STREPTOCOCCUS EQUI SUBSP. ZOOEPIDEMICUS BIOFILM RELATED WITH YEASTS

ETCHECOPAZ ALEJANDRO; BUSTOS CARLA; MUÑOZ ALEJANDRA; IOVANNITTI CRISTINA; GUIDA NORA; MESPLET MARIA

Amsterdam

Congreso; 29th European Congress of Clinical Microbiology and Infectious Diseases; 2019

European Society of clinical microbiology and infectious deseases

Background: Microorganisms of microbiota cohabit and interact each other and with the host. Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is a resident bacterium of upper respiratory tract and genital mucous of healthy horses and it is an opportunistic pathogen. It may produce infections in another animals and it is also associated with meningitis, bacteraemia, nephritis, arthritis and pneumonia in humans. Usually, S. zooepidemicus infections in horses may be chronic and persistent being an important therapeutic challenge. Biofilm development is associated with this type of infections because it confers an increased resistance. Biofilm allow it to become an opportunistic pathogen when the environment of mucous change. The interaction of S. zooepidemicus with other microorganism included yeasts and mixed biofilm production may be important for its pathogenic role. The aim of this study was to evaluate in vitro kinetics of S. zooepidemicus biofilm and its interaction with yeasts.Materials/methods: Individual and mixed biofilm formation of 3 S. zooepidemicus and 3 yeast isolates (Candida glabrata, C. albicans and Rhodotorula mucilaginosa) were studied at 24, 48 and 72 h stained with gentian Violet for quantitative assay and acridine orange and alcian blue for qualitative assay.Results: Different kinetics of S. zooepidemicus biofilm were identified showing the highest production at different times for each isolate in our study. Interaction between S. zooepidemicus and yeast was identified by quantitative assay that was confirmed microscopically by qualitative assay. The kinetic of mixed biofilm was the same for all interactions being the highest at 24 h of production. Polysaccharide extracellular matrix around and between S. zooepidemicus and yeasts isolates and large cellular agglomerates were observed by qualitative assays. Regarding the interaction with C. glabrata and Rhodotorula mucilaginosa, equal or higher biofilm production was observed, while in the mixed biofilm with C. albicans an equal or lesser biofilm production was presented.Conclusions: These studies showed in vitro development of S. zooepidemicus biofilm and different behavior in interaction with yeasts that are usually present in the equine mucous. This work contributes to understand opportunistic infections by S. zooepidemicus and their recurrences that permits the incorporation of new therapeutic strategies.