2,798 research outputs found

    Prevalence of Mycobacterium avium subsp. paratuberculosis infection in sheep flocks from three regions of Antioquia, Colombia

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    Paratuberculosis or Johne’s disease is a slow-developing infectious disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) affecting mainly domestic ruminants and producing a significant economic threat to livestock production systems. Although reports on paratuberculosis in small ruminants in Colombia are very scarce, the Colombian sheep industry has identified paratuberculosis as one of the causes of its low development. There have been reports of MAP infection in sheep flocks, mainly in the Cundiboyacense Plateau and the Bogotá savannah, but the prevalence of MAP infection in sheep and goat populations in Colombia is yet unknown. Therefore, the present study aimed to accurately estimate the prevalence of MAP infection at flock level in a sheep population of 24 flocks located in three regions of the province of Antioquia, Colombia. ELISA test as well as culture and direct qPCR were used as diagnostic tools. Overall, 456 blood serum samples were analysed and at least one seropositive animal was found in 17 (70% IC: 51.2-0.90) out of the 24 study flocks and, in total, 37 animals showed positive ELISA results (8% IC: 5.5-10.5). Regarding MAP direct detection, 90 faecal pools from the 24 flocks were cultured and subjected to qPCR diagnosis. Both direct qPCR and culture detected 25 (27.7%) and 64 (71.1%) faecal pools as MAP positive, respectively. More specifically, MAP positive pools were detected in 45.8% (IC: 24.3-67.3) and 83.3% (IC: 67.3-99.3) of the flocks by direct qPCR and culture, respectively. MAP infection is widespread in sheep flocks in the study regions and the combination of several diagnostic tests was necessary to achieve a more accurate and precise infection detection of this important pathogen

    Paratuberculosis control strategies in dairy cattle: A systematic review

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    Background: Mycobacterium avium subsp. paratuberculosis is the causative agent of paratuberculosis (PTB), incurable enterocolitis, affecting domestic and wild ruminants. Economic losses, impacts on animal health and welfare, and public health concerns justify its herd-level control.Aim: To systematically collect information to answer: What are the control and eradication strategies of PTB in dairy cattle worldwide?Methods: The search procedure was carried out on October 2nd, 2019, and updated on August 3rd, 2021, using OVID®, SciELO, and Redalyc databases, and the registers from the International Colloquium on Paratuberculosis (1991–2018). The inclusion criteria considered articles published in English, Portuguese, and Spanish and in peerreviewed journals. The exclusion criteria included irrelevant topics, species other-than bovines, and not original articles. Definitive studies were obtained through the consensus of the authors on eligibility and quality. Data extraction was performed, considering bibliographic information, control and outcome strategies, follow-up time, and results.Results: Twenty-six relevant studies were found, reporting the use of three grouped control strategies: hygiene and management strategy (HMS), test-and-cull strategy (TCS), and vaccination strategy (VS). The HMS was the most common one (20/26), followed by TCS (17/26) and VS (7/26). Combined control strategies such as TCS-HMS (12/26), TCS-VS (1/26), and HMS-VS (1/26) were also described, and the consideration of the three control strategies (TCSHMS-VS) was reported in two articles. The HMS included practices such as neonates/juvenile livestock hygiene, biosecurity, prevention of infection introduction into the herd, and environmental management. Within HMS, the most frequent practices were to remove calves from their dams as soon as possible after birth and to keep the minimal exposure of calves and heifers to adult cattle. As limitations, within the HMS, it is considered that some strategies cannot be included due to lack of compliance, or the application of the same strategy among one study and another may have a different degree of interpretation; publication bias was not controlled since the results of the control programs in endemic countries may be not available.Conclusion: The main PTB control strategies in dairy cattle worldwide are HMS, TCS, and VS. The use of one or several combined strategies has been found to succeed in controlling the disease at the herd-level

    Prevalence and Risk Factors of Mastitis among Dairy Buffaloes from the Departments of Antioquia and Córdoba, Colombia

