Atividade antimicrobiana in-vitro do plasma rico em plaquetas (PRP) sobre a microbiota ocular de equinos hígidos em Minas Gerais.

Abstract

In equine ophthalmology, ulcerative keratitis is among the most common affections and, in general, arises as a consequence of some trauma suffered. Although trauma is the primary cause, subsequent contamination by pathogenic or resident bacteria of the horse's ocular microbiota can have undesired consequences. Under physiological conditions, the normal microbiota coexists with the host's immune status. It serves as a barrier, ensuring the health of the ocular surface and inhibiting the proliferation of pathogens. However, in the imbalance of immune barriers, the normal microbiota can become pathogenic and lead to infection, acting as an opportunistic agent. The aim of the present study is to demonstrate the antimicrobial effect of platelet-rich plasma (PRP), its time of action and its correlation with the concentration of its same components in-vitro on Staphylococcus sciuri, a bacterium with high prevalence in the normal ocular microbiota of horses. in the municipality of Minas Gerais, evaluating several antimicrobial tests in the search for faster, more sensitive methods with more stable data. For the preparation of the PRP, eight adult Quarter Horse (QM) horses were used, which only supplied the blood for processing. After blood collection, a complete blood count was performed, obtaining platelet count, erythrocyte and leukocyte count in an impedance hemocytometer. The individual PRP was prepared by the double centrifugation protocol and then the PRPs were added into a pool, followed by testing their interaction in culture with Brain heart infusion (BHI) broth at different dilutions against six strains collected from different animals. After 3, 6, 12 and 18 hours, was evaluated the colony forming units (UFC) count on a 5% horse blood agar plate, and the optical density reading by spectrophotometry, were evaluated for each time. Our study demonstrates that Staphylococcus sciuri, commensal microorganism of the ocular microbiota of healthy horses in the municipality of Minas Gerais, is more susceptible than the standard “American Type Culture Collection” (ATCC) strain Staphylococcus aureus, a pathogenic microorganism, used for the validation of our study. The antibacterial effect presented in this study was bacteriostatic for up to 6 hours. Where our most concentrated dilutions of PRP 1:1 (5) and 1:2 (6) were the most effective, ensuring that this antibacterial effect is volume dependent.