Isolamento e identificação da bactéria Staphylococcus aureus na mastite bovina com teste preliminares do protocolo ouro

Abstract

Mastitis is a common mammary infection in dairy cattle caused by microorganisms, harming the animal's health, reducing milk quality and production, and consequently causing economic losses. The present study aimed to isolate and identify the bacterium Staphylococcus aureus, with preliminary biochemical tests of the gold standard. The gold standard is a protocol of biochemical, microbiological and molecular tests, which can take more than 72 hours. Many producers are unable to perform many of these analyses; by identifying an alternative to the most important tests, it is possible to develop a preliminary protocol for the isolation and identification of S. aureus. Mannitol Salt Agar stands out for being a culture medium with a high saline concentration, mannitol enzyme widely used to identify S. aureus. The Catalase test is an enzyme present in bacteria that, when in contact with hydrogen peroxide solution, produces oxygen and water to protect itself. This test is widely used to differentiate Staphylococcus spp. and Streptococcus spp. Other tests are gram stain and cell morphology. Samples were collected from 10 individuals diagnosed with mastitis, 6 from a commercial farm, and none for the genus Staphylococcus. And 4 samples at the UTFPR experimental farm, Dois Vizinhos campus, with 2 of them Staphylococcus aureus herd. The results showed the presence of the bacteria in the region and the importance of rapid techniques such as Mannitol and Catalase for a possible diagnosis of the pathogen for treatment. However, preventive measures for herd management and control are essential, as once infected by the agent, they can lead to major production losses. Testing alternatives are crucial in this process, but if the disease persists, more complex analyses such as molecular analyses must be carried out.