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    Background: Mastitis is the most common disease among dairy buffaloes worldwide, and it significantly affects the economic profitability of buffalo farms as well as animal welfare and public health. Methods: This study was conducted between 2018 and 2019 at the Colombian departments of Antioquia and Córdoba, where 41% of the country’s total buffalo population is concentrated. Overall, 1,018 dairy buffaloes, including 603 in Antioquia and 415 in Córdoba, distributed among 11 farms, were assessed in the study. These animals were evaluated using the California mastitis test (CMT) and somatic cell count (SCC) to determine the presence of subclinical mastitis (SM). They were considered positive for SM when the results of CMT were higher than traces and SCC was >200,000 cells/mL. Results: The total prevalence of the disease was 7.9%, and microbiological culture was performed on the samples obtained from the SM-positive animals. The main isolated bacterium was coagulase-negative Staphylococcus. Furthermore, risk factors affecting milking routine, hygiene, and farm facilities were determined. Manual milking, milking in the barn, non-disinfection of milkers' hands, etc., were identified as risk factors for the disease. Conclusion: To the best of our knowledge, this is the first large-scale study of mastitis among buffaloes in Colombia

    Presence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in bulk-tank milk of bovine dairy farms in Antioquia, Colombia

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    Background: antibiotic resistance is spreading worldwide. It is important to evaluate whether foods of animal origin constitute a reservoir of resistance genes. Objective: the aim of the present study was to assess the occurrence and characterize extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae from bulk-tank milk samples of dairy farms located in Entrerríos, Antioquia (Colombia). Methods: a total of 120 randomly selected raw milk samples (one bulk-tank milk sample per dairy farm) were collected between September and October, 2013. A commercial chromogenic agar was used for screening presumptive ESBL-E. Identification of genus and species of isolates was performed with a commercial biochemical identification kit. The ESBL production was confirmed using the double disc synergy test. An antimicrobial susceptibility test was performed by the agar disc diffusion method and the automatized broth microdilution method. The ESBL-positive isolates were analyzed for the presence of bla genes by polymerase chain reaction (PCR) and sequencing. For the exploration of risk factors, information on dairy farm management practices was recorded using a questionnaire and the associations of predictors and results were tested with a logistic regression analysis. Results: the ESBL-E were isolated from 3.3% (4/120; CI 95%: 3-3.5%) of the samples. Farm size was the only factor associated with the presence of ESBL-E (OR = 11.5; CI 95%: 1.14-115.54; p = 0.038). All isolates were resistant to several antibiotics and harbored blaCTX-M-96 (alternate name CTX-M-12a) enzymes. Conclusion: although apparent frequency of ESBL-E was low, the presence of these resistant bacteria in milk may constitute a public health risk and should be further investigated. .   Resumo Palavras chave: CTX-M-12A, gado, leite crua, resistência aos antibióticos, saúde pública

    Factors associated with Mycobacterium avium subsp. paratuberculosis in dairy cows from Northern Antioquia, Colombia

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    Background: Johne´s disease (JD) is a severe enteritis that affects ruminants and has been diagnosed in cattle and sheep in Colombia. However, epidemiological information on the disease in this country is scarce. Objective: to identify factors associated with the JD serum enzyme-linked immunosorbent assay (ELISA) status of dairy cows. Methods: a cross-sectional study was carried out in 307 asymptomatic adult Holstein dairy cows from 14 herds in nine districts of Belmira and San Pedro de los Milagros municipalities during November, 2007. Nineteen to 29 cows, ≥ 2 years of age were randomly selected and blood sampled from every herd. A commercial ELISA kit was used to analyze sera. Information regarding cow related factors (age, farm-born, parity, and daily milk yield) and herd management practices (i.e. herd size, herd average milk production, current presence of symptomatic animals, cattle purchase, own animals grazing in foreign pastures, feeding of calves before weaning, manure spread on pastures, and sighting of birds in feed storing areas) was collected using questionnaires. Descriptive statistics were computed for all variables and a multivariable logistic regression model was constructed (p 1 parity. The OR was 0.74 times lower (OR = 0.26; 95% CI: 0.096-0.70; p<0.01) in herds feeding calves with pooled colostrum from several cows, compared to herds feeding calves with colostrum from their own dams. Conclusion: JD seroprevalence was 10 and 70% at animal and herd-level, respectively. Cow and herd factors “parity” and “feeding of calves before weaning” showed weak and strong association with positive results, respectively

