12 results on '"Hannah Schubert"'
Search Results
2. Factors Influencing the Detection of Antibacterial Resistant Escherichia coli in Faecal Samples from Individual Cattle
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Jordan E. Sealey, Matthew B. Avison, Hannah Schubert, Emma F. Puddy, Tristan A Cogan, Virginia C. Gould, Kristen K Reyher, and Andrea Turner
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Sample handling ,Veterinary medicine ,Future studies ,business.industry ,Biology ,Amoxicillin ,Logistic regression ,medicine.disease_cause ,Odds ,Cefalexin ,medicine ,Livestock ,business ,Escherichia coli ,medicine.drug - Abstract
AimsTo investigate whether on-farm antibacterial usage (ABU), environmental antibacterial resistant (ABR) Escherichia coli prevalence, and sampling and sample handling methodologies are associated with ABR E. coli positivity in individual faecal samples from dairy heifers.Methods and ResultsThree hundred and sixty-four heifers from 37 farms were sampled via rectal or faecal pat sampling. Samples were stored at -80°C for variable periods before microbiological analysis. Data analysis was through a multilevel, multivariable logistic regression approach.Individual rectal samples had increased odds of positivity for amoxicillin, cefalexin and tetracycline-resistant E. coli. Sample storage for 6-12 month was associated with decreased odds of finding amoxicillin and tetracycline-resistant E. coli. On-farm ABU had little influence, and environmental ABR E. coli prevalence had no significant influence on on the odds of sample-level positivity for ABR E. coli.ConclusionsSampling methodology and sample handling have a greater association than on-farm factors with the detection of ABR E. coli in individual faecal samples from dairy heifers.Significance and Impact of the StudySampling and storage methodologies should be considered carefully at the point of designing ABR surveillance studies in livestock and their environments and, where possible, standardised between and within future studies.
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- 2021
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3. Limited phylogenetic overlap between fluoroquinolone-resistant Escherichia coli isolated on dairy farms and those causing bacteriuria in humans living in the same geographical region
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Oliver Mounsey, Katy Morley, Emma F. Puddy, Katy Turner, Hannah Schubert, Philip B Williams, Virginia C. Gould, Karen E. Bowker, Paul North, Matthew B. Avison, O. Martin Williams, David C Barrett, Kristen K. Reyher, Tristan A Cogan, Alasdair P. MacGowan, and Jacqueline Findlay
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single nucleotide ,Microbiology (medical) ,Veterinary medicine ,Farms ,Bacteriuria ,Population ,Single-nucleotide polymorphism ,bacteriuria ,geographic area ,Biology ,medicine.disease_cause ,Genome ,polymorphism ,farming environment ,Genetic linkage ,medicine ,Escherichia coli ,SNP ,Animals ,Humans ,AcademicSubjects/MED00740 ,Pharmacology (medical) ,fluoroquinolones ,education ,genome ,Escherichia coli Infections ,Phylogeny ,Original Research ,urinary tract ,Pharmacology ,whole genome sequencing ,education.field_of_study ,Phylogenetic tree ,Bayes Theorem ,medicine.disease ,Anti-Bacterial Agents ,Infectious Diseases ,AcademicSubjects/MED00290 ,cattle ,augmentative and alternative communication ,Cattle ,Female ,escherichia coli ,AcademicSubjects/MED00230 ,Fluoroquinolones - Abstract
SynopsisBackgroundOur primary aim was to test whether cattle-associated fluoroquinolone-resistant (FQ-R) Escherichia coli found on dairy farms were a significant cause of bacteriuria in humans living in the same 50 × 50 km geographical region located in South West England. Another aim was to identify risk factors for the presence of FQ-R E. coli on dairy farms.MethodsFQ-R E. coli were isolated during 2017-18 from 42 dairy farms and from community urine samples. Forty-two cattle and 489 human urinary isolates were subjected to WGS, allowing phylogenetic comparisons. Risk factors were identified using a Bayesian regularisation approach.ResultsOf 489 FQ-R human isolates, 255 were also 3rd generation cephalosporin-resistant (3GC-R), with strong genetic linkage between aac(6’)Ib-cr and blaCTX-M-15. We identified possible farm-to-human sharing for pairs of ST744 and ST162 isolates, but core genome SNP distances (71 and 63, respectively) were smaller in pairs of ST744 and ST162 isolates from different farms (7 and 3 SNPs, respectively). Total farm fluoroquinolone use showed a positive association with the odds of isolating FQ-R E. coli while total dry cow therapy use showed a negative association.ConclusionsThis work suggests that FQ-R E. coli found on dairy farms have a limited impact on community bacteriuria within the local human population, however, this appears greater than observed for 3GC-R E. coli when studied in parallel. Reducing fluoroquinolone use may reduce the on-farm prevalence of FQ-R E. coli, and this reduction may be greater when dry cow therapy is targeted to the ecology of resistant E. coli on the farm.
