137 research outputs found

    Antimicrobial resistance patterns of Campylobacter from feedlot cattle

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    Aims: This study examined 448 Campylobacter strains isolated in 1999 and 2000 from US feedlot cattle for resistance to 12 antimicrobials. Methods and Results: Isolates were tested for antimicrobial susceptibility using the E-test method. Approximately 60% (n = 267) were resistant to one or more antimicrobials, and 19·6% (n = 88) were resistant to two or more antimicrobials. Of the Campylobacter jejuni isolates, 49·1% (n = 187) were resistant to tetracycline, 10·2% (n = 39) were resistant to nalidixic acid, 8·4% were resistant to trimethoprim/sulfamethoxazole, and 1·8% (n = 7) were resistant to ciprofloxacin. Resistance to any of the other eight antimicrobials was 1·3% or less, but 14·4% (n = 55) were resistant to two or more antimicrobials. In the Campylobacter coli group, 65·7% (n = 44) were resistant to tetracycline, 52·2% (n = 35) were resistant to trimethoprim/sulfamethoxazole, 22·4% (n = 15) were resistant to nalidixic acid, and 9·0% (n = 6) were resistant to ciprofloxacin. Resistance to any of the remaining eight antimicrobials was 3·0% or less, although 49·3% (n = 33) were resistant to two or more antimicrobials. Conclusions: Although antimicrobials are widely used in US feedlot cattle production, our results demonstrate generally low levels of resistance to a broad range of commonly used antimicrobials relative to other recent studies. Significance and Impact of the Study: Resistance data on Campylobacter isolated from this major US livestock commodity is lacking. This overview enhances current knowledge and provides a basis for further studies

    Antimicrobial resistance patterns of Campylobacter from feedlot cattle

    Get PDF
    Aims: This study examined 448 Campylobacter strains isolated in 1999 and 2000 from US feedlot cattle for resistance to 12 antimicrobials. Methods and Results: Isolates were tested for antimicrobial susceptibility using the E-test method. Approximately 60% (n = 267) were resistant to one or more antimicrobials, and 19·6% (n = 88) were resistant to two or more antimicrobials. Of the Campylobacter jejuni isolates, 49·1% (n = 187) were resistant to tetracycline, 10·2% (n = 39) were resistant to nalidixic acid, 8·4% were resistant to trimethoprim/sulfamethoxazole, and 1·8% (n = 7) were resistant to ciprofloxacin. Resistance to any of the other eight antimicrobials was 1·3% or less, but 14·4% (n = 55) were resistant to two or more antimicrobials. In the Campylobacter coli group, 65·7% (n = 44) were resistant to tetracycline, 52·2% (n = 35) were resistant to trimethoprim/sulfamethoxazole, 22·4% (n = 15) were resistant to nalidixic acid, and 9·0% (n = 6) were resistant to ciprofloxacin. Resistance to any of the remaining eight antimicrobials was 3·0% or less, although 49·3% (n = 33) were resistant to two or more antimicrobials. Conclusions: Although antimicrobials are widely used in US feedlot cattle production, our results demonstrate generally low levels of resistance to a broad range of commonly used antimicrobials relative to other recent studies. Significance and Impact of the Study: Resistance data on Campylobacter isolated from this major US livestock commodity is lacking. This overview enhances current knowledge and provides a basis for further studies

    Salmonella prevalence and antimicrobial resistance in swine from 5 US states from 2003 to 2005

