Quercetin: effects on adherence, biofilm formation and survival of S. aureus producing bovine mastitis

CÁCERES ME; GIACOMODONATO MN; BUZZOLA F

Congreso; XVIII Congreso Argentino de Microbiología General ? SAMIGE; 2022

SAMIGE

Bacterial biofilms cause numerous problems in the industrial and clinical environments. Staphylococcus aureus (S. aureus) is a pathogen that produces bovine mastitis and its ability to form biofilms would be associated with chronic infections. Flavonoids, such as Quercetin (Q), are natural compounds present in many fruits and vegetables that have analgesic, antimicrobial and antioxidant properties. This study was aimed to evaluate the action of different doses of Q on adherence, survival and biofilm formation of S. aureus. Three strains (RA18, RA24 and MB326) isolated from subclinical bovine mastitis were analysed. The effects of different doses of Q (12.5, 25 and 50 µg/ml, hereinafter Q12.5, Q25 and Q50, respectively) on the biofilm formation in polystyrene microplates in trypticase soy broth supplemented with glucose 0.25% (TSBg) or Milk-TSBg (in equal proportions; hereinafter Milk), were evaluated. Culture wells without Q (untreated) were added as controls. Plates were incubated at 37 °C under static conditions for 24 h. Biofilm formation was quantified using the crystal violet staining technique and spectrophotometric reading at OD595. The effects of Q50 on the adherence to the polystyrene microplates were also evaluated at 37 °C for 6 h, and CFU/ml counts of the supernatants were performed. A significant decrease in RA18 biofilms treated with Q50 and Q25 was observed compared to controls in TSBg, (p