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- 2021
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4. Reduced Antibacterial Drug Resistance and bla CTX-M β-Lactamase Gene Carriage in Cattle-Associated Escherichia coli at Low Temperatures, at Sites Dominated by Older Animals, and on Pastureland: Implications for Surveillance
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Virginia C. Gould, Lucy Vass, Hannah Schubert, Kristen K. Reyher, Katy Morley, Katy Turner, Robert E. Arbon, Jacqueline Findlay, Matthew B. Avison, Oliver Mounsey, Tristan A Cogan, Emma F. Puddy, Madeleine Evans, David C Barrett, and Gwen Rees
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0303 health sciences ,Veterinary medicine ,Ecology ,030306 microbiology ,Tetracycline ,medicine.drug_class ,Antibiotics ,Cefquinome ,Amoxicillin ,Biology ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Ciprofloxacin ,03 medical and health sciences ,Antibiotic resistance ,Streptomycin ,medicine ,Escherichia coli ,030304 developmental biology ,Food Science ,Biotechnology ,medicine.drug - Abstract
Little is known about the drivers of critically important antibacterial resistance in species with zoonotic potential present on farms (e.g., CTX-M β-lactamase-positive Escherichia coli). We collected samples monthly between January 2017 and December 2018 on 53 dairy farms in South West England, along with data for 610 variables concerning antibacterial usage, management practices, and meteorological factors. We detected E. coli resistant to amoxicillin, ciprofloxacin, streptomycin, and tetracycline in 2,754/4,145 (66%), 263/4,145 (6%), 1,475/4,145 (36%), and 2,874/4,145 (69%), respectively, of samples from fecally contaminated on-farm and near-farm sites. E. coli positive for blaCTX-M were detected in 224/4,145 (5.4%) of samples. Multilevel, multivariable logistic regression showed antibacterial dry cow therapeutic choice (including use of cefquinome or framycetin) to be associated with higher odds of blaCTX-M positivity. Low average monthly ambient temperature was associated with lower odds of blaCTX-ME. coli positivity in samples and with lower odds of finding E. coli resistant to each of the four test antibacterials. This was in addition to the effect of temperature on total E. coli density. Furthermore, samples collected close to calves had higher odds of having E. coli resistant to each antibacterial, as well as E. coli positive for blaCTX-M. Samples collected on pastureland had lower odds of having E. coli resistant to amoxicillin or tetracycline, as well as lower odds of being positive for blaCTX-M. IMPORTANCE Antibacterial resistance poses a significant threat to human and animal health and global food security. Surveillance for resistance on farms is important for many reasons, including tracking impacts of interventions aimed at reducing the prevalence of resistance. In this longitudinal survey of dairy farm antibacterial resistance, we showed that local temperature—as it changes over the course of a year—was associated with the prevalence of antibacterial-resistant E. coli. We also showed that prevalence of resistant E. coli was lower on pastureland and higher in environments inhabited by young animals. These findings have profound implications for routine surveillance and for surveys carried out for research. They provide important evidence that sampling at a single time point and/or single location on a farm is unlikely to be adequate to accurately determine the status of the farm regarding the presence of samples containing resistant E. coli.
