thumbnail of Kuster-Therio-2004

Determining sample size for the morphological assessment of sperm

September 17, 2004

Kuster CE, Singer RS, Althouse GC Theriogenology 61:691-703 Morphologic assessment of spermatozoa is an integral component in the analysis of semen. Whether a technician rapidly screening semen quality at a commercial stud, a veterinarian performing breeding soundness examinations, a clinician at a reference andrology laboratory providing auditing or diagnostic services, or a researcher evaluating morphology…

Read More
thumbnail of Singer-Lancet-2003

Antibiotic resistance—the interplay between antibiotic use in animals and human beings

September 17, 2003

Singer RS, et al The Lancet: Infectious Diseases 3:47-51 Antibiotic-resistant bacteria were first identified in the 1940s, but while new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. Today, the excessive use of antibiotics compounded by the paucity of new agents on the market has…

Read More
thumbnail of Hoar-AJVR-2003

Regional risk of exporting shipments of bluetongue virus antibody-positive cattle from the United States

September 17, 2003

Hoar BR, Carpenter TE, Singer RS, Gardner IA American Journal of Veterinary Research 64:520-529 OBJECTIVE: To create a stochastic model to quantify the risk that shipments of cattle from regions within the United States would contain animals seropositive for bluetongue virus and to determine shipment-level accuracy of serologic testing by use of a competitive ELISA…

Read More
thumbnail of Cooke-JAVMA-2002

Enrofloxacin resistance in Escherichia coli isolated from dogs with urinary tract infections

September 17, 2002

Cooke CL, Singer RS, Jang SS, Hirsh DC Journal of the American Veterinary Medical Association 220:190-192 OBJECTIVE: To assess the strain heterogeneity of enrofloxacin-resistant Escherichia coli associated with urinary tract infections in dogs at a veterinary medical teaching hospital (VMTH). In addition, strains from other veterinary hospitals in California were compared with the VMTH strains…

Read More

Antibiotics in agriculture: when is it time to close the barn door?

September 17, 2002

Lipsitch M, Singer RS, Levin BR Proceedings of the National Academy of Sciences 99:5752-5754

Read More
thumbnail of Jeffrey-Avian-Diseases-2002

Virulence factors of Escherichia coli from cellulitis or colisepticemia lesions in chickens

September 17, 2002

Jeffrey JS, Nolan LK, Tonooka KH, Wolfe S, Giddings CW, Horne SM, Foley SL, Lynne AM, Ebert JO, Elijah LM, Bjorklund G, Pfaff-McDonough SJ, Singer RS, Doetkott C Avian Diseases 46:48-52 This study was designed to compare virulence factors of cellulitis-derived Escherichia coli to colisepticemic E. coli in order to clarify whether E. coli associated…

Read More
thumbnail of Singer-Epi-Infection-2001

Selection bias in infectious disease epidemiologic studies using Escherichia coli and avian cellulitis as an example

September 17, 2001

Singer RS, Atwill ER, Carpenter TE, Jeffrey JS, Johnson WO, Hirsh DC Epidemiology and Infection 126:139-145 In epidemiological studies of infectious disease, researchers often rely on specific cues of the host, such as clinical signs, as surrogate indicators of pathogen presence. A selection bias would manifest if the specific visual cues used in sampling for…

Read More
thumbnail of Singer-BTV-viremia-JVDI-2001

Maximal predicted duration of viremia in bluetongue virus infected cattle

September 17, 2001

Singer RS, MacLachlan NJ, Carpenter TE Journal of Veterinary Diagnostic Investigation 13:43-49 Central to the development of rational trade policies pertaining to bluetongue virus (BTV) infection is determination of the risk posed by ruminants previously exposed to the virus. Precise determination of the maximal duration of infectious viremia is essential to the development of an…

Read More
thumbnail of Singer-Vet-Micro-2000

Persistence of cellulitis-associated E. coli DNA fingerprints in successive broiler chicken flocks

September 17, 2000

Singer RS, Jeffrey JS, Carpenter TE, Cooke CL, Atwill ER, Johnson WO, Hirsh DC Veterinary Microbiology 75:59-71 Avian cellulitis in broiler chickens is primarily caused by Escherichia coli. Previous research found that the E. coli isolates of cellulitis origin were unique to each ranch, suggesting that these E. coli were endemic within the ranch environment.…

Read More
thumbnail of Singer-JVDI-2000

A statistical model for assessing bacterial colony selection strategies: A case study of Escherichia coli and avian cellulitis

September 17, 2000

Singer RS, Johnson WO, Jeffrey JS, Chin RP, Carpenter TE, Atwill ER, Hirsh DC Journal of Veterinary Diagnostic Investigation 12:118-126 A general problem for microbiologists is determining the number of phenotypically similar colonies growing on an agar plate that must be analyzed in order to be confident of identifying all of the different strains present…

Read More

Bighorn sheep die-off due to presumptive Type C botulism in southern California

September 17, 2000

Swift PK, Wehausen JD, Ernest HB, Singer RS, Pauli AM, Kinde H, Rocke TE, Bleich VC Journal of Wildlife Diseases 36:184-189 During a routine telemetry flight of the Mojave Desert (California, USA) in August 1995, mortality signals were detected from two of 12 radio-collared female desert bighorn sheep (Ovis canadensis) in the vicinity of Old…

Read More

Assessing cellulitis pathogenicity of Escherichia coli isolates in broiler chickens assessed by an in vivo inoculation model

September 17, 1999

Jeffrey JS, Chin RP, Singer RS Avian Diseases 43:491-496 The purpose of this study was to identify Escherichia coli isolates that could be characterized as cellulitis pathogens. Twelve E. coli isolates from diagnostic cases of cellulitis or mixed infections with various serotypes were compared for ability to produce cellulitis and internal lesions indicative of systemic…

Read More
thumbnail of Singer-Av-Dis-1999

Spatial heterogeneity of Escherichia coli isolated from avian cellulitis lesions in broilers

September 17, 1999

Singer RS, Jeffrey JS, Carpenter TE, Cooke CL, Chin RP, Hirsh DC Avian Diseases 43:756-762 Avian cellulitis in broiler chickens is characterized by subcutaneous lesions that result in economic losses because of the partial or complete condemnation of the carcasses at processing. Escherichia coli is the primary causative agent of this condition. Previous research with…

Read More

Evaluation of severe disease induced by aerosol inoculation of calves with bovine respiratory syncytial virus (BRSV)

September 17, 1999

Woolums AR, Anderson ML, Gunther RA, Schelegele ES, LaRochelle DR, Singer RS, Boyle GA, Friebertshauser KE, Gershwin LJ American Journal of Veterinary Research 60:473-480 OBJECTIVE: To develop a model of bovine respiratory syncytial virus (BRSV) infection that induces severe disease similar to that seen in some cattle with naturally acquired BRSV infection. ANIMALS: 25 male…

Read More

Interferon gamma production during bovine respiratory syncytial virus (BRSV) infection is diminished in calves vaccinated with formalin-inactivated BRSV

September 17, 1999

Woolums AR, Singer RS, Boyle GA, Gershwin LJ Vaccine 17:1293-1297 Formalin-inactivated respiratory syncytial virus (FI-RSV) vaccination has been associated with severe disease in humans. Research in mice suggests that FI-RSV may prime for decreased interferon gamma (IFN-gamma) production at subsequent infection. Interferon-gamma production by peripheral blood mononuclear cells (PBMC) was measured following challenge of calves…

Read More