    Prevalence of Mycobacterium avium subsp. paratuberculosis and associated risk factors in dairies under mechanical milking parlor-systems in Antioquia, Colombia

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    El presente estudio tuvo como objetivo determinar la prevalencia de Mycobacterium avium subsp. paratuberculosis (MAP) según muestras ambientales y explorar los factores de riesgo a nivel de hato asociados a la infección por MAP en hatos lecheros bajo sistemas de sala de ordeño mecánico y basados en pastoreo de prados. Los hatos de estudio (n= 94) se ubicaron en 60 distritos de cinco municipios de la región Norte de la Provincia de Antioquia, Colombia. Los hatos fueron visitados una vez en 2016 para recolectar dos muestras ambientales compuestas y completar un cuestionario de evaluación de riesgos. La identificación de MAP se llevó a cabo utilizando un método de PCR cuantitativo en tiempo real basado en la secuencia IS900. Un hato se consideró como MAP-positivo si una o ambas muestras ambientales resultaron positivas mediante la técnica molecular. La información sobre los factores de riesgo se analizó utilizando un modelo de regresión logística multivariable. La prevalencia aparente a nivel de hato encontrada fue de 14.9 % (14/94; IC 95 %: 7.7-22.1), oscilando entre 0 y 33.3 % a nivel municipal. Los hatos en los que predominaban razas distintas a la Holstein pura (estas son, Jersey, cruzas de Jersey) tenían más probabilidades de estar positivamente infectados con MAP-qPCR que aquellos en los que predominaba el ganado Holstein puro (OR= 3.7; IC 95 %: 1.1-15.2). El presente estudio reporta la prevalencia de MAP en hatos lecheros de la Provincia de Antioquia (Colombia), y la asociación entre la positividad ambiental de MAP con la raza predominante en el hato.The present study aimed to determine Mycobacterium avium subsp. paratuberculosis (MAP) prevalence according to environmental samples and to explore the herd-level risk factors associated to MAP infection in dairy herds under mechanical milking parlor and pasture grazing-based systems. The study herds (n= 94) were located in 60 districts from five municipalities in the Northern region of the province of Antioquia, Colombia. Herds were visited once in 2016 to collect two composite environmental samples and to complete a risk assessment questionnaire. MAP identification was carried out using a quantitative real-time PCR method based on the IS900 sequence. A herd was considered as MAP-positive if one or both of the environmental samples were found positive by the molecular technique. The information on risk factors was analyzed using a multivariable logistic regression model. The apparent herd-level prevalence found was 14.9 % (14/94; 95 % CI: 7.7-22.1), ranging from 0 to 33.3 % at municipality-level. Herds where other than Pure-Holstein breeds were predominant (i.e. Jersey, Jersey crossbreeds) were more likely to be MAP-qPCR positively infected than those on which where pure-Holstein cattle was predominant (OR=3.7; 95 % CI: 1.1-15.2). The present study reports MAP prevalence in dairy herds in the province of Antioquia (Colombia), and the association between MAP environmental positivity with the predominant breed in the herd

    Fecal culture and two fecal-PCR methods for the diagnosis of Mycobacterium avium subsp. paratuberculosis in a seropositive herd

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    Background: paratuberculosis is a slow-developing infectious disease, characterized by chronic granulomatous enterocolitis. This disease has a variable incubation period from 6 months to over 15 years, and is caused by Mycobacterium avium subsp. paratuberculosis (MAP). Its detection by direct and indirect diagnostic techniques has been of special interest. Objective: to report the diagnosis and detection of MAP using several diagnostic tests in a herd of the Northern region of Antioquia, Colombia. Methods: serum samples from the study herd were analyzed, using a commercial ELISA (enzyme-linked immunosorbent assay) kit. Fecal samples were cultured by duplicate using Herrold´s egg yolk medium (HEYM), and analyzed by an endpoint IS900-specific nested PCR protocol, and a commercial F57-real-time PCR kit. Results: eight out of 27 serum samples in the study herd resulted ELISA-positive. None of fecal samples resulted positive to HEYM culture by duplicate and none were found to be positive by F57-real-time PCR. Seven of the 27 fecal samples were found to be positive by end-point IS900-specific nested PCR. Agreement was found between ELISA and end-point IS900-specific nested PCR in one of the animals. Conclusion: the present study gives information about the agreement between direct and indirect MAP-detection techniques, using different matrixes from animals under the same husbandry conditions

