Identificación fenotípica de Staphylococcus aureus meticilino resistente mediante cultivo microbiológico a partir de muestras de leche de vacas con mastitis subclínica y muestras de secreciones orofaríngeas del personal encargado del ordeño

Abstract

The general objective of this research is to identify phenotypically methicillin-resistant Staphylococcus aureus (MRSA) by means of microbiological culture from milk samples of cows with subclinical mastitis and samples of oropharyngeal secretions from milking personnel. The location of the dairy herds where the samples were taken was in the village of 12 de octubre, Yanayacu parish, Quero-Tungurahua canton. To determine the positive cases of mastitis, the CMT test was performed and reported a prevalence of 35%, that is, 28 positive cases of subclinical mastitis out of 80 cows sampled. The biochemical tests used to identify S. aureus were: blood agar, mannitol salt agar, gram stain, catalase and coagulase test. A prevalence of S. aureus of 42% was identified in milk samples from subclinical mastitis positive cows. The antibiotic sensitivity tests of the S. aureus positive milk samples showed a 100% resistance to beta-lactam antibiotics, therefore they are considered methicillin-resistant Staphylococcus aureus strains. Microbiological cultures and biochemical tests with nasal swabs from the milkers identified a 100% prevalence of Staphylococcus aureus. Similarly, a 100% prevalence of MRSA strains was identified through phenotypic processes. Key words; Prevalence, Subclinical mastitis, MRSA, Resistance, betalains.