Browsing by Author "Singer, Randall"

Now showing 1 - 5 of 5
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    Antimicrobial use and resistance: The risk to humans
    (2004-09-18) Singer, Randall
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    Changes in the Porcine Intestinal Microbiome in Response to Infection with Salmonella Enterica and Lawsonia Intracellularis
    (2015-05-13) Borewicz, Klaudyna; Kim, Hyeun; Singer, Randall; Gebhart, Connie; Sreevatsan, Srinand; Johnson, Timothy; Isaacson, Richard; isaac015@umn.edu; Isaacson, Richard
    Salmonella enterica is a leading cause of food borne illness. Recent studies have shown that S. enterica is a pathogen capable of causing alterations to the composition of the intestinal microbiome. A recent prospective cross-sectional study of French pork production farms found a statistically significant association between Lawsonia intracellularis and carriage of S. enterica. In the current study the composition of the gut microbiome was determined in pigs challenged with S. enterica serovar Typhimurium and or L. intracellularis and compared to non-challenged control pigs. Principal coordinate analysis demonstrated that there was a disruption in the composition of the gut microbiome in the colon and cecum of pigs challenged with either pathogen. The compositions of the microbiomes of challenged pigs were similar to each other but differed from the non-challenged controls. There also were statistically significant increases in Anaerobacter, Barnesiella, Pediococcus, Sporacetigenium, Turicibacter, Catenibacterium, Prevotella, Pseudobutyrivibrio, and Xylanibacter in the challenged pigs. To determine if these changes were specific to experimentally challenged pigs, we determined the compositions of the fecal microbiomes of naturally infected pigs that were carriers of S. enterica. Pigs that were frequent shedders of S. enterica were shown to have similar fecal microbiomes compared to non-shedders or pigs that shed S. enterica infrequently. In a comparison of the differentially abundant bacteria in the naturally infected pigs compared to experimentally challenged pigs, 9 genera were differentially abundant and each exhibited the same increase or decrease in abundance between the two groups. Thus, there were similar changes in the GI microbiome associated with carriage of S. enterica regardless of whether the pigs were experimentally challenged with S. enterica or acquired it naturally.
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    Data, Model Documentation, and Output Supporting "Optimizing syndromic health surveillance in free ranging great apes: the case of Gombe National Park"
    (2018-05-24) Wolf, Tiffany, M; Wang, Wenchun, A; Lonsdorf, Elizabeth V; Gillespie, Thomas; Pusey, Anne; Gilby, Ian; Travis, Dominic A; Singer, Randall; wolfx305@umn.edu; Wolf, Tiffany M
    Syndromic surveillance is an incipient approach to early wildlife disease detection. Consequently, systematic assessments are needed for methodology validation in wildlife populations. We evaluated the sensitivity of a syndromic surveillance protocol for respiratory disease detection among chimpanzees in Gombe National Park, Tanzania. Empirical health, behavioral and demographic data were integrated with an agent-based, network model to simulate disease transmission and surveillance. Surveillance sensitivity was estimated as 66% (95% Confidence Interval: 63.1, 68.8%) and 59.5% (95% Confidence Interval: 56.5%, 62.4%) for two monitoring methods (weekly count and prevalence thresholds, respectively), but differences among calendar quarters in outbreak size and surveillance sensitivity suggest seasonal effects. We determined that a threshold weekly detection of ≥2 chimpanzees with clinical respiratory disease leading to outbreak response protocols (enhanced observation and biological sampling) is an optimal algorithm for outbreak detection in this population. Synthesis and applications: This is the first quantitative assessment of syndromic surveillance in wildlife, providing a model approach addressing disease emergence. Coupling syndromic surveillance with targeted diagnostic sampling in the midst of suspected outbreaks will provide a powerful system for detecting disease transmission and understanding population impacts.
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    Ecology of antibacterial resistance
    (2006-09-23) Singer, Randall
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