Abstract

BONIFAZ, Nancy; GALARZA, Ximena; FUERTES, Byron  and  BELTRAN, Janss. MOLECULAR DETERMINATION OF THE ETIOLOGICAL AGENT OF BOVINE MASTITIS FROM ANDEAN PRODUCTION UNITS. La Granja [online]. 2024, vol.39, n.1, pp.139-149. ISSN 1390-8596.  https://doi.org/10.17163/lgr.n39.2024.08.

Bovine mastitis is a disease that affects the farms of small and medium producers in the cantons of Cayambe and Pedro Moncayo, Pichincha Province-Ecuador. Treating this disease is not easy due to the different microorganisms that cause it. This study focused on the molecular determination by means of polymerase chain reaction (PCR) of the etiological agents of mastitis, having multiple advantages when recognizing family, gender and species of microorganisms. It is a method capable of detecting resistance genes of antibiotics, an important analysis when diagnosing and treating diseases. The aim of this research is to identify bacteria causing bovine mastitis by using biochemical and molecular tests. Biochemical tests such as: Gram staining, Catalase, Coagulase, and Mannitol Salt Agar were efficient to obtain pure strains and determine the gender of some bacteria. Specific primers (RNA16S) were used for the molecular identification of 9 etiological agents causing the disease in the productive units. The microorganisms found were Staphylococcus pasteuri, Staphylococcus warneri, Staphylococcus sp., Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus saprophyticus, Sphingomonas sp., Streptococcus dysgalactiae, Streptococcus uberis, mostly present in clinic mastitis. To detect resistance genes, specific primers were used, of which 7 samples presented the gene for resistance to blaTEM (β-lactam) and 6 samples presented the gene for resistance to tetA (tetracyclines). Multi-resistance was identified in the species Staphylococcus pasteuri, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus uberis, Sphingomonas sp.

Keywords : Mastitis; PCR; sequencing; biochemistry.

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