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    The Collaboration in Animal Health and Food Safety Epidemiology (CAHFSE), a USDA joint program of ARS, APHIS, and FSIS was established to track food borne pathogens and monitor animal health issues. Fecal samples (n=9020) were collected and cultured for Salmonella from pens of pigs near slaughter weight (generally~ 22 weeks old) from swine farms in five U.S. states. A prevalence of 8.0, 10.1, and 8.5% was observed in 2003, 2004, and 2005, respectively The top 10 serotypes accounted for 94% of the total Salmonella isolates with S. Derby (45%), S. Typhimurium var. 5- (15%), and S Heidelberg (9%) comprising the top three serotypes each year. Salmonella Give was found in 8% of samples in 2003, 3% of samples m 2004, but was not found in the top 10% of ISolates m 2005. The percentage of Salmonella isolates that were susceptible to all of the 16 antimicrobials tested increased from 6% in 2003 to 15% in 2005. At the same time, the percentage of isolates resistant to 10 or more antimicrobials increased from 1% to 15%. The increase in multiple drug resistance was coincident with an increase in the percentage of S. Derby isolates. Overall, frequency of resistance to individual antimicrobials was relatively stable from 2003 to 2005 and observed differences were related to changes in serotypes over time, which highlights the importance of reporting resistance data by individual serotype. CAHFSE provides a mechanism to monitor changes in serotypes of Salmonella as well as antimicrobial resistance patterns over time

    Antimicrobial resistance in Salmonella from 1997-2003 NARMS swine samples

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    A total of 3246 swine slaughter and 3147 swine diagnostic Salmonella isolates from the National Antimicrobial Resistance Monitoring System (NARMS) for the years 1997-2003 were tested for antimicrobial resistance. No resistance was detected in any Salmonella isolates for ciprofloxacin or amikacin. For all other antimicrobics tested, more resistance was observed in diagnostic isolates compared to slaughter isolates

    Salmonella serotypes from 1997-2003 NARMS swine diagnostic, on-farm, and slaughter samples

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    The veterinary component of the National Antimicorbial Resistance Monitoring System (NARMS) identified 8527 Salmonella isolates from swine samples in the years 1997-2003. Fifty-one Salmonella serotypes were identified from 3147 diagnostic, 2138 on-farm, and 3246 slaughter samples

    Distribution of \u3ci\u3eCulicoides sonorensis\u3c/i\u3e (Diptera: Ceratopogonidae) in Nebraska, South Dakota, and North Dakota: Clarifying the Epidemiology of Bluetongue Disease in the Northern Great Plains Region of the United States

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    The presence or absence of the biting midge Culicoides sonorensis Wirth & Jones (Diptera: Ceratopogonidae), a primary vector of bluetongue viruses (genus Orbivirus, family Reoviridae, BTV) in North America, was assessed on ranches and farms across the Northern Great Plains region of the United States, specifically Nebraska, South Dakota, and North Dakota, as part of a 2-yr regional study of BTV exposure among cattle. Blacklight/suction trap samples totaling 280 2-night intervals were taken at 140 aquatic sites (potential larval habitat for C. sonorensis) on 82 livestock operations (ranches and farms) that span a south-to-north gradient of expected decreasing risk for exposure to BTV. In Nebraska, C. sonorensis populations were common and widespread, present at 15 of 18 operations. Of 32 operations sampled in South Dakota, seven of which were sampled in successive years, 18 were positive for C. sonorensis; 13 of 14 operations located west of the Missouri River were positive, whereas 13 of 18 operations east of the river were negative. Of 32 operations sampled in North Dakota, seven of which were sampled both years, 12 were positive for C. sonorensis. Six of eight operations located west and south of the Missouri River in North Dakota were positive, whereas 18 of 24 operations east and north of the river were negative for C. sonorensis. These data illustrate a well-defined pattern of C. sonorensis spatial distribution, with populations consistently present across Nebraska, western South Dakota, and western North Dakota; western South Dakota, and North Dakota encompass the Northwestern Plains Ecoregion where soils are nonglaciated and evaporation exceeds precipitation. In contrast, C. sonorensis populations were largely absent east of the Missouri River in South Dakota and North Dakota; this area comprises the Northwestern Glaciated Plains Ecoregion and Northern Glaciated Plains Ecoregion where surface soils reflect Wisconsinan glaciation and precipitation exceeds evaporation. In defining a well-demarcated pattern of population presence or absence on a regional scale, the data suggest that biogeographic factors regulate the distribution of C. sonorensis and in turn BTV exposure. These factors, ostensibly climate and soil type as they affect the suitability of larval habitat, may explain the absence of C. sonorensis, hence limited risk for exposure to BTV, across the eastern Northern Plains, upper Midwest, and possibly Northeast, regions of the United States