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- 2021
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5. Reduced Antibacterial Drug Resistance and
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Hannah, Schubert, Katy, Morley, Emma F, Puddy, Robert, Arbon, Jacqueline, Findlay, Oliver, Mounsey, Virginia C, Gould, Lucy, Vass, Madeleine, Evans, Gwen M, Rees, David C, Barrett, Katy M, Turner, Tristan A, Cogan, Matthew B, Avison, and Kristen K, Reyher
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Aging ,Farms ,Public and Environmental Health Microbiology ,Temperature ,Amoxicillin ,Cattle Diseases ,Tetracycline ,beta-Lactamases ,Anti-Bacterial Agents ,Feces ,Ciprofloxacin ,Drug Resistance, Bacterial ,Escherichia coli ,Streptomycin ,Animals ,Cattle ,Escherichia coli Infections - Abstract
Little is known about the drivers of critically important antibacterial resistance in species with zoonotic potential present on farms (e.g., CTX-M β-lactamase-positive Escherichia coli). We collected samples monthly between January 2017 and December 2018 on 53 dairy farms in South West England, along with data for 610 variables concerning antibacterial usage, management practices, and meteorological factors. We detected E. coli resistant to amoxicillin, ciprofloxacin, streptomycin, and tetracycline in 2,754/4,145 (66%), 263/4,145 (6%), 1,475/4,145 (36%), and 2,874/4,145 (69%), respectively, of samples from fecally contaminated on-farm and near-farm sites. E. coli positive for bla(CTX-M) were detected in 224/4,145 (5.4%) of samples. Multilevel, multivariable logistic regression showed antibacterial dry cow therapeutic choice (including use of cefquinome or framycetin) to be associated with higher odds of bla(CTX-M) positivity. Low average monthly ambient temperature was associated with lower odds of bla(CTX-M) E. coli positivity in samples and with lower odds of finding E. coli resistant to each of the four test antibacterials. This was in addition to the effect of temperature on total E. coli density. Furthermore, samples collected close to calves had higher odds of having E. coli resistant to each antibacterial, as well as E. coli positive for bla(CTX-M). Samples collected on pastureland had lower odds of having E. coli resistant to amoxicillin or tetracycline, as well as lower odds of being positive for bla(CTX-M). IMPORTANCE Antibacterial resistance poses a significant threat to human and animal health and global food security. Surveillance for resistance on farms is important for many reasons, including tracking impacts of interventions aimed at reducing the prevalence of resistance. In this longitudinal survey of dairy farm antibacterial resistance, we showed that local temperature—as it changes over the course of a year—was associated with the prevalence of antibacterial-resistant E. coli. We also showed that prevalence of resistant E. coli was lower on pastureland and higher in environments inhabited by young animals. These findings have profound implications for routine surveillance and for surveys carried out for research. They provide important evidence that sampling at a single time point and/or single location on a farm is unlikely to be adequate to accurately determine the status of the farm regarding the presence of samples containing resistant E. coli.
