Singer Epidemiology

Singer RS, Cooke CL, Maddox CW, Isaacson RE, Wallace RL Journal of Veterinary Diagnostic Investigation 18:319-325 Many epidemiological studies of Salmonella rely on conventional bacteriological culture methods to detect Salmonella in fecal samples. These culture-based methods are inefficient for epidemiological studies in populations with a low prevalence of Salmonella. The objective of this study was…

Goldberg TL, Gillespie TR, Singer RS Applied and Environmental Microbiology 72:6049-6052 Repetitive-element PCR (rep-PCR) is a method for genotyping bacteria based on the selective amplification of repetitive genetic elements dispersed throughout bacterial chromosomes. The method has great potential for large-scale epidemiological studies because of its speed and simplicity; however, objective guidelines for inferring relationships among…

Singer RS, Hofacre CL Avian Diseases 50:161-172 The ways in which antibiotics are used in poultry production have changed considerably during the past decade, mainly because of concerns about potential negative human health consequences caused by these uses. Human health improvements directly attributable to these antibiotic-use changes are difficult to demonstrate. Given that some antibiotics…

Patterson SK, Singer RS Journal of Veterinary Diagnostic Investigation 18:172-181 Many methods are used to detect antibiotic resistance genes in samples. The objective of the study reported here was to compare polymerase chain reaction (PCR) analysis of community DNA with fecal culturing for detecting antibiotic resistance genes in cattle samples. In the laboratory-based portion of…

McEwen SA, Singer RS Preventive Veterinary Medicine 73:169-176 Risk assessment seeks to estimate the probability and impact of human health effects due to antimicrobial resistance arising from antimicrobial use in animals. Potential ecological pathways for the flow of antimicrobial resistant bacteria and resistance determinants through the food supply and environment are diverse and complicated and…

Singer RS, Reid-Smith R, Sischo WM Preventive Veterinary Medicine 73:153-161 Epidemiologists studying antimicrobial resistance are often interested in analyzing the association between antimicrobial resistance and antimicrobial use in animals, and on the impact of antimicrobial use in animals on the occurrence of resistance in bacteria affecting human populations. Given the various potential antimicrobial use data…

Miller GY, McNamara PE, Singer RS Preventive Veterinary Medicine 73:163-168 Economics seeks to understand and explain the allocation of resources within society and to suggest appropriate policy to achieve goals such as optimal efficiency. Relating antimicrobial use and antibiotic resistance is a complex task and requires very clear and careful analyses of many relationships. To…

Okura M, Fang J, Salto ML, Singer RS, Docampo R, Moreno SN Journal of Biological Chemistry 280:16235-16243 The phosphoinositide-specific phospholipase C (PI-PLC) is an important component of the inositol phosphate/diacylglycerol signaling pathway. A newly discovered Trypanosoma cruzi PI-PLC (TcPI-PLC) is lipid modified in its N terminus, targeted to its plasma membrane, and believed to play…

Hoar BR, Carpenter TE, Singer RS, Gardner IA Preventive Veterinary Medicine 66:79-91 Strategies designed to minimize the probability of bluetongue virus (BTV) introduction to new areas should be based on a quantitative assessment of the probability of actually establishing the virus once it is introduced. The risk of introducing a new strain of bluetongue virus…

Singer RS, Sischo WM, Carpenter TE Journal of Clinical Microbiology 42:5502-5511 Pulsed-field gel electrophoresis (PFGE) has been used extensively in epidemiological investigations of bacteria, especially during food-borne outbreaks or nosocomial infections. The relationship between similarities in PFGE patterns and true genetic relatedness is poorly understood. In this study, computer-simulated populations of Escherichia coli isolates were…

Schrader JS, Singer RS, Atwill ER Avian Diseases 48:522-530 Cellulitis has emerged as an economically important disease of broiler chickens. The impact of environmental risk factors on the incidence of cellulitis has not been evaluated in the United States. Escherichia coli (E. coli), the causative agent, is introduced through skin scratches during the grow out.…

Singer RS, Patterson SK, Meier AE, Gibson JK, Lee HL, Maddox CW Antimicrobial Agents and Chemotherapy 48:4047-4049 This study evaluated the relationship between florfenicol resistance and flo genotypes in 1,987 Escherichia coli isolates from cattle. The flo gene was detected in 164 isolates, all of which expressed resistance to florfenicol at MICs of >/=256 microg/ml.…

Hurd SH, Doores S, Hayes D, Mathew A, Maurer J, Silley P, Singer RS, Jones RN Journal of Food Protection 67:980-992 The potential impact on human health from antibiotic-resistant bacteria selected by use of antibiotics in food animals has resulted in many reports and recommended actions. The U.S. Food and Drug Administration Center for Veterinary…

Jeffrey JS, Singer RS, O’Connor R, Atwill ER Avian Diseases 48:189-195 Matched sampling of Escherichia coli from broiler house litter and bird lesions of either cellulitis or colibacillosis was conducted to investigate the relationship of pathogenic E. coli to those found in the environment. Isolates were collected from six broiler flocks representing six geographically disparate…