    Antimicrobial susceptibility of salmonella isolates from swine

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    The emergence of antimicrobial resistance among bacteria is of growing concern to practitioners and producers. Problems associated with the emergence of resistance include treatment failure, prolonged shedding, and the development oflong term carriage of the resistant bacteria in the host. The emergence of resistance among Salmonella species is particularly worrisome as it is a zoonotic agent and is ubiquitous in nature

    Prediction of overall survival for patients with metastatic castration-resistant prostate cancer : development of a prognostic model through a crowdsourced challenge with open clinical trial data

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    Background Improvements to prognostic models in metastatic castration-resistant prostate cancer have the potential to augment clinical trial design and guide treatment strategies. In partnership with Project Data Sphere, a not-for-profit initiative allowing data from cancer clinical trials to be shared broadly with researchers, we designed an open-data, crowdsourced, DREAM (Dialogue for Reverse Engineering Assessments and Methods) challenge to not only identify a better prognostic model for prediction of survival in patients with metastatic castration-resistant prostate cancer but also engage a community of international data scientists to study this disease. Methods Data from the comparator arms of four phase 3 clinical trials in first-line metastatic castration-resistant prostate cancer were obtained from Project Data Sphere, comprising 476 patients treated with docetaxel and prednisone from the ASCENT2 trial, 526 patients treated with docetaxel, prednisone, and placebo in the MAINSAIL trial, 598 patients treated with docetaxel, prednisone or prednisolone, and placebo in the VENICE trial, and 470 patients treated with docetaxel and placebo in the ENTHUSE 33 trial. Datasets consisting of more than 150 clinical variables were curated centrally, including demographics, laboratory values, medical history, lesion sites, and previous treatments. Data from ASCENT2, MAINSAIL, and VENICE were released publicly to be used as training data to predict the outcome of interest-namely, overall survival. Clinical data were also released for ENTHUSE 33, but data for outcome variables (overall survival and event status) were hidden from the challenge participants so that ENTHUSE 33 could be used for independent validation. Methods were evaluated using the integrated time-dependent area under the curve (iAUC). The reference model, based on eight clinical variables and a penalised Cox proportional-hazards model, was used to compare method performance. Further validation was done using data from a fifth trial-ENTHUSE M1-in which 266 patients with metastatic castration-resistant prostate cancer were treated with placebo alone. Findings 50 independent methods were developed to predict overall survival and were evaluated through the DREAM challenge. The top performer was based on an ensemble of penalised Cox regression models (ePCR), which uniquely identified predictive interaction effects with immune biomarkers and markers of hepatic and renal function. Overall, ePCR outperformed all other methods (iAUC 0.791; Bayes factor >5) and surpassed the reference model (iAUC 0.743; Bayes factor >20). Both the ePCR model and reference models stratified patients in the ENTHUSE 33 trial into high-risk and low-risk groups with significantly different overall survival (ePCR: hazard ratio 3.32, 95% CI 2.39-4.62, p Interpretation Novel prognostic factors were delineated, and the assessment of 50 methods developed by independent international teams establishes a benchmark for development of methods in the future. The results of this effort show that data-sharing, when combined with a crowdsourced challenge, is a robust and powerful framework to develop new prognostic models in advanced prostate cancer.Peer reviewe

    Serotypes and Antimicrobial Resistance in Salmonella Isolates from Swine, NARMS-EB 1997-2000

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    The National Antimicrobial Resistance Monitoring System (NARMS) was developed in 1996 as a collaborative effort between the FDA, USDA, and CDC to monitor antimicrobial resistance development in enteric organisms in humans and animals. Salmonella was selected as the sentinel organism
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