of Fish Diseases
2008;31:765-773.
Cobbold RN, Davis MA, Rice DH, Szymanski M, Tarr PI, Besser TE,
Hancock, D.D. 2008.
Associations between bovine, human, and raw milk and beef isolates
of non-O157 Shiga-toxigenic Escherichia coli within a restricted
geographic area of the USA. Journal of Food Protection.
2008;71(5):1023-7.
Davis MA, Besser TE, Eckmann K, MacDonald JK, Green D, Hancock DD,
Baker KNK, Warnick LD, Soyer Y, Wiedmann M, Call DR,
Multidrug-resistant Salmonella Typhimurium, Pacific Northwest,
United States. Emerg Infect Dis. 2007 Oct;13(10):1583-6.
Davis MA, Hancock DD, Besser TE, Daniels JB, Baker KNK, Call DR.
Antimicrobial resistance in Salmonella enterica serovar Dublin
isolates from beef and dairy sources. Veterinary Microbiology Vet
Microbiol. 2007 Jan 31;119(2-4):221-30. Epub 2006 Sep 1.
Dunowska M, Morley PS, Traub-Dargatz JL, Davis MA, Patterson G, Frye
JG, Hyatt DR, Dargatz DA. Comparison of Salmonella enterica serotype
Infantis isolates from a veterinary teaching hospital. J Appl
Microbiol 2007; 102(6):1527-36.
Davis MA, Rice DH, Sheng H, Hancock DD, Besser TE, Cobbold R, Hovde
CJ. Comparison of cultures from rectoanal junction mucosal swabs and
feces for detection of Escherichia coli O157 in dairy heifers.
Applied and Environmental Microbiology 2006;72(5):3766-70.
Davis MA, Sheng H, Newman J, Hancock DD, Hovde CJ. Comparison of a
waterless hand hygiene preparation and soap and water hand washing
to reduce coliforms on hands in animal exhibit settings.
Epidemiology and Infection 2006;134(5):1024-8.
Cobbold RN, Rice DH, Davis MA, Besser TE, Hancock DD. Long-term
persistence of multi-drug-resistant Salmonella enterica serovar
Newport in two dairy herds. Journal of the American Veterinary
Medical Association 2006;228(4):585-91.
Davis MA, Cloud-Hansen KA, Carpenter J, Hovde CJ. Escherichia coli
O157:H7 in Environments of Culture-Positive Cattle. Applied and
Environmental Microbiology. 2005;71(11):6816-22.
Sheng H, Davis MA, Knecht HJ, Hancock DD, Van Donkersgoed J, Hovde
CJ. Characterization of a shiga toxin-, intimin-, and enterotoxin
hemolysin-producing Escherichia coli ONT:H25 strain commonly
isolated from healthy cattle. Journal of Clinical Microbiology.
2005;43(7):3213-20.
Sheng H, Davis MA, Knecht HJ, Hovde CJ. Rectal administration of
Escherichia coli O157:H7: novel model for colonization of ruminants.
Applied and Environmental Microbiology 2004;70 (8):4588-4595.
LeJeune JT, Davis MA. Outbreaks of zoonotic enteric disease
associated with animal exhibits. Journal of the American Veterinary
Medical Association 2004;224(9):1440-1445.
Davis MA, Hancock DD, Besser T, Rice DH, Hovde CJ, DiGiacomo R,
Samadpour M, Call DR. Correlation between geographic distance and
genetic similarity in an international collection of bovine fecal
Escherichia coli O157:H7 isolates. Epidemiology and Infection
2003;131:923-930.
Davis MA, Hancock DD, Rice DH, Call DR, DiGiacomo R, Samadpour M,
Besser T. Feedstuffs as a vehicle of cattle exposure to Escherichia
coli O157:H7 and Salmonella enterica. Veterinary Microbiology
2003;95:199-210.
Davis MA, Hancock DD, Besser TE, Call D. Evaluation of pulsed-field
gel electrophoresis as a tool for determining the degree of genetic
relatedness between strains of Escherichia coli O157:H7. Journal of
Clinical Microbiology 2003;41:1843-1849.
Besser TE, Hancock D, Davis MA. The veterinarian's role in
controlling the emergence and dissemination of drug-resistant
bacteria. Journal of Veterinary Medical Education 2003;30(2):136-9.
Davis MA, Hancock DD, Besser TE. Multiresistant clones of Salmonella
enterica: The importance of dissemination. Journal of Laboratory and
Clinical Medicine. 2002 Sep;140(3):135-41.
Hancock D, Besser T, LeJeune J, Davis M, Rice D. The control of VTEC
in the animal reservoir. International Journal of Food Microbiology
2001;66:71-78.
Hancock D, Besser T, Gay J, Rice D, Davis M, Gay C. The global
epidemiology of multiresistant Salmonella enterica serovar
Typhimurium DT104. Chapter 11, Emerging Diseases of Animals, Edited
by C Brown and C Bolin. 2000 ASM Press, Washington, DC.
Akiba M, Rice DH, Davis MA, Masuda T, Sameshima T, Nakazawa M,
Hancock DD. A comparison of Escherichia coli O157 isolates from
cattle in Japan and the USA by molecular biological methods.
Epidemiology and Infection. 2000;125(1):221-4.
Davis MA, Hancock DD, Besser TE, Rice DH, Gay JM, Gay C, Gearhart L,
DiGiacomo R. Changes in antimicrobial resistance among Salmonella
enterica serovar Typhimurium isolates from humans and cattle in the
northwestern United States, 1982-1997. Emerging Infectious Diseases
1999;5(6):802-806.
Alexander ER, Boase J, Davis M, Kirchner L, Osaki C, Tanino T,
Samadpour M, Tarr P, Goldoft M, Lankford S, Kobayashi J, Stehr-Green
P, Bradley P, Hinton B, Tighe P, Pearson B, Flores GR, Abbott S,
Bryant R, Werner SB, Vugia DJ. Escherichia coli O157:H7 Outbreak
Linked to Commercially Distributed Dry-Cured Salami --1994
Washington and California, MMWR 1995;44(09);157-160.
Bell BP, Goldoft M, Griffin PM, Davis MA, Gordon DC, Tarr PI,
Bartleson CA, Lewis JH, Barrett TJ, Wells JG, Baron R, Kobayashi J.
A multistate outbreak of Escherichia coli O157:H7 -- associated
bloody diarrhea and hemolytic uremic syndrome from hamburgers.
Journal of the American Medical Association 1994;272:1349-1353.