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- 2020
6. Posttraumatic stress disorder after minor trauma – A prospective cohort study
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Katharina Angerpointner, Antonio Ernstberger, Stefanie Weber, Karen Tschech, Hannah Schubert, Maximilian Kerschbaum, and Tanja Herbst
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0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Adolescent ,610 Medizin ,Poison control ,Disease ,behavioral disciplines and activities ,Suicide prevention ,Severity of Illness Index ,Occupational safety and health ,Stress Disorders, Post-Traumatic ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Surveys and Questionnaires ,mental disorders ,Injury prevention ,medicine ,Humans ,Posttraumatic stress disorder PTSD Anxiety disorder Minor trauma Road traffic accident ,Prospective Studies ,Prospective cohort study ,Aged ,business.industry ,Depression ,Accidents, Traffic ,Human factors and ergonomics ,General Medicine ,Middle Aged ,medicine.disease ,030104 developmental biology ,Emergency medicine ,Female ,business ,030217 neurology & neurosurgery ,Anxiety disorder - Abstract
Background: Posttraumatic stress disorder (PTSD) can arise as a reaction to a traumatic experience. While many data concerning PTSD in severely injured patients are available, little is known about this disease in slightly injured patients after road traffic accidents. It is rather assumed that PTSD does not exist after objectively slight injuries. Methods: In total, 36 patients (Injury Severity Score < 16) after road traffic accidents were included in this prospective cohort study. Next to demographic and accident-specific data, the PDI (Peritraumatic Distress Inventory: individual experienced distress directly during or immediately after the traumatic event), THQ (Trauma History Questionnaire) and the BDI-II (Beck Depression Inventory-II: self-report measurement tool to examine the severity of depression) were assessed immediately after trauma (t0). Six weeks (t1) and 3 months (t2) after trauma the Impact of Event Scale – Revised (IES-R), a screening instrument for PTSD, and the BDI-II were collected. Results: Overall 2 patients showed critical measurement values in IES-R after 6 weeks. A strong correlation between PDI and IES-R at t1 and t2 could be detected (p < 0.05). Furthermore, a significant correlation of BDIII and IES-R after 6 weeks and 3 months was found (p < 0.05). Neither age or sex showed a significant correlation to IES-R (p≥0.05). Conclusion: The present study showed that symptoms of PTSD can also occur after minor trauma. Especially high peritraumatic distress is associated with developing a PTSD. The occurrence of PTSD should be considered not only in severely injured patients, but also in slightly injured patients after road traffic accidents., kostenfreier Zugang zum Volltext (final version) beim Verlag über o. a. personalisierten Link (https://authors.elsevier.com/c/1a2-c15pGbzReh) - dieser ist allerdings nur bis 31.12.2019 gültig!!!
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- 2020
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7. Molecular epidemiology of Escherichia coli producing CTX-M and plasmid AmpC-type β-lactamases from dairy farms identifies a dominant plasmid encoding CTX-M-32 but no evidence for transmission to humans in the same geographical region
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Oliver Mounsey, Winnie W. Y. Lee, Nerissa Newbold, Jacqueline Findlay, Kristen K. Reyher, Katy Morley, Hannah Schubert, Virginia C. Gould, Matthew B. Avison, and Tristan A Cogan
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Genetics ,Whole genome sequencing ,0303 health sciences ,education.field_of_study ,Phylogenetic tree ,Molecular epidemiology ,030306 microbiology ,Population ,Context (language use) ,Biology ,medicine.disease_cause ,03 medical and health sciences ,Plasmid ,medicine ,education ,Gene ,Escherichia coli ,030304 developmental biology - Abstract
Third-generation cephalosporin resistance (3GC-R) in Escherichia coli is a rising problem in human and farmed animal populations. We conducted whole genome sequencing analysis of 138 representative 3GC-R isolates previously collected from dairy farms in South West England and confirmed by PCR to carry acquired 3GC-R genes. This analysis identified blaCTX-M (131 isolates: encoding CTX-M-1, −14, −15, −32 and the novel variant, CTX-M-214), blaCMY-2 (6 isolates) and blaDHA-1 (one isolate). A highly conserved plasmid was identified in 73 isolates, representing 27 E. coli sequence types. This novel ~220 kb IncHI2 plasmid carrying blaCTX-M-32 was sequenced to closure and designated pMOO-32. It was found experimentally to be stable in