Ciencias Agropecuarias

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Subject: search.filters.subject.BOVINOS LECHEROS

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    Potencial de resistencia a los antimicrobianos de Staphylococcus aureus inductor de mastitis subclínica de bovinos lecheros y presente en secreciones nasales de los ordeñadores
    (2024-02) Bedoya Lozada, Paul Sebastián; Vela Chiriboga, Andrea Carolina
    Staphylococcus aureus is one of the saprophytic bacteria commonly found on the skin and mucous membranes of animals, being one of the bacteria with the highest incidence in subclinical mastitis. At present, one of the most relevant problems is the reckless and indiscriminate application of antibiotics, leading to subclinical mastitis presenting different resistance mechanisms to various antibiotics available on the market. The objective of the following research is to evaluate the antimicrobial resistance of Staphylococcus aureus in dairy cows and milkers in the Quero canton, Yanayacu-Mochapata parish, Tungurahua province, Caserío 12 de Octubre on the Velazco family farm. Eighty milk samples were collected and tested for subclinical mastitis using the California Mastitis Test. We found 28 positive animals for subclinical mastitis, of which 12 were positive for Staphylococcus aureus. Five samples were also taken from the milkers by means of a nasal swab, resulting in all samples positive for Staphylococcus. aureus. The samples were taken to the microbiology laboratory of the Faculty of Agricultural Sciences of the Technical University of Ambato where: type of hemolysis, gram staining, biochemical tests in salt-mannitol and catalase/coagulase test were carried out. Finally, the bacteria were isolated and the respective antibiogram with the Kirby-Bauer method was performed. The prevalence of subclinical mastitis was 35% of the total samples and 42% were samples positive for Staphylococcus aureus. The results in dairy cows were: none of the samples were resistant to gentamicin, chloramphenicol and rifampicin; 8.3% were resistant to clindamycin, 25% of the strains were resistant to novobiocin and 16.6% were resistant to linezolid. In the milkers the results were 40% of the strains resistant to gentamicin, 40% resistant to rifampin, 60% of the samples resistant to clindamycin and 60% resistant to novobiocin. Keywords: subclinical mastitis, Staphylococcus aureus, biochemical tests, resistance.
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    Evaluación de pruebas diagnósticas para brucella abortos en bovinos lecheros
    (2017) Soria Rojas, Monica Abigail; Rosero Peñaherrera, Marco
    Bovine brucellosis is a disease that presents with worrying frequency, even knowing that this is an anthropozoonotic disease, has not been studied in depth and much less eradication has been achieved. The most common laboratory tests in our country are Rose Bengal (RB) and competitive ELISA (ELISA c), which in the present investigation were evaluate the values of sensitivity, specificity and predictive values. Likewise with the use of the above mentioned tests, it was possible to determine data of actual and apparent prevalence of the event of interest. This essay was carried out in Salache, a neighborhood that is located at 3.849 msnm, belonging to the parish Eloy Alfaro of the canton Latacunga, in the province of Cotopaxi. In which blood samples of 147 bovine were taken, these samples were submitted to Rose Bengal, categorized as screening test; once the results have been obtained those false positives, true positives and false negatives will be submitted to the ELISA c confirmatory test. According to the data reported by the laboratory, the sensitivity and specificity calculations were performed, for Rose Bengal (88.89% and 69%) and ELISAc (88.89% and 0%); we also determined the data for the positive predictive value, which coincided in the two tests at 0.29, while the negative predictive value was for RB of 0.98 and competitive ELISA of 0. For this it is concluded that Rose Bengal to have greater specificity than competitive ELISA, it is recommended its use when the population has a low prevalence of the disease to treat whereas if we know the presence of the same and we need to avoid its dissemination would be used a test with greater sensitivity.