Browsing by Author "Singer, Randall S."

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    Determination of the antibiotic and antibiotic resistance footprint in surface water environment of a metropolitan area: Effects of anthropogenic activities
    (2022-09-26) He, Huan; Bueno, Irene; Kim, Taegyu; Wammer, Kristine H.; LaPara, Timothy M.; Singer, Randall S.; Beaudoin, Amanda; Arnold, William A.; heh@umn.edu; He, Huan; University of Minnesota Department of Civil, Environmental, and Geo- Engineering; University of Minnesota Department of Veterinary and Biomedical Sciences; University of St Thomas Department of Chemistry; Minnesota Department of Health
    This study investigated geospatial distributions of antibiotics and antibiotic resistance genes (ARGs) in surface waters and their associations with anthropogenic activities. During July‒October 2020, the concentrations of antibiotics (water and sediment) and ARGs (sediment) were measured at 39 sites in the Twin Cities metropolitan area (Minnesota) that experience a gradient of impacts related to human activities. For water samples, the number of antibiotics detected and the concentrations of certain antibiotics (e.g., sulfonamides) positively correlated with urbanization indicators (e.g., urban percentage, population density, number of wastewater discharge points; ρ =0.32‒0.46, p =0.003‒0.04) and negatively correlated with undeveloped land indicators (e.g., forest; ρ =-0.34‒-0.62, p =<0.00001‒0.04). Antibiotics in sediments exhibited geospatial distribution different from that in corresponding water samples and exhibited no associations with anthropogenic factors. Relative abundances of ARGs were not associated with anthropogenic factors, but several ARGs (e.g., blaoxa, mexB, and sul2) were inversely related to the organic content of sediments (ρ =-0.38‒-0.44, p =0.01‒0.04). Strong correlations were found among relative abundances of various ARGs and intI1 (ρ ≥ 0.67, p < 0.05), highlighting their co-occurrence in (sub)urban surface waters. These results identified promising anthropogenic/environmental factors for predicting antibiotic geospatial distributions and useful gene markers to monitor ARGs in surface waters.
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    E-supplement to: Efficacy of antibiotic and non-antibiotic interventions in preventing and treating necrotic enteritis in broiler chickens: a systematic review
    (2022) Bueno, Irene; Ricke, Isabel; Hwan, Haejin; Smith, Emily; Nault, Andre; Johnson, Timothy; Singer, Randall S.
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    Efficacy of antibiotic and non-antibiotic interventions in preventing and treating necrotic enteritis in broiler chickens: a protocol for a systematic review
    (2020) Bueno, Irene; Smith, Emily; Hwang, Haejin; Nault, Andre J.; Valeris-Chacin, Robert; Singer, Randall S.
    Necrotic enteritis is one of the most common and economically important bacterial diseases affecting the broiler industry. Limitations on the use of antimicrobials have highlighted the need to evaluate the efficacy of non-antibiotic alternatives and management strategies. However, the available evidence on the efficacy of non-antibiotic interventions for necrotic enteritis has not been systematically synthesized. Here we present a protocol to conduct a systematic review of the literature to assess the efficacy of non-antibiotic interventions compared to antibiotic interventions in preventing and treating necrotic enteritis cases in broiler chickens.
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    Efficacy of prebiotics and probiotics on growth performance in poultry: A protocol for a systematic review
    (2020) Hwang, Haejin; Miller, Elizabeth A.; Johnson, Abigail; Valeris-Chacin, Robert; Nault, Andre J.; Singer, Randall S.; Johnson, Timothy J.
    The use of prebiotics and probiotics as dietary additives in poultry has been practiced widely as an alternative to antibiotics and to support gut health. Despite the wealth of products available, there is currently a lack of clear scientific evidence that the use of prebiotics and probiotics beneficially impact growth performance in poultry. The aim of this protocol paper is to document the process of a systematic review addressing the following review question: Does oral administration of a prebiotic (defined as dietary fiber, dietary carbohydrates, oligosaccharides, or yeast cell wall) or probiotic (defined or undefined single or mixed cultures of living bacteria, fungi, and/or yeast) provide beneficial effects on growth performance in broiler chickens and turkeys? The proposed systematic review will provide evidence on the effectiveness of prebiotics and probiotics for enhancing growth performance in poultry, and will help to alleviate high skepticism, criticism, and confusion over the use of prebiotics and probiotics in poultry among poultry producers.
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    Systematic review protocol of the efficacy of prebiotics and probiotics in reducing the colonization and shedding of Campylobacter and Salmonella in broilers and turkeys
    (2020) Valeris-Chacin, Robert; Nault, Andre J.; Hwang, Haejin; Weber, Bonnie; Bueno, Irene; Johnson, Timothy J.; Pieters, Maria; Singer, Randall S.
    Use of prebiotics and probiotics as an alternative to antibiotics is increasing in poultry 16 production. However, there is still uncertainty about their efficacy in controlling the spread of 17 human pathogens in poultry. This paper describes the protocol for a systematic review assessing18 the efficacy of prebiotics and probiotics in reducing the colonization and shedding of 19 Campylobacter and Salmonella in broiler chickens and turkeys. The objective of this protocol is 20 to document the methodology that will be used for the systematic review a priori.