cattle and human transconjugant E. coli even in the absence of selective pressure and was found by multiplex PCR to be present on 26 study farms representing a remarkable range of transmission over 1500 square kilometres. However, the plasmid was not found amongst human urinary E. coli we have recently characterised from people living in the same geographical location, collected in parallel with farm sampling. There were close relatives of two blaCTX-M plasmids circulating amongst eight human and two cattle isolates, and a closely related blaCMY-2 plasmid found in one cattle and one human isolate. However, phylogenetic evidence of recent sharing of 3GC-R strains between farms and humans in the same region was not found.ImportanceThird-generation cephalosporins (3GCs) are critically important antibacterials and 3GC-resistance (3GC-R) threatens human health, particularly in the context of opportunistic pathogens such as Escherichia coli. There is some evidence for zoonotic transmission of 3GC-R E. coli through food, but little work has been done examining possible transmission (e.g. via interaction of people with the local near-farm environment). We characterised acquired 3GC-R E. coli found on dairy farms in a geographically restricted region of the United Kingdom and compared these with E. coli from people living in the same region, collected in parallel. Whilst there is strong evidence for recent farm-to-farm transmission of 3GC-R strains and plasmids – including one epidemic plasmid that has a remarkable capacity to transmit – there was no evidence that 3GC-R found on study farms had a significant impact on circulating 3GC-R E. coli strains or plasmids in the local human population.
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- 2019
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8. Characterization of AmpC-hyperproducing Escherichia coli from humans and dairy farms collected in parallel in the same geographical region
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David C Barrett, Oliver Mounsey, Virginia C. Gould, Maryam Alzayn, Matthew B. Avison, Katy Turner, Kate J. Heesom, Jacqueline Findlay, Hannah Schubert, and Kristen K. Reyher
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0301 basic medicine ,Microbiology (medical) ,Farms ,medicine.drug_class ,030106 microbiology ,Cephalosporin ,Population ,Biology ,geographic area ,beta-Lactamases ,03 medical and health sciences ,proteomics ,Bacterial Proteins ,Phylogenetics ,farming environment ,medicine ,polycyclic compounds ,Escherichia coli ,Humans ,Pharmacology (medical) ,education ,Escherichia coli Infections ,Phylogeny ,Cephalosporin Resistance ,Pharmacology ,Genetics ,education.field_of_study ,whole genome sequencing ,Phylogenetic tree ,cefoperazone ,phylogenetic analysis ,Amoxicillin ,biochemical phenomena, metabolism, and nutrition ,Antimicrobial ,bacterial infections and mycoses ,Anti-Bacterial Agents ,Cefoperazone ,030104 developmental biology ,Infectious Diseases ,mutation ,escherichia coli ,medicine.drug - Abstract
ObjectivesTo characterize putative AmpC-hyperproducing third-generation cephalosporin-resistant E. coli from dairy farms and their phylogenetic relationships; to identify risk factors for their presence; and to assess evidence for their zoonotic transmission into the local human population.MethodsProteomics was used to explain differences in antimicrobial susceptibility. WGS allowed phylogenetic analysis. Multilevel, multivariable logistic regression modelling was used to identify risk factors.ResultsIncreased use of amoxicillin/clavulanate was associated with an increased risk of finding AmpC hyperproducers on farms. Expansion of cephalosporin resistance in AmpC hyperproducers was seen in farm isolates with marR mutations (conferring cefoperazone resistance) or when AmpC was mutated (conferring fourth-generation cephalosporin and cefoperazone resistance). Phylogenetic analysis confirmed the dominance of ST88 amongst farm AmpC hyperproducers but there was no evidence for acquisition of farm isolates by members of the local human population.ConclusionsClear evidence was found for recent farm-to-farm transmission of AmpC-hyperproducing E. coli and of adaptive mutations to expand resistance. Whilst there was no evidence of isolates entering the local human population, efforts to reduce third-generation cephalosporin resistance on dairy farms must address the high prevalence of AmpC hyperproducers. The finding that amoxicillin/clavulanate use was associated with an increased risk of finding AmpC hyperproducers is important because this is not currently categorized as a highest-priority critically important antimicrobial and so is not currently targeted for specific usage restrictions in the UK.