    Enhancing Energy Production with Exascale HPC Methods

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    High Performance Computing (HPC) resources have become the key actor for achieving more ambitious challenges in many disciplines. In this step beyond, an explosion on the available parallelism and the use of special purpose processors are crucial. With such a goal, the HPC4E project applies new exascale HPC techniques to energy industry simulations, customizing them if necessary, and going beyond the state-of-the-art in the required HPC exascale simulations for different energy sources. In this paper, a general overview of these methods is presented as well as some specific preliminary results.The research leading to these results has received funding from the European Union's Horizon 2020 Programme (2014-2020) under the HPC4E Project (www.hpc4e.eu), grant agreement n° 689772, the Spanish Ministry of Economy and Competitiveness under the CODEC2 project (TIN2015-63562-R), and from the Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Pesquisa (RNP). Computer time on Endeavour cluster is provided by the Intel Corporation, which enabled us to obtain the presented experimental results in uncertainty quantification in seismic imagingPostprint (author's final draft

    Opuntia ficus-indica seed pomace extracts with high UV-screening ability in a circular economy approach for body lotions with solar protection

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    Opuntia ficus-indica seed pomace, a by-product of seed oil extraction, was investigated due to its richness of phytochemical compounds and high antioxidant capacity. The pomace was subjected to hydrothermal extraction using water under subcritical conditions to solubilize various compounds. Different final heating temperatures 120 to 220 °C were applied, and the resulting filtered extracts were analyzed using HPLC and HPSEC to determine the monosaccharide profile and molecular weight of the oligomers. Notably, extractions performed at temperatures between 120 and 180 °C yielded extracts characterized by elevated levels of glucuronic acid and exhibited higher molecular weights. In contrast, extractions conducted at 200 and 220 °C were distinguished by their enriched xylose content and relatively low molecular weights, falling below 23.6 kDa. The extracts were tested for total phenolic compounds, as well as antioxidant activity using spectrophotometric methods such as TEAC, DPPH, and FRAP. Results showed that increasing temperature led to a corresponding increase in phenolic compounds (from 7.7 to 13.7 gGAE/100 g) and antioxidant activity, with the maximum observed at 200 °C. These phenolic compounds enriched extract were used to produce a body lotion with sun protection factor of 8, with rheological behavior similar to that of commercially available products but without the need for additional UV filters and antioxidants. The lotion was shown to be safe for topical use and did not cause skin irritation. This study highlights the potential of O. ficus-indica seed pomace as a valuable source of phytochemical compounds and demonstrates the feasibility of using hydrothermal extraction to produce eco-friendly commercially interesting compounds.Fundação para a Ciência e a Tecnologia | Ref. UIDB/50006/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50006/2020Xunta de Galicia | Ref. ED481D-2022/018Xunta de Galicia | Ref. GRC-ED431C 2022/08Agencia Estatal de Investigación | Ref. TED2021-131555B-C22Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/0

    Near-Room-Temperature Reversible Giant Barocaloric Effects in [(CH₃)₄N]Mn[N₃]₃ Hybrid Perovskite

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    [Abstract] We report giant reversible barocaloric effects in [(CH₃)₄N]Mn[N₃]₃ hybrid organic–inorganic perovskite, near its first-order cubic-monoclinic structural phase transition at ₀ ∼ 305 K. When driving the transition thermally at atmospheric pressure, the transition displays a large change in entropy of ∼80 J K⁻¹ kg⁻¹ and a small thermal hysteresis of ∼7 K, as well as a large change in volume of ∼1.5%. When driving the transition with pressure near room temperature, the transition displays large changes in entropy of ∼70 J K⁻¹ kg⁻¹, which represent a giant barocaloric response. Hybrid perovskites with similar barocaloric response and lower operating temperatures may find applications in environmentally friendly cooling.The authors are grateful for financial support from Ministerio de Economía y Competitividad MINECO and EU-FEDER (MAT2017-86453-R), Xunta de Galicia (ED431G/09), FAMEPA (COOPI-07771/17), and ERC Starting Grant no. 680032Xunta de Galicia; ED431G/0
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