LACTIC ACID BACTERIA FROM THE REPRODUCTIVE TRACT OF MARES AS POTENTIALLY BENEFICIAL STRAINS TO PREVENT ENDOMETRITIS

SILVA JESSICA ALEJANDRA; CASTAÑARES MARIANA; MOUGUELAR HORACIO ; AGUILAR VALENCIANO JAVIER ; NADER-MACÍAS FÁTIMA; PELLEGRINO MATÍAS

Congreso; Congreso Conjunto SAIB-SAMIGE 2021. LVII Reunión Anual de SAIB y el XVI Congreso Anual de SAMIGE; 2021

Sociedad Argentina de Investigación Bioquímica y Biología Molecular y la Asociación Civil de Microbiología General

Endometritis is the most frequent inflammatory disease in mares that can cause subfertility and subsequently economic losses in horse breeding. Between 25%-60% of the cases are due to uterine infections, requiring the local and systemic application of antibiotics, ecbolic drugs, uterine lavage, among others. The development of probiotic formulas for the prevention of different infections in animals are consistent with the reduction of the antibiotics use to achieve more sustainable systems. Probiotics are defined as "live microorganisms that are administered to the host in adequate amounts to produce a beneficial physiological effect". These microorganisms should be isolated from the host in which they will be applied, based on the host and mucosal specificity of the indigenous microbiota, in order to favor their adaptation and maintenance in the tract. Lactic acid bacteria (LAB) are a heterogeneous group that include different genera, being lactobacilli the most frequent microorganisms isolated from the indigenous vaginal microbiota of mares. The aim of this work was to isolate, phenotypically identify and evaluate surface-adhesive properties of LAB from mare?s reproductive tract. Vaginal swabs samples obtained from 15 healthy mares from Córdoba (Argentina) were seeded on MRS agar pH 5.5 and incubated at 37°C during 24-48 h. Phenotypic identification was performed by morphological and phenotypic characteristics as Gram staining, catalase reaction, nitrate reduction and indol production. Also, surface-adhesive characteristics as hydrophobicity, auto-aggregation, biofilm formation and exopolysaccharide (EPS) production were evaluated. Thirty strains were isolated from the swabs, and on the base of phenotypic results, 96.66% of the microorganisms were included in the LAB group. According to the morphology of the strains, 43.33%, 16.66% and 40% were cocci, coccobacilli and bacilli, respectively. All the strains showed a range of auto-aggregation from medium (36.66%) to low (63.33%), and low degrees of hydrophobicity. The biofilm formation of the strains was performed in different culture media: MRS and LAPTg with and without Tween (-T). In general, an increased biofilm formation was observed in media without the surfactant, being the biofilm formed in LAPTg-T higher than in MRS-T. Also colonies grown on agar medium with different carbohydrate sources were macroscopically observed, and EPS (+) strains were evidenced by their ropy/mucous phenotype. From the evaluated strains 43.33% were EPS (+) in the media with different source of sugars. These results contribute to advance in the characterization of host and tract-specific beneficial LAB strains for their further selection and inclusion in the design of a probiotic product to prevent equine endometritis.