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- 2019
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9. Reduced antibacterial drug resistance and blaCTX-M β-lactamase gene carriage in cattle-associated Escherichia coli at low temperatures, at sites dominated by older animals and on pastureland: implications for surveillance
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Tristan A Cogan, Lucy Vass, Oliver Mounsey, Matthew B. Avison, Emma F. Puddy, Katy Turner, Hannah Schubert, Katy Morley, Virginia C. Gould, David C Barrett, Robert E. Arbon, Kristen K. Reyher, Madeleine Evans, Jacqueline Findlay, and Gwen Rees
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2. Zero hunger ,0303 health sciences ,Veterinary medicine ,030306 microbiology ,medicine.drug_class ,Tetracycline ,Antibiotics ,Cefquinome ,Amoxicillin ,Biology ,Antimicrobial ,medicine.disease_cause ,3. Good health ,Ciprofloxacin ,03 medical and health sciences ,Streptomycin ,medicine ,Escherichia coli ,030304 developmental biology ,medicine.drug - Abstract
Little is known about the drivers of critically important antibacterial resistance in species with zoonotic potential present on farms (e.g. CTX-M □-lactamase-positive Escherichia coli). Here, we collected samples, monthly over a two-year period, on 53 dairy farms in the South West of England, and data for 610 variables concerning antimicrobial usage, management practices and meteorological factors. We detected E. coli resistant to amoxicillin, ciprofloxacin streptomycin and tetracycline, respectively, in 2754/4145 (66%), 263/4145 (6%), 1475/4145 (36%) and 2874/4145 (69%) of all samples from faecally contaminated sites. E. coli positive for blaCTX-M were detected in 224/4145 (5.4%) of samples. Multilevel, multivariable logistic regression showed antibiotic dry cow therapeutic choice (including use of cefquinome or framycetin) to be associated with increased odds of blaCTX-M positivity. Low temperature was associated with reduced odds of blaCTX-ME. coli positivity in samples and to reduced odds of finding E. coli resistant to each of the four test antibacterials. This was additional to the effect of temperature on total E. coli density. Furthermore, samples collected close to calves had increased odds of having E. coli resistance to each antibacterial or positive for blaCTX-M. Samples collected on pastureland had reduced odds of having E. coli resistant to amoxicillin or tetracycline, and being positive for blaCTX-M.ImportanceAntibacterial resistance poses a significant threat to human and animal health and global food security. Surveillance for resistance on farms is important for many reasons, including to track the impacts of interventions aimed at reducing the prevalence of resistance. In this epidemiological survey of dairy farm antibacterial resistance, we show that local temperature, as it changes over the course of a year, is associated with the prevalence of antibacterial resistant E. coli. Also, that prevalence of resistant E. coli is higher in indoor environments and in environments inhabited by young animals. These findings have profound implications for routine surveillance and for surveys carried out for research. They provide important evidence that sampling at a single time-point and/or single location on a farm is unlikely to be adequate to accurately determine the status of the farm with regard to the presence or number of resistant E. coli.
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- 2019
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10. First data-driven approach to using individual cattle weights to estimate mean adult dairy cattle weight in the UK
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Hannah Schubert, Harriet L. Mills, Sarah Wood, and Kristen K Reyher
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Animal science ,Antimicrobial use ,Dual purpose ,Automatic milking ,Biology ,Body weight ,Breed ,Dairy cattle ,Standard deviation - Abstract
IntroductionKnowledge of accurate weights of cattle is crucial for effective dosing of individual animals with medicine and for reporting antimicrobial usage metrics, amongst other uses. The most common weight for dairy cattle presented in current literature is 600 kg, but this is not evidenced by data. For the first time, we provide an evidence-based estimate of the average weight of UK dairy cattle to better inform decisions by farmers, veterinarians and the scientific community.MethodsWe collected data for 2,747 dairy cattle from 20 farms in the UK, 19 using Lely Automatic Milking Systems with weigh floors and 1 using a crush with weigh scales. These data covered farms with different breed types, including Holstein, Friesian, Holstein-Friesian and Jersey, as well as farms with dual purpose breeds and cross-breeds. Data were used to calculate a mean weight for dairy cattle by breed, and a UK-specific mean weight was generated by scaling to UK-specific breed proportions. Trends in weight by lactation number, DIM and production level were also explored using individual cattle-level data.ResultsMean weight for adult dairy cattle included in this study was 617 kg (standard deviation (sd) 85.6 kg). Mean weight varied across breeds, with a range of 466 kg (sd=56.0 kg, Jersey) to 636 kg (sd=84.1, Holsteins). When scaled to UK breed proportions, the estimated mean UK dairy cattle weight was 620 kg. Overall, first-lactation heifers weighed 9% less than cows. Mean weight declined for the first 30 days post-calving, before steadily increasing. For cattle at peak production, mean weight increased with production level.ConclusionsThis study is the first to calculate a mean weight of adult dairy cattle in the UK based on on-farm data. Overall mean weight was higher than that most often proposed in the literature (600 kg). Evidence-informed weights are crucial as the UK works to better monitor and report metrics to monitor antimicrobial use and are useful to farmers and veterinarians to inform dosing decisions.
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- 2018
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11. City Play
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Elger Blitz and Hannah Schubert
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- 2017
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12. Emergence of distinct genetic variants in the population of primary Bartonella henselae isolates
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Mardjan Arvand, Hannah Schubert, and Juliane Viezens
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Immunology ,Population ,Biology ,Cat Diseases ,Microbiology ,Polymerase Chain Reaction ,SmaI ,Genotype ,Pulsed-field gel electrophoresis ,Animals ,Humans ,Typing ,Primary isolate ,Serial Passage ,education ,Genetics ,education.field_of_study ,Bartonella henselae ,Genetic heterogeneity ,Cat-Scratch Disease ,Genetic Variation ,Sequence Analysis, DNA ,biology.organism_classification ,Bacterial Typing Techniques ,Culture Media ,Electrophoresis, Gel, Pulsed-Field ,Infectious Diseases ,Angiomatosis, Bacillary ,Cats - Abstract
Bartonella henselae isolates from different hosts display a marked genetic heterogeneity, as determined by pulsed-field gel electrophoresis (PFGE). The aim of the present study was to determine whether different genetic variants may coexist within the population of distinct B. henselae isolates and could be detected by PFGE. Three primary B. henselae isolates and the B. henselae reference strains ATCC 49793 and 49882 were subjected as single colony derived cultures in quadruplicate to PFGE analysis upon restriction with SmaI or NotI. Up to 4 fragment differences were found among the cultures obtained from each primary isolate, indicating the coexistence of genetic variants in the population of primary B. henselae isolates. The clonal relatedness of the genetic variants was confirmed by arbitrarily primed PCR and multi-locus sequence typing. In contrast to the primary isolates, no variants were detected among the single colony derived cultures of the high-passage ATCC strains. We hypothesized that the coexistence of different genetic variants may represent a feature that is restricted to primary or low-passage B. henselae isolates. The primary isolates were serially passed in vitro and then subjected as single colony derived cultures to PFGE analysis, which now revealed identical patterns among the quadruplicate cultures of each high-passage isolate. These results suggest that the population of a primary B. henselae isolate is composed of distinct genetic variants, which may disappear upon repeated passages on artificial culture media. Generation of genetic variants by B. henselae may represent an escape mechanism to circumvent the host specific immune responses.
- Published